Isolation mounts - DLE 35

[DHC8]

Hey guys,

I am just wondering what your thought are on anti vibration mounts. I have a pair of DLE 35's that I am mounting on my Ziroli 101" B25 and I am just concerned with long term vibration effects on the plane. These are the mounts I have,

http://www.6starhobby.com/engine-mou...pairs-set.html

I have herd some say that it's not good for gassers to be mounted on anti vibration kind of mounts, but never found any definitive reason why not to use isolation mounts.

[Vettster]

Interesting subject. I have no experience with rubber mounted engines, but I would thing that maybe it possible that the vibrations would actually get worse. Easy way to test is mount it to a test stand without the rubber mount and check the vibrations on a plank that is mounted 4-5feet behind and attached to the bench. You can then place your smart phone there after downloading a Vibration Meter app. I downloaded it to test for vibrations in my turbine. Insanely sensitive. Then mount the rubber engine mount and repeat.

ie.. you could also place planks sidewise. The idea was to simulate the tail and the wing tips

[JoeT]

We used to use Anti Vibration mounts aka Lord Mounts aka Motocross Radiator Support mounts on our giant scale planes, for quite some time. There are some good points and bad points.

The Good:
They reduced noise when the engine running at flying speed.

Cons:
At idle, there is visible movement of the engine. (Even when heaved tight)
Low throttle showd more vibration through the airframe, at just above idle, the amplitude of the power pulses seems to resonate
Required special "loose" mounting of canisters and mufflers as to not break headers (eventually).

Personally, I'm not a fan of soft mounts, I still have them on my Chapman Raven, but it will be coming off this winter in favor of the traditional laminated plywood solid mount.

[Ramjet]

I don't think you are going to get much vibration from a 35cc , Joe is correct rubber mounts cause more problems then they solve they can also cause throttle control problems or premature linkage or servo failure , thrust problems . I found the engines actually shook more with rubber mounts though it does seem to make less noise.

[Cosmith]

I don't think you are going to get much vibration from a 35cc , Joe is correct rubber mounts cause more problems then they solve they can also cause throttle control problems or premature linkage or servo failure , thrust problems . I found the engines actually shook more with rubber mounts though it does seem to make less noise.

Totally agree with this, I know they shouldn't let the engine move much but any movement independent of your throttle servo is going to cause an issue...I've noticed this before with loosening engine mounts. Gassers are very sensitive to throttle movement especially near the bottom end...if one click of trim can change idle by 100 or so rpm, imagine if the engine can move say 1mm closer/further from the throttle servo.

[lofl]

Make yourself a pair of homemade "Hyde" mounts. Easy to make and work great. I'm using one on an OS 33gt.
here is a link to learn how: http://www.ofremmi.info/HowTo/Hyde-mount/HydeMount.htm

To stiffen it up a bit add a second wrap with rubber.