Helpless Female Needing Assistance With Bearings

Susan_in_SF

Wood and Metal Goddess
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Jul 18, 2017
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Hi Guys,
I have a nice Baldor dental lathe / polisher that where one spindle is making noise. I'd like to replace the bearings. I understand that I need a drift set to install the bearings properly. I went to amazon, and saw these type of kits (shown below). It seems like these kits were made for car bearings. The blue kit in the middle of the pic has more smaller parts than the other sets, but I am not sure if these were meant for small machine roller bearings. Am I looking at the wrong items for my application?

Thank you, for helping my helpless self ;-)Screenshot_2018-09-26-12-36-51.png
 
Those are bearing installers not drifts. I'm guessing the bearings in your machine are very small. IS there a manual that says to use a drift? That refers to a type of punch (a drift punch). Those are readily available and inexpensive to boot. I real nice set (and the set I own) is the Starrett S565WB Drive Pin Punch 8-Piece Set.

Oh and you're clearly not helpless since you're asking for help and you're willing to attempt the repair... To remain silent, doing nothing, or risk damaging your machine due to say, overconfidence, would make you helpless in my book. Let us all know how you make out!

John
 
Hi Susan,

I wouldn't buy anything until I knew exactly what the job required. I don't know the Baldor lathe that you mention, but the dental lathes that I have seen are quite small, more akin to watch makers lathes. They might not even use roller or ball bearings, more likely bronze sleeves. In which case would likely require specalised tools.
 
I just looked up what a dental lathe is. I am surprised! A dental lathe is nothing more than a typical Baldor induction motor with a specialized shaft sticking out of each end... So, I'd image the bearings get replaced just like any other Baldor motor bearings.
 
Hi Jgedde,

In that case I agree. Still I don't think any of those kits would be suitable.
 
A suitably sized piece of pipe or tubing would likely do the job; mainly, you just want to drive on the inner race of the bearings, not pushing on the outer race, which could damage the bearing balls and/or races, the outer races generally fit snugly in the end bells and should be easy to disassemble.
 
Hi Susan, John is correct- you have a lathe, you can probably make a small cylindrical tool to push the bearings out using a press. Or something press-like
mark
 
You will need a puller to pull the bearings of the shaft of motor. A 2 jaw puller should work. To put them on either a press or pipe as stated touching only on the inner race.
Good luck.
 
As as motorcycle mechanic in my mid 20's to 30's I replace many a bearing drifting it in with a small drift punch taking care to not scar the shaft or touch the ball bearing. Light hammering the drift as you move it around the inner race slowly working it down.

Another method I have used replacing the bearing on a Craftsman 150 drill press motor was to put the armature in the freeze and place the new bearing on a small wattage candelabra light bulb to gently heat up the bearing. Then drift the bearing on per previous paragraph or find a suitable piece of iron pipe that will only put force on the inner race and slowly press/drift the bearing on.

Best of luck on learning something new!
 
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