I am stepping up to a Venture 50 from a T-Rex. I purchased an OS 50SX-H engine and I cannot install it. The fan hub will not correctly fit the engine. It has a 1/4 inch shaft with a 3/8 land close to the engine case. The hub stops at the land about 3/8 from the front bearing. It allows the crank shaft to move back and hit the back plate. When fitting it into the frame it places the engine about 6.5 mm to low and therefore will not fit....I believe just putting the hub on this way is wrong. The engine is designed to have a thrust washer against the front bearing like the ones on the planes. If the hub would be able to fit close to the bearing it would be fine.....except that now the end of the crank shaft now will hit the bottom of the start shaft.....no fit. I believe I could fix it if I had a lathe by inlarging the 1/4 hole to 3/8 to clear the land near the bearing and cut off 6.5mm from the end of the crank shaft....

I don't think this should be necessary.....not everyone has a lathe. I know that I am not the only one that could be haveing this problem......the vendor was no help.....he said good luck.

Can anybody help ?

Hey, here's a first....maybe not. I am going to answer my own question. I have done some reasearch and believe I have solved my own problem. What I seem to have is a Venture 30 that the vender is calling a 50. The guys that are trying to convert their 30's are having the same problems. The frames are the same...therefore the 50 size engine will not fit corectly in the 30 frame. It seems the boom is longer and the rotor is different for the 50. Anyway I am out of luck after spending the money and don't want to buy the Webra engine that is supposed to fit. If only I had a lathe, I could modify the fan hub and make it fit correctly.

I didnt know what was going on as I don't mess with Ventures but I was going to say if you need a hammer or a drill you probably aren't doing something right.

Just a short answer....to clarify or give a better impression. I am retired 4 years now from 35 years as an electronic / mechanical model maker for the Navy (civilican of course). I sure know what a hammer is. If I was still working I would have used a Navy machine to fix my problem in ten minutes, which is really the vendors problem. Also I don't believe in doing patch jobs, which they suggested...what ever works.

Cool. Ex AT1 here, P3 Flight Tech