Drill Press Problem

[rolltide4469]

Need some suggestions........My drill bits seem to have a wobble to them and make my holes larger than they should be. I cannot figure out why....its worse with the larger bits (10mm, 10.5mm). Its a brand new Jet press so I don't think it would be the problem but the bits are new as well. I'm stumped even though its probably something simple...Any ideas?

TIA

 

[Fibonacci]

If you are having some wobble, that means that something is out of concentric on your system.

Have you verified that your bits are straight? I have gotten new bits out of the package and had them be a little bent. Try rolling them across a piece of glass to check.

If all of your bits are out, it sounds like maybe the chuck is a bit out of alignment on your drill press.

 

[Chthulhu]

I'm guessing you don't have a dial indicator, or you would have already used it to check for runout. For now, take the largest bit you have that will fit into the chuck and lock it in, making sure you leave some of the smooth shank of the bit visible. Set your press to the lowest speed and start it running. Take a toothpick, bamboo skewer, sliver of wood, or whatever and with a steady hand, slowly bring the tip into contact with the spindle just above the chuck. If you feel it touching and not touching as the drill turns, you have runout in the spindle; it may be either bent or badly machined, and should be replaced under warranty *if* it's outside the specifications which should be stated in your manual.

If it seems to be smooth there instead, check again against the bare shank of the bit, as close to the chuck jaws as you can get. If it's touch and no-touch there, then the chuck itself is either too sloppy or there's something on the spindle taper where the chuck mounts to throw it off.

Figure out where the wobble is. If the spindle seems to run true, remove the chuck and make sure the tapers on the spindle and in the chuck are clean and smoooth. If the spindle wobbles, you need to check it again with the chuck off and using a dial indicator to see how much it runs out. If it's outside Jet's specified tolerance, they should replace either the spindle or the whole press for you.

 

[ghostrider]

Thanks for the advice Mike. I'll remember that if I ever have this problem.

For the OP, I just recently bought a Colt five-star bit brand new, and as soon as I put it in the chuck I could see it was crooked. Sometimes it happens.

 

[ed4copies]

It can also happen that the bit is not sharp.

When you cut are you getting out ribbons or sawdust??

Ribbons are preferred and indicate a nice sharp cut.
If the bit is dull, it will move as you try to push it in--elongating the hole

 

[Whaler]

I would also pop the chuck off and thoroughly clean the inside of the taper as well as the taper on the chuck.

 

[Dan_F]

I had the same problem with my Delta, which was also new. Turns out the chuck was not running true, can't remember how far off it was, but it was considerable (when measured on my lathe with a dial indicator). In the end I bought a cheap chuck from Woodcraft, Golden Goose brand, which was only off .001, much better than the expensive Jacob's brand chuck that I tried as the first replacement. I got a second GG for my lathe. Occasionally, you don't get what you pay for. My drill press still has some runout, but it comes from the press itself, so I do my drilling on the lathe with a collet chuck.

Dan

 

[rolltide4469]

Thanks for all the input. I tried to see if the bit or the chuck was out of line but from what I can tell they seem ok. I used the wood trick. I'm thinking that since its only with the two larger bits that it might be that they are dull. I just ordered a replacement brad point bit to see if that will fix it. If not I will return for more suggestions. Everyone on here is a big help and I don't think I would have made it this far in my turning adventures without all of you.....I tend to get a little frustrated and walk away from projects if I can't figure out what went wrong. Bad way to be but at least here I can find all the help I need. Thanks again!

 

[wouldentu2?]

I had the problem mentioned and found the drill bit and the table were not perpendicular. I had been using two drill bits using one size smaller than 7mm, remove that one without disturbing the blank and inserting the 7mm and re-drilling the hole. I then use medium CA and glue the blank. When I screw up a turning and go to reuse the tube I found the medium did a much superior job adhering the blank.

 

[okiebugg]

drill press

A fairly easy first check is to use your handle and run the quill all the way to its farthest extended position.

Take ahold of the quill and rock it front to back and side to side.

You will see and feel immediately if you have runout that involves the mounting or wear of the quill shaft.

After doing that, if you dont see/feel runout, there are some excellent suggestions here on this thread