Can't help with dimensions but as your shaft is short why not adapt the converter shaft used when fitting these units to a Bridgeport originally supplied with a factory 6F / 8F electric power feed unit. Power feed Bridgeports have a shorter feedscrew barely extending past the end of the table connected to the power feed unit by a coupler. This coupler is connecvted to the power feed by a roll pin in a cross drilled hole.

It would seem quite practical to make your own coupler using a roll pin at the power feed end and whatever seems reasonable at the feed screw end. The converter shaft is fixed in the power feed unit so you need to make proper provision for assembly and disassembly. Key and keyway may be too difficult. I'd probably put two flats at 90° on the shortened feedscrew and use a pair of gub screws.

Take care when shortening the feedscrew not to restrict table movement. When used on a Bridgeport the standard Servo brand power feed, and presumably others, fits tight up against the end of the table and contacts the knee a couple of inches before Bridgeports own unit does so resticting travel. Servo sell an (expensive) extension kit to regain the extra travel. There is a drawing included in the extension kit installation instructions on their web site which clearly shows where and how all the parts go together. Probably very useful reference for anyone considering engineering a fitting kit for their machine. See this page **LINK** and download the pdf file KP-0640 "Shaft Extension Kit for Bridgeport Installation Drawing". The drawing is on page 4.

I'd probably make an extension / adapter unit to go between your table and the power feed unit rather than make a new end bracket as David did. That way you can just cut the feed screw and make up a suitable, short, coupler. Sidesteps the tricky turning job on the long screw but you do have to source something suitably chunky for the extender unit and buy the conversion shaft so its a more expensive job.

Clive.

Edited By Clive Foster on 13/06/2016 13:47:02

Eek. That shaft end is not a pretty sight. Spacer, coupler and adapter shaft looks the way to go for a reasonably easy job. Nasty surprise when I checked the UK prices of those Bridgeport adapter shafts. Over £40, could have sworn I saw them at £14 ish not that long ago, so modifying one of those isn't viable. Davids article has the vital dimensions to make your own which doesn't seem too bad a job. Something between 1 and 2 inches for the spacer / adapter on the end of the table should give plety of room for a coupler. Making the coupler integral with the adapter shaft by simply boring a suitable hole in the end will cut down the length needed.

Clive