Colchester Headstock Sleeve

My Student 1800 was missing the oft misplaced tapered Headstock bush for turning between centres. I bought one off ebay a few years back and popped it on a shelf.......came to use it today and of course it’s the wrong size .

Questions are.

A- Does anyone have the correct one lying around they wish to sell? Or know where i might obtain one.

B- Any idea’s what the one i have is off. Dimensions are 1.622” at the fat end. 1.500” at the thin end. 2.490” Long. With a 3mt oil upt middle.

There are a few on ebay, but at least two which are advertised for my machine, clearly are not, so i’m a bit wary, twice bitten and all that.

The hole in my headstock measures 1.766”,bit awkward to measure the far end hole, but approx 1.675” with the bush being around the same length as the one i have.

Now here's a knotty little riddle.

My Bantam 2 has a bastard size taper up the head stock, which is rumoured to be MT4.5, or some such. It seems Mr Colchester didn't want us buying standard fittings so he made the head stock a funny size, though it may be something to do with the size of the bearings carrying the head stock. Mr Lathes.co.uk has got some comments thereon.

Anyway I'd have assumed that your Student was the same, but it can't be. I made a bush for my Bantam, but it's 1.517 - 1.362 by 3.07 ins long.

However, when I bought the lathe I was given what was supposed to be the "right" bush, which is much too large. Squirrel that I am I've kept it, and it is 1.809 - 1.656 x 3.036 long. All these dimensions measured with calipers, so somewhere handy but not precise. While those dimensions aren't exactly what you've shown above, they look something useful.

You are welcome to try the second bush and see if it is what you are looking for, send me a PM with your address and advise so on here and I'll pop it in the post next week.

Hope this works! Rgds Simon

That’s very kind of you Simon. Interestingly the dimensions you have given are remarkably close to one on ebay. I suppose the slightly larger fat end could account for the bush sticking out a bit. Will drop you a PM.

When I had a Chipmaster with the taper thing missing I convinced myself it was Jarno, which is as

**LINK**

Doesn't help you in finding one of course, but I never needed one, for between centres just chuck a bit of bar i the 3 jaw and turn a point on it

It sounds like it might be the 'thin end' of an MT5 taper. 1.5" is the fat end of MT4.5 so it can't be that.

This thread suggests the Student has an MT5 taper: /www.model-engineer.co.uk/forums/postings.asp?th=104715

If that's the case you just need an MT5 to MT3 reducing sleeve - or an MT5 centre.

Neil

Yes, it's 4.5MT. It's fairly common, as the Boxford X10 series lathes (280, 330, etc) with the D1-3" camlock have them, as well as the Chipmaster and Bantam lathes. I don't think the Harrison D1-3" camlock lathes are like that.

I suppose the thinking was that 4MT was too restricting and 5MT too big for the spindle.

Good call Neil, just tried a 5mt -1mt reducing sleeve i had lying about and it seems to fit perfectly. No good for my purposes, but proves a point. 👍

The thanks are due to Les Jones 1

Hi Alan

My lathe did not come with spindle taper plugs

I made two, one Morse and one NC taper at the same time. I did not use a chuck or centres.

I posted posted the method here here a while back.

**LINK**

Regards
John

Alan - I've sent you a PM.

Rgds Simon

Just to update this thread, Simon kindly sent me the bush he had, and it fitted perfectly. (Thanks Simon)The taper is indeed 5mt, but the fat end is larger than a drill sleeve so it sticks out of the headstock a little way.

I therefore have a bush going spare. (My ebay purchase)

So if anyone can identify it, and make use of it, the same deal as Simon did for me will apply.

Let me know your address and i will post out at my cost.

If it suits your needs, you make a minimum donation to charity of £10

If it does not fit, you return to me, or someone else who’s machine it may fit.

These tend to be advertised between £30 and £70 on ebay

Edited By Alan Waddington 2 on 31/08/2018 14:12:17

Hi Alan, have you still got the bush, my Harrison is reported to be 41/2 MT

thanks

Richard

Hi Richard, yes still on a shelf, PM me your address and i will send it to you.

Without drawing it up in CAD your adapter sound awfully close to #13 Jarno taper.

There are three different bush sizes referred to in this thread, which one are you referring to?

Alan sent pm

Jarno tapers all have the same taper, 2 degrees 15 minutes.

A 5MT / 3MT sleeve should be available from someone like Warco or Chester, since the BH600 and Craftsman are 5MT Mandrels, and came with a sleeve. Possibly, some of their successors did as well.

Howard

Are you sure? I'm no Rachel Riley but I get 2.8664 degrees included angle.

Peter!

Quite right

Taper according to Engineers Edge is 1;20 which I make 2.8624052 degrees (2 degrees 51.44314 minutes)

Shouldn't have relied on my memory, from the last time that I turned one!

Howard