[Tomcat104]

Have an odd question; can i use regular drill bits in my cnc router? drill bits

I have a need, for the first time to drill 3 holes in 1" aluminum and my router will not cut round holes in the aluminum. So.......I wondered if I could slow my router down to 400 - 500 rpm and use regular Craftsman Carbide Drill bit?

I need some experience here please.

I have read many a bit mfg's advice against using regular drills and how much better off I would be BUYING their drill bits. I just wonder if they don't have a anterior agenda???

[Jim Dawson]

If you are talking about carbide masonry drill bits, no, not the right geometry for that type of work. That is not to say that they can't be used in metal, just not in that application, they do have a use in removing broken taps/drill bits and drilling hard metal, but manually. The other problem is getting a router spindle down to 500 RPM is going to be next to impossible unless you have a very special spindle.

I would spot the holes with a v-bit, or anything you have that would make a good ''center punch'' type divot. The drill the holes to size on a drill press.

[Tomcat104]

Thanks Jim, I knew that was the "right" answer when I asked.

I am disabled from a massive stroke and walk (barely) with a cane. I have a drill press in my work shop but it's in the back yard and it has rained here for over a week and is supposed to rain every day here until next weekend. Guess I'm gonna have to get "mud tires" for my cane.

Thanks for the reply.

[ger21]

How much power does your spindle have, and how slow will it go? That's the determining factor.
If you can get your spindle down to 8000rpm, then you can use a 1/8" bit, and maybe 1/4". If you drill with the 1/8", and then follow with a 1/4" bit, you should be OK. Peck drill with shallow pecks

Anything larger than that, and your rpm will be too high, and you likely won't have enough spindle power.

[Tomcat104]

Spindle will go down to 720RPM. It is a 2.2kw Chinese spindle.

I need to drill 10 holes, 5 of which are are 0.15625", 4 at 3/8" and 1 at .5". Do you think I should stay at 8000RPM for the smaller ones or should I slow the spindle down? And, what if I first did the .5" hole at .25" first?

I'm going to try to find a way to my drill press first but peck drilling on the CNC is my back-up plan.

[ger21]

I would not run that spindle below 6000 rpm, if you don't want to fry it.
And I wouldn't try to drill larger than 1/4" either.
I'd drill 1/8" holes on the CNC, and then use them as starter holes at the drill press. They don't need to be very deep.
That's what I do.

[Tomcat104]

Thanks for your reply. I'm just going to wait until I have access to the drill press.

I've already used a punch to make some "starter" holes.

Thanks again. I really don't want to damage my spindle.

[RCaffin]

Stub drills are safer as well. They don't wander like ordinary jobber drills. And slightly bent jobber drills are utterly useless in a CNC!

Cheers
Roger

[ger21]

Yes, I use short length bits. I get them from McMaster-Carr.

[Tomcat104]

Thank you.

I wondered if Stub Drills would make a difference.

[RCaffin]

I buy Chinese cutters from selected sources (Carbide Chiu), but I buy Swedish Dormer stub drills.

Cheers
Roger