Pen blank question

[leehljp]

I bought a few dozen pen blanks of different kinds back with me and of course there are different sizes. Some are close to 3/4 by 3/4 or larger and some are smaller. On the larger ones, I was wondering if I can get two pens from each by cutting them diagonal on the band saw and drilling them. Drilling first and then cutting the diagonal would be better.

What is the minimum size you would consider doing this?

Currently, everything is in the "thinking" stage and it will probably be February before I get my little Taig lathe set up. I got everything through customs without a problem.

[boblon]

Unless they are quite a bit larger that 3/4 square it seems pretty risky to me.

The ones you would really want to do it with would be the ones with very interesting grain or the expensive ones. These are the very same ones that if you blew out a blank drilling the hole you would no longer be able to match the grain even if you got two good halves out of the four triangular blanks you started with.

Sometimes my hole come through almost dead center on the bottom, but most times it's off at least a little.

You could try on scrap wood, or an blank you don't mind losing and see how well you can drill through without blowing it out.

Me, I don't think I'd do it.

Good Luck,
BobL.

[kwgeorge]

I have done quite a few pens with very thin blanks. ½” is pretty much normal for me as I salvage a lot of cut offs from larger turning blanks. I have also gone smaller than that several times but did not measure the blank so I could not tell you the smallest I have done. Drilling prior to cutting may be a good idea so you can get the added strength of the surrounding wood. The drilling fixture that I built comes in handy when doing smaller blanks as it is adjustable and will support the blank on 3 sides while drilling.

[Scottydont]

Drilling smaller blanks are prone to blow out so if you are going to try it drill with less pressure and clean the flutes out often. You can even use a damp sponge to cool the drill bit if necc.

[boblon]

Ok, so I'm a slouch at drilling pen blanks [:I]

This has stirred something in me. Call it a challenge, call it hope...whatever. But I've got some left over antler tips from penmaking I thought were too small to use. I guess I'll have to find out now.

Still, considering that .5 Inches equals 12.7 Millimeters and 12.7 minus 7 mm for the drill bit equals 5.7. Add in twice the tube thickness and we've got to be down to about 2.5 MM left per edge. Asumming you drill DEAD straight. And you still have to turn it.

And Ken, you say you've drilled blanks SMALLER than 1/2"?

I am impressed (of course you do that to me a lot )

BobL.

[sdmaker]

I have used 1/2 inch blanks also. just gotta make sure you drill it straight. There is not much left to turn afterwords, so you cant get real fancy with the design.

[mudder]

quote:Originally posted by boblon

Ok, so I'm a slouch at drilling pen blanks [:I]

This has stirred something in me. Call it a challenge, call it hope...whatever. But I've got some left over antler tips from penmaking I thought were too small to use. I guess I'll have to find out now.

Still, considering that .5 Inches equals 12.7 Millimeters and 12.7 minus 7 mm for the drill bit equals 5.7. Add in twice the tube thickness and we've got to be down to about 2.5 MM left per edge. Asumming you drill DEAD straight. And you still have to turn it.

And Ken, you say you've drilled blanks SMALLER than 1/2"?

I am impressed (of course you do that to me a lot )

BobL.

I've drilled a blank that was 3/8" and it was Corian! (well....382 to be exact) I have also drilled and turned many wood blanks of 7/16 and probably as small as 3/8".
A slimline turns to a diameter of .330-.335 depending on the whose kit it is so I would have no problem believing that Ken regularly does it. It's not really impressive, you need a good jig and a drill that does not walk.

Mudder

[boblon]

Well, maybe it's different in real life, but going just by the numbers, your numbers in fact, it still seems impressive. Lets use your numbers, and lets use the larger of the blanks you mention and the smaller number for pen diamter.

7/16 = 0.4375 &nbspminus the given pen diameter
&nbsp &nbsp &nbsp &nbsp &nbsp-0.330
--------------
&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp= 0.1075 &nbspthis has to be split for both sides of the pen
&nbsp&nbsp&nbsp/2 = 0.05375

So, approx. 54 thousanths is left IF you drill perfectly straight, and you still have to turn it.

Could be a numbers game like I said , but still seems impressive. Either way, you guys are drilling some mighty fine, straight holes!

BobL.

[mudder]

Lets look at it this way.

You need to drill a .275 hole in a .375 piece of material (the final turned dimension is .330). I set up my pen jig using a piece of 1/4" drill rod to make sure it is straight and centered to the jig. I use a shortened drill when my blanks are so small and I use a real slow feed rate. If you cannot drill a 2-1/4" deep hole without the drill walking over .050 then you need to look into the way you are drilling. (Ie. Dull drill, too much drilling pressure). It's not all that amazing, give it a try and I'll bet that you'll find that out. I would not suggest drilling a burl or highly figured wood that has twisted grain, but with the right technique it is not a big trick.

Mudder