R/C-C/L conversion

After it came to my attention that the Sig Fazer instructions
show how to convert to c/l and the A.M.A magazine showing conversions of some Hobby Shack (I think)warplanes for scale c/l flying, I began to believe that this would open up the selections of planes for c/l and wonder what is involved in these conversions other than leadouts and control platforms.
I can not be specific about planes because I am not attempting this yet, I am just interested in the how does it work end of it.
I am also needing information on the conversion of r/c engines as I just purchased a OS Max -H 40 P for the Banshee and Ringmaster 35 that I am building. The actual throttle arm is not there so I thought that I might be able to put a screw back in the hole that the linkage was attatched with to hold the carb open or do I need to get a venturi, a needle valve,
and a retiming?
Thank You,
Gary Grimstad

LAST EDITED ON Aug-13-00 AT 05:56 AM (EST)

As you said, it is essentially a matter of putting a belcrank and leadout wires in the plane to convert it over to RC. However, (there are always those "howevers", aren't there?) we usualy put a larger engine on our CL planes so the nose mount needs to be made strong enough and vibration free. We are also flying with a lighter wing loading, so the plane will (be able to) turn tighter. The tighter turns can put greater stress on the plane than the heavier wing loading of the RC plane. If there is dihedral in the wing, most, if not all of this should be removed, and if you want a truly aerobatic plane you want to have a fully symetrical airfoil. Watch your leadout location so you get a vertical balance, or the plane is going to be wanting to bank out or in, depending on the improper location.

I have never been a real fan of some of these "make them into CL planes." The SIG Fazer, for instance, has a horribly wide wing, and thin airfoil by our "normal" standards. The wood is not going to be "contest" grade for CL, which means the plane will probably builld heavier. I have seen several of these flown as CL planes. I still was never impressed.

As to the Max 40, if the "P" means Pylon version, there may be a slight difference in timing over the others, but, generally, these make good Stunt engines out of the box. They should have a needle and venturi fitted, however. I have made a number of venturis for these for other people. The biggest problem is the needle size is for the .135 OS, but it is a longer needle than currently available from OS. I generally fit the engine with the longer ST needle valve which I have and then bore the cross hold slightly larger to accomodate and adjust the venturi size accordingly. If you have a good engine, they work fine. We, also, have a strap on tongue muffler available that we have developed for these that weighs about 9/10 of an ounce.

So Leonard,
Do I need to send the engine to you, Or do I just need to order the parts and install them myself? My engine experience is nil, however if it was a Chevrolet............
Thanks for your reply,
Gary

As long as you are willing to drill the cross hole yourself with a 5/32 bit (no big deal) you can install it yourself. I can make the venturi, send you an appropriate size ST needle, and even drill the cross hole in the venturi for the St needle. You drill the cross hole in the case to fit and it will drop in.

When you drill the cross hole larger, close the crankshaft and put a piece of paper towel or the like in the venturi hole and pack it down to keep shavings from going into the engine. After the hole has been enlarged, just turn the engine upside down and pull out the paper towel. You are done.