Harrison 140 headstock taper

[Nick HopwoodParticipant @nickhopwood71702]

Can anybody tell me what taper is used in the headstock of a Harrison 140? The handbook says 3 morse but it obviously is not. Thanks.

[Nick HopwoodParticipant @nickhopwood71702]

[Keith LongParticipant @keithlong89920]

Hi Nick

I may well be wrong about this but I think that Harrisons usually have a "bush" in the business end of the spindle and the 3MT taper is actually in that bush. Colchester do the same trick. On Colchesters the actual spindle taper is NOT a Morse taper but seems to be one of their own.

Your best bet is to measure the end of the spindle with a DTI and see what the taper actually is.

I've got the same issues with an old IXL Leader that I just acquired, it's headstock is a Colchester Master clone and I'm missing the spindle nose bush. The upside is that when i get round to machining one it can have whatever fitting I like inside!

Keith

Edited By Keith Long on 20/09/2012 15:42:31

[Ian S CParticipant @iansc]

Just been looking up your lathe, if the bore is 1 3/8", and the bore at the spindle nose is 1 5/8", you will find its called a 4.5 morse taper. Its a modified standard MT, not sure if its MT 4, or MT 5, proberbly the thick end of MT 4.

My Taiwanese lathe has a 5 MT spindle, with a 3 MT bush, I'd hate to have to pay for MT 5 tooling! Ian S C

[Nick HopwoodParticipant @nickhopwood71702]

Many thanks for your prompt replies. Looking at the handbook again it does look as though there is a bush in the headstock. Looks like another project for the future!

[blowlampParticipant @blowlamp]

My Harrison M250 (D13 camlock spindle nose, 35mm through bore) has a reducer bush to allow a centre to be fitted.
Every reference I've seen, claims that this bush is a 5MT to 3MT, but I think it might actually be a 4.5MT to 3MT as the dimensions don't seem to marry up for a 5MT.

Your situation may be similar.

Martin.

[michael coleParticipant @michaelcole91146]

Same here with my boxford. 4.5 MT to 3MT bush in the headstock. Still availabe new from boxford.

[KWILParticipant @kwil]

Harrison M300 is MT5, tailstock is MT3

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