Engine Mounts: Barnstormers Pattern Site

Return to Building Techniques

Vibra Damp vs. Hyde Mount

Hanson Rotr-Mount

This discussion came from the web site nscra-list@eskimo.com (To subscribe to the list send an email message to: nsrca-list-request@eskimo.com and in the subject line of the message put: subscribe). It is an extensive discussion about the advantages and disadvantages of both mounts. Remember, there are advantages to both mounts, the Vibra Damp is great, light, cheap and works well with any engine in the class of the YS120 NC but it may not be up to the SC or 140 FZ. You be the judge.

Vibra Damp vs. Hyde Mount

Well, here's some straight skinny. There have been many thousands of flights with the VibraDamp mount with 120 4-cycles., standards through N/C's & A/C's and I use one myself on my NC. However, for the SC's and the 140's the mount is not sufficient to do the job. I recommend either the Hyde mount or the MK 140 mount for SC's and anything larger. Just like Gene stated, you do not want to use a nosering on the VibraDamp mount. If you are having thrust alignment problems with it, replace the rubber bushings and use slow CA to bond the rubber to the aluminum mounting beam. Another option is to replace the rubber with the MK rubber which comes with their 140-mount. I believe this is available from Indy R/C. The holes in the MK rubber are undersized from the VibraDamp rubber, but you can enlarge it with a piece of heated wire. This is a firmer rubber than the original and should give increased longevity.
SamTurner

Cheers Sam!!
Your Right on the life of the mount and the upgrade using the MK hard plastic/Clear Rubber?. But The Vibration is overwhelming !! I did that very early on. I built two Epicure2 models, One With The Hyde Mount, And One with the Vibra/Brown Beam setup. All Things being as close to equal as possible !! The Difference was beyond belief !! There was even a noted difference in battery life !! AKA more flights on a charge ! There are alot of Hyde Mount Clones out there from various sources, And even detailed Plans and instructions on how to make those mounts. But The Point here is this, Cheaper Can be very self defeating in this game, I mean really, How many guys here use a 12.95 servo for elevator? As a manufacture, I know the price tag on Research and Develpoment. If The guys building these models had to cover the cost of the Hours we spend there, Those Mounts would exceed $500.00 Each, And Kits alone would be Like Buying a good used car! This isnt a volume market . Buying and supporting products from innovative Modelers like the Hydes is the only way to Go. Without the genius of some of these cottage industries WE would all be face with Far worse problems than a $50.00 Price difference .

After extensive testing on both mounts, Bad News Dudes, The Hyde Style Mount is Really the ONLY mount !!!! Vibra mounts Can not and Do not provide the isolation nor proper thrust control.. If you try to add a nose ring to that style Mount, The rear isolaters will break or wear out at an increased rate!! Due to the engine hopping around and pivoting off the nose ring. We here in the chicagoland area have given up on modifications to try to fix this problem. The Mount you reffered to is a good Quality mount, Well Made And Very Light, But I as well as others here feel That it was really a 2 stroke mount and not really desidned as a 4 stroke mount. The Hyde Mount or, Some of the clones Ive seen from canada, Will offer you much more in the long haul. Gene Maxwell

Gene, Good, point. But you missed my point. What I'm saying is that for the A/C's and less, the VibraDamp mount is fine. I can demonstrate this to anyone who wants to come down and see the difference in my Pursuit with the VibraDamp and an NC vewrsus a fellow flyer's Storm EX with the Hyde and a 140. Anyone who sees it will see that there is significantly less motion at the ends of the wings and the stab on my plane....and on any of the Pursuits at our field...and ALL of them use the VibraDamp mount. However, the mount is out of it's league with SC's and 140's. Sam

Well.... I guess the 400+ flights I have on my Ariel with the YS140 and the Dave Brown vibra damp mount are just a fluke. I have replaced the rubbers only once. Tony Stillman

I have tryed all the mounts out there and there is no question, hands down the Hyde mount is by a long shot the BEST there is out there, not to say that the othor mounts don`t work. The down side is the size and weight of this thing. I loved the von. mount but found that the vibration was on the average side and if you tried to put a nose ring on it, like Gene said the rubbers wore out in a short period of time the plus side of the mount was it was disgustinly simple to install and about 1/3`rd of the weight . BUT the Hyde mount beats them all hands down in performance no doubt about it Byran Hebert

Final thought on soft mounts. I agree with Bryan the Hyde style mount is clearly the best setup. One big advantage is that it is designed for a nose ring. Any soft mount that I have seen has some variable thrust if a nose ring is not being used. I would love to hear arguments to the contrary. There are hard pushes and pulls where you can verify this in the air. Yes it is fairly subtle, but observable. Tom Feland

I used the Vibra/ Brown/ Whatever combo on all my models for a long time and I never felt the need for the nose ring untill I did the following test. >From Knife edge Flight, Rudder to true vertical,Then Let Go of the rudder. Wow, the model Always went oppisite The Rudder Used !! I put in the Nose Ring And WOW problem was Mostly solved. But The rear Mounts were a big Problem then. The Next Model Had a hyde Mount, The improved rear engine support Combined with a nose ring Was clearly one of the best ways to both Isolate The Vibration as well as Control Thrust Changes in High G as well as Low G Loads. I also felt the the up/down thrust changes that took place were even evident If You Pulled To hard on take off. This is especially true on models like the Nice Try and The Finesse, Which are Both a little pitch sensetive to begin with. Every model I have ever seen With The Vibra Mount Had invisible aileron tips at full throttle. And a severe Harmonic thing going on near the Mid Range .Though I agree, You will see a lot of shaking at the low end with the hyde mount, Question ?? Where Do We Spend the Most Time on the Throttle? Side By Side, Two Models Built at the same time, One W/ Hyde. One W/ Vibra. Guess Which one gets three more flights per charge? Guess Which one needed The servos changed the most? Guess Which one got stress Cracks first? Was The answer Worth The 50-60 dollar Price difference ? You Be the Judge. Gene

You bring up some interesting points on the softmounts. On My Sequel and previous ship, a Pursuit I have used the VD mount. The thrust changes for up & down have not been much of a problem, but side thrust has been until I did the CA thing with it like Sam mentioned. I had 326 logged flights on my Pursuit prior to selling it and replaced the VD isolators 4 times. Yes, it was a pain. Dave Brown Products have sent me on 2 occassions a new set n/c, but Sally Brown wrote me a hand written note asking me to let her know how many flights I get off the new set. Since I always have an extra set or 2 handy, I still have the set she sent me. I have a Hyde mount on my Brison 5.8 and its amazing how the mount really works. I have had many conversations with Meryle Hyde on the installation of the mount I got and I'm glad I went that route on the 5.8 on my IMAC plane. The other bad part about the VD mount is that only the isolators are available as a spare part. On the Pursuit, one of the parts had a oval shape to it and I called them for a replacement part, not available. They did send me a new complete mount at a very discounted price, so their service is very good. 1 last note, over the past few years, I know alot of people that have broken headers if the pipe system is not mounted correctly when the VD mount is used. After seeing my 5.8 in action on a Hyde Mount, I think the next one for my pattern plane will be a Hyde mount. Evan Chapkis

Hanson Rotr-Mount

Return to Top of Page - Return to Building Techniques

I have Dick Hanson's Rotor Mount in my 91A/C powered Runaway. While the Rotor mount allows a goodly amount of side to side rocking, it sure doesn't seem to transfer much vibration to the airframe. I realize this is only a .91, but the design of Dick's mount appears to have a lot of merit. And BOY does it require a nose ring. Has anyone used one of these Rotor Mounts on the bigger machines? John Forehand

John, I used a Hanson Rotomount in my AC powered Elan and it worked very well. Simple and effective. Had no significant problems with vibration using the AC in the Elan. You are definitely right saying it has to have a nose ring, due to the nature of the mount. The mount actually just holds the engine allowing it to pivot around the center bolt in the mount, while the nose ring keeps every thing lined up. The nose ring is not an add-on option, it is required as part of the design. Don Atwood

The Hanson Rotr-Mount works quite well. I was quite pleased with it, and after working out the required snubber ring set up for the YS 1.4, it really did perform as advertised. Dick will sell them seperately. They are made of hard maple, attach to the firewall with a single 10-32 bolt thru center, and literally "hang" off the nose ring, with a limiter pivot 90 degrees to the long axis. The pivot is secured in a rubber tubing snubber, surrounded by a ply bracket. Adjustable tension against the snubber allows an ADJUSTABLE vibration-dampening mount that works very well. Once adjusted, it is quite smooth, and no additional strain on headers....I like it.... Bob Pastorello

Return to Top of Page - Return to Building Techniques