FILENAMES: Tailstok.gif Tailstok.jpg DESCRIPTION: These are a picture and a diagram about a lathe tailstock repair. Posted by Ted Edwards . The following description was provided: ================================================================= Tailstock Repair Ted Edwards 2001 Jul 29 Ted_E@bc.sumpatico.ca Additional files: TAILSTOK.GIF, TAILSTOK.JPG After several years of (ab)use, the cast iron threaded bushing in the tailstock of my Smithy finally gave up the ghost. I say abuse because until recently, the Smithy was my most powerful drill press. As a result, more than reasonable force was applied to the tailstock screw on some jobs. One other cast iron bushing was replaced with a bronze one some years ago. These are the only two repairs I've had to make to the machine so I can't complain. I decided to replace the worn (stripped) bushing with a bronze one. The bushing has a 12m1.75 left hand thread (60 degree). I would have to make an internal threading tool that could thread 12mm diameter about 20mm deep or, alternately, a tap. I decided on the tap. The only non-obvious aspects of the tap are: It was made from OCS, hardened and tempered. The flutes were machined with a regular 3/8" end mill and a spin index. The bushing is a light press fit into the tailstock ram. It is held in place with a 5m0.8 setscrew half in the bushing and half in the ram. This half-hole was made by mounting an oversized (1" diam.) piece of round stock in the 4-jaw. The work piece was then offset 10mm and the hole drilled and tapped. The piece was then moved to the 3-jaw for turning the OD and drilling and tapping the central hole.