Drill press speed for pen blanks?

[sbwertz]

What speed should I be running my drill press to drill wooden pen blanks with a 7mm bit?

The chart on my drill press says 2400 RPM for a 1/4" bit in hardwood, but it seems MUCH too fast. It screams when I drill at that speed. I've been drilling at 1500 RPM and it still seems too fast.

When drilling on the lathe I run it in it's slowest speed...about 600 rpm.

 

[PenMan1]

Sharon:
On the DP I like to use between 800 and 1100 rpms. That works very nicely for wood. With acrylic, pr, et al, I make a center punch "dot" and drill about 1500 rpms.

 

[sbwertz]

I should have mentioned that I'm using a brad point bit.

 

[randyrls]

Sharon; Yes; 2400 is tooo fast. 600 to 1000 is about right.

I don't like to use brad point bits because they are hard to sharpen. It is important to have a sharp drill bit. I sharpen mine whenever I notice that I have to press harder while drilling.

On acrylics, cut the blank over long, drill the hole just the length of the brass tube, cut off the excess.

 

[brez]

Sharon,

I drill at 600 rpm. It is slower but it does not build up a much heat and cracking blanks are a rarity. Also be sure to pull out and clean the bit freguently.

Mike

 

[leestoresund]

+1, Mike

 

[sbwertz]

Well, it is a brad point bit right now. First time it goes through the drill doctor it won't be any more LOL.

I pull out about every quarter inch. I have no problems with blowout or blanks shattering in the vise, but it squeals at this speed. I will slow it down.

I bought one of the colt bits, but have a problem with it deflecting on entry in any wood with a strong grain. It will deflect about a 32nd of an inch, following the grain. It is a brand new 7mm bit, longer than my other bits. When I withdraw it, I can see it flex to the side as it comes out of the blank. It results in an oval entry hole and is off center at the bottom. I don't have that problem with my shorter brad point.

Thanks for all the input.

 

[KenV]

Two measures -- successful outcomes and comfort for the operator. I find that given similar outcomes from the first, the second wins most all the time.

One of the diamond "credit card" sharpeners can keep a brad point bit sharp for a long time -- then the drill doctor.

Side note -- Drill Doctors are good for general bit sharpening, but are not a high precision tool grinder -- I send the special (large sizes used for fancy stuff) out to a tool and die guy for sharpening. Same with end mills.

Hope to see you at the Desert Wood Turning Roundup --

 

[fernhills]

What speed should I be running my drill press to drill wooden pen blanks with a 7mm bit?

The chart on my drill press says 2400 RPM for a 1/4" bit in hardwood, but it seems MUCH too fast. It screams when I drill at that speed. I've been drilling at 1500 RPM and it still seems too fast.

When drilling on the lathe I run it in it's slowest speed...about 600 rpm.

Is that chart, not for bit size, but for thickness of material ?

 

[jedgerton]

800 rpm for me. Seems to work well. BTW I purchased a 7mm pen turners bit from Woodcraft 4 years ago. It's never been sharpened and it's still working fine! Your mileage may vary.

John

 

[Mark]

I drill at 600 rpm for most all materials. I love the Wood River bits from WC.

I bought a set of the Colt and ended up packing them up and storing them. They are much longer which was nice, but I too, found they would deflect when drilling hardwood and acrylics. I am not happy with them at all...

Just my $.02

 

[MesquiteMan]

I drill EVERYTHING pen related at 1,900 rpm and have great results. I have never split a blank and the cut is nice and clean.

 

[LeeR]

With pen blanks, or most any piece of wood I'm drilling. I use a "backer board" -- usually a thin piece of plywood scrap, under the piece to be drilled. No blowouts, and no edge tearing. I've only drilled a few acrylic blanks so far, but I've used the same technique, and had nice clean drilling. I back out of the hole often, and I also have a shop vac running to suck up the drill debris.

Sort of off topic, but use a small square to periodically check to make sure your DP table is perpendicular to the bit. They can get jarred easily, and a couple degrees can cause a real problem when trying to get really straight bores.

 

[sbwertz]

800 rpm for me. Seems to work well. BTW I purchased a 7mm pen turners bit from Woodcraft 4 years ago. It's never been sharpened and it's still working fine! Your mileage may vary.

John

That is what I am using now.