Milling bit on the drill press

[Matthew N. Masail]

It was mentioned that a milling bit on the drill press might be a good way to work brass. btw the pin is finished and looks great, I was able the break out most of the waste after hack sawing, but I'd like a way to produce them faster.

I was wondering what kind of bit and at what RPM? can I build a jig with wooden blocks and T tracks to guide to brass through the cotter or do I have to have a special vise?

[Bruce Haugen]

I have no idea what bit would work, but you will likely find that it won't very well. The quill on a regular drill press is not designed to handle the lateral stress that a metal-working mill handles with ease. There's a reason that a mill has such beefy components.

[Mark Baldwin III]

I'll second what Bruce said. Drill presses aren't really stout enough to run end mills. You'll probably have to continue making the pins the way you made the first one.

[John Coloccia]

Besides not working well (especially if you don't have a quill lock) and thrashing the bearings, I think you stand a good chance of the vibration and loads causing the chuck to loosen and fall out of the taper.

[Edward Clarke]

If you can find the correct sized collet then you might try putting the end mill into a router. You'd probably want to run it at low speed.

[Jessica Pierce-LaRose]

The only time I've ever used a drill with side loads is with a sanding drum; and I would always let the paper do the work - no pushing on the drum. Even then, the other end of the drum had a large bearing that mounted in the base to help receive any sideways load to minimize pressure on the quill. As John states, loads against the side can make the chuck fall off the taper. That's not fun, and potentially dangerous.

That said, a question to the knowledgeable folks on these matters, rather than a suggestion, as I know little of metal working : could one use a center-center cutting end mill as flat-bottomed drill bit Matthew's situation? That is, rather than the standard milling operation of plunging a bit, and then working side to side, could Matthew make a series of slow cuts, plunging only, then raising the bit, moving the work slightly to the side, with the bit clear of the work (in some sort of jig or carriage) and making another plunging cut? With care, I would imagine it would leave a cleaner surface needing less finishing work than doing the same operation with any sort of drill bit I can think of.

[george wilson]

I don't know what pins you refer to. As said,a drill press spindle isn't designed for sideways cutting loads. And,unless your chuck has a screwed on collar above the chuck(as some do),there is just a short taper holding the chuck on,and it can fly off still rotating,and gash you severely so that flesh will be missing from a groove the width of the cutter.

IF your drill press has a milling type table with cranked screws on it for in and out and sideways,AND,AND,AND a screw on collar above the chuck,you could do some light milling on brass-not steel. I recommend about 400 RPM. A router has much,much too high an RPM to mill brass,even slowed down. I,d use about a 6mm end mill if I were you(I assume you are metric),and not mill off more than 4 or 5 mm deep at a time.

Be sure you have the milling table AND the screwed on chuck collar. Some drill presses have them,but many do not. I knew a guy who routed the palm of his hand,and I don't know if it ever healed properly.

You can buy a Chinese milling table pretty cheaply that will serve for simple milling. I would NOT rely on a WOODEN TRACK. Brass is a dangerous metal because it can GRAB severely. you will not be able to hold it,and may get you fingers ruined because it will happen so fast you cannot react.

[Terry Beadle]

I use an end mill in my DP quite often. Mostly to remove waste for mortises. I do not put a side load on the end mill. I've found that plunge cuts, about 1/8th to 1/4 inch deep do the job. Then move the piece slightly so that the end mill takes a half width plunge cut.

I've used this technique on brass and bronze. Bronze being the tougher, I took very lite plunge cuts.

This technique is detailed on metal working web sites and is not some thing I've developed. The key is not to do side ways cutting like you would if you had a real mill. Take several plunge cuts. Only after the plunge cuts are completed can you do a very lite side ways clean up.

For the pin you talked about for your plane, I would make a jig with a drilled hole for the pin material. Then in the center, a hole for the bit to plunge down into. You could regulate the depth of cut with washers or even oak depth stops. I'd not recommend taking more than 5 ~ 7 thou deep plunge cuts at a time. A clamping bolt in the jig would keep the pin from turning.

I use a heavy x - y table on my DP that I got from Grizzly. Not the cheap one but the more expensive one that costs about $150 or so.

One last comment is that this technique is not for production situations but for one off a bit more time consuming operations.

[Bruce Page]

George is spot on! I had a DP chuck come loose milling some aluminum – it got very exciting for a few seconds! Could you make a wooden dado jig to cut the flat on the table saw? You would need some sort of locking set screw to keep the pin from rotating but once you got the details worked out it would be easily repeatable.

[george wilson]

When I was in high school shop,I was routing with an electric router and had the chuck come off!! It was just held on by a short taper too!! The taper was a bit over 1/2" long. Fortunately the chuck and bit got trapped in the wood under the router base. I thought that was a very dangerous way to construct a router.

[ray hampton]

When I was in high school shop,I was routing with an electric router and had the chuck come off!! It was just held on by a short taper too!! The taper was a bit over 1/2" long. Fortunately the chuck and bit got trapped in the wood under the router base. I thought that was a very dangerous way to construct a router.

how are router chuck held on the router in this day and age

[Ryan Baker]

I have tried, in a pinch, to do some light milling on my drill press several times. Every time I have tried it, I have had the chuck fall out of the taper, which means ruining the piece in the best case. That's not to mention the force on the spindle. It's just not a good idea.

As George said, brass is soft but grabby. Making this kind of cut in a small rod that is already hard to hold well enough is very dangerous. I wouldn't try it.

[Matthew N. Masail]

Thanks everyone, I think I'll give this one a pass. I was looking for a way to make it simple, and having to take many small plunge cuts and then stop to step up for the next depth is not my cup of tea. if I can find a good metal file it should speed things up. I was able the break the brass pieces between the hacksaw cuts, as George said I might, by putting a screwdriver in and twisting it sideways. here is picture of the finished pin, 9mm contact surface and 7mm thickness left in the center: I like the fact that if brings the pin closer to the blade giving better clearance from the front block.

235351

[phil harold]

everyone whose chuck fell of...
your missing a screw to to anchor it on the taper
yes I do use the mill bit to drill to almost depth
I move to next position with a cross slide vice (http://www.use-enco.com/1/1/2454-30801-palmgren-cross-slide-work-positioners-levelers.html)
then I take the last couple thousandths off like I would a mill

Is Brass catchy!
Yes so is most metal when milling, so please secure workpiece,
round stock secure with v blocks

My drill press is a 1961 south bend
and I have a cheap Taiwanese mill now for large drill bits and milling operations now, and only use the drill press on occasions when the mill is setup for another procedure and i need to do something fast and dirty

[John Coloccia]

I'm sorry Phil, but that's not right. The vast majority of drill presses simply have a taper with no screw to hold anything in. There's nothing missing.

[Terry Beadle]

Not to argue but to reason.

Check it out: http://www.youtube.com/watch?v=gJYWUX0g6A8

This is by Rudy Kouhoupt, a noted machinist.

Also, on my DP a high rpm is better than a low speed one.

[John Coloccia]

Terry, a lot of people put rags in piles and never get a fire and use PVC for compressed air and never get an explosion. One thing he has going for him in the video is that his drill press has a quill lock, and that will significantly cut down on the vibration. Still, there are plenty of people that have had the chuck fall right out of the quill, and it's extremely dangerous when it happens. I've had it happen to me with a fly cutter going through metal. That was very exciting and it's just dumb luck I didn't hurt myself a lot worse than the couple of scrapes I got. Significantly unbalanced loads are just not tolerated well. They work to wiggle that chuck loose. That's why you'll never see a mill that uses a simple taper. They all use collets and chucks with draw bolts.

[george wilson]

Correct,John. Most DP chucks just have a taper,no screw. I'm not saying that some couldn't have a screw,I just haven't seen them,but I haven't made a study of the subject. The best type of chuck arrangement for keeping the chuck on is the chuck and spindle that has the extra captured ring on top. The spindle has a threaded area that the ring screws onto,preventing the chuck from coming loose. My old 1963 Craftsman DP has it. A Delta variable speed drill press I bought several years ago for the toolmaker's shop had it. I DID have to buy a Jacobs chuck of the same design for it. The Chinese copy didn't run true,but at least the Jacobs still fit. The Jacobs made the drill press run true,though the vibration was still excessive on that new machine!

I don't know how many drill press models have this type chuck,but for the average home shop grade DP,it is the best design. By the way,Jacobs has now gone Chinese,so I don't know if their new chucks are accurate or not. My old 1963 Sears has a real one that is still accurate to this day.

I knew Rudy. He had just a tiny little workshop,and specialized in miniature machining projects,writing articles as he did. I wouldn't take his use of the drill press as gospel since he only did light work which you can get away with.Notice that he is only taking cuts of .008" to .010" per pass. BUT,hear those grabby sounds while he's traversing the cut? That is the sound of the cutter grabbing sideways as he goes along. The light cut saves him from the chuck flying loose. I also submit that if you look carefully at his crossfeed table,it moves in little jerky motions. This means that the gibs are not tightened down enough,allowing the cutter to jerk the table along as it grabs. It should have been tightened up until the screw feed had to push the table along with a little frictional resistance.

I have a similar crossfeed table which I bought in about 1963,made better than the newer ones. I admit that I did some light brass milling way back then when I had nothing better,BUT,I did have the secured type chuck on my Sears drill press,don't forget that. At that stage,I was mostly experimenting with machining metal,and had a long way to go,both in experience and machine acquisition.

I'll also mention that end mills are fragile unless in a very rigid machine,and it is VERY easy for their corners to get broken off when they grab,messing up the end mill. HSS is pretty brittle.

[Johnny Kleso]

My Chinese DP has one lower bearing and no upper.. The drill point can move around a good amount..
Like holding a baseball bat out with one hand vs two..


You can do it in a pinch but don't invest a lot of money unless you have a tried and true method...

[phil harold]

I'm sorry Phil, but that's not right. The vast majority of drill presses simply have a taper with no screw to hold anything in. There's nothing missing.
Here is an image from the manual of my drill press showing the screw, also you will notice it describes routing with the drill press.
I guess all drill presses are not created equal...
235370

[george wilson]

They apparently,and expectedly aren't. I know the old Delta drill press at work that threw its chuck had no screw,but it seems like a good idea.

I have drilled out more than one drill press chuck in order to make it easier to press them off of arbors they were mounted to.