Discussion in 'General Experimental Aviation Questions' started by Armilite, Aug 21, 2015.
Have you ever had an Ultralight/Kitplane Gear Drive Fail?
Yes, 3 times, but none of the above, they were all PPG belt drives.
Haven't flown much behind a gear, but I have blown out the belts on a multi-belt drive.
Nope! I have seen several belt-drive failures, but never a gear-drive.
The Sunburst Had a Cuyuna 430 engine and a planetary gear reduction. The end of the engine crank shaft snapped off.
We had a Cuyuna from our field fail at a neighboring field recently. He called it a crank failure too, but I don't know what part of the crank. Anyway, that's not a gear-drive failure. I concede that there is the possibility that the drive contributed t these failures, but they are still engine failures, not gear-drive failures.
No time with gears but several belt failures.
If you had only a Belt Drive Failure, what Failed if you know, Belt(What Type of Belt), Bearing, Backing Plate, Pulley, and list the Brand Name if known. I'm sure many People would like to know WHY it failed, WHAT Brand Failed, What Rpms it failed, on What Engine it failed on, HP used.
Mine broke one belt in a multi-belt system. The broken belt jammed in the system and took out the rest of them. That was 30+ years ago, so I don't remember what brand.
I should point out that none of the three belt drive failures I've had were the belt itself. Once the aluminum prop shaft fractured, once the eccentric for adjusting belt tension came loose, once the mounting bolts broke. Poor design, in every case. Belts rarely fail without warning if pay attention to them during preflight.
So far 0% failures for gear Drives.
That's nice to know it wasn't account of the Belt/Belts. Each Type of Belt Drive, Belt has a Service Life. Like all things, People push them limits. I have heard of some older Hegar Belt Drives that failed for some of these same reasons, Bolts, Backing Plate Cracking, Pulleys, Bearing, etc.
The only Gear Box failure I have read about was an A/B box with some rare 3.0 Gears. Most common Gear Ratio's was 2.0, 2.25, 2.58 ratio's for the A/B.
Separate names with a comma.