[HELP] What's mt taper?

[Andy T]

Hi all, the headstock spindle of my lathe has a taper in it. MT3 is to small & MT4 is to big. Any idears what it could be ?
Drawing not to scale and measurements + - 0.005 ish
   

[awemawson]

Name the lathe.

Or go to Tony Griffith's site lathes.co.uk and see the spec for your lathe

[Andy T]

(06-06-2017, 03:34 AM)awemawson Wrote: Name the lathe.

Or go to Tony Griffith's site lathes.co.uk and see the spec for your lathe

It's a Turnell & Odell lathe, and a guess at the age is around 1920's but could be 1940's as Turnell & Odell made alott of munitions equipment in WW2
   

[awemawson]

Very unusual for Tony not to have it listed. Could that name be a distributor rather than the maker. Send Tony some clear pictures and get his comments, he is very well informed re: lathes

[awemawson]

Or you could speak to the makers !!!!!!

http://toengineering.co.uk/contact-us/

[Mayhem]

Nice bit of detective work Andrew!

[Andy T]

I've had a chat with Tony from Lathes.co.uk today and he thinks it could be a 3 1/2 morse taper or some other eaven a possible a one off, He's now included this lathe on his site and I'm providing all information I have.
I've sent 2 emails to Turnell & Odell some weeks back to two different departments without reply, perhaps a simple phone call will be the way to go.
I had looked on Wikipedia and read that there was only one 1/2 morse taper and that was the 4 1/2 but then again I don't think all info on that site is 100% accurate.
So, still lost with this taper but hope someone will have some Idea in the future. Thanks Andrew & Mayhem for your comments :)

[awemawson]

Googling "Turnell & Odell" and Lathe came up on the second page of findings with a page from I think an in house publication showing one of their very early lathes.

I see that there is an Odell still as Managing Director, so he's the one I'd target for information as it's also his family history.

I did wonder if it was a Jarno or B&S taper, but your measurements don't tie up with either, so it may well be a custom one. I've not done the maths, but does it work out to be whole degrees or perhaps a recognisable fraction of an inch per inch or foot ? Don't rule out metric measurements even though it's an earlish English lathe.

(Tapers less than 7 degrees 'lock' and need a clout to release, whereas those greater than 7 degree self release)

[texx]

most likely a morse 3.5 ...yes some machinery did use this size .i think Sebastian 16x60 lathe maybe one of them . mate has a lathe that is 4.5 and a pain to find stuff for .

[Roadracer_Al]

A pragmatic solution is to either build a new spindle (as a benchtop lathe, the spindle shouldn't be very big) with a common taper whilst preserving the original spindle for posterity, or to have the original spindle bored by a cnc shop to a more common taper.

OR... just had a thought. Speaking of CNC shops, you could pay someone to whip up a few spindle taper adaptors, if not a dozen or more blank shanks which can be adapted to whatever use further down the road. And you'd get them out of whatever material you want such as 4140.