How accurate should a Pillar drill be?

J

Julia

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The workshop I use has a donated pillar drill of unknown vintage. I noticed there is an alarming amount of wobble in the drill bit when it's spinning. I'm assuming someone hasn't bent all my drill bits, and thus it's the drill that is at fault. I had a play with obvious tightenable parts on the outside, and managed to get runout to under 0.5mm (sorry I'm metric). Is this about as accurate as I can expect, or is it worth me dismantling the whole thing, servicing it, and trying to put it back together in better condition than it's in now.

Thanks

J
 
You could have a bent spindle, which is repairable. You could also have bad bearings, which are replaceable. Bearings need adjustment, which is easy. If everything else is tight, it might be worth disassembly. 0.5 mm is .020", which is a lot of runout for a machine spindle.
 
Try the chuck in another machine, if the runout is the same it's likely the chuck. If you can put the chuck in the spindle of a lathe it should run true. If you don't have a suitable MT sleeve to fit the chuck in the lathe get a piece of straight shaft as large as will fit in drill chuck. set it in drill chuck then set the other end in the lathe chuck. spin the lathe it the chuck shank is running true then it's not the chuck however if it wobbles there is your problem.
 
Julia said:
How would I tell if it's the drill chuck?

J
Click to expand...
Put something that is known to be straight like a new dowel pin into the chuck and check that for runnout. Now remove the chuck and check just the spindle for runout. the difference is the chuck runout.
 
Downunder Bob said:
Try the chuck in another machine, if the runout is the same it's likely the chuck. If you can put the chuck in the spindle of a lathe it should run true. If you don't have a suitable MT sleeve to fit the chuck in the lathe get a piece of straight shaft as large as will fit in drill chuck. set it in drill chuck then set the other end in the lathe chuck. spin the lathe it the chuck shank is running true then it's not the chuck however if it wobbles there is your problem.
Click to expand...

Unfortunately I don't have any other tools in the shop which the chuck would fit in. The shop is still coming together, so there's no lathe, or mill. The pillar drill is the first proper machine shop type tool we have.

Flyinfool said:
Put something that is known to be straight like a new dowel pin into the chuck and check that for runnout. Now remove the chuck and check just the spindle for runout. the difference is the chuck runout.
Click to expand...


That I can do!

Thanks

J
 
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