edg
Senior Heliman
Location: San Francisco, CA
| Hi, I hope I get get some advice on this:
When I got my Jetcat it ran great and had reliable startups. It was sitting around a while while I built the NH-90 for it, and now the NH is nearly done, I got problems. Test flight a couple months ago, I had some butane ignition problems. I've solved that and the butane fires up every time just fine. Today I dropped it in the fuse and gave it a test start.
Butane ignited. It strarted spinning up, but then it shut down. Right after shut down, it sounded like it was trying to do its cool down spin cycles, but wha I heard was just a wierd sound from the starter motor and I couldn't see anything spinning. It just kept doing this for a LONG time -- I assume since no spin = no cooling it just kept up until the temp dropped on its own.
So, I pull out the mechs and look at the manual. I see the part about cleaning the "O-ring" and compression nut with a q-tip and alcohol. I try to find a diagram of this, but can't seem to find anything. What I see in there, on the starter motor shaft, is : a collar with a set screw, followed by a about a 20mm long cylindrical thingy, then a nut with a hole in it (which I assume is the compression nut).
So, I get some alcohol and q-tip and stary swabbing around the area. I'm really not sure what the "O-ring" is. I then do a test rev of the starter motor with the GPU. It seems to rev ok. Gets up to about 6500 RPM and seems fine to me.
I then try and fire it up again. Same thing happens. The GPU "Last Off Condition" was "Low-RPM". Motor again makes a wierd sound when cooling down and no belts spinning.
I'm not sure what the problenm is. Is the "cylinder thingy" on the shaft a 1-way bearing or something? I'm not entirely sure how to detect a problem. Basically I can hold the collar on the starter shaft and spin the belts by hand. I assume this slippage is normal. However I can also hold the collar and spin the cylinder thing a bit. I'm not sure if I should be able to do this or not. It doesn't spin freely. It just seems to stick a bit when rotated in 1 direction.
Any ideas? Thanks! |
