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Re: Star Blast bearing failure

Started by proteus, 06/19/2007 02:31PM
Posted 06/19/2007 02:31PM | Edited 06/19/2007 03:46PM Opening Post
Which axis are you replacing?

I assume it's the altitude axis with the tension adjustment knob? Since you didn't tell us which axis, I read a review and they mentioned bearings in the altitude axis.

My take is if it uses standard roller ball bearings you'll have to go find those to replace the stock bearing(s).

Needle bearings will lock up when you tighten the tension knob. Thrust bearings won't work either since they only take loads in one direction, in this case best for the bottom pivot of the mount and not the altitude.

I'm guessing you'll need a roller bearing(s) for this to work. Most likely metric size I would assume since I don't know anything about this scope and mount but it is Chinese.

Measure the original bearing(s). If metric, then look for that size exactly.

A little more info to us would help. I know a lot of places to buy bearings that are hard to find and cheap. Joe

edit, went back to read the review again and it was Rod's.

another edit, it's possible they used thrust bearings because of the tension adjustment, but not a good use here. Again, more info to stop my guessing.

even another edit: Hey Greg, are you the same Greg N in the Losmandy yahoo group? I'm the person who posted the latest worm block mod, single piece duplex pair. Still working on it and the drawings are about done and will be posted. Joe
Posted 06/19/2007 09:48PM #1
Cage, usually metal or ball separator, usually phenolic are used to keep the balls separated and evenly spaced. Races, inner or outer are what the balls roll in, e.g. grooves.

You know a picture would be great of what you're taking apart. A picture truly is worth a thousand words.

Thrust bearing used like you described sounds nuts or cheap. But then if no contact is made in the center shaft all the weight is pushing down on the plastic separator and that's gonna fail quick.

Give us a picture and some dimensions. That will make it easier for us to quit guessing. Glad to know who you are. I'll PM you sometime when I get my mod done. Joe
Posted 06/19/2007 09:50PM #2
A cage

Greg Nowell said:


While I have all these smart people here: what is the correct term for the assembly that keeps the ball bearings together? A cage? A ball race?

regards
greg n