Drill Press Chuck Drops off

[Vince Shriver]

About a yr ago I changed the chuck on my Delta drill press to an Albrecht. It accepts bits 1/32 to 1/2. Up until now I've love the upgrade. HOWEVER, today it started simply dropping off the machine. I've replaced it several times, gaving it a couple good whacks with a piece of wood between it and a hammer. As soon as the bit gets tight in a hole, off it comes again. Any suggestions? TIA, Vince

[Dan Friedrichs]

Is the chuck falling off the arbor, or is the arbor coming out?

If it's just the chuck, I assume you're just not getting it seated in the taper correctly. Clean both sides REALLY WELL. You want no oil or residue. Inspect both sides carefully for any nicks, protrusions, etc. It really should just "grab" when you seat it.

[Keith Westfall]

No WD 40, no oily cleaner - maybe some alcohol or something like that.

[Keith Weber]

Acetone is great for cleaning bare metal without a residue. I've never understood the whole vertical taper seat without a drawbar that needs to defy gravity.

[Vince Shriver]

Thanks, Keith. I agree, the taper seat is a mystery to me too.

[Kevin Womer]

My drill press chuck has done that a couple of times, I just wipe it down with a rag and press it back on. I'm going to try the acetone next time it happens. It's not a real great dp just an old Cummins I bought at a garage sale about 10 years ago.

[glenn bradley]

Acetone or naphtha work for me. As mentioned; clean and dry, arbor and chuck.

[Ronald Blue]

I will presume that it has a morse taper arbor that the chuck mounts to. Pop it out so as to make it easier to inspect and clean. As has already been said wipe free of oil. Inspect both the chuck and arbor for any galling. Hopefully that won't be a problem. Open the chuck up so the jaws are retracted and place on a solid surface. Never let the jaws take the impact as that can cause internal damage that will make you sad. If you don't have a brass hammer use the block of wood as before and seat the arbor into the chuck. The angle used is known as a locking taper and has been around for many many years and works quite well.

[CPeter James]

I suspect that the drill press had a #33 Jacobs taper and not a Morse taper that uses a shank. Once you get both the taper and the chuck hole really clean, ( I like alcohol) rub the taper with some chalk. That sometimes makes a big difference. Also, check to be sure that you have not raised a burr eith inside the chuck or on the spindle taper. This will prevent the chuck from seating properly.

CPeter

[pat warner]

Big drills, deep holes?

[Vince Shriver]

Pat, 1/4" bit into 3" solid beech block. I see galling on the arbor, so I'm going to replace that. Chuck walls looks very clean. How can one side be scared up and the mating surface remain gall-free? And how the heck does debris get in there in the first place? Anyway, I'm hoping for the best, and trying to get a little smarter in the process.

[Ronald Blue]

If you have a sharpening stone you can probably knock the high spots down and if they are extremely bad use a small file. If you want to see how things are mating up and if you need to file or stone it more simply take a permament marker and color the arbor with it and the slip the chuck on by hand to see how it is mating up. Black is easiest to see. Of course if you are happy with the contact clean it off because it is enough to affect the tapers locking together. It's possible and likely the chuck is harder than the arbor. What about Silver and Deming bits? !/2' shank but larger bit sizes. As I stated earlier retract the jaws before re-installing. You can use the drill like an arbor press and reinstall. I would bottom it against the table several times firmly to insure it is fully engaged on the taper. Good luck.

[pat warner]

Chucks get pulled of their spindles all the time.
It's their nature, especially with big bits in deep holes.
Moreover, a small diameter bit, if stuck deeply in the work, can be hell to back out too. Deep holes, whence the drill bit is deeply engaged, grab the bit ferociously. If you don't retract and vacuum as you drill, the friction will become enormous. Your spider lever can and will pull a chuck off its arbor.
So key here is to vac. out the chip as it's created.
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Your Albrecht is harder than your spindle and scraped it as it spun off.
If you can dress it so the run-out (of the Albrecht) is where it should be (<.003" TIR) you are back to ground zero.
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But always expect a failure. Your best defense is prevention.
That is, don't let the work squirm* (clamp it), & vac. out the chip.
Match the RPM to the cut rate, drill sharpness and quill travel, a balancing act indeed.
A VFD and sharp drill bits will help a lot.

Have any idea of the RPM you were drilling?
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* In order for the drill to drill as normal (90°) as possible, the work must be clamped before the drill enters it.
And that means you have to know the drill coordinates before you drill. A fence and stops will help.
But note, if you clamp the work after the drill enters the stock, you risk moving the stock (significantly or slightly, it does not matter) and the drill will enter in a screw-ball fashion and jamb in deep holes.

[Vince Shriver]

Pat, I appreciate your comprehensive reply. I wound up putting the chuck in the freezer for an hour or so, then onto the arbor, and then the arbor into the quill. Drilling 3" into that tight-grain beech block was pushing it too much. I really have no idea what speeds to use for various materials, so I just keep it at 250 all the time. Anyway, thank you again for your explanations and advise. Vince

[Ben Rivel]

Pat, I appreciate your comprehensive reply. I wound up putting the chuck in the freezer for an hour or so, then onto the arbor, and then the arbor into the quill. Drilling 3" into that tight-grain beech block was pushing it too much. I really have no idea what speeds to use for various materials, so I just keep it at 250 all the time. Anyway, thank you again for your explanations and advise. Vince
Print this out, laminate it and keep it next to your drill press:

https://www.fnal.gov/pub/takefive/pdfs/Drill_Press_Speed_Chart.pdf

[Vince Shriver]

Ben, Thanks very much for posting the drill press link. I'm sure others besides me will find the chart very useful. Awesome.

[Myk Rian]

It's possible the tapers don't match due to manufacturing errors. Wouldn't be the first time.

[Vince Shriver]

You're right of course, Myk; nothing's ever for sure. So far everything's work as it should.