Third world tool abuse

[NeiljohnUK]

Usually stainless steel bodied with various heat resistant materials including Inconel or even Invar used for the clamping sections of the jaws that hold the glass, we have had all s/s one's but they don't work so well.

What gets really interesting is some glass lathes have two 6 jaw chucks back to back on the working side of the headstock as the 'master' work holders, a further 6 jaw on the outside of the head stock for stability, and one 6 jaw either side of the tail-stock, all are driven from the same motor via toothed belts or gears inside the 'stocks', the tail-stock slides along the bed with a very long splined shaft supplying the rotary drive. The burner sits on a motorised saddle and moves up and down at different speeds to suit the job, with the burner being on for the slow working passes and off/reduced for the return, that's how fibre optic's fibres are made in the 'bulk' before pulling them down into fibre on a tower. Those often have a 6 jaw to hold the 'preform' too.