I'm building a B-17 and want to keep the throttle servos on the front side of the firewall. Initial thought is to mount them on phenolic sheet mounts driectly on the engine mount lugs. Photos will show idea. The reason is to keep throttle set up as simple as possible and in an easy to get to location.

I would like inputs from those of you who have actually used a similar setup, perhaps not an engine mounted servo but at least installing servos on the front side of the firewall. How successful was your setup, what kind of servos did you use, what are the best servos with respect to vibration, etc.

Thanks,
Speedbrake

I think with that setup you're just begging to have your servo shaken to bits and possible have the mount fail in flight. That cantilevered mount is going to actually amplify the vibrations from your engine, which is already going to be pretty bad because you're mounting it to the engine mount of a 4 stroke. It will be better to go the traditional route and put the servo somewhere behind the firewall and drill a hole for a tube to go out to the throttle.

If you decide to try it, find some servos that have good seals or are waterproof. Fuel residue inside the servo housing is not going to work out very well. I have heard of people mounting servos out front so hopefully some will post of their experience.

I have to agree with a previous post, I think the vibration will be excessive, and having it cantilevered mounted will amplify it for sure, and on a 4 stroke which only generates a great amoumnt of vibration will only be asking for a problem, great idea if it would work.

And the Allen head of the screw WILL work its way into the wood, and loose the compression that is holding things together.

Les

Several years ago I raced giant scale AT-6's. I had the throttle servo mounted under the engine and a straight shot to the carb. I monted the plate on rubber and used the regular servo mounts on the plate. Worked great for three years.

I have mounted the throttle and choke servo right onto the motor box on gassers without any problem but yes, there can be a vibration problem. Just another not to do thing I have gotten away with.

I have always mounted on the firewall when doing this. I think your setup is not good esp as it is a 4st.

Thanks for the inputs. I might try mounting on the firewall and using bellcranks. A previous B-17 project had servos mounted on the back side of the firewall and they were difficult to set up. I'll keep messing with it until I find a good solution.