On 12/15/2014 9:51 PM, Lance Eggleston firstname.lastname@example.org [SOUTHBENDLATHE] wrote:
Group,I had a 17" LeBlond with a large, cast iron faceplate. The original threaded hole was too big so someone made an internal and external threaded sleeve for it, then welded it to the faceplate around the front.
As long as there's enough thickness, a sleeve like that should work fine. If not intended to be a permanent fitting into a chuck or other attachment it should have some slots or holes to use a spanner for removal.
If the size difference is so much that the shoulder of the chuck won't touch the spindle shoulder, the adapter will need its own, larger, shoulder.
Something I'd like to see someone try is an L taper adapter for a threaded spindle. For a bigger challenge, a D1 adapter.
I went the other way on the 17" LeBlond by modifying an L-00 chuck backplate to screw onto the 2-7/8" 5TPI spindle thread. Turned off the outside threads, faced the back until it was just thicker than the nose length then bored and threaded the inside, along with the register bore.