Colchester Student Question

Hello Charles,

On my machine it is .750" O.D. x 10 TPI. Have no idea of the metric one if that applies. If you need any scans from the Student instruction and spares manual, please advice.

DickGays, Leicester, UK.

Hello Charles,

Seeing your question this morning I looked at my cross slide lead screw and sent you a hasty reply. My earlier reply was inacurate. Something at the back of my mind has been telling me all day that 10 TPI can't be right, and it isn't. It looks like 10, but us in fact 5 TPI with double start. The cross slide moves .200" per turn, not .100". My apologies for this stupid mistake.

Dick Gays, Leicster, UK

Thanks Dick. Close but no cigar. My search for a 3/4" 10tpi left hand acme/square continues.....

Charles

Are you sure, Dick? Or does the dial indicate .200" per rev? Otherwise that means .400" removed off the diameter per rev of cross-slide screw.

Tom

Yes Tom, I a m sure of this on my machine which I believe to be standard. It does have combined imperial/metric dials and when in metric mode removes 10 mm off the diameter per turn which is of course near to the .400". I'm not sure what gear ratio they use to convert from imperial to metric, can have a look if you like.

Dick Gays, Leicester, UK.

Unlike some Taiwanese machine copies of Colchester lathes that indicated that 2.5mm = 0.1000".

Tom

In article , Dick Gays writes

Odd...

I checked a friend's Colchester Student operating manual and also measured the actual screw on his machine yesterday, and it has a 6 tpi single-start lead-screw.

Six ??? So what does he have on the dial as regards numbers

-- Regards,

John Stevenson Nottingham, England.

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In article , John Stevenson writes

Good point...

I'll have another look when I next go to see him.