DP Runout/wobble

[hitekrednek]

Does anyone have any ideas on correcting a slight bit of runout in a drill press. It only shows up toward the business end of a bit and is virtually non-existant at the chuck?

[Tom Miller]

First, you need to figure out where the problem is. A dial indicator is nearly a must for this.

If possible, start out with the largest diameter piece of drill rod you can chuck; the longer the better to magnify your runout. This'll be better than trying with a drill bit since you'll be able to check runout at all positions.

Chuck the rod, determine the position of max runout, and put a mark on the chuck and the rod at this position. Now, rechuck the rod at 180 degrees. Recheck max runout. Did it stay with the rod or the chuck?

If the chuck, and assuming the chuck is a morse taper, repeat the above procedure, but comparing chuck and morse taper drive. If the runout follows the chuck, get a new chuck. If it follows the morse taper drive, get a new DP(?).

Regards,
Tom

[Popeye]

Before you buy a new chuck though..... pull it and clean it and the internal taper very well and reset it. Then check it again. Pat

[kwgeorge]

I am going to be the one to ask, do you think you may be pushing to hard? Excessive force on the bit will cause it to flex and give the results you are seeing.

Ken

[hitekrednek]

The runout is there when there is no load on the bit (spinning freely). It isn't a lot but there are some pen blanks that I want to drill where I have very little room for error. I've already checked/cleaned the MT and no change. Guess I'll have to get a dial indicator and see where the problem is.

[LCHIEN]

Does anyone have any ideas on correcting a slight bit of runout in a drill press. It only shows up toward the business end of a bit and is virtually non-existant at the chuck?

I don't know how much you've done but check the obvious first...

i assume that you're sure its not the bit???
easy to get a bent bit and mistake it for runout.
Sometimes you can unchuck, rotate, and rechuck a bit and have much less runout,
maybe play in the jaws and or maybe by repositioning the bit you have
cancelled the errors.
Also are you inserting the bit far enough into the chuck? the more the better.

I always chuck a bit carefully, snug on one hole of the chuck then rotate and finish tightening the other two to even the load.

[hitekrednek]

Loring,

I think that perhaps your last suggestion was the one. I hadn't been tightening the chuck from all three holes. It seems to make quite a bit of difference. Thanks!

[LCHIEN]

Loring,

I think that perhaps your last suggestion was the one. I hadn't been tightening the chuck from all three holes. It seems to make quite a bit of difference. Thanks!

glad to have helped a fellow Texan.