RCU Forums - prop problems

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Hi there. I am a flight instructor and I have played with an Aerobird Challenger for awhile. I had a student give me a .40 trainer that he had flown twice and crashed twice. I fixed it and I'm attempting to fly it. Here is the problem. The propellor keeps coming lose when i start it. It seems to happen when it is a little bit flooded. I'm using an electric starter and a plastic spinner that he gave me. I have tried a lock washer. And double nutting it seems to work but the second nut doesn't fit on all the way. Should this be loctited? Any help would be greatly appreciated

RE: prop problems

Sounds like a fuel locked engine. Take out the glow plug and spin the prop with your starter to get the fuel out of the engine head. Replace the glow plug and try to start again except do not prime the engine, just let the compression of the starter prime it as it spins the prop. If it still floods then you have a fuel tank/fuel system problem somewhere.

RE: prop problems

I'll put my money on you not tightening the prop nut enough. One nut on a two stroke is enough, you just need to sock it down REAL tight.

Not sure what you mean by "I am a flight instructor" though. If all you've flown is an Aerobird, and this is your first glow plane, you really don't have nearly enough experience to be an instructor. (Unless you're talking full scale. ;) )

Welcome to RCU!
Dennis-

RE: prop problems

Quote:

ORIGINAL: cficfiimei

Hi there. I am a flight instructor and I have played with an Aerobird Challenger for awhile. I had a student give me a .40 trainer that he had flown twice and crashed twice. I fixed it and I'm attempting to fly it. Here is the problem. The propellor keeps coming lose when i start it. It seems to happen when it is a little bit flooded. I'm using an electric starter and a plastic spinner that he gave me. I have tried a lock washer. And double nutting it seems to work but the second nut doesn't fit on all the way. Should this be loctited? Any help would be greatly appreciated

Welcome aboard. I presume you're a full scale flight instructor.

With that .40, one of my RC students had that happen with a prop he had never reamed. He had to wind it down the threads, to get it on the prop shaft. Then he would put the washer and nut on, but they would not provide adequate clamping force. The prop hub was tight on the threads. When I reamed it for him, and he tightened it down good, it never spun off again.

So, if the prop won't slip over the prop shaft, all the way to the backplate, without turning it like a nut... ream the prop.

Good luck,
Dave Olson

RE: prop problems

Another trick is to make a couple of sandpaper friction discs & insert one between the spinner plate & the engine drive collarr, plus one between the prop & the spinner plate.