View Single Post
Old
  (#4)
sikeston34m
RC-Monster Brushless
 
sikeston34m's Avatar
 
Offline
Posts: 2,085
Join Date: Sep 2007
12.30.2007, 01:12 AM

Quote:
Originally Posted by cadima View Post
I'm going to throw in my experience on bearings cause I too have searched the planet for something that can handle a bit of thrust. At a minimum, it'd be nice to not have a grindy bearing each time I take off one of the wheel hubs. Unfortunately, I haven't found the bearing. I tried Acer ceramics. Fried them right up. In fact, they were shot before my steel bearings went out (I specifically mixed steels with ceramics to compare life having similar conditions). They costed me a boatload also. I ended buying mass quantities of steel bearings and just toss em when they get gritty. The friction loss in ceramics is neglible to me considering the $. I do run ceramics in my Neu motor, however (cause the loading is easy on the bearings).

Now my problem may not be entirely the same as yours. I find the root cause of most my failures is dirt working their way in. I have not found thrust to be an issue in the front/rear diffs. It sounds to me like you had a bad shim job which will toast any bearing. Once they are sloppy, you cannot shim again to compensate. Your bearing will be out of concentricity with the race. Are you certain with new bearings and a good shim job the problem keeps happening? The spiral cut gears require very close tolerances, more than one would think.
I'm pretty sure I know when most of the damage happened. I jumped and held the throttle until it landed. It wasn't a big jump, but I think it was enough. Dirt was not the issue.

When I opened it up and checked the inboard bearing, I could feel where the balls dented the race. If that makes sense. I'm sure this took the ball bearings out of round also. It went downhill from there.

My Ceramic Nitride bearings just came in. I haven't gotten them installed yet. I ordered the good ones, the ones manufactured to tight tolerances. From everything I've read, Ceramic Nitride ball bearings are MUCH harder than conventional ball bearings. However, there isn't any indication of harder bearing races being using with them. So, I won't know how they hold up until I try them.

I'm hoping I just got a bad set of regular bearings. This is my first time replacing them. I feel like my shim job was good. I did my research and went with the recommendation the first time.

I got my new motor wound tonight. Soon I will put the new bearings in along with installing the new motor. We'll see how it works out.
   
Reply With Quote