Using drill chuck for end mill in a pinch?

[Micro Milling]

OK, I waiting on my end mill holder, and I want to use my new mini-mill. Yet by all the posts about using the drill chuck, it seems that if I use the drill chuck dooms day will come.

Is it really that bad to use the drill chuck for cutting 1/8 inch brass? Assuming the end mill doesn't come loose will my cuts really be that in-accurate where you will notice it by just looking at it?

Assuming again the end mill doesn't come loose, will I damage the end mill where the drill chucks grips into it, so that when I put the end mill back into a collet it won't be smooth anymore?

[scadvice]

OK...I'll wade in. First of all you can mill with a drill chuck without hurting your machine. Here is what to consider and be aware of.

1 A quick tightening (without a key) is a no no. Use the smallest key locking chuck you have only.
2 Use 1/4 the speed and feeds. Depth of cuts cannot be very much maybe 20% of the diameter of the cutter max. That's max!
3 Exspect it to have some chatter. think about the small size spindles those machines have. That goes for later, after you get your cutters, keep them as close to the spindle as you can.
4 The cutters will runout a lot and cut more on one side than the other and you may not get a good a finish.

So...some slight risk to the spindle if your not careful...poor finish maybe...chattering most likely

I suggest slowwww starting with .01 deep cuts...with chatter increase...the feed rates.

Have fun... use a little cutting oil or wd-40... dab on with a small brush... that will help slightly.

It's your machine...I'm just saying how I would do it if I had your size of machine.

Steve

[Jeff Davis]

I tried it once.. 3/8" endmill in my X1 and I couldn't wait until my end mill holder showed up. Tightened the heck out of the chuck. This was my first cnc cut and was a simple 1" square in 1/8" plastic. Started out great for the first half of the cut. Then something didn't look right, before I could stop the machine I had made a nice little groove in my virgin table.... I believe it is still there to remind me to listen to my elders You may get lucky, but when I ordered my X3 I ordered my holders with the machine!

Jeff

[Crevice Reamer]

The chuck is NOT made for sideways motion. The chuck is ONLY made for vertical motion.

When you TRY to cut sideways with an end mill in the chuck, what will probably happen is the CHUCK will come off of its TAPER (It is only a slip fit) and then the spinning sharp endmill (Still attached to the chuck) may well come flying AT you.

This can be EXTREMELY dangerous. Please don't do it.

CR.

[Geof]

Crevice Reamer is correct; it is almost certain the chuck will work its way off the Jacobs taper and that can be very bad news at a few thousand rpm.

[hoss2006]

OK, I waiting on my end mill holder, and I want to use my new mini-mill. Yet by all the posts about using the drill chuck, it seems that if I use the drill chuck dooms day will come.


Is it really that bad to use the drill chuck for cutting 1/8 inch brass? Assuming the end mill doesn't come loose will my cuts really be that in-accurate where you will notice it by just looking at it?

Assuming again the end mill doesn't come loose, will I damage the end mill where the drill chucks grips into it, so that when I put the end mill back into a collet it won't be smooth anymore?

I'm sure I was one of the ones that warned you before.
It's a bad tactic yes, but if you must, keep the endmill size to 1/4 inch
or smaller and feed slow with light cuts as scadvise suggested.
In brass the side loads would be minimal. The runout of the chuck will also leave a less than ideal finish.
Also, chuck the endmill as far up into the chuck as possible to limit side loading. Endmills are hardened, you should
have little worry of marring the shank. If you can't wait, just be careful.
Hoss

[scadvice]

I knew I'd take a hit or two for saying yes you can... but as hoss said, light cuts, side loads.
Steve

[Micro Milling]

Thanks for everyones advice, I decided not to use the drill chuck and wait. It wasn't worth it especially for the many points you brought up.

I just really wanted to use my machine, you know how it is getting the machine and not being able to use it because of those small little parts.

Anyway I got lucky and my end mill holder just arrived in the mail today, didn't think it would get here and I would have to wait through christmas weekend to monday. I would go crazy as I will be getting a rotary table for christmas, and not be able to use it.

[Jeff-Birt]

It will also destroy your drill chuck. When I took over one of the machine shops at work I found a very nice Albrecht drill chuck in on of the Bridgeports with a 3/8" or so end mill in it. The chuck's jaws were toast, completely deformed from all the side load. It was just about $100 to buy just the three replacement jaws for the drill chuck.