Headstock Handle for the ML7 Lathe

The other end of the bar was reduced to fit inside the headstock. This was machined using a fine feed and an HSS tool for the best finish possible. The centre was drilled to final size too.

The 10° internal taper in the end of the bar was added using a boring bar with the top slide set over by 10°.

The chuck was unscrewed to check the fit if the part in the headstock but it was found to be too large.

A measurement of the ML7 bore showed it to be 15.19mm, not the 0.620" given in the plans, so the part was reduced to suit.

A recheck confirmed the expanding mandrel fitted the bore.

The chuck was moved to the rotary table for cross-drilling and tapping of the grub screw thread.

The part was reversed in the chuck and the slits cut with a 1/16" slitting saw in the milling machine.

The off-cut from the handle was used to create both the drawbar head and the cone nut. After drilling the centre, the chuck was mounted on the milling machine to add the flats.

The chuck was moved to the rotary table to orientate the part for cross-drilling for the t-bar.

Staying with the rotary table, the part was reverse in the chuck and drilled for the non-rotation pin for the cone nut.

Back on the lathe, the thread was added to the cone nut, and the top-slide was set to 10° to turn the taper on the cone.....

...then the cone and drawbar head were separated by parting.

The cone nut was held on an M6 screw to hand file a radius on the nose.

The drawbar head was recessed in the back using a boring tool, and checked for a good fit with the back of the expanding mandrel.

The drawbar was reduced at the end to 6mm and cut with an M6 thread to match the cone nut.

The drawbar was assembled in the mandrel so the position of the grub screw could be marked. Then the drawbar was recessed in this area with the parting tool.

The drawbar was transfer drilled from the handle and reamed to final size.......

....before fitting the T-bar pin.

The short crank length was chosen and the piece of flat steel marked out and the two holes were drilled 6mm on the drill press.

The tapered sides were cut on the milling machine by mounting the part on a piece of scrap aluminum plate using two 6mm holes drilled at the correct height to make the taper.

The radii were filed by hand and then trimmed using the same plate. Light cuts were used whilst rotating the part by hand BUT avoiding climb milling at any point which could lead to sudden failure.

The standard M8 nut was thinned on the lathe. The nose of the tailstock chuck was used to set the nut square in the chuck before machining.

The small hole in the crank was drilled to 8mm and the handle spindle was assembled with the thin nut, so that the thread could be machined to length.

This photo shows the handle mounted on the crank with the thin nut and shortened thread.

A press brake pair of jaws were used in the vice to fold the thick metal handle neatly.

The width of the jaws was measured and copied to the second fold to get the same angle in both cases.

The formed crank was checked for clearance against the change wheel cover on the lathe.

Then the crank was silver-soldered to the expanding mandrel......

....and cleaned up using citric acid in hot water.

Finally, the M5 retaining grub screw had to be shortened to fit flush with the mandrel body.

The finished handle on the lathe.