Pen Mill Diameters

[PhilSmith]

I've recently gotten into pen turning and have purchased (among other things) a pen mill set.

The mill set I purchased supposedly has 7mm, 8mm, 3/8in, and 10mm cutters. I've found that the 7mm and 8mm cutters are of "expected" size, but the 3/8in. and 10mm cutters appear to be the same size. That is they're both 8.63mm or 0.34in in diameter. (Based on an inquiry, the company I purchased from sent me a second set for comparison. And the second set is sized the same as the first.)

The 3/8" brass tubes I have on hand have an OD of 0.368 or 9.36mm and an ID of 0.354 or 8.99mm.

Can anyone tell me the OD/ID of 10mm tubes? Are they any different from the 3/8"ers? And should the 3/8" and 10mm cutters be of different sizes.

Thanks....

Phil

 

[LostintheWoods]

Phil, your post made me curious, so I went out and checked my two sets (both PSI) and they both came up 0.3390" on the smaller two, and 0.3531" for the larger two. Not a big size differential spread by any means, but a difference, none the less. BTW, in answer to your question, a 10mm tube is 0.3625" ID, 0.3845" OD. Hope this helps.

 

[gerryr]

I'm assuming that your set is like the PSI set I bought from somewhere, can't remember now. It has one cutter head and four shafts, correct? The only two things out of that set you really need are the cutter head and the 7mm shaft. Most pen kits are not the size of the other shafts anyway so you will need to make sleeves for most of them. Now you need to buy a diamond file so you can keep the cutter head honed so it will cut. I actually have four of them. I went on vacation for a couple of weeks and sent all of them to Paul in OKC to be sharpened.

One other thing, if the cutter head is 1/2" in diameter, you will need a 3/4" head also, unless you never plan to make anything except slimlines and Euros. If it's 5/8", you can make a lot of kits without needing the 3/4" head.

And welcome to the IAP.

 

[cdcarter]

On anything bigger than a 10 mm, I've just started doing mine on a belt sander and checking with a try square. I never get anything in the barrel anyway, and if I did, the mill probably wouldn't get it. Faster, and works fine for me.