Chipping Workpieces At Headstock

I would use a high speed tool with a VERY high positive rake.
jimsehr
 
Thanks for the feedback to everyone.

I ordered some HSS and hopefully my lessons can advance :grin big:
 
When I taught at the votech, I used a 2x2 piece of wood on a sander as an example of what the tool bit should look like. Made a good visual. Might try that to get a visual on what you want to do with the HSS.
 
hobby ist said:
I thought taking even a tiny tiny fraction of a mm off would solve it, but it still chipped out on the headstock end.
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hobby ist said:
I tried with and without bushings but it didn't help. As far as that flare effect I think that's just from debur/reaming it to clean up the inside and it pushes into essentially "empty" space as the tolerance is not super super tight between the tube and the plastic.
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From the picture above it looks to me like the flare on the brass insert may be putting too much outward pressure on the end of the plastic. There has to be some pressure to hold the pen between centers but then the cutting tool adds pressure in the direction of the cut.
Whats more is that the work has probably heated up a bit towards the end of the pass which puts even more pressure on the centers.

Any news on how things got sorted out?
 
Tozguy said:
.........snip...........
Any news on how things got sorted out?
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He hasn't posted since April, just another one that comes and goes as he needs something!

One thing that wasn't mentioned was how he had this set up in his lathe. Was he chucking on one end and a center in the other end? If he was, probably had the center tightly driven into the end of the pen blank. That right there would have messed up the end along with using carbide. Who knows.....
 
My guess is he was chucking on a bushing used for the particular pen he was turning. Plus a bushing in the other end with the center into it.The bushing is a size guide for the diameter. If he was doing strictly between centers, he was pushing a bit too hard. Either way, his best bet is HSS. Lots of pen turners use metal lathes for doing their pens.
 
As said, don't use insert (carbide) tooling with acrylic material. Carbide inserts cut better at high speed. If you run at the extreme low end the chipped end is going to happen. Been there, done that. Use HSS bits and them you can set the speed to your hearts content. Have Fun.

"Billy G"
 
There is one of the pen turning companies that sells an adapter to use wood lathe tools on a metal lathe toolpost. Not much really but a rod that clamps in the toolpost to rest your tools on. I can see from your photos you had no epoxy or CA bond between the brass and plastic material. I used to scuff the outside of the tubes up with 60 grit then glue on the wood or plastic with a generous application of thick CA. Granted most of what I made were razors and shaving brushes but I also did quite a few shop pencils for friends as gifts.
 
Yeah, I remember my brother getting into the pen making craze way back years ago. I made several different mandrels for some of the blanks he needed that the common mandrels would not work for his needs at the time. I haven't looked lately, probably have any mandrel configuration imaginable available today.
 
Tip : if turning a square blank round, try a hand belt sander traveling opposite direction than lathe, get it close to final diameter then use sharp chisel. Gota go light and use corse paper ,lots of dust.
 
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