Bobalu
Member
Lately I've been noticing my blanks are not always square. I get some tiny gaps when I join the barrel to mating parts. Is that an indication of a dull pen mill?
Unsquare blanks
- Thread starter Bobalu
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Not sure about a dull mill but more so the method of holding the blank which is not allowing it to remain square to the cutter head and/or the wrong shaft on the mill head.
Bobalu
Member
I've been using my workbench vise to hold the blanks while I drill with a cordless drill. I might be getting some wobble there. Maybe the next time I'll mount the pen mill in my drill press and see if things improve.
I use a dedicated pilot shaft for each size tube, 7MM, 10MM, 3/8", etc and have conversion bushings for the ones that aren't covered in the stock set, so I'm going to rulle that out for now. I've been using a wet stone to sharpen the mill, but I need to get a diamond hone or go carbide.
Thanks for the advise.
in my experience a dull mill might do a lot of things but unsquare is not one of them, I'd vote on not keeping the corded drill square. I use a drill press most of the time with seldom an issue.
OKLAHOMAN
Member
Take a good look at the end of the blanks after milling, making sure the brass is smooth and shiney with no waves. If useing the right size bushings over your 7 MM shaft and a sharp mill you should get a nice smooth end on the blank.
Lenny
Member
How are you sharpening your trimmer? You should only hone the back side and not the face (not sure if thats a good explaination) .. trying to hone the face could result in uneven cuts. Check out this thread maybe there is something here that might help
http://www.penturners.org/forum/showthread.php?t=33377&highlight=sharpening+barrel+trimmer
Also, try using a countersink to slightly chamfer the ends of the tubes, or check out the real nice tool one of our members makes for sanding the ends after trimming.
http://www.penturners.org/forum/showthread.php?t=33377&highlight=sharpening+barrel+trimmer
Also, try using a countersink to slightly chamfer the ends of the tubes, or check out the real nice tool one of our members makes for sanding the ends after trimming.
Rick_G
Member
Since I started turning between centers I have stopped using my mill. I cut the blank as close as possible to the brass tube and then using JohnnyCNC's bushings I turn the blank round. once round I take the bushings off and mount the blank between centers with just enough pressure to hold it and using a narrow sharp parting tool cut the wood off square to the tube. Once the ends are square I put the bushings back in and continue as normal. It's a little extra work but I haven't had a problem with my blank not being square to the tube since I started doing it this way. Also saves me buying or making a pen mill shaft for each type of pen I make.
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Bobalu
Member
Maybe this is the culprit. I WAS sharpening the face, not the back side. Add that to the process of drilling with a cordless drill, and my problem might just be figured out.
Paul in OKC
Member
I use a cordless drill with the pen mill all the time.
OKLAHOMAN
Member
Paul, me too.. Just can't see if the mill is sharp and the pen mill bushing fits inside the tube snug how it would mill uneven...
ed4copies
Local Chapter Manager
IF this is true, the blank has to be square unless the mill shaft is bent, just below the mill.
Sharp or dull, the blank will be cut evenly (perhaps poorly, but evenly).
Bobalu
Member
I went out and bought a DMT diamond sharpener today and sharpened my pen mill (back side, not top edge). Squared up a few blanks. Apparently that was the problem, as they all turned out fine, even using my cordless drill. Case closed.