Angle drill bearings

[Reed Gray]

I got some fancy bearings, recomended by an engineer, to replace the stock bearings (6 bearings total, and 4 different sizes) in my Sioux/Milwaukee angle drills, and I just went through the first set. I got somewhere between 350 and 400 bowls (8 to 14 inch diameter) out of them before they failed. This is comparable to what I get from the stock bearings. I asked my tool repair guy why they failed, and he said dust. I said that they were supposed to be sealed bearings, and he said that dust still gets in eventually. He also said that using them as sanders was beyond the use and abuse that they were intended for. I am redoing them with the same bearings again, and will keep better records as to how many bowls I get before failure again. This was the first time that I have ever heard the bearings fail. There was a small click, and within 5 minutes the drill wouldn't run any more. Usually, they start making funny noises slowly over a month or so, and steadily get worse until they fail. After that I will get a brand new drill with stock earings and wear it out while keeping records.

I had figured that since I was running the drill at slower speeds (I actually have a 1/4 inch piece of cork under the trigger) that maybe they would last longer, but not in this case. The slower disc speed (600 rpm and less) does make sanding actually go faster.

I haven't done anything to the extent that I do it the same way all the time, so I reserve the right to change my mind in the future.

Bearings:
1 625ZZ NSK
1 629 2ZHJEM SKF
1 6000 2RSJEM SKF
3 R4BZZ NSK

robo hippy