Milling Delrin on a drill press

[gone_wheelin]

I've got a project that I want to start work on that will require me to do some mill work on Delrin sheet stock. The stock will be anywhere from 1/2" to 1" thick. I already have a 12" benchtop drill press and have a cross-slide vise on order.

Can this be done safely with a drill press? I do not have access to a mill nor the funds available to purchase one.

Thanks in advance,

Ethan

[BENDER]

Does the drill press have a tapered spindle, or a drawbar? If it's just a press fit taper spindle, it may pull the chuck out of the spindle if you try and mill with it.

[gone_wheelin]

This is gonna sound kind of lame but, I haven't even unboxed it yet. Still looking for a place to set it up. Looking over the specs in the manual though and it looks like it has a tapered spindle that is keyed at the top, where it connects to the drive assy.

What exactly is a drawbar?

[BENDER]

Originally Posted by gone_wheelin

This is gonna sound kind of lame but, I haven't even unboxed it yet. Still looking for a place to set it up. Looking over the specs in the manual though and it looks like it has a tapered spindle that is keyed at the top, where it connects to the drive assy.

What exactly is a drawbar?

A drawbar is basically a really long bolt that runs through the center of the spindle and threads into the chuck/toolholder. Once tightened down the tool can't come loose from the spindle.

[gone_wheelin]

Well, I guess I could give it a try on a practice piece to see if it will work.

Thanks.

[Big Mike]

I've done light milling operations with my drill press and a 2-axis vise. Mostly aluminum.
My press has a tapered spindle, no drawbar. I've never had the chuck come off. I just have to be careful not to bind things up.
Working with Delrin I think you'll be fine as long as you use good judgement and don't force things...

[gone_wheelin]

Thanks for the input guys.

I figured as long as I go slow and take my time, I should be okay.

[RCCrawlerTT]

What type of bit would you use for an application like this?

[mrmaxxman]

a 2 flute mill bit will work best imo

[gone_wheelin]

I was checking the McMaster site and found a couple of different options. They have a vibration free end mill http://www.mcmaster.com/param/asp/PS...MainWidth=1073 that I was thinking of picking up.

But that does raise another question, how small is too small for an end mill? I was thinking or picking up a 1/8", 3/16" and probably a 1/4" and 1/2". The larger bits would be for clearing out the bulk of the material and the smaller for the perimeter. And I would think that I want a square end as opposed to round or ball, correct?

[BENDER]

Originally Posted by gone_wheelin

I was checking the McMaster site and found a couple of different options. They have a vibration free end mill http://www.mcmaster.com/param/asp/PS...MainWidth=1073 that I was thinking of picking up.

But that does raise another question, how small is too small for an end mill? I was thinking or picking up a 1/8", 3/16" and probably a 1/4" and 1/2". The larger bits would be for clearing out the bulk of the material and the smaller for the perimeter. And I would think that I want a square end as opposed to round or ball, correct?

Small endmills require more RPM's, and need a slower feed rate. The larger diameter endmills will deflect less, and have more cutting flute length. You do want square ended as opposed to a ball endmill. You could get away with high speed steel endmills too, instead of carbide. Carbide endmills are more expensive and really for harder materials. H.S.S. will work fine for cutting plastic.

[gone_wheelin]

So am I correct is using the smaller end mill for just the perimeter, where I would like a smaller corner radius and the larger end mills for cleaning out the rest of the material?

Thanks again for all your input.

I will eventually be picking up an real benchtop mill, once I have the funds and space for one, but for now this will have to do.

[BENDER]

Originally Posted by gone_wheelin

So am I correct is using the smaller end mill for just the perimeter, where I would like a smaller corner radius and the larger end mills for cleaning out the rest of the material?

Thanks again for all your input.

I will eventually be picking up an real benchtop mill, once I have the funds and space for one, but for now this will have to do.

Correct, the smaller endmills will allow you to do more detailed work.

[gone_wheelin]

Cool, thanks again for you help.

[gone_wheelin]

One last question, for now.

Is this is set of end mills worth buying: http://www.mcmaster.com/ctlg/DisplCt...th=1073#scroll

And would it be worth picking up a couple of the vibration free end mills, like the ones I posted a link to earlier?

[BENDER]

Originally Posted by gone_wheelin

One last question, for now.

Is this is set of end mills worth buying: http://www.mcmaster.com/ctlg/DisplCt...th=1073#scroll

And would it be worth picking up a couple of the vibration free end mills, like the ones I posted a link to earlier?

Yeah, those should work fine. I believe the "vibration free" tools are for really high RPM applications, I'm not real familiar with that term though. But, your drill press and most manual mills will never reach any RPM close to that of a CNC mill.

[RandyatBBY]

gone_wheelin If you are not able to do what you want in your shop, you can come down to my shop and use the mill. It is a little drive but you are welcome.

[gone_wheelin]

Bender- Thanks. I will hold off on the vibration free bits for now then.

Randy- Thanks for the invite. I might just take you up on that offer if this doesn't work. You going to the two-day race in May?

[RandyatBBY]

I am putting on a boat race that weekend. It is the my favorite thing to do in RC. sorry I have not been able to go to GP or ROCKS in a month and I am getting withdrawls!

[gone_wheelin]

Is it both days?