Dan Vincent

I have this Davis Diesel conversion head for Cox .049 & .051 engines that has a variable R/C arm.

There is an "O" ring on the screw and when it gets oily, it slips. I've never seen another one so it may be a short run item.

Just wondering if this thing worked or am I using it wrong.

Hope Bob Davis will check in on this one and give some info.

ddd

Wash the O-ring, it should not normaly get oily. You loosen it adjust compression then tighten it for servo control. We made hundereds of them as R/C was not ready for more then two channels at the time.

RDJeff

My Feedback: (11)

I'll be watching this one, as I picked one up a while back that is brand new.

Dan Vincent

Thanks for the info Bob.

It seems like a good idea now, with all the light-weight radio gear on the market.

What kind of RPM drop can I expect when the compression is backed off? I know it doesn't take much power drop to get most 1/2A's to lose altitude.

Jim Thomerson

I have an Indian Mills .75 which starts and runs nicely. I have to hold the compression screw in place running it on the bench. I has planned to replace the compression screw with a larger set screw. However, I may actually take up flying RC and use the Mills with the compression screw as the throttle. One never knows. [8D]

AMB

DAN if I remember my conversation correctly a few months back when he got my back into the cox 049 and or 051 , that 1ittle back off on the compression drops the rpm about 50% or more maybe to around 6K ??? or so, no way will the plane stay in the air on that reduced thrust just land it martin


Post note "he" was Bob Davis

Dan Vincent

Thanks Martin, that should be enough for landing a 1/2A. I'm visualizing a 1/2A float plane doing touch and goes.