|spring loaded ER11 diamond drag engraver|
|Drag engraver apart|
A hard brass pipe(Albion Alloys, metric K +S!)
Polished 6mm steel shaft from an inkjet printer with a spring, I'm not sure where that came from!
I chopped the steel shaft with a hacksaw and stuck it in the lathe. I wrapped the shaft in masking tape to protect it from the jaws of the lathe, then drilled the centre to receive the diamond tip bit and trimmed the other end to take the spring. The spring is squeezed on. This is important for a couple of reasons. It ends up >6mm diameter therefor holding the shaft into the brass tube and so the collet.
That's morealess it. The extra lug at the end is just because I cut the main body of the shaft too short. The grey crap is PTFE/graphite dry lube.
To use...(engineers close your ears), I put it onto the spindle as usual then tighten the nut until the collet pinches the brass tube enough to stop the shaft moving, then loosen the nut a smidge. It should return when pushed in. So I'm using the collet slightly loose...