The bits are slipping in my brand new Craftsman drill press. I love it! Except for the bits that are slipping. I am tightening the heck out of the chuck but still the bits slip some. Any hints ? ( All of my bits are a few years old, and I am a newbie to metal working ... ) This is usually happening when drilling in aluminum extrusions that tend to grab the bit.
I had the same problem with a 12" bench Delta drill press, and a friend suffers with two Crapsman drill presses. The problem is that good chucks are expensive, and would represent a large fraction of the cost of the whole drill press. So, the manufacturer cuts corners.
I solved the problem with my Delta DP350 by replacing the original chuck with a Jacobs JT33 heavy-duty keyed 1/2-inch chuck (MSC #08590093, $84).
My drill press cost $200, and the replacement chuck costs $84; this is why the original chuck proved useless.
You will still need to tighten at least two holes, and I tighten all three holes, but this Jacobs chuck has not slipped yet. Unlike its predecessor. Precision matters.
You will also need two sets of 6JT wedges (four wedges total) to remove the old chuck without bodging something (MSC #08592966, $7/set).
The two sets are needed on my friend's Crapsman drill presses, as the gap between the bottom of the spindle and the top of the chuck is too large for one wedge set to fill. The Delta needs only one set.
The wedges of a set are used nose to nose, pushed together with a big C-clamp. Or hammered, the traditional method.
Buy new bits. MSC sells lots of kinds. Don't cheap out here. If you are drilling a lot of holes of a size, buy a bunch of that size.
And, use coolant, to keep the aluminum from welding to the drill bit and rendering the bit quite dull. Denatured alcohol works well, and so does kerosene, for hand drilling. This makes a huge difference.
On a drill press, I use a flood of water-based coolant: a one-gallon little giant coolant pump and Cool-Mist dissolved in water. This works best if the drill press table has coolant troughs and drains, so one can easily plumb the coolant circulation system.
Just fyi, Craftsman power tools are about an order of magnitude lower quality than their hand tools--which themselves hover around middling, mebbe occasionally good
Altho the quality of their relatively new ratcheting box wrenches is atrocious--the goddamm hole is not even concentric/symmetric on the wrench end, and the box is not offset. Visavis similar style Crescents (reversible) from Sam's, which appear almost like Armstrongs et al. And the Crescents were a lot cheaper, iirc.
All good stuff and I just saved your entire reply in my notes.
Just so I know, if I do have to replace the chuck, why would a more expensive one make a difference with slipping bits? By that I mean what is different mechanically about a premium one ? Do they have ridges that grip the bits or something ?
Actually, Crapsman power tools are vitually *identical* to the no-name imports you find at bigger suppliers, HF, etc. Sears just springs for a goddamm printed/stamped label and mebbe a paint job.
Altho, I should also add that often there is not much of a diff. in price, so no harm, no foul. And, Sears proly has a better return policy than your local supplier.
Or, you can also try what I've been doing lately, going thru my local supplier's scrap heaps. Lotsa parts for my existing imports, some neat finds, AND, I might be getting about 3 complete pedestal drill presses (17", w/ slipping chucks) for real cheap. O'course, I gotta rummage around to complete them.... Fun, tho.
Used is another option. I prefer PennySaver to goddamm ebay. If you find a good price on a pedestal drill pressr, and still want benchtop, you can always cut the shaft, either on a band saw, or abrasively. Or w/ a hack saw. :(
Actually a very good question. I think tolerances is the answer. In a jacobs, all three jaws likely come down nice, tight, and symmetrically, just from one chuck key hole.
In an import, there is likely asymmetrical slack/slop, and mebbe even some camming, so that after a little operation stress, the "cocking" of the initially-tight drill then releases, and the bit is actually *totally* loose. Like a sloppy dowel pin that first wedges tight, and then drops loose.
Three out of five times, my 5/8 chuck drops the bit--cuz I refuse to tighten from all three holes!! Other than that, it runs pretty true. :)
It's sort of a game now, to see if I can make it thru one hole without having to re-tighten the chuck.
A good chuck has hardened jaws with fairly narrow ridges to contact the drill shank. This narrow ridge displaces some of the steel in the soft drill shank, allowing a better grip.
A good chuck also has better bearing surfaces, so of a given amount of tightening force more goes to the grip and less goes to fighting stiction.
Note that what I use on my drill press at present is a 1/2" Jacobs keyless chuck (patterned after the Albrecht chucks). It grips pretty well just from hand tightening (no key needed), and the torque of cutting tightens it even more, so it normally will not slip.
The exception (for both this and normal Albrecht chucks) is when you are trying to grip something with a hardened shank such as an end mill (not a good idea anyway for most things). Albrecht has an answer to this problem, too. There are chucks made with diamond grit embedded in the faces of the jaws, so it will get a grip on a smooth hardened shank. But it is a significantly more expensive chuck, and it is typically made with a 30-taper, 40-taper or R8 shank to fit a milling machine, not a drill press.
I do have genuine Albrecht drill chucks on several other machines, including all the tailstock chucks for my Compact-5/CNC, some of the ones for my 12x24" Clausing, and even the little Cameron Precision sensitive drill press. I also have a 5/8" clone of the Albrecht for the Clausing lathe, but it is not as good as a real Albrecht. Some of the clones, such as Rohm, are pretty good. Others are not.