I dabble in bagpipe making, which is a lot like making pens. The basic premise is the same, a hole is made in a piece of wood, and the wood is then mounted on the lathe and the outside turned around the inside.
How to drive the piece on the lathe after boring was what gave me trouble over the years; I used to turn a piece with the spur center, make my endbore start on the center of the same end so it would be concentric with the spur marks, and put the bored piece back on the spur center for turning. This usually meant trimming off the end with the spur marks after turning.
Well, I was doing it the hard way :eusa_doh:; I recently read a comment by pipe maker David Quinn about turning between centers, and realized there was a much easier method for turning a hollow piece. Just mount the piece beween 60 degree centers, and let the friction of the center provide the drive!
Here is a decorative end piece for a Uilleann pipe part; it has been re-mounted here for a photo pose after finishing:
This piece started as a turning square; a 7/64" hole was drilled through and each end of the hole was prepared with a center bit and mounted as shown. It was completely turned from the square between the live and dead centers as shown. The tools have to be kept sharp, of course, and light cuts taken, but it is surprising how much force is provided by the small drive area. Since every thing is turned completely between centers, it can be removed and re-mounted with perfect concentricity every time.
This technique can be applied to many projects; pens, lamps, pipes, even tiny beads. I needed to make a small bead for a tuning pin to go with the cap; I drilled a 3/32" hole for the brass pin wire through a 1/4" square x 1/2" long piece of teak, mounted the piece between the centers and quickly turned the tiny bead. It was not necessary to center prep the ends of the small piece for this.
I now use this method for mounting the square-bored pipes I'm now experimenting with, to turn their ends round. For tapered pieces with the larger end being too big for the diameter of the standard center, I turned a larger wood cone drive-center on a screw center.
Regards, John
How to drive the piece on the lathe after boring was what gave me trouble over the years; I used to turn a piece with the spur center, make my endbore start on the center of the same end so it would be concentric with the spur marks, and put the bored piece back on the spur center for turning. This usually meant trimming off the end with the spur marks after turning.
Well, I was doing it the hard way :eusa_doh:; I recently read a comment by pipe maker David Quinn about turning between centers, and realized there was a much easier method for turning a hollow piece. Just mount the piece beween 60 degree centers, and let the friction of the center provide the drive!
Here is a decorative end piece for a Uilleann pipe part; it has been re-mounted here for a photo pose after finishing:
This piece started as a turning square; a 7/64" hole was drilled through and each end of the hole was prepared with a center bit and mounted as shown. It was completely turned from the square between the live and dead centers as shown. The tools have to be kept sharp, of course, and light cuts taken, but it is surprising how much force is provided by the small drive area. Since every thing is turned completely between centers, it can be removed and re-mounted with perfect concentricity every time.
This technique can be applied to many projects; pens, lamps, pipes, even tiny beads. I needed to make a small bead for a tuning pin to go with the cap; I drilled a 3/32" hole for the brass pin wire through a 1/4" square x 1/2" long piece of teak, mounted the piece between the centers and quickly turned the tiny bead. It was not necessary to center prep the ends of the small piece for this.
I now use this method for mounting the square-bored pipes I'm now experimenting with, to turn their ends round. For tapered pieces with the larger end being too big for the diameter of the standard center, I turned a larger wood cone drive-center on a screw center.
Regards, John