Looking for a real oddball thread-on backing plate for a Seneca Falls lathe...

[jpackard56]

Anybody have a 1 and 7/16 x 12 thread-on lathe chuck backing plate in their stash somewhere ? Apparently that is what I need to attach to the old Seneca Falls lathe that I've been fooling with......

 

[projectnut]

I doubt you're going to find anything other than occasionally on eBay when someone is parting out a machine. You might want to consider taking one with a larger bore, removing the threads, pressing in a plug and single point the appropriate threads. I have a circa 1916 Seneca Falls Star #20 machine that has the same size spindle. Over the years I've made more than half a dozen backing plates for different chucks.

I also made a threaded test plug to be sure the new threads fit the spindle properly. I can test the fit with the plug rather than have to remove the backing plate and try it on the spindle.