A friend of mine has a 12 speed pillar drill, Clarke badged. It is the sort that has 3 pulleys.

Drilling a few holes in Perspex made the centre main bearing run very hot! The cast iron block (?) which supports the three pulleys was getting hot in the middle and I assume this is because the centre bearing is bad.

A quick look at the offending item, gave no signs of any lubrication points, indeed it looked as if getting the centre shaft out of its bearing housing was not going to be easy. Can anyone throw any light on what type of bearing this would be? Or is it likely to be a shaft in a reamed hole in the block! Before I attempt to dismantle it, I would not mind some more info.

Thanks,

Andrew.

Thanks Nicholas!

The exploded diagram looks to be the information I am after. I did not realise that the centre pulley is on a crank! Makes me wonder what could possibly cause so much heat to be generated? The drill has had very little use as my friend would normally use his mill for drilling. In fact I doubt he has ever changed the speed! he is not exactly very savvy when it comes to things mechanical!

So I must assume the ball race is the culprit for the excess heat, at least it looks simple to change, contrary to my first quick impression.

Thanks again,

Andrew.

I have done a strip down and found the eccentric shaft to be a sloppy fit in the pillar drill, top block, however this doesn't rotate. The ball race that connects the multi step pulley wheel to the other end of the eccentric shaft is in good order. I put it all back together for some trial drilling. Guess what, the centre portion of the top block got quite hot.

Checking the bearing's temperature revealed that it was about the same temperature as the centre of the block! I give up, I cannot see why there is so much heat generated and where it is coming from.

Andrew.