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Step 7: Alternative Chuck

If you don't have a Jacobs chuck, spare barrel trimmer, or don't want to go through what was described in the previous step, an alternative way is to make your own jam chuck.

I have lots of 3/4" x 3/4" x 2" cutoffs of ebony due to the longer length that my ebony pen blanks come in, and I used one to make a jam chuck. This is initially how I made all these pens, but I had issues with concentricity since the wood could still spin off axis easily. It's especially because I was turning between two centers; I now know that it would've been better if my jam chuck would've been big enough to at least be clamped in a jaw chuck on one end...

In any case, for a jam chuck you want to narrow down one end to be an end you can shove into the hole of the brass tube in the long section of the pen. That means you should taper down to a 7mm diameter, which you can use calipers to check with.

Once you're happy with the diameter, continue cutting in with a spindle gouge or parting gouge until you get to a diameter you can snap with your fingers.

Again, I highly recommend you start with a piece of wood that you can turn to fit in a chuck rather than turning between centers (so you'd have a chuck on one end securely holding concentricity and a live center on the other end). Below is how I set up my jam chuck between centers, though. You shove the ~7mm portion into the hole and tighten your tailstock as much as possible so that you don't knock the wood off axis.

Since you don't have bushings to control the end diameter, it's more difficult to ensure a proper fit with the slimline kit. I had to take this off the lathe to check against bushings, which isn't good for keeping concentricity.