My Engraving and Micro-Machining Solution

[magicniner]

This is what I cobbled together to utilise the spare engraving spindle (the one I'm holding) which came with, but didn't fit, my Gravograph IM3, and subsequently used for micro-machining with my own home-brew spindle.

For constant depth engraving (good for about 20 degrees off centre either way on a 20mm cylinder and on non-level or irregular surfaces) the brass nose has a spherical socket at it's tip, which accepts a steel sphere with a through hole for the cutter and a flat to follow the work surface.
Adjust the amount of cutter tip protrusion and that's as deep as it will cut.
The Del-Tron R702 is a Micrometer Stage with a spring between the micrometer and the moving slide to allow the cutting pressure to be set for different materials and screwed down solid for Micro-Machining.

The spindle in the mount is one I knocked up from an ER11 Collet chuck on a 10mm shank, a bit of ally bar and some bearings, at the moment I use this for micro-machining but I'm planning an attachment allowing the same function as the brass nose on the engraving spindle.

The size differential between the driving pulley on the mill spindle and the cutting spindles gives 28800rpm cutting speed for 6000rpm mill speed, the belt is from Polyurethane drive belt sold by length, cut to length and welded by me using a cigarette lighter.

I hope this will inspire someone else to fulfil their engraving/micro-machining requirements ;-)

- Nick