Drill Press or Drill/Mill Machine

Darren; I'm sure I'll be corrected by many people, but my mini mill is not at its best trying to drill over 1/2 inch. You can use a boring head to make a hole that big, but you would be better off with a larger machine. You are in the NYC area, and there a lot of used equipment dealers around there. Buy a used drill press for drilling holes, and a used mill for milling.

gary

I'd suggest using the Google Groups search:

Punch in this group and then probably "drill mill/drill" or something similar. There have been a ton of threads on this topic here already.

To summarize, if you plan to mill at all, get a mill/drill. I've only been on this group a short while, but I've seen several threads already on this topic and nobody has had anything good to say about using a drill press as a mill. They just aren't made for the lateral loads you'll see.

If you're interested in mini-mills, you may want to check out the info available at:

(Yes, I know it says lathe, but the popular mini-lathe is made by the same company that makes a popular mini-mill and there is info on both there. There are also several Yahoo! groups specifically for those machines..."minimill" and "GrizHFMinimill" are two of them for the small mills.)

--Donnie

I hope such books do not exist. I asked the same question not long ago, and quickly learned that drill presses are not designed to take the transverse loads of milling. Further, taper mounted chucks are not designed for transverse loads, and bad things happen (picture sharp object flying around your shop) when they are subjected to them.

Grizzly is not at the top of my list, but this group is a great source of recommendations. Ask about square vs. round columns; also look at some of the smaller knee mills just in case.

IMHO, you will want an ER (probably 32) collet chuck and collets, all the more so if you get a round column mill-drill. You will also want a good chuck for some drill bits and non-round shanks on hole saws, etc. Note that dials come in 0.1 and 0.125 inch/rev; I prefer 0.1, though I would also find the 0.2 inch/turn of larger mills to be fine. Users of

0.125 dials assure me that one adapts, but it's a process I would rather skip unless something like a longer travel comes with it.

I considered a mini mill but went with what amounts to a Rong Fu 31. Use google groups to read archives of this group. The smart answers to my dumb questions will teach you a lot. Mill-drills are great as long as you know what you are buying.

Bill

A drill press is a drill press is a drill press. You can't mill on it. Forget it. OK, you _can_ mill on a DP, but you won't repeat that abuse after having seen the result, ruined work pieces, ruined mills, ruined the DP, wasted money and waisted time.

HTH, Nick

Use a hole-saw to make 1.5" holes in .25 stainless and use low speed but firm downpull and a good lubricant. Or better yet, get a trepanning tool because hole-saws are primarily for softer materials such as wood and plastics. The trepanning tool may cost as much as a drill press though! And make sure to sandwich the plate so when the final chip is cut away you won't lose a hand as the piece picks up the same speed as the spindle.

Thanks. I'll combine the important parts and reply in one post...

There are? Can someone name one?

Unfortunately space will not allow for that. And anything approaching

200lbs would be too much. :-(

Too late.

Yeah, I was actually looking at a couple on Ebay. I'd try for this:

but is is too heavy, and the seller has zero feedback anyway.

I've already seen all that. And there was nothing *specific* enough to clue mee in as far as what machine would meet my needs.

this group a short while, but I've seen several >threads already on this topic and nobody has had anything good to >say about using a drill press as a mill. They just aren't made >for the lateral loads you'll see.

Yes, I read all that. But I was thinking of using the drill press as a mill on materials like Delrin and nylon(in addition to the more conventional drilling of metals, like that stainless steel I mentioned).

available at:

Yeah, I was at I found little that would let me know if these machines were powerful enough for my stated purpose.(Drilling a 1-1/2" hole through a

1/4" thick stainless steel).

Thanks.

Darren Harris Staten Island, New York.

I have this model drill press. I bought it because it went down to 140 RPM which allows me to drill larger holes than with most drill presses in its size and price range. Considering its cost, I've been happy with it generally, although the belts that came with it are very tight and because of that, is a major PITA to change speeds.

I think you'll be sorely disappointed with using any drill press as a mill. I had a RF31 type mill/drill that was a far better drill press than the Grizzly would be as a mill. If you needed to mill and drill on one machine, I'd search for a used mill/drill of the appropriate size. I'd think you'd want an RF31 or larger if you're going to drill 1.5" holes. I don't remember what the lowest spindle speed is on the RF31...

Peter

At least the author of that book is recognized for his contributions to HSEs: Rudy Kouhoupt

Nick

Are you sure about that? Weight was a big concern of mine, and frankly I'm still glad that I did not buy a 2500 pounder just yet. However, I probably should strip my 31 to clean and lube everything. The fact that I was able to move it as one 670 lb thing has allowed me to avoid that step. My point is that with guidance from experts here, you could probably plan to disassemble, clean, lube, and reassemble something heavier than you might otherwise think is ok.

Bill

Darren..to drill or saw a hole that big in Stainless, takes a solid heavy machine. You need a lot of downward pressure to cut/drill stainless, else it work hardens in a heartbeat. Im not sure there is ANY mill/drill out there that is capable of doing this on any regular basis.

Id even think hard about doing this on a Bridgeport, unless you use a hole saw.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

I don't know that I'd totally agree. I lived with an HF mill-drill for several years before I got my Bridgeport. While the BP is several boxcars more accurate and more convenient to operate, there isn't a whole lot of difference in the power of the two machines.

That being said, there are a couple other angles here. First, I cringe when people simply say, "stainless." Stainless is a term that covers a number of alloys, some of which machine nicely, and some of which machine about like a concrete block. I once turned an 7 1/2" flywheel out of a piece of stainless. I chucked a slice of 8" round in my lathe and shoved a HSS tool into it... and watched the end get sliced off the tool. Carbide tools cut it nicely, but, if I pushed it a little too hard and stalled the lathe, I'd snap the edge off the tool. And this was an alloy (it's been a few years and I forget which) that was supposed to machine easily.

And then, the OP put a limit of 200 lbs on the machine. I tend to doubt that anything weighing close to that will have either the rigidity or the power to drive a 1 1/2 inch drill through a piece of even the more easily machined stainless alloys.

Bottom line: A 1 1/2 inch hole in a piece of stainless is not a trivial machining task.

Jerry

Ok. I'm starting to get that impression. Will it make a difference if I get a drill with twice as much horse power as the drill I mentioned?(ie: Grizzly G7948). Though that obviously means the drill cannot be a bench top.

As for the stainless, I'm obviously going to have to be flexible at this point, but it'll be between 303, 304, 316 & 316L.

Thanks.

Darren Harris Staten Island, New York.

Why not use a boring setup - and circle cut it out. Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

Gunner Asch wrote:

Fred Eisner? I think that he sells on Ebay as:

and you can probably email him from there.

If you are even thinking of a mill, get a mill. 200 pounds won't cut it. You need slow speed as much or more than you need high HP. As others have said, use a hole saw for the 1 1/2" holes. I just recently had to make a number of 1 9/16" holes in 1" mild steel plate. I bought an "Agressor" brand 1 1/2" hole saw and ran it at the slowest speed I have on my old US machine tool vertical mill (350 rpm.)--(Lot's of lube). It took 1 1/2 minutes per hole. In my case, I had to bore the hole the rest of the way to get to 1 9/16" within a few thou. Consider this decision to be a major big deal on your part and figure out a way to solve the 200 pound max. problem. Hire riggers if needed. Get a lot of friends. Take the thing apart, move the pieces and put it back together (as others have said).

Pete Stanaitis

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snipped-for-privacy@mail.c> Since there are no places near me that sell used machines of the type I

Yes, a 1.5" hole in SS would be a heavy job even for a BP. You might consider one of the 'Rotabroach' type annular cutters. These require a lot less power to 'drill' a hole.

Dan Mitchell ============

Ditto that. The Rotabroach tooling works like a charm as long as you use plenty of coolant. Otherwise, you can easily get lulled into a false sense of security with them and burn 'em out.

Yup! And back them out an clear them frequently when drilling deep holes, as the small flutes tend to clog easily.

On the plus side, they leave a very round hole with a good interior finish. Almost as good as reaming. Hole size regulation isn't too good, but likely as good as with a drill. You can always ream or bore after if a better hole is needed.

If all you need is a decent large hole, and all you have is a small machine, they're an excellent option.

Plus, you end up with all those nice little round plugs left over to make something else out of! :-)

Dan Mitchell ============

I did win a Rotabroach on Ebay yesterday.(I'd just have to find out if any 1-7/16" cutters are available for it.

All this talk about stainless steel is making me think again about using Delrin instead. It would be much easier to drill or mill out those little bearing cups in Delrin, and I would think that the bearings would roll in Delrin with less friction than in stainless steel. The Delrin may not last as long, but the bearings themselves would actually last longer, and I don't think I'd need to grease them.

Thanks.

Darren Harris Staten Island, New York.