Thread: Turn between centres before drilling to insert pen tubes?

Yes, flaring out the tube ends is a problem. What I do to overcome the problem, is use the bushes in the ends, but put these between the centres, turn the majority of the blank off like this, until I have about a mm to get to finished size. Then remove the bushes and put the brass tube between centres and finish off with very light cuts. Works for me.

There are certainly many tips and tricks that can be used to improve the pen making process that don't necessarily require a huge investment in new gear. Search "kurt Hertzog pen turner" for a heap of useful pen tutorials / articles.

In your situation the contact area between the pen tube and the centers is minimal so not much friction to "drive" the tube & blank, and being brass to steel there is also a "self lubricating" aspect as well. Using the pen bushes as Ironwood suggests increases the surface area, & even though that (most of that area) is concentric to the lathe axis it significantly increases the friction, (not to mention the hugely increased end contact area).

Scary sharp tools also reduces problems. A diamond honing plate is not really that expensive over the long term. Pen Barrel trimmers do require sharpening to work efficiently. Drill bits are the same - its a quantum leap in quality from an el-cheapo "jobber" bit to something like a Sutton Viper drill bit, and another step again using a well sharpened Sutton Viper drill bit.

I use a modified pen turning technique because I turn a lot of segmented pen blanks (where centering the tube within the segmented blank is critical to the final outcome) so the process will avoid many of the issues you are facing,

1. pre-cut blanks to slightly oversize in length.
2. carefully mark orientation for two tube pen types,
3. carefully mark centers on each end,
4. use a awl to "spot" the centers,
5. turn each blank to round between centers using a "steb center" drive and a small dia live center,
6. place ER Collet Chuck on headstock spindle, mount blank using matching collet,
7. with suitable drill bit mounted in Jacobs Chuck bring it up to the "spot" with the tailstock "free" until the point of the drill bit engages in the "spot."
8. lock down the tailstock then advance drill to past midway of the blank.
9. remove blank, end for end, then remount in the Collet Chuck.
10. repeat steps 7 & 8.
11. glue in pen tubes using your favourite glue.
12. remount the tube in Collet Chuck and use pen barrel trimmer in Jackobs chuck or turn away blank excess.
13. mount blank on mandrel using bushes or between centers
14. turn as per your preferred method.

I highly recommend Vermec ER Collet Chucks - very well made! A set of dedicated pen jaws work well but they are no match for the accuracy and precision one is able to achieve with a machinists ER Collet Chuck. Drilling from both ends may be slower but there is no blow out on drill exit.

What RPM are you running the lathe at when turning your blanks? The slower it is the more likely it is for a chisel to catch in the wood and stop it turning.
It would be a good idea to get something that will dissolve the lacquer on your chisels and remove it altogether and it won't cause you any grief in the future.

Thanks Treecycle, I'm now running the lathe fairly fast, somewhere close to 2,000 rpm. I filed the toolrest flat, got rid of the grinding marks and cleaned up the bottom of the chisel. Things have improved a bit and perhaps it's because some of the wood has soft and hard spots in it where the tool catches, I don't know, it's all a learning curve at the moment.

Originally Posted by Old Hilly

Thanks Treecycle, I'm now running the lathe fairly fast, somewhere close to 2,000 rpm. I filed the toolrest flat, got rid of the grinding marks and cleaned up the bottom of the chisel. Things have improved a bit and perhaps it's because some of the wood has soft and hard spots in it where the tool catches, I don't know, it's all a learning curve at the moment.

I'd be running your lathe as fast as it will go, on mine that's about 3400rpm.