Getting back into RC models (2001)
I ran into an old friend who told me that many of the old group who flew models were back at it, so I re-joined the fun after more than fifteen years inactivity .
from left -
Charles Polk, Dwain Ferguson, George Hilliard
Floyd Harp, Raymond Curry, Waylon Woods and myself
Floyd Harp, Raymond Curry, Waylon Woods and myself
A few short videos.... Small prop...big bite WW-1 Era Biplane
Kadet Crunch
Honker (reconditioned 2001)
This Honker biplane was sound structurally but needed new covering. It is the only RC plane I know of that has solid balsa wings. It is a good flyer that can be flown in a fairly small space though it would not be considered a park flyer by todays standards. This one is powered by an Enya 19 that has just enough power to get the plane airborne but hauls it well when up to speed.
Quickie 500 (served to renew my flying skills - 2001)
This Quickie 500 was almost ready to go after the long years of storage in the barn rafters. The upper surface of the wing is rough with embedded dust from the hot storage. Power is an Enya 40. Both this and the Honker served to recondition the skills of a long time inactive flyer.
Sopwith Pup (acquired at Weatherford, Texas swap meet winter 2002)
This Flair (English model) Sopwith Pup was bought ($200 with motor / less servos) at a swap meet and has been a great flyer. It came with a Saito 56 4-stroke that is a good power match. I've enjoyed greatly the transition into 4-strokers as they sound much better than a 2-stroke. They are also more fuel efficient. This plane was for me the beginning of an era of floaters (planes with low wing loading that generally fly slower) that I've found very suitable to current interest and aging skill abilities. 4-strokers are also good matches for floaters as they idle down very well allowing greater lift planes to settle on landings.
J-3 Cub (acquired at the Weatherford, Texas swap meet winter 2004)
Another swap meet plane and floater is this Goldberg J-3 Cub. The Cub seems to be my favorite plane to carry to the field. Especially enjoyed is early evening flying with little wind. The model has a fabric type covering, a 50 Saito 4-stroke and was purchased with motor and servos for $200 and has been a great flyer. I've now had it a couple of years. Both it and the Sopwith Pup are well built planes by others that I'm proud to own.
PT-19 (acquired by swapping a sail boat steering conversion kit I sell - 2005)
This Hanger 9 PT-19 ARF was traded for and completed. It is powered by an Enya 1.2 4-stroke I'd had for years and never run. This is a large great flying plane with more than six feet of wingspan and capable of good slow speed aerobatics including the lumcevek, which always gets attention at the field. It will do three reverse tumbles with a fair amount of ease... mostly a matter of timing the move from full up elevator to full down.
Skybolt (taken out of mothballs 2006)
Very recently revived was this Sig Skybolt powered by a HB 61 PDP. Interestingly, I built it for the American Bicentennial celebration during 1976 thirty years ago when age thirty. Turning sixty this year, it is half my age so I celebrated our birthdays by pulling it from moth balls. Like the Quickie 500, it has thin wings and flies fast. I also wanted to have it ready to fly on the 4th of July to celebrate the nations birthday. Will I be around, will it be around to fly twenty years from now for the 250th birthday?
Note: Because of an installation error installing new radio gear, the aileron arms jammed (slightly larger aileron servo hung the pointy z bend rods on a cross platform) on the third outing and steerage lost, which could easily have caused the loss of this old plane. Cutting power and glided into a grove of trees fifteen feet off the ground proved fortunate. There was no structural damage, not even a broken prop but the epoxy paint finish is brittle with age and chipped in many places on the leading edges of wings. When the plane hit the trees, it sounded like it shredded but amazingly the smaller limbs that caught and held it must have absorbed the impact. Some touch up has it looking ok, but the model can't be flown regularly without it's finish suffering, though I will fly it again July 4th and as many following years as it and I are able. Some where a set of wheel pants are stored... finding them could be a challenge.
Phaeton 90 (reclaimed from the barn rafters 2006)
This recently finished Balsa USA Phaeton 90 was started twenty years ago just prior to getting out of RC planes for the many years. It is powered by a discarded weed eater gas motor. The poor power to weight ratio of these engines limits performance but basic aerobatics are within most biplane abilities and that is true for this plane... though it just doesn't have a lot of vertical performance many modelers often enjoy.
It was fun to do the motor conversion as I've a basic machine shop with lathe and mill. The motor is also very economical on fuel, and this plane if powered by a glow engine would burn $2 per flight of fuel compared to the 10 cents it cost for the gas/oil mix though admittedly, a glow engine would offer more performance.
At the cheap fuel price, I can fly a lot and the plane is super fun to do takeoffs, landings and touch n goes as it has exceptional ground handling manners as well as an easy to manage glide slope.
Akrobat II (reclaimed from the barn rafters fall 2006)
Needed in the hanger is a plane suitable for windy days. A suitable candidate was also stored in the barn rafters that has never been built. A Gerry Graham Akrobat II, a sport flyer with a thick high lift wing but without the square inches of a floater.
The Akrobat was built during Jan & early Feb 2007 and is powered by a YS-120 four stroke and has Ultracote covering.
Extended Remarks on the Akrobat
The plane is
finished and awaiting a couple of weeks cure on the cowl
and wheel pant paint. Here it is on
it's storage rack.
Late March and the Akrobat remains unflown (full story)
Future Planes (Feb, 2007)
Late March and the Akrobat remains unflown (full story)
Future Planes (Feb, 2007)
Two planes are in the future, the first... a Sig Kadet LT-25 trainer for the grandkids to learn if they wish.. It will be my first laser cut build and is reported to be a delight. It will be powered by an old Enya .29 to make for a lazy slow flyer.
The second is a 1/4 scale Balsa USA Cub that will be powered by a Ryobi weed trimmer gas engine.
A hanger of models are passed on (Late Feb, 2007)
An unexpected third plane has been added to the build list. It fills a long time wish to build a Sterling PT-17 Stearman. A man came by our flying field and explained he had to dispose of his fathers RC gear. His dad was gone and mother had kept his stuff stored in the garage, but she had recently moved to an assisted living center. Along with several planes in various stages of construction were several boxed kits, one of them the Sterling Stearman long since out of production... and I brought it home with bitter sweet feelings... it represented a modeler that hadn't finished all the projects he'd hoped...
The same day the Stearman kit was acquired, the LT-25 kit arrived. The Balsa USA Cub came a week ago and now a few days after getting the Stearman, the vision of the many planes unfinished by the previous owner of the Stearman kit have refreshed my memory of the personal goal made to clear out the inventory of unfinished builds in the barn. There are three left, a Das Box Fly bipe, a little stick and a P-51 Mustang. I'd really feel better about tackling the new builds if the goal of clearing the old projects gets done. The wing of the little stick had suffered a good bit of damage in storage so it was trashed... two weeks later, another modeler lamented the need for a little stick fuselage... he had a wing.
The Das Box Fly
Is fully built and ready for covering but thought is that it would make a good aerobatic trainer for the grandson if he infact follows through and learns to fly... thus there is no hurry to finish it.
P-51 Mustang (Late Feb, 2007)
This airplane has an interesting story. It was given to me back in the early '80s by a then pilot for WalMart. It is a D&B Models kit having a fiberglass fuselage and foam wing. The plane had been started by the PO and if I recall correctly the sheeting was on the wing but I finished sheeting the flaps and ailerons, sealed the wing with finishing resin and painted the whole with K&B two part epoxy paint, shortly afterwards discovering the sheeting joints in the wing had curled to a sickening appearance.
My first impression and the assumption that stayed with me over the years was chemical attack to the foam from the finishing resin through the wing sheeting joints. I expected there were hollow indentations in the foam at each joint from the chemical attack and thus the model was likely ruined if the attack was deep.
Retrieved the plane from the barn last night to assess to either trash can or save. The wing was pitiful to look at and my first impression was it was history, this plane would never fly. The years of storage in the barn rafters had allowed moist air to further attack the sheeting and it was now fully delaminating in places as well as covered with twenty years of barn dust. I wished a picture had been taken of how it looked.
It was easy to pull some of the delaminated sheeting up and see that the foam core had not suffered the feared chemical attack. What had happened - why had the sheeting joints curled up? Will the plane ever fly?
P-51 Progress
Kadet
LT-25 by Sig (mid march)
While waiting for the core bond glue from Sig needed for the P-51, the LT-25 Kadet was started and framing is finished. This laser cut kit is very close to precision in its build and is no question the easiest kit build I've done.
This trainer was chosen to satisfy some interest by the wife and grandkids. Reasons for the choice are,
While waiting for the core bond glue from Sig needed for the P-51, the LT-25 Kadet was started and framing is finished. This laser cut kit is very close to precision in its build and is no question the easiest kit build I've done.
This trainer was chosen to satisfy some interest by the wife and grandkids. Reasons for the choice are,
- the kit has been spoken highly of by several contributors to RC Universe
- a tail dragger was needed for our rough field
- on hand is an old Enya .29 that starts easy and runs great
- wing is held on by rubber bands
for more forgiveness during rough landings
- the Kadet series are acclaimed for flying slower and having a forgiving nature, which will yield more reaction time and perhaps a quicker learning curve
- at 62 inches of wingspan, this is a large enough plane to be seen easily yet Sig suggest strongly that a .25 motor is all the plane needs
- at slightly more than 4 lbs the
young grandkids (8 & 10) can easily carry it to the flight line
Color scheme will
be red and black to match school colors
The old Enya .29 is
not as strong as modern .25 engines and if it proves inadequate, a 4
stroke will be aquired.
CA
Glue Reaction Notes
Slow Progress (end of March)
Some work on several planes though I don't like having three planes in progress but it happens when waiting on things ordered. The long struggle and failure to get a motor to run well also played a part.
Akrobat - Have given up on the YS motor and will go with either a Saito 1.25 or a Zenoa G20. Have ordered a G20 and if it fits ok it will be the choice, if not... a Saito 1.25 will be ordered and the G20 laid back for the Stearman. This plane was finished two months ago and now some back tracking is needed to fit a different engine. I've learned a lesson... Don't set a model up for a motor unless it is known to run well.
P-51 - Wing sheeting on the foam wing has been removed and replaced with wing ready for a final choice of finish. Will either cover with Ultracoat, glass cloth and paint or coverite and paint. Fuselage is ready for painting.
Kadet trainer is covered and ready for assembly. The grandkids are getting excited. I've put it on front burner.
The Kadet is finished (excepting some wing trimmings dependent on what the grandkids come up with for decals). Though this is a small trainer and a simple build, I've never built a better kit. Not only was the fit on all parts excellent but the plane built to the prescribed weight and balance point. My hope is the wife and grandkids get many enjoyable flights from it.
Slow Progress (end of March)
Some work on several planes though I don't like having three planes in progress but it happens when waiting on things ordered. The long struggle and failure to get a motor to run well also played a part.
Akrobat - Have given up on the YS motor and will go with either a Saito 1.25 or a Zenoa G20. Have ordered a G20 and if it fits ok it will be the choice, if not... a Saito 1.25 will be ordered and the G20 laid back for the Stearman. This plane was finished two months ago and now some back tracking is needed to fit a different engine. I've learned a lesson... Don't set a model up for a motor unless it is known to run well.
P-51 - Wing sheeting on the foam wing has been removed and replaced with wing ready for a final choice of finish. Will either cover with Ultracoat, glass cloth and paint or coverite and paint. Fuselage is ready for painting.
Kadet trainer is covered and ready for assembly. The grandkids are getting excited. I've put it on front burner.
The Kadet is finished (excepting some wing trimmings dependent on what the grandkids come up with for decals). Though this is a small trainer and a simple build, I've never built a better kit. Not only was the fit on all parts excellent but the plane built to the prescribed weight and balance point. My hope is the wife and grandkids get many enjoyable flights from it.
The Zenoah
G20 arrived
and looks to be an excellent choice for the Akrobat except dealing with
the cowl. The Akrobat has a cowl shaped off a large spinner and
would have the carb and muffler well out the sides of the cowl.
I'm
not sure that is acceptable. Another issue is a relief was cut in
the bottom of the cowl for the valve cover of the YS 4 stroke and it
would both look goofy having no purpose and would allow air to escape
the cowl without ventilating the motor so would have to be closed up
meaning more work on a plane I thought was finished. It would
also mean some amount of work removing the beam mounts and mounting the
G20 to a firewall given three degrees right thrust. At this point
I'm not sure what I'll do... maybe go with a Saito 1.25 as it would be
a lot easier installation on what is all ready there and save the G20
for the Stearman.
Saito 1.25 - Deciding not to use the G20 on the Akrobat due to cowl butchering, a Saito 1.25 was aquired but has not been broken in yet. Fitting to the Akrobat will take some effort because the motor is smaller than the YS so new beam mount adapters will be needed. Centering, fore/aft positioning and three degree right thrust considerations will combine to challenge the installation which must now align the spinner to the cowl rather than align the cowl to the spinner (much easier) as the cowl is now set from the previous YS installation.
The Kadet has flown and experienced a slight mishap during her first outing but after the grandkids and their dad got a bit of stick time. Taxing back to the flight line, another flier landed hot and hit the Kadet crunching her front end a bit. She is repaired and flying again and well with the old Enya .29 doing fine.
The Saito 1.25 has been broken in.
Saito 1.25 - Deciding not to use the G20 on the Akrobat due to cowl butchering, a Saito 1.25 was aquired but has not been broken in yet. Fitting to the Akrobat will take some effort because the motor is smaller than the YS so new beam mount adapters will be needed. Centering, fore/aft positioning and three degree right thrust considerations will combine to challenge the installation which must now align the spinner to the cowl rather than align the cowl to the spinner (much easier) as the cowl is now set from the previous YS installation.
The Kadet has flown and experienced a slight mishap during her first outing but after the grandkids and their dad got a bit of stick time. Taxing back to the flight line, another flier landed hot and hit the Kadet crunching her front end a bit. She is repaired and flying again and well with the old Enya .29 doing fine.
The Saito 1.25 has been broken in.
Wow...
what a comparison
between the Saito and the YS. The YS gave nothing but problems
and the Saito yielded none. It has been run forty minutes with
the first ten minutes at 4,000 rpm or less and five turns of needle
valve open as reccomended. The second tank was kept 6,000 or
less. Some leaning of the top end began with the third tank and
the fourth tank it was run up for just a second to high rpm of 8,700
with a 15-8 master air screw prop and then set back to 8,300 where it
will be kept for the initial flights. Idle and
transistions were super. Yet... is to flip the test bed
inverted as
the installation will be inverted. Idle mix will be adjusted
inverted and if all is well, the work to fit to Akrobat will commence.
A good bit of work was needed to make the motor conversion. A 1/2 inch aluminum plate was milled to accept the motor and this plate mounted to the existing beams. With the YS, hardwood beam shims were used but with the smaller footprint Saito and weight to burn because it's lighter, a yoke was milled from 1/2 inch aluminum in an attempt to hold the integrity of the mounts. The elevator and throttle servos required swapping to accommodate the throttle hook up on the other side. Even though the mount was much heavier, two additional ounces of weight were added and a spinner nut turned and threaded for the motor shaft and spinner screw. If only I'd known this would be the engine... I'd not gone with the removable stabilizer and the extra tail weight it added and I'd gone with a lighter tail wheel bracket and saved close to a half pound of total weight.
The Akrobat Maiden (April 25, 2007)
Came on a blustery day with a 15 mph cross wind. I'd not run the motor inverted and rather than get oil residue on our patio table where planes are often tied down with wire, the plane was taken to the field and if all went well it could be flown. All wasn't well... the flight box gel cell battery has been cratering for six months and wouldn't turn over the new Saito when glow was added. Improvising by wrapping a shop rag around the three forefingers as done when polishing Army boots, it hand started easily. It had shown a slight tendency to load up on idle when upright and now inverted, was more noticeable. One adjustment did the trick and the engine idled without faltering, though having a bit more shake at idle than preferred, perhaps it is still a bit rich. Things went well after all.
Flight required three clicks of right turn. This plane has a lot of vertical stab and rudder and the strong cross wind yawed the tail to leeward as passes were made. It was not good conditions for a maiden, especially not knowing the flight and stall characteristics. Bringing it in as one would a plane that will tip stall... it touched down.... rolled a few feet... and with up elevator added to hold it down it went airborne again coming down fifteen feet further down the runway but on its feet to a smooth stop. It handled the taxi back to the flight line even with the very strong cross winds. This plane indeed has a lot of lift and unless it has some tip stall issues, it should land fine steep and slow with the nose up.
With only one flight in such harsh conditions it's too early to tell if I like it. Initial thought was not but in fairness it needs flown in better conditions before drawing conclusions. Even though the plane is given to yaw both on the ground and in the air by strong crosswinds, the large rudder will easily overcome tracking struggles. Ailerons were quite sensitive, causing some distraction from other observations that might have been apparent given more alertness.
A few comments about the engine... It starts easy and runs flawless and is very easy to adjust... but has two negatives. It shakes a fair bit at idle unless more leaning is needed and it likes fuel, which somewhat surprised me... I've two other Saito four strokes that are very fuel stingy. A 16oz tank will yield only about 10 minutes of run time. A timer will be needed with this plane. If one is willing to yield esthetic's and turn the muffer down somewhat on an inverted engine... the exhaust is outside the prop blast and the plane gets much less oil. Clean up was very easy.
One anecdote... the mods made for the Saito, the Akrobat was ready to take to the field for final motor testing and flying if all went well. Needed was to replace my T handled hex wrenches to the flight box because they are very often needed at the field. Picking one from the clutter on the work bench I noticed a screw that looks like no other screw used in model airplanes... if your mind lept ahead to the elevator servo arm retainer screw... you would be correct. When I swapped the two servos it somehow had been left off. This was a fitting find relative to the emotions I've been feeling about the first flight of this plane that has been so difficult to get finished and flying... I'd begun to feel that this one might shouldn't be... and without that screw... it likely would not have survived the first flight.
What Next?
Work will restart on the P-51. Next effort is to seal the wing to get ready for paint. Contemplated is the use os Sky Loft materiel I've had for years (similar to silkspan). Plans are to test to see if it can be applied using water base sanding sealer... probably dumb... but I'd like to test the idea... on a scrap of course.
Then it is a choice between two planes... the Balsa USA 1/4 Cub or an old Sterling PT-17 Stearman. An opportunity a week ago came to break in the Ryobi engine and insure that it was suitable for the cub... and I'm fairly happy with it. The only problem occured during too quick of decleration causing the engine to load up and shake for a couple of seconds or even die if the idle is very low. Timing the decleration similar to that of a servo shows that there may be no problem. The motor intended for the Stearman is the Zenoah G20 EI and I've not run it yet but will soon as I'm leaning on the Stearman build first.
Also... Linda asked if I'd like a plane for my birthday... silly question... eh. So, I've sorta been looking around and who knows, something might capture the imagination (was kinda looking at a Balsa USA 1/4 Nieuport 17) but haven't asked around yet about this kit's ratings.
More Akrobat Flight Time
Has quickly changed my first impression (of not liking) during that first blustery outing. Reducing aileron throw to 75%, giving them 40% exponential, and 20% differential did the trick... the plane is now smooth. A 45 degree down glide showed a slight curl up and nose heavy condition so one ounce of weight was removed and tested and now a down slope glide holds straight.
The plane takes off and flies great at half power and full power doesn't increase its flying speed much though it certainly raises vertical performance so the match up with the Saito 1.25 seems good. It will require a lot of throttle flying to increase fuel enonomy by avoiding burning unneccesary amounts when not needed.
A flap down landing was pretty and I'm looking forward to a spoiler landing but I'd left the onboard glo on and so only got two flights and missed a chance to test a spoiler landing on a nice still day... I'd wondered why the motor wouldn't kill as idle was lowered... it got so low that one could count the revolutions by sight. A land switch settup including glow and very low idle is obviously a possibility. Preliminary altitude test of both flaperons and spoilers didn't show that much if any pitch mix would be needed.
Something that is apparent is the three degrees of engine right thrust called for seems to be excessive as vertical tracking under full power has to be corrected by left rudder. This is one of those times when premonition should have been listened to over the designers wishes. I've concluded that the right thrust called for must have been due to some quirk of the prop drive unit originally used with this design and should not have been set using a direct drive shaft engine. Because of the alignment of the large spinner, removing the thrust would not be simple. Modern radios do help here however as some left rudder mix can be programmed at higher throttle settings to counter the excess thrust.
The Zenoah G-20 ei
Break in went very smooth. The motor kicked on the third hand flip at which the choke was turned off and it came to life the next flip. Idle was smooth and low. After about a half hour running time, it was run up and reached 8,200 with a 16-8 APC prop. This motor seems to be about equivelant to a 1.2 4c. It will however be much cheaper to operate as it is uses much less fuel than a glow motor and the fuel is considerably cheaper. The G-20ei is a sweet motor with the only drawback a high current drain on the electronic ignition. An EU outfit however suggested less drain and good operation could be had from a three cell battery pack rather than a four, which is the route I've gone, using three cells from a surplus tool battery pack. As my quick charger has an adjustable knob for charge current, it is easy to adjust charging for the three cell pack.
Ultra Stick Lite (May 3, 2007)
Linda had said she wanted to get me a plane for my birthday so after a good bit of option sorting, an Ultra Stick Lite to match up with the G-20 is on order. On the short list and strongly in the running were an F6F Hellcat and A-6 Texan but were given up on in part because they both had retracts and our field is a bit rough for them. Also, as has been mentioned before, my hanger has several floaters that aren't great windy day fliers and the Akrobat that was hoped to be a reasonably good windy day flier didn't prove that. The stick was chosen also in hopes it makes a reasonably good windy day flier.
Some work
has been done on the P-51. The hardwood wing hold down block is forward because of the aft radiator on the P-51 and it has been fit and set with silicone adhesive, which works better on fiberglass than epoxy. The wing in that area is simply foam and 1/16" sheating so the holes needed drilled, the hardwood block tapped and then the wing holes drilled oversize to 1/2", tape placed across the holes and then the holes filled with epoxy (leaving them recessed somewhat) to be redrilled for the 1/4 inch nylon bolts.
Also, a test strip was made to see if water based sanding sealer would install SkyLoft covering to the wing and it seems it will work so the wing covering should get done soon and then it will be on to painting.
Close to my birthday... (May 22)
So with a rain day from work, I started my birthday present from Linda... the Ultra Stick Lite. The wing halves are joined and flaps and ailerons are installed. Dowels at leading edge and nylon bolts are fit. Horizontal stab is glued in place and the motor is fit to the firewall. ARF planes are much faster builds!
The P51 has seen some progress with covering on one surface of the wing. After apprehension of using the water based sanding sealer... it looks to be working well. The Sky Loft is simply saturated with water, shaken out and draped over the back of a chair with a towel under and in the time it takes to lay on a coat of sanding sealer the covering has shed the excess water and is ready to be layed over the wet sealer to be squeeged with a spunge working towards the fringe. So far so good. The plane that once seemed unlikely to ever get finished is slowly but steadily making progress.
More racks are needed for plane storage.
The decision between the Ultra Stick Lite and the Hellcat was a tough one... but, there have been some steering conversions sold recently so there is some airplane mad money and the Hellcat dream may happen yet. On that note, a few observations from other flyers... one retired a bit early with health issues and there isn't a lot of extra money to refurbish the hanger and two others had health issues that prohibit building. Having a full hanger doesn't seem to be a bad thing.
The Akrobat II
Has been flown enough now to be fairly well debugged. Some changes that were needed,
The Ultra Stick Lite (May 25)
Is ready!
Power is a Zenoah G20 ei
The Stick has flown and flies well.
The G20 is a good match for this plane
for sport flying giving it good vertical
performance for large loops and vertical
rolls.
Balance was perfect with the electronic
ignition and a 1800 mah three cell nicad
pack located forward where the fuel tank normaly sits and the fuel tank positioned in the wing cavity. The electronic ignition is noted to be a power hog but others have discovered that it does better on three rather than four cells. The 3 cell pack is reasonable on weight and yields an hour run time... enough for my usual three flights for an afternoon and of course can be quick charged for additional flights.
It was a bit windy during maiden day flights... and hopes for a windy day flyer seem obtained.
The second day was very cloudy but little wind and the USL continued to show its fun side. It will do almost unlimited vertical... just drop the nose a few degree and it keeps climbing. Crow mode allows very slow landings even with no wind. A vertical eight was no sweat. What is a sweat is keeping orientation with the clear covering... maybe it was the cloudy skies... we'll see... maybe some bright decals are needed.
I really like this plane! Floyd has commented in the past that the Hanger 9 PT-19 is likely my best flying plane and now suggest it may become a rare sight at the field. I gotta agree to the idea that this plane may become the most often flown... in part because it is fun but also because it is so economical.
My high about this plane is due to the combination of air frame and engine. The G-20 in my opinion is destined to become a popular RC engine unless Saito releases the gas four stroke that is rumored.
The engine
Enjoying the Ultra Stick Lite (June 10)
I've flown it exclusively for two weeks now and find it a very fun plane to fly. One can either fly fairly nice aerobatics or slow to a crawl using "crow mode". Crow also allows very slow nose up with full elevator flying (harrier) at only a slight bit of throttle with little concern for stall.
Switching mixes in allows quick rolls and tight loops.
BTW... The problem with the dying turned out to be simply a bit too rich on low end.
The enjoyment of the Zenoah G-20 ei continues... a great motor and good match for the USL.
Update (Sept 07)
The summer has been spent enjoying most of the models in the hanger, especially the Ultrastick Lite. The P-51 is still not painted, it was so humid this summer from rains almost every day so the painting was just canceled for a while. The last couple of days have seen a little pre-paint prep work on it.
A good buy came along on some planes from a modeler getting out of RC. Three interested me and were purchased. The first is another Cub, not needed in the hanger but it was super clean and has a Saito 90 twin, a fairly expensive motor. I've never owned a twin cylinder model engine so jumped on the good price. It has been flown once and sounds really great but I'm not sure the plane flies as well as my Goldberg, though it was a windy day and I'll reserve full judgement until experiencing a smooth outing. The plane is cleaner than the old Goldberg. A decision will be made about which to keep and the other sold.
The second plane, also very clean, is/was a quarter scale clipped wing Horizon Taylor Craft having a Zenoa 23 engine. Unfortunately it was crashed on the 3rd flight by letting it get too slow and stalling when I failed to account for a downwind turn while negotiating the base leg to final for a crosswind landing. Almost all of my flying has been floaters that require power fully off during landings and the heavy clipped wing plane that needed power kept on surprised me.
The Talor Craft has extensive windows with lower windows providing for side ground visibility so it is structurally not strong in the mid section and it broke in half, with extensive up front damage but no damage aft of the cockpit and minor damage to the wing. Ironically the cowl with some effort is repairable, though the wind screen and all but one side window are toast. If the windows can be had, the plane is rebuildable otherwise it needs a new fuselage. Fortunately, a picture was taken of it and my Grandson the day before the crash.
A good bit of work was needed to make the motor conversion. A 1/2 inch aluminum plate was milled to accept the motor and this plate mounted to the existing beams. With the YS, hardwood beam shims were used but with the smaller footprint Saito and weight to burn because it's lighter, a yoke was milled from 1/2 inch aluminum in an attempt to hold the integrity of the mounts. The elevator and throttle servos required swapping to accommodate the throttle hook up on the other side. Even though the mount was much heavier, two additional ounces of weight were added and a spinner nut turned and threaded for the motor shaft and spinner screw. If only I'd known this would be the engine... I'd not gone with the removable stabilizer and the extra tail weight it added and I'd gone with a lighter tail wheel bracket and saved close to a half pound of total weight.
The Akrobat Maiden (April 25, 2007)
Came on a blustery day with a 15 mph cross wind. I'd not run the motor inverted and rather than get oil residue on our patio table where planes are often tied down with wire, the plane was taken to the field and if all went well it could be flown. All wasn't well... the flight box gel cell battery has been cratering for six months and wouldn't turn over the new Saito when glow was added. Improvising by wrapping a shop rag around the three forefingers as done when polishing Army boots, it hand started easily. It had shown a slight tendency to load up on idle when upright and now inverted, was more noticeable. One adjustment did the trick and the engine idled without faltering, though having a bit more shake at idle than preferred, perhaps it is still a bit rich. Things went well after all.
Flight required three clicks of right turn. This plane has a lot of vertical stab and rudder and the strong cross wind yawed the tail to leeward as passes were made. It was not good conditions for a maiden, especially not knowing the flight and stall characteristics. Bringing it in as one would a plane that will tip stall... it touched down.... rolled a few feet... and with up elevator added to hold it down it went airborne again coming down fifteen feet further down the runway but on its feet to a smooth stop. It handled the taxi back to the flight line even with the very strong cross winds. This plane indeed has a lot of lift and unless it has some tip stall issues, it should land fine steep and slow with the nose up.
With only one flight in such harsh conditions it's too early to tell if I like it. Initial thought was not but in fairness it needs flown in better conditions before drawing conclusions. Even though the plane is given to yaw both on the ground and in the air by strong crosswinds, the large rudder will easily overcome tracking struggles. Ailerons were quite sensitive, causing some distraction from other observations that might have been apparent given more alertness.
A few comments about the engine... It starts easy and runs flawless and is very easy to adjust... but has two negatives. It shakes a fair bit at idle unless more leaning is needed and it likes fuel, which somewhat surprised me... I've two other Saito four strokes that are very fuel stingy. A 16oz tank will yield only about 10 minutes of run time. A timer will be needed with this plane. If one is willing to yield esthetic's and turn the muffer down somewhat on an inverted engine... the exhaust is outside the prop blast and the plane gets much less oil. Clean up was very easy.
One anecdote... the mods made for the Saito, the Akrobat was ready to take to the field for final motor testing and flying if all went well. Needed was to replace my T handled hex wrenches to the flight box because they are very often needed at the field. Picking one from the clutter on the work bench I noticed a screw that looks like no other screw used in model airplanes... if your mind lept ahead to the elevator servo arm retainer screw... you would be correct. When I swapped the two servos it somehow had been left off. This was a fitting find relative to the emotions I've been feeling about the first flight of this plane that has been so difficult to get finished and flying... I'd begun to feel that this one might shouldn't be... and without that screw... it likely would not have survived the first flight.
What Next?
Work will restart on the P-51. Next effort is to seal the wing to get ready for paint. Contemplated is the use os Sky Loft materiel I've had for years (similar to silkspan). Plans are to test to see if it can be applied using water base sanding sealer... probably dumb... but I'd like to test the idea... on a scrap of course.
Then it is a choice between two planes... the Balsa USA 1/4 Cub or an old Sterling PT-17 Stearman. An opportunity a week ago came to break in the Ryobi engine and insure that it was suitable for the cub... and I'm fairly happy with it. The only problem occured during too quick of decleration causing the engine to load up and shake for a couple of seconds or even die if the idle is very low. Timing the decleration similar to that of a servo shows that there may be no problem. The motor intended for the Stearman is the Zenoah G20 EI and I've not run it yet but will soon as I'm leaning on the Stearman build first.
Also... Linda asked if I'd like a plane for my birthday... silly question... eh. So, I've sorta been looking around and who knows, something might capture the imagination (was kinda looking at a Balsa USA 1/4 Nieuport 17) but haven't asked around yet about this kit's ratings.
More Akrobat Flight Time
Has quickly changed my first impression (of not liking) during that first blustery outing. Reducing aileron throw to 75%, giving them 40% exponential, and 20% differential did the trick... the plane is now smooth. A 45 degree down glide showed a slight curl up and nose heavy condition so one ounce of weight was removed and tested and now a down slope glide holds straight.
The plane takes off and flies great at half power and full power doesn't increase its flying speed much though it certainly raises vertical performance so the match up with the Saito 1.25 seems good. It will require a lot of throttle flying to increase fuel enonomy by avoiding burning unneccesary amounts when not needed.
A flap down landing was pretty and I'm looking forward to a spoiler landing but I'd left the onboard glo on and so only got two flights and missed a chance to test a spoiler landing on a nice still day... I'd wondered why the motor wouldn't kill as idle was lowered... it got so low that one could count the revolutions by sight. A land switch settup including glow and very low idle is obviously a possibility. Preliminary altitude test of both flaperons and spoilers didn't show that much if any pitch mix would be needed.
Something that is apparent is the three degrees of engine right thrust called for seems to be excessive as vertical tracking under full power has to be corrected by left rudder. This is one of those times when premonition should have been listened to over the designers wishes. I've concluded that the right thrust called for must have been due to some quirk of the prop drive unit originally used with this design and should not have been set using a direct drive shaft engine. Because of the alignment of the large spinner, removing the thrust would not be simple. Modern radios do help here however as some left rudder mix can be programmed at higher throttle settings to counter the excess thrust.
The Zenoah G-20 ei
Break in went very smooth. The motor kicked on the third hand flip at which the choke was turned off and it came to life the next flip. Idle was smooth and low. After about a half hour running time, it was run up and reached 8,200 with a 16-8 APC prop. This motor seems to be about equivelant to a 1.2 4c. It will however be much cheaper to operate as it is uses much less fuel than a glow motor and the fuel is considerably cheaper. The G-20ei is a sweet motor with the only drawback a high current drain on the electronic ignition. An EU outfit however suggested less drain and good operation could be had from a three cell battery pack rather than a four, which is the route I've gone, using three cells from a surplus tool battery pack. As my quick charger has an adjustable knob for charge current, it is easy to adjust charging for the three cell pack.
Ultra Stick Lite (May 3, 2007)
Linda had said she wanted to get me a plane for my birthday so after a good bit of option sorting, an Ultra Stick Lite to match up with the G-20 is on order. On the short list and strongly in the running were an F6F Hellcat and A-6 Texan but were given up on in part because they both had retracts and our field is a bit rough for them. Also, as has been mentioned before, my hanger has several floaters that aren't great windy day fliers and the Akrobat that was hoped to be a reasonably good windy day flier didn't prove that. The stick was chosen also in hopes it makes a reasonably good windy day flier.
Some work
has been done on the P-51. The hardwood wing hold down block is forward because of the aft radiator on the P-51 and it has been fit and set with silicone adhesive, which works better on fiberglass than epoxy. The wing in that area is simply foam and 1/16" sheating so the holes needed drilled, the hardwood block tapped and then the wing holes drilled oversize to 1/2", tape placed across the holes and then the holes filled with epoxy (leaving them recessed somewhat) to be redrilled for the 1/4 inch nylon bolts.
Also, a test strip was made to see if water based sanding sealer would install SkyLoft covering to the wing and it seems it will work so the wing covering should get done soon and then it will be on to painting.
Close to my birthday... (May 22)
So with a rain day from work, I started my birthday present from Linda... the Ultra Stick Lite. The wing halves are joined and flaps and ailerons are installed. Dowels at leading edge and nylon bolts are fit. Horizontal stab is glued in place and the motor is fit to the firewall. ARF planes are much faster builds!
The P51 has seen some progress with covering on one surface of the wing. After apprehension of using the water based sanding sealer... it looks to be working well. The Sky Loft is simply saturated with water, shaken out and draped over the back of a chair with a towel under and in the time it takes to lay on a coat of sanding sealer the covering has shed the excess water and is ready to be layed over the wet sealer to be squeeged with a spunge working towards the fringe. So far so good. The plane that once seemed unlikely to ever get finished is slowly but steadily making progress.
More racks are needed for plane storage.
The decision between the Ultra Stick Lite and the Hellcat was a tough one... but, there have been some steering conversions sold recently so there is some airplane mad money and the Hellcat dream may happen yet. On that note, a few observations from other flyers... one retired a bit early with health issues and there isn't a lot of extra money to refurbish the hanger and two others had health issues that prohibit building. Having a full hanger doesn't seem to be a bad thing.
The Akrobat II
Has been flown enough now to be fairly well debugged. Some changes that were needed,
- Servo used to switch the on board glow micro switch was an old servo given to me and was flakey
- Tail wheel steering springs needed more tension
- Different scheme was needed to secure wheel pants... is there a good system?
- 16 oz fuel tank was replaced with a 24 oz because the Saito 1.25 is fuel hungry
The Ultra Stick Lite (May 25)
Is ready!
Power is a Zenoah G20 ei
The Stick has flown and flies well.
The G20 is a good match for this plane
for sport flying giving it good vertical
performance for large loops and vertical
rolls.
Balance was perfect with the electronic
ignition and a 1800 mah three cell nicad
pack located forward where the fuel tank normaly sits and the fuel tank positioned in the wing cavity. The electronic ignition is noted to be a power hog but others have discovered that it does better on three rather than four cells. The 3 cell pack is reasonable on weight and yields an hour run time... enough for my usual three flights for an afternoon and of course can be quick charged for additional flights.
It was a bit windy during maiden day flights... and hopes for a windy day flyer seem obtained.
The second day was very cloudy but little wind and the USL continued to show its fun side. It will do almost unlimited vertical... just drop the nose a few degree and it keeps climbing. Crow mode allows very slow landings even with no wind. A vertical eight was no sweat. What is a sweat is keeping orientation with the clear covering... maybe it was the cloudy skies... we'll see... maybe some bright decals are needed.
I really like this plane! Floyd has commented in the past that the Hanger 9 PT-19 is likely my best flying plane and now suggest it may become a rare sight at the field. I gotta agree to the idea that this plane may become the most often flown... in part because it is fun but also because it is so economical.
My high about this plane is due to the combination of air frame and engine. The G-20 in my opinion is destined to become a popular RC engine unless Saito releases the gas four stroke that is rumored.
The engine
- runs smooth with very little vibration
- starts easy by hand propping
- is very stingy on fuel
- offers reasonable power to weight ratio
- idles very low
- has great transitions
- allows the fuel tank to be located at balance point
- is quiet
- deposits only a few small oil drops
on the plane
- can do most aerobatics including a vertical eight with large loops
- has good vertical
- can tear up the sky like a sport
plane or put around like a cub
- can land at crawl speed
- can do short takeoffs
- is lightly loaded
- can knife edge climb
Enjoying the Ultra Stick Lite (June 10)
I've flown it exclusively for two weeks now and find it a very fun plane to fly. One can either fly fairly nice aerobatics or slow to a crawl using "crow mode". Crow also allows very slow nose up with full elevator flying (harrier) at only a slight bit of throttle with little concern for stall.
Switching mixes in allows quick rolls and tight loops.
BTW... The problem with the dying turned out to be simply a bit too rich on low end.
The enjoyment of the Zenoah G-20 ei continues... a great motor and good match for the USL.
Update (Sept 07)
The summer has been spent enjoying most of the models in the hanger, especially the Ultrastick Lite. The P-51 is still not painted, it was so humid this summer from rains almost every day so the painting was just canceled for a while. The last couple of days have seen a little pre-paint prep work on it.
A good buy came along on some planes from a modeler getting out of RC. Three interested me and were purchased. The first is another Cub, not needed in the hanger but it was super clean and has a Saito 90 twin, a fairly expensive motor. I've never owned a twin cylinder model engine so jumped on the good price. It has been flown once and sounds really great but I'm not sure the plane flies as well as my Goldberg, though it was a windy day and I'll reserve full judgement until experiencing a smooth outing. The plane is cleaner than the old Goldberg. A decision will be made about which to keep and the other sold.
The second plane, also very clean, is/was a quarter scale clipped wing Horizon Taylor Craft having a Zenoa 23 engine. Unfortunately it was crashed on the 3rd flight by letting it get too slow and stalling when I failed to account for a downwind turn while negotiating the base leg to final for a crosswind landing. Almost all of my flying has been floaters that require power fully off during landings and the heavy clipped wing plane that needed power kept on surprised me.
The Talor Craft has extensive windows with lower windows providing for side ground visibility so it is structurally not strong in the mid section and it broke in half, with extensive up front damage but no damage aft of the cockpit and minor damage to the wing. Ironically the cowl with some effort is repairable, though the wind screen and all but one side window are toast. If the windows can be had, the plane is rebuildable otherwise it needs a new fuselage. Fortunately, a picture was taken of it and my Grandson the day before the crash.
The loss is tempered
because the cost was less than the price of a new engine and it also
came ready to fly with receiver, battery and all servos. The
plane was a very nice scale looking plane and flew well other than my
inexperience with keeping some power on.
The third plane is called a New Bee and has a Saito .30. Again a bargain with the cost about half that of a new motor and it also came ready to fly.
The Twin Cylinder Cub (March, 2008)
The crash of the Taylor Craft was followed by the crash of the new Cub. I was putting around real slow and it tip stalled and fell 40 feet and went nose in. Damage was serious but not fatal, it took out the firewall, front deck, cowl, and forward bulkhead. Amazingly the windows survived though the windscreen was creased and crinkled. The wing had minor damage where a strut pulled out half of one rib.
The Cub is now rebuilt but not yet flown. It took some patience to piece together but it survived and looks well. The windscreen has some slight blemishes remaining after using a little heat to undo the crinkles, but will do. A new cowl was needed and otherwise everything else was simply glued back together.
Some effort has been given to setting the radio up to make the Cub a better flying model. Checking the aileron throws showed 1/16 more down than up. On a flat wing foil, a down aileron will have more drag than the corresponding up aileron and on such a long wing as the Cub has, the leverage forces are much greater and cause a yaw moment along with the roll that produces a wallow. Two efforts can reduce this. First, some rudder coordination will counter the tail yaw and second some aileron differential will help balance the drag between each wing thereby reducing the yaw force.
To start, 50% differential has been dialed in meaning that the inboard to the turn aileron goes up twice as far as the outboard goes down. 35% rudder mix was added to coordinate the turns and counter the yaw effect of the turn. Finally, per the suggestion of another flyer at the field who used to fly full scale Cubs, to reduce tip stall tendency, some spoiler mix was given to the throttle. What this means is that as the throttle is reduced, both ailerons trim upward to simulate washout. I've started with 1/4 inch at low throttle, which is fully neutralized by mid throttle. The plane is ready for a nice day for testing. I'm not sure however that this plane will achieve the nice qualities of the Goldberg Anniversary Edition Cub above. The latter was built with a generous amount of washout and is very forgiving and will stall only forward. I do not know if this was a Goldberg design or was a builder option, regardless it makes the plane a very nice fun plane to play with.
Flying report
The aileron differential and rudder mix were exactly what the Cub needed to stop the wallering. The aileron up trim did the job in stopping the tip stalling at slow speeds. At half throttle, ailerons begin moving towards a spoiler position with 1/4 inch total up at low throttle. The rebuilt plane is flying well with these trims.
The Phaeton 90
The weed whacker conversion survived a year and a half when the magneto coil failed, leaving the option to convert to electronic ignition or abandon. Power was poor but it flew the Phaeton realistically, which was fun for a while as it was interesting and cheap to do the conversion costing $12. More performance was wanted and wanting to stay with gas, another Zenoah G-20 was acquired and fitted to the Phaeton for a gain of 1,600 rpm and an amazing difference in power and aerobatic ability. The G-20 is not only much more powerful it is much lighter but unfortunately that advantage was lost because I'd shortened the front end of the Phaeton by an inch to provide for the heavy weed conversion motor. Thus, 12 oz of lead were needed to get balance. A bonus was that the cowl could now be fitted, whereas previously the magneto flywheel prevented installation.
I've flown the Phaeton twice since repowering and it is a blast. It doesn't have unlimited vertical but it will do very large loops and will power through inverted loops without hesitation. The Phaeton 90 specs out between 11-12 lbs and mine now is heavy at 13 lb 6 oz due to the shortened firewall and the heavier covering and a heavy tail wheel bracket. It flies well but no doubt would fly considerably better if two lbs lighter.
What's Ahead?
With the bench now cleared by the completion of repairs to the Cub and refitting of the motor on the Phaeton, what next has been given some thought and it seems time to paint and finish the P-51 Mustang. The plane has indeed waited a very long time to fly. All that is needed is an additional receiver.
Beyond that is the rebuild of the Taylor Craft. It was given a few hours work recently debrieding it of broken windows and sorting out whether a reconstruction is in order. A picture will be offered of its condition. It also went in on its nose but damage is more extensive. The forward bottom section of the Cub survived with the landing gear still in place. The Taylor Craft is wiped out from the cabin forward with all windows and windscreen destroyed. Amazingly however the cowl though crinkled a good bit can be salvaged. The wing has a bit of damage to about five inches of the leading edge. With some effort, the plane can be rebuilt. The damaged parts are in good enough condition to either salvage or use as patterns for replacement. I'm actually beginning to sense the challenge of seeing it restored.
Floyd has offered a Spitfire that his cousin built that has never flown. He said it is painted but control surfaces are not hinged and it needs a motor. It is a .60 size Pica kit if I recall correctly. I don't have a motor or receiver and it probably needs a .90 four stroke. It does not have retracts, which I consider a plus for our fairly rough flying field.
Of course, in the box yet are a quarter scale Balsa USA Cub and the old Sterling PT-17 Stearman. They probably will wait for another winter building season.
PT-19
This doesn't amount to much, but is interesting. The PT-19 is powered by an Enya 1.2 four stroker, which now has been broken in enough to loosen up a bit and not spit its prop too often. It seemed that the engine had lost a little performance so the break in head shim was removed though the performance was still off slightly. This plane was a favorite in that it would do the Lumcevak but it had suffered a shootdown requiring a new firewall and repairs after which cranking out the tumbling maneuver was not nearly as predictable as previous. The Lumcevak tumble requires a timed movement of the elevator from full up to full down along with holding full aileron, rudder and throttle after initiating a climbing snap roll. Where I used to hit it three out of four, it was now one of five and demoralizing. I figured the problem was likely a CG change resulting from the repairs and wasn't sure I'd find the magic settings again.
The plane had been flown by my second transmitter and because it had some elevator mix when engaging the flaps I'd not bothered to set it up in the latest 3rd transmitter. Recently it was taken to fly but with the new transmitter, which finally forced a setup. Flying saw a return of the performance it once had and the predictable nailing of the Lumcevak almost every time. Remember, the Lumcevak is a three axis maneuver with the 3rd axis being the auto gyro action of the motor at full throttle. The light turned on... after the rebuilding of the firewall, the throttle setting had been limited to less than full in the transmitter setup. I'm guessing what happened is the sub trim was moved lower, which limited the upper throw and I mentally didn't pick up on it.
The P-51
Is nearing completion after twenty five years. It is now painted and motor and radio gear fitted. Discovered however is a balance issue with an often found tail heavy condition. Years ago hardwood 1/4 dowel push rods had been fitted and the balance point was found to be three inches aft of the landing gear mounts whereas it should be one and one half inches aft. There were actually three push rods with the third for the scale tail wheel location. A short list of things to do to minimize the amount of lead needed in the nose was made including;
The plane has been tentatively weighed and is expected to come in around nine pounds plus any balance weight needed. After the changes noted above, the 5 lb 10 oz plane now balances one inch forward of CG but the 3 lb 4oz wing balances 1 1/4 inch aft so it looks like the effort to correct the CG issue has worked and no additional weight will be needed. Interesting is that the plans are fairly well done but the weight line in the spec box is blank. At nine pounds, loading would be 30.3 oz/ft, not excessive for a war bird so it should fly.
I was very wrong with the initial thoughts that the weight issue had been corrected. Needed was 9 oz of weight added fully forward in the motor compartment cowl. The ready to fly weight is 9lbs 9 oz for a wing loading just above 32 oz/sq ft.
The P-51 Is Finished after Twenty Five Years (April 10, 2008)
The P-51 finally took to the air on a cool blustery Sunday evening just before dark. The wind blew hard all day and I waited till late knowing that no one would show at the field anyway and perhaps the wind would slacken in the evening hours.
As expected, a good bit of right rudder was needed to keep the plane from drifting left and avoiding overcorrecting was difficult. As well, rotation required significant elevator. A plus was that power up produced no nose over tendancies. Roll axis was quick, much too quick for my liking and fortunately the plane flew nearly in perfect trim with only two clicks of roll trim needed.
With the plane high, it was slowed and the 1st flap position set with a resulting strong pitch down. I'd have to land hot without flaps. Power off sink rate was significant as expected with the heavier wing loading and with the strong headwind power was kept up to do a hot wheel landing. I gave elevator too quickly to hold the tail down and it ballooned.
Both Aileron and elevator throw was diminished to 80% with 50% exponential. Rudder was also given 50% exponential. When preparing to mix some elevator up trim with the 1st flap position, I noted that the standard radio settup all ready had some down elevator mix... it was causing the down pitch and readjusted to no pitch change at the 1st flap position.
The second flight saw a better take off roll as I had a handle on the need for a good bit of rudder and the rudder was less sensitive given the exponential. Breaking ground however required a lot of elevator. Roll rate was much better. The 1st flap position was tested and no pitch was noticed. After boring a few holes in the sky, the plane was lined up and flaps engaged and power set for a good glide slope. When ground effect was reached, up elevator was given and it needed full up to keep the nose up. The elevator was given some differential with the up throw increased. The motor had sagged very slightly in loops so it was richened a few clicks, otherwise it ran flawless.
Another take off and landing and the increased up elevator throw was better and alowed flairing with a 1st position flap landing. Two of the four landings for the outing suffered from a bit of bounce on landing. With the brisk wind, I was simply happy to get it down without mishap. Given the very blustery headwind, we will see how it goes with some smoother air.
The HB-61 seemed well matched. It is turning 11,700 on a 12x6 APC. This faster plane might enjoy a stronger pitiched prop, perhaps an 11-12 x 8. The plane is much faster than most in my hanger and the last flight with the loss of some daylight saw visibility challenging with the silver airplane. I was also growing cold and hands were getting numb. With the buffeting winds, I didn't do an inflight balance test. The plane is not overly sensitive on elevator with quite a bit of throw and it took a lot of elevator to get it off the ground and a lot to flare it so it might be nose heavy and if so I'd be very happy to get rid of some of the nose lead that was added, though I don't want to experience this plane even close to tail heavy as it does a very wicked snap roll and I believe will have no problems doing spins. Best I could tell in the strong winds, it tracks through very large loops nicely and climbs without major amounts of right rudder. It has good vertical performance and will do large loops and cuban eights.
Rolls seem a bit sloppy and might benefit from some differential but with the single servo on ailerons and the bell cranks locked within the wing, there will be no differential. Multiple aileron rolls did seem much better after exponential on the elevator was set and it was given differential with more up than down. A little down elevator will pitch the nose down sharply but a corresponding up pitch requires a lot of elevator.
The results of an inflight balance test will be interesting. Current balance point is set per plans with the exception that it has the position point above the wing whereas I balanced under the wing though that shouldn't make a difference. In argument that the plane is nose heavy is the requirment of a lot of elevator to rotate and a lot of elevator to flare the stall but those could be higher wingloading virtues. In argument that it is not nose heavy is the wicked snap rolls it can do.
P-51 Flying report from outing two
The second outing was only a few days later and several of the guys were at the field to watch. I discussed with them the issue of needing a great deal of elevator to get airborn. They offered that it could be nose heavy but to be very cautious about getting CG aft on a war bird. My plans were to do an in flight CG test using the 45 degree down glide method an observing for either a curl up or down tuck.
To my great surprise, the plane lurched into the air as it was gaining speed and was eight to ten feet up before reaction time allowed getting the nose pitched for level flight. I was fortunate it hadn't snapped. As altitude was being sought, my thoughts were how could it be that a few days ago it took great amounts of elevator to get airborn and today it lurched into the air before it had obtained full run up speed. One of the guys hollered, "what did you change?" "Nothing", I replied. A couple of seconds later, it came to me that maybe I did change something and the light turned on about what it was.
This plane is the only plane I've owned where the wing hold down bolts are in the front of the wing rather the rear and is this way because the radiator scoop on a P-51 is under the wing aft and this is part of the fiberglass fuselage on this model. Hence, the wing is tucked between it and the fuselage and the bolts are located near the leading edge in a faired section of the middle of the wing. What had happened was that on the first outing, I'd not tightened these bolts as much as today and the slight bit of incidence change produced dramatically differing results from the foiled stab. I loosened the bolts very slightly for the next flight getting the fairing section as even as possible and this proved to be the sweet spot. The next takeoff was perfect requiring only a bit of elevator to get airborn.
The bird was rung out a bit and a down glide was done to check the CG... No upturn or tuck under meant it was ok. So, the plane was put through some paces and it will do the dramatic lumceva
k tumbles following a snap
roll. These were first done very high after checking first that
the plane will pull out of a spin without issues.
On the third flight of the day, something was heard when the plane touched down and was discovered to be a wheel strut torsion arm block had broken loose inside the wing. Either it had not been glued adequately or the old brittle epoxy failed. There was no damage otherwise to the plane, which continued a normal landing roll. The gear on this plane has a generous forward rake and unlike many war birds, has no issues on our rough grass field.
The area of most concern has nothing to do with the flight... I'd forgotten how nasty a .60 size two stroke glow powered plane gets. I'm spoiled by the gassers when it comes time to clean em up.
Several planes needing repairs (May 19)
The twin engined Cub needs the exhaust stacks repaired. One of the flexible exhaust stacks broke. I ordered some replacement stacks and got the wrong size.
The P-51 needs the torsion block reglued within the wing. I'm not sure what effort will be required. Maybe as simple as injecting some epoxy.
The PT-19 received slight damage this past weekend. On the third flight of the day, there was some kind of trouble shortly after takeoff. It wasn't responding perfectly to control movements and was occassionally doing weird stuff. It went a good way out before a good bit of fighting got it aimed back at the runway and I hollered out I had trouble and aimed to set it down crosswise to the runway (into the wind) rather than risk going around to line up. The goal was to get it on the ground as soon as possible with no thoughts of any go around. It took a lot of fight to hold it level and bring it back from several rolls and get it to the field, it needed a bit more power to make it but wouldn't respond, and it glided into the sloped rough about six feet off the runway and bounced up and then actually onto the runway. I noted quickly some deformity of the wing above one of the wheel struts. Yep, it was the strut mount that had not been rebuilt.
The only issue reported about this ARF was that the wing strut hardwood mounts were simply glued to balsa ribs. The other strut had come loose only after a few flights and had been easily repaired because the harwood block had broken loose and allowed working through the hole and installing ply wood false ribs carrying the load to the leading edge and spars. After making a pattern for these, extras were made for the other side of the wing but the block wouldn't break loose so was never dealt with. Now it will be. There is little damage and the fix will be easy, especially that I've got the ribs.
The cause of the damage is attributed to radio interference. After a range and battery checks, the plane was left on the table turned on with transmitter off. At several instances over the next few minutes, the surfaces went spastic. After a short while, there was no more interference. Whoever else was using that frequency was not at our field and was likely flying a park flier at one of the local parks. I'd love to be flying on 2.4 spread spectrum but can't afford to replace all the radio gear.
And of course, the Taylor Craft still needs its entire fore section rebuilt. I've discovered that a large hanger of planes requires a good bit of maintenance.
The third plane is called a New Bee and has a Saito .30. Again a bargain with the cost about half that of a new motor and it also came ready to fly.
The Twin Cylinder Cub (March, 2008)
The crash of the Taylor Craft was followed by the crash of the new Cub. I was putting around real slow and it tip stalled and fell 40 feet and went nose in. Damage was serious but not fatal, it took out the firewall, front deck, cowl, and forward bulkhead. Amazingly the windows survived though the windscreen was creased and crinkled. The wing had minor damage where a strut pulled out half of one rib.
The Cub is now rebuilt but not yet flown. It took some patience to piece together but it survived and looks well. The windscreen has some slight blemishes remaining after using a little heat to undo the crinkles, but will do. A new cowl was needed and otherwise everything else was simply glued back together.
Some effort has been given to setting the radio up to make the Cub a better flying model. Checking the aileron throws showed 1/16 more down than up. On a flat wing foil, a down aileron will have more drag than the corresponding up aileron and on such a long wing as the Cub has, the leverage forces are much greater and cause a yaw moment along with the roll that produces a wallow. Two efforts can reduce this. First, some rudder coordination will counter the tail yaw and second some aileron differential will help balance the drag between each wing thereby reducing the yaw force.
To start, 50% differential has been dialed in meaning that the inboard to the turn aileron goes up twice as far as the outboard goes down. 35% rudder mix was added to coordinate the turns and counter the yaw effect of the turn. Finally, per the suggestion of another flyer at the field who used to fly full scale Cubs, to reduce tip stall tendency, some spoiler mix was given to the throttle. What this means is that as the throttle is reduced, both ailerons trim upward to simulate washout. I've started with 1/4 inch at low throttle, which is fully neutralized by mid throttle. The plane is ready for a nice day for testing. I'm not sure however that this plane will achieve the nice qualities of the Goldberg Anniversary Edition Cub above. The latter was built with a generous amount of washout and is very forgiving and will stall only forward. I do not know if this was a Goldberg design or was a builder option, regardless it makes the plane a very nice fun plane to play with.
Flying report
The aileron differential and rudder mix were exactly what the Cub needed to stop the wallering. The aileron up trim did the job in stopping the tip stalling at slow speeds. At half throttle, ailerons begin moving towards a spoiler position with 1/4 inch total up at low throttle. The rebuilt plane is flying well with these trims.
The Phaeton 90
The weed whacker conversion survived a year and a half when the magneto coil failed, leaving the option to convert to electronic ignition or abandon. Power was poor but it flew the Phaeton realistically, which was fun for a while as it was interesting and cheap to do the conversion costing $12. More performance was wanted and wanting to stay with gas, another Zenoah G-20 was acquired and fitted to the Phaeton for a gain of 1,600 rpm and an amazing difference in power and aerobatic ability. The G-20 is not only much more powerful it is much lighter but unfortunately that advantage was lost because I'd shortened the front end of the Phaeton by an inch to provide for the heavy weed conversion motor. Thus, 12 oz of lead were needed to get balance. A bonus was that the cowl could now be fitted, whereas previously the magneto flywheel prevented installation.
I've flown the Phaeton twice since repowering and it is a blast. It doesn't have unlimited vertical but it will do very large loops and will power through inverted loops without hesitation. The Phaeton 90 specs out between 11-12 lbs and mine now is heavy at 13 lb 6 oz due to the shortened firewall and the heavier covering and a heavy tail wheel bracket. It flies well but no doubt would fly considerably better if two lbs lighter.
What's Ahead?
With the bench now cleared by the completion of repairs to the Cub and refitting of the motor on the Phaeton, what next has been given some thought and it seems time to paint and finish the P-51 Mustang. The plane has indeed waited a very long time to fly. All that is needed is an additional receiver.
Beyond that is the rebuild of the Taylor Craft. It was given a few hours work recently debrieding it of broken windows and sorting out whether a reconstruction is in order. A picture will be offered of its condition. It also went in on its nose but damage is more extensive. The forward bottom section of the Cub survived with the landing gear still in place. The Taylor Craft is wiped out from the cabin forward with all windows and windscreen destroyed. Amazingly however the cowl though crinkled a good bit can be salvaged. The wing has a bit of damage to about five inches of the leading edge. With some effort, the plane can be rebuilt. The damaged parts are in good enough condition to either salvage or use as patterns for replacement. I'm actually beginning to sense the challenge of seeing it restored.
Floyd has offered a Spitfire that his cousin built that has never flown. He said it is painted but control surfaces are not hinged and it needs a motor. It is a .60 size Pica kit if I recall correctly. I don't have a motor or receiver and it probably needs a .90 four stroke. It does not have retracts, which I consider a plus for our fairly rough flying field.
Of course, in the box yet are a quarter scale Balsa USA Cub and the old Sterling PT-17 Stearman. They probably will wait for another winter building season.
PT-19
This doesn't amount to much, but is interesting. The PT-19 is powered by an Enya 1.2 four stroker, which now has been broken in enough to loosen up a bit and not spit its prop too often. It seemed that the engine had lost a little performance so the break in head shim was removed though the performance was still off slightly. This plane was a favorite in that it would do the Lumcevak but it had suffered a shootdown requiring a new firewall and repairs after which cranking out the tumbling maneuver was not nearly as predictable as previous. The Lumcevak tumble requires a timed movement of the elevator from full up to full down along with holding full aileron, rudder and throttle after initiating a climbing snap roll. Where I used to hit it three out of four, it was now one of five and demoralizing. I figured the problem was likely a CG change resulting from the repairs and wasn't sure I'd find the magic settings again.
The plane had been flown by my second transmitter and because it had some elevator mix when engaging the flaps I'd not bothered to set it up in the latest 3rd transmitter. Recently it was taken to fly but with the new transmitter, which finally forced a setup. Flying saw a return of the performance it once had and the predictable nailing of the Lumcevak almost every time. Remember, the Lumcevak is a three axis maneuver with the 3rd axis being the auto gyro action of the motor at full throttle. The light turned on... after the rebuilding of the firewall, the throttle setting had been limited to less than full in the transmitter setup. I'm guessing what happened is the sub trim was moved lower, which limited the upper throw and I mentally didn't pick up on it.
The P-51
Is nearing completion after twenty five years. It is now painted and motor and radio gear fitted. Discovered however is a balance issue with an often found tail heavy condition. Years ago hardwood 1/4 dowel push rods had been fitted and the balance point was found to be three inches aft of the landing gear mounts whereas it should be one and one half inches aft. There were actually three push rods with the third for the scale tail wheel location. A short list of things to do to minimize the amount of lead needed in the nose was made including;
- Using a 1300 mah battery pack made from inexpensive power tool
battery from Harbor Freight. This allowed a compact arrangement that
will fit very close to the firewall compared to the flat arrangement
situated further aft
- Moving the servo tray forward of CG from the position just aft
of the CG. The tray was home made with a switch mounted forward
on the tray and then a bay for the receiver and then the throttle
followed by the rudder and elevator servos aft. The tray was
reduced to just that necessary for the three servos moving them forward
about 4.5 inches. The receiver will be located over the fuel tank
and the switch mounted in the fuselage side
- Eliminating the push rod on the rudder by using pull/pull wires
- Reworking the elevator and tail wheel push rods from 1/4 round hardwood to 5/16 square balsa and reducing the wire sections to the minimum
The plane has been tentatively weighed and is expected to come in around nine pounds plus any balance weight needed. After the changes noted above, the 5 lb 10 oz plane now balances one inch forward of CG but the 3 lb 4oz wing balances 1 1/4 inch aft so it looks like the effort to correct the CG issue has worked and no additional weight will be needed. Interesting is that the plans are fairly well done but the weight line in the spec box is blank. At nine pounds, loading would be 30.3 oz/ft, not excessive for a war bird so it should fly.
I was very wrong with the initial thoughts that the weight issue had been corrected. Needed was 9 oz of weight added fully forward in the motor compartment cowl. The ready to fly weight is 9lbs 9 oz for a wing loading just above 32 oz/sq ft.
The P-51 Is Finished after Twenty Five Years (April 10, 2008)
The P-51 finally took to the air on a cool blustery Sunday evening just before dark. The wind blew hard all day and I waited till late knowing that no one would show at the field anyway and perhaps the wind would slacken in the evening hours.
As expected, a good bit of right rudder was needed to keep the plane from drifting left and avoiding overcorrecting was difficult. As well, rotation required significant elevator. A plus was that power up produced no nose over tendancies. Roll axis was quick, much too quick for my liking and fortunately the plane flew nearly in perfect trim with only two clicks of roll trim needed.
With the plane high, it was slowed and the 1st flap position set with a resulting strong pitch down. I'd have to land hot without flaps. Power off sink rate was significant as expected with the heavier wing loading and with the strong headwind power was kept up to do a hot wheel landing. I gave elevator too quickly to hold the tail down and it ballooned.
Both Aileron and elevator throw was diminished to 80% with 50% exponential. Rudder was also given 50% exponential. When preparing to mix some elevator up trim with the 1st flap position, I noted that the standard radio settup all ready had some down elevator mix... it was causing the down pitch and readjusted to no pitch change at the 1st flap position.
The second flight saw a better take off roll as I had a handle on the need for a good bit of rudder and the rudder was less sensitive given the exponential. Breaking ground however required a lot of elevator. Roll rate was much better. The 1st flap position was tested and no pitch was noticed. After boring a few holes in the sky, the plane was lined up and flaps engaged and power set for a good glide slope. When ground effect was reached, up elevator was given and it needed full up to keep the nose up. The elevator was given some differential with the up throw increased. The motor had sagged very slightly in loops so it was richened a few clicks, otherwise it ran flawless.
Another take off and landing and the increased up elevator throw was better and alowed flairing with a 1st position flap landing. Two of the four landings for the outing suffered from a bit of bounce on landing. With the brisk wind, I was simply happy to get it down without mishap. Given the very blustery headwind, we will see how it goes with some smoother air.
The HB-61 seemed well matched. It is turning 11,700 on a 12x6 APC. This faster plane might enjoy a stronger pitiched prop, perhaps an 11-12 x 8. The plane is much faster than most in my hanger and the last flight with the loss of some daylight saw visibility challenging with the silver airplane. I was also growing cold and hands were getting numb. With the buffeting winds, I didn't do an inflight balance test. The plane is not overly sensitive on elevator with quite a bit of throw and it took a lot of elevator to get it off the ground and a lot to flare it so it might be nose heavy and if so I'd be very happy to get rid of some of the nose lead that was added, though I don't want to experience this plane even close to tail heavy as it does a very wicked snap roll and I believe will have no problems doing spins. Best I could tell in the strong winds, it tracks through very large loops nicely and climbs without major amounts of right rudder. It has good vertical performance and will do large loops and cuban eights.
Rolls seem a bit sloppy and might benefit from some differential but with the single servo on ailerons and the bell cranks locked within the wing, there will be no differential. Multiple aileron rolls did seem much better after exponential on the elevator was set and it was given differential with more up than down. A little down elevator will pitch the nose down sharply but a corresponding up pitch requires a lot of elevator.
The results of an inflight balance test will be interesting. Current balance point is set per plans with the exception that it has the position point above the wing whereas I balanced under the wing though that shouldn't make a difference. In argument that the plane is nose heavy is the requirment of a lot of elevator to rotate and a lot of elevator to flare the stall but those could be higher wingloading virtues. In argument that it is not nose heavy is the wicked snap rolls it can do.
P-51 Flying report from outing two
The second outing was only a few days later and several of the guys were at the field to watch. I discussed with them the issue of needing a great deal of elevator to get airborn. They offered that it could be nose heavy but to be very cautious about getting CG aft on a war bird. My plans were to do an in flight CG test using the 45 degree down glide method an observing for either a curl up or down tuck.
To my great surprise, the plane lurched into the air as it was gaining speed and was eight to ten feet up before reaction time allowed getting the nose pitched for level flight. I was fortunate it hadn't snapped. As altitude was being sought, my thoughts were how could it be that a few days ago it took great amounts of elevator to get airborn and today it lurched into the air before it had obtained full run up speed. One of the guys hollered, "what did you change?" "Nothing", I replied. A couple of seconds later, it came to me that maybe I did change something and the light turned on about what it was.
This plane is the only plane I've owned where the wing hold down bolts are in the front of the wing rather the rear and is this way because the radiator scoop on a P-51 is under the wing aft and this is part of the fiberglass fuselage on this model. Hence, the wing is tucked between it and the fuselage and the bolts are located near the leading edge in a faired section of the middle of the wing. What had happened was that on the first outing, I'd not tightened these bolts as much as today and the slight bit of incidence change produced dramatically differing results from the foiled stab. I loosened the bolts very slightly for the next flight getting the fairing section as even as possible and this proved to be the sweet spot. The next takeoff was perfect requiring only a bit of elevator to get airborn.
The bird was rung out a bit and a down glide was done to check the CG... No upturn or tuck under meant it was ok. So, the plane was put through some paces and it will do the dramatic lumceva
k tumbles following a snap
roll. These were first done very high after checking first that
the plane will pull out of a spin without issues.On the third flight of the day, something was heard when the plane touched down and was discovered to be a wheel strut torsion arm block had broken loose inside the wing. Either it had not been glued adequately or the old brittle epoxy failed. There was no damage otherwise to the plane, which continued a normal landing roll. The gear on this plane has a generous forward rake and unlike many war birds, has no issues on our rough grass field.
The area of most concern has nothing to do with the flight... I'd forgotten how nasty a .60 size two stroke glow powered plane gets. I'm spoiled by the gassers when it comes time to clean em up.
Several planes needing repairs (May 19)
The twin engined Cub needs the exhaust stacks repaired. One of the flexible exhaust stacks broke. I ordered some replacement stacks and got the wrong size.
The P-51 needs the torsion block reglued within the wing. I'm not sure what effort will be required. Maybe as simple as injecting some epoxy.
The PT-19 received slight damage this past weekend. On the third flight of the day, there was some kind of trouble shortly after takeoff. It wasn't responding perfectly to control movements and was occassionally doing weird stuff. It went a good way out before a good bit of fighting got it aimed back at the runway and I hollered out I had trouble and aimed to set it down crosswise to the runway (into the wind) rather than risk going around to line up. The goal was to get it on the ground as soon as possible with no thoughts of any go around. It took a lot of fight to hold it level and bring it back from several rolls and get it to the field, it needed a bit more power to make it but wouldn't respond, and it glided into the sloped rough about six feet off the runway and bounced up and then actually onto the runway. I noted quickly some deformity of the wing above one of the wheel struts. Yep, it was the strut mount that had not been rebuilt.
The only issue reported about this ARF was that the wing strut hardwood mounts were simply glued to balsa ribs. The other strut had come loose only after a few flights and had been easily repaired because the harwood block had broken loose and allowed working through the hole and installing ply wood false ribs carrying the load to the leading edge and spars. After making a pattern for these, extras were made for the other side of the wing but the block wouldn't break loose so was never dealt with. Now it will be. There is little damage and the fix will be easy, especially that I've got the ribs.
The cause of the damage is attributed to radio interference. After a range and battery checks, the plane was left on the table turned on with transmitter off. At several instances over the next few minutes, the surfaces went spastic. After a short while, there was no more interference. Whoever else was using that frequency was not at our field and was likely flying a park flier at one of the local parks. I'd love to be flying on 2.4 spread spectrum but can't afford to replace all the radio gear.
And of course, the Taylor Craft still needs its entire fore section rebuilt. I've discovered that a large hanger of planes requires a good bit of maintenance.