Mill headstock reference plane
Normally when setting up work in the mill the reference plane is the surface of the mill table. Sometimes this is not very convenient and a reference plane at the headstock would be more useful.
This simple tool mounts in a collet in the mill headstock and provides such a reference plane.
This simple tool mounts in a collet in the mill headstock and provides such a reference plane.
It consists of a disc of 50 mm diameter mild steel, 12 mm in thickness, attached to a 10 mm diameter shaft that can be chucked in a collet. The disc was was cut with the bandsaw and mounted in the lathe chuck. It was faced on one side, centre drilled and drilled out to 6.8 mm. The hole was counterbored 10 mm to a depth of 4 mm. The centre hole was then tapped M8.
The shaft was prepared by facing both ends of a 45mm length of 10 mm round stock. One end was then turned down to 8 mm for a length of 12 mm. The end was chamfered and threaded M8 using a tailstock dieholder.
Both parts were the screwed together with some epoxy resin in both threads. After the resin has cured the shaft was mounted on an ER32 collet chuck on the lathe and the outside face of the large disc was then faced. The final facing cuts were very small and the feed slow to ensure a good surface finish. A small centre drill is used to drill a conical hole in the end of the shaft to remove any vestige of a centre "pip".
The tool can then be transferred to the mill for use as a reference plane. If the surface becomes damaged then it is easy to pop it back in the lathe and true up the face again.
This tool was initially made to facilitate making fabricated dovetail slides.
The shaft was prepared by facing both ends of a 45mm length of 10 mm round stock. One end was then turned down to 8 mm for a length of 12 mm. The end was chamfered and threaded M8 using a tailstock dieholder.
Both parts were the screwed together with some epoxy resin in both threads. After the resin has cured the shaft was mounted on an ER32 collet chuck on the lathe and the outside face of the large disc was then faced. The final facing cuts were very small and the feed slow to ensure a good surface finish. A small centre drill is used to drill a conical hole in the end of the shaft to remove any vestige of a centre "pip".
The tool can then be transferred to the mill for use as a reference plane. If the surface becomes damaged then it is easy to pop it back in the lathe and true up the face again.
This tool was initially made to facilitate making fabricated dovetail slides.