Boidman
Key Veteran
Location: Lipo Alley
| Interesting thoughts, guys. Thanks.
I mostly think that lack of lubrication, from the factory, and then as regular maintenance, is the worst enemy of the bearings. Many of these little helicopters, at least in my corner of the world, never get any lube added, ever. Some guys end up replacing bearings due to damage after crashes often enough to never be really concerned about regular lubing. Can't hardly argue with what seems to work for them.
Some of us used to go over everything on a helicopter, right after landing, with a temp gun. Mostly just for fun, but sometimes looking for a clue about a problem. I don't think any numbers were ever written down, though.
The tail bearings were always the warm/hottest (ignoring the top motor bearing), and the front top tail drive bearing as measured actually just close at the aluminum fit, was next. Different belt brands, without lube, and pushing the limits of sane tension, got surprisingly warm.
The main shaft bearings had the lowest temps. I don't recall thinking that the temps were enough to believe that a viscosity change might cause any lube to be more inclined to exit the bearings, stage left. |
