Does anyone know where you can buy a soft mount for the DA motor to stop airframes falling apart?

If not is there any good/recomended ways to make them...

Help me out

Cheers

Kingsley

P.S. for a 50R i also have the original DA mounts 3inch but need 3 1/4 for the new plane. WH extra 300.

Or is this just a dumb idea?

A properly tuned DA50 along with a well balanced prop and spinner are very smooth. Though I know soft mounts are used for gas engines, I personally do not like the idea because I feel it can cause throttle linkage problems.

Besides, WH planes are well built and can handle gas engines very well

Looks like 3 1/4" standoffs could flex somewhat, adding to the vibration..Best thing would be a 1/4" aluminum plate between the 3" standoffs and the firewall, adds stiffeness......Cut the center out of the plate to make it lighter...]
Haven't heard of DAs breaking the legs off, but the Chinese engines do....And the very early 3W 60s and some twins, before they changed the design....Fixed a few....

For years I always soft mounted my gas engines and always had vibration problems, broken canopies, cowls, etc. This past year I hard mounted a 2.4 & a 3.2 in two different planes and the problems - for the most part - have disappeared. I was told this many times but never believed it - now I do.

- The hard mount setup provides "mass balancing" - If the firewall and fuselage structure is well designed -it prevents the engine from moving -- the reaction forces are simply absorbed by all the mass -
Improper mounting is common on single cyl setups. long legged standoffs are at the front of the line.
Maybe you can't twist em -but twist -they do.
the best standoffs are still maple blocks, thru drilled and pulled solid with long bolts .
then - two sides bridged with thin ply plates.

Don M.---Would you mind sharing with us, which type soft/mount gave you problems?---
Thanks

I tried a large set of Lord mounts on a Q42 / Byron Pitts

A set of B & B soft mounts on a Brison 2.4 / Midwest 300S

A Great Planes Iso Mount on the Brison 2.4 / P - 51

I really don't know if they gave me problems or not but my cowls & canopies were always cracking and you could feel & hear the vibration in the airframe. This summer I put the 2.4 in a Balsa Nova 120 and a TS52 in a 27% Ultimate both hard mounted. Neither one of these planes gave any vibration problems. Maybe it was the different airframes I don't know. I am in the process of removing the soft mount from the P - 51 and install the 2.4 back in hard mounted. This maybe a better test.

I have soft mounted my glow engines for years ( Du Bro & Hyde mounts ) and am very pleased with those results but was never convinced that it was a good idea with a gasser. Maybe I'm wrong, I have been once or twice before.

I agree with Dick about the longer standoffs being an issue with twisting forces. The longer ones have to be transferring a twisting force to the firewall due to basic physics. Engines and propellers provide a source of torque, and that motion is transferred to the standoffs, with the longer ones magnifying (leveraging) that twisting force. With a little bit of thought and easy design work, twisting of the motor mounts and excessive vibration becomes a non issue. Simply put, using a motor mount designed from wood, lightened to eliminate unneccesary weight, but still providing a solid "foot" that pairs engine mounting bolts with the firewall, effectively transfers engine pulses and eliminates vibration.

I've never purchased an after market metal standoff or used aluminum/metal post supports to hang an engine and have never experienced the high vibration issues others seem to have. Perhaps that due to the wood motor mounts used. Don't know for sure, but that's about the only differences I've seen between my installations and others. My planes stay together just fine for a couple of years or until I sell them or crash them. Never had one shaken apart to date.

Thanks Don---I too have been very happy with Hyde/Mount results---
Thanks

hey guys has anyone got a picture of a wooden mount. Id like to see the maple mounts you talk about dick

Cheers

kingsley

Here's the Hyde mount. Member Slyder (I think) is the owner of the model. Or was back in the day.

I use 1" ash dowel stock from Lowes.