Milling with a drill press

I was looking at the manual for my powermatic drill press. It looks like

  • it uses a 3/4" spindle

  • Jacobs J33 chuck that threads onto the spindle (that is, this is not a typical morse taper way of attaching chucks, the chuck is firmly attached to spindle by a threaded collar)

  • It uses two ZZ99R12 bearings to support the spindle (see page 13 of the manual, item 44 on the parts list).

I looked these bearings up. See McMaster item 60355K38, page 1083. The specs say, max RPM 10,700 (way over my maximum 4,800), max radial load

1,787 lbs. They are made for side loaded electric motors like on belted compressors and meet ABEC-1 standards, whatever that is.

So, then, I am thinking that this drill press should be capable of being used for light milling, the chuck would not fall out like on morse tapered drill presses.

Powermatic manuals are on my PM webpage

formatting link

Picture of the chuck is here:

formatting link
I would not want to ruin is and would like to hear some opinions. I may also call Powermatic company if this matter seems worth pursuing.

Thanks

i
Reply to
Ignoramus15474
Loading thread data ...

formatting link

Three jaw drill chucks aren't designed for side loads. Depending on how small the chuck closes and how worn out it is, it will only really has 'line' contact on the endmill shank.

You can probably get away with a small endmill and really light cuts, but you'll also need an XY table.

Reply to
skuke

This question has been asked so many times and answered so many times here. I feel you should read more here and not just dump your political crap.

And if you *think* it works, why not just *try*?

Nick

Reply to
Nick Mueller

Skuke, would you have an idea, just how light are the loads that would be permitted. I agree on the need for a real X-Y table etc.

i
Reply to
Ignoramus10399

You've been around here long enough that I'm going to skip all the don't do it comments, well all but one. :)

DON'T DO IT!

Now, with that said, if you just have to do it, I'd take the chuck out and make an endmill adapter that would screw into it's place. It would be threaded like your chuck on one end, and have a hole in it the size of my favorite endmill on the other. A set screw in the side would hold the end mill in place.

Reply to
Dave Lyon

Ned, that's good that it seems that I have not missed many issues.

Late last night, before going to bed, I measured the play of the chuck. I used a dial indicator with 0.001" scale. It seems that if I apply sideways force of abouot 40 lbs, the indicator travels approximately 0.001-0.002" off center. (I hope that I am clear).

That was with the quill locked.

Thanks Ned. I will play with it tonight, if I find time. I think that "do not mill with a drill press" is a good start for most drill presses. This one seems to be more of an exception due to bearings, threading collar on chuck etc.

i
Reply to
Ignoramus10399

Dave sez:

"> DON'T DO IT!

Great advice, Dave, but probably wasted in this case. A couple of quotes are in order. "Fools rush in" and "Experience keepeth a dear school, but a fool learneth no other way.

Bob Swinney

Reply to
Robert Swinney

I think you've addressed the most serious objections to milling on a drill press. Your chuck won't fly off, and your spindle bearings will tolerate side loads.

Presumably your spindle bearings aren't preloaded, so that's a potential source of chatter. Any play between the quill and the head is also a problem, so lock the quill if you can. As skuke says, a chuck isn't an ideal endmill holder, so keep an eye on that.

I'd give it a shot and see what you can get away with. Start with something like a 1/4" endmill in aluminum and see what happens. "You should never mill on a drillpress" is one of the bits of RCM dogma I object to.

Ned Simmons

Reply to
Ned Simmons

Iggie

Friend of mine's dad bent his Industrial Delta drill press quill milling slots for wooden puzzles. It didn't take much, maybe 10# of force? The problem is even the slightest instability gets magnified so quickly you can't get the drill shut off fast enough to save the quill. After he replaced the quill, he built a ball bearing collar with stout metal legs that supported the chuck just above the key hole and locked into the drill press head frame. Worked great after that. He made some very cool

3-D puzzles which he sold at craft fairs. He got so successful, he bought a small NC mill with the profits, which made even better puzzles.

Jim

Reply to
Jim McGill

Jim, thanks, that is something that I did not think about. I appreciate the word of caution.

i
Reply to
Ignoramus10399

Dogma it is, but it's sound advice. Drill presses, even robust drill presses, aren't built for the type of loading one experiences with milling. I own a BP that weighs near 1 ton and find it's not the most rigid of machines. I'd be a fool to expect a 100 pound machine to yield acceptable conditions. That doesn't mean it won't work-----it just won't work well. Keep your expectations low and you may not be disappointed. You can expect the cutter to grab more than it would on a mill-----things are far more limber. You can expect that a cut won't ever quite end---because of the springiness in the machine and the spindle relaxing more with each pass. You can expect that if you're trying to hold something square, it may be impossible (spindle deflection). But it will work. Sure will make a mill/drill look good-----and that boggles the mind.

Harold

Reply to
Harold and Susan Vordos

Harold, thanks for advise, though my drill press is 350 lbs, not

100. I woul duse it for minor things only. i
Reply to
Ignoramus10399

Ned, if you were forced to use it, could you tell me a few things about how you would use it;

1) TO what extent you limit how hard the drill press is used (ie, taking to the extreme, you would not run a 4" face mill on it) 2) How would you be choosing feeding speeds and mill RPM.

What I expect to do, are things such as making a slot somewhere, and stuff like this. I would not expect to do involved or heavy work on this DP. It often happens that I need something little done (like Don Foreman said, something that would fit my hand easily), and it would be great to be able to do it.

While I hate to say that accuracy is not the issue, I think that I would be unlikely to need extremes of accuracy.

i

Reply to
Ignoramus10399

Like most dogma, there's some truth behind it, but blind adherence to generalizations is foolish.

You could make much the same comparison between a Bridgeport and a large Cinci vertical mill. Would you run a 4" face mill on the BP if you had a larger machine available? Of course not. Could you if your expectations were not too high and had no alternative? Sure.

I happen to own a drill press similar to Iggy's as well as a vertical mill that's about half again as heavy as a BP. While I have no plans to do any milling with the drill, I wouldn't hesitate to do so if it were necessary.

Someday I'll make a list of the often repeated RCM dogma that bugs me most, but here's a start.

Don't mill with your drill press. Wedge type toolposts are better than piston because they're more rigid. You can't power tap with an Albrecht chuck. Democrats want to take your guns and land. Republicans want to put religion back in school and toss Granny out in the snow.

Ned Simmons

Reply to
Ned Simmons

I assume you mean the spindle, not the quill? I bent the spindle on a drill press and though I don't remember exactly how, I'm sure I was also doing something unwise. But Iggy's JT33 spindle with locking ring doesn't have a skinny neck between the bearing and the chuck like a spindle with a simple tapered mount. The threaded retaining collar is about an inch in diameter right up to the bearing. A comparable Jacobs taper is about 5/8", often with a smaller diameter undercut between the taper and bearing.

Ned Simmons

Reply to
Ned Simmons

Wes, you know, if I can use 1/4" end mills on this press, I will be very happy.

i
Reply to
Ignoramus10399

I don't think the column has enough rigidity irrespective of any issues with the spindle. Maybe a 1/4" EM might work.

Wes

Reply to
clutch

I tried using a small mill, it seems to work just fine. I will check out my endmills tonight to see just what I have, I have a couple of lbs of smallish endmills, including some tiny carbide thingys.

i
Reply to
Ignoramus10399

I agree... I basically have quite a few small sized milling bits, both for making slots as well as for regular endmills. So, I think, if I need to do some very minor milling, I could do it.

Reply to
Ignoramus10399

You need rigidity for carbide. Carbide doesn't flex much at all.

Wes

Reply to
clutch

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.