Well luckily a member of this forum has a whole mandrel/feedscrew/ gearing setup for a model D. The feedscrew is 5" and marked TD, the mandrel is 11 13/16 and marked TD, and all the gearing comes with it! That's quite the difference. I went ahead and gonna get it to make the machine right.FellowCollector wrote:The threads only on the feed screw of my Triumph D 2 measure 4 ⅝". The threads only on the feed screw of one of my Home D models measures 4 ½". So if your Triumph feed screw threads measure 4 ½" this certainly would be a contributing factor to your problem.
Doug
Pics of what he has below.