What chuck for Arundel j4 junior m24x2.5 spindle?

[valius]

Good day.

So i have decided to try out wood turning. Went out and bought myself a lathe, wich happens to be arundel j4 junior. It came with two chuks....sorby precision combination chuks....but it seems I'm missing parts for them to work properly.

The question is what chuck thread size will work for me? On internet it says they threads are m24x2.5 for in er and m20x2.5 for outer spindle threads. I don't seem to be able to find those sizes in any chuks at all. Am i missing something? Maybe someone who owned this lathe has any advice?

Thank you.

 

[Jacob]

Good day.

So i have decided to try out wood turning. Went out and bought myself a lathe, wich happens to be arundel j4 junior. It came with two chuks....sorby precision combination chuks....but it seems I'm missing parts for them to work properly.

The question is what chuck thread size will work for me? On internet it says they threads are m24x2.5 for in er and m20x2.5 for outer spindle threads. I don't seem to be able to find those sizes in any chuks at all. Am i missing something? Maybe someone who owned this lathe has any advice?

Thank you.

You should be able to buy an insert to fit a larger chuck to a smaller spindle. Has to be made for the job, to screw back tight against the washer on the spindle. Try Sorby for starters.
Arundel J4 an excellent lathe. I moved up from the junior and bought the J4 "senior".

 

[Sachakins]

If you are sticking with sorby chuck try here
https://www.intertoolsonline.co.uk/...ccessories/threaded-inserts-for-patriot-chuck

 

[John Brown]

Old thread, I know, but did you ever get any definitive answer to this? My Arundel J4 has a diameter of 20.75mm and a pitch of around 2mm, and I'm completely at a loss as to what it can possibly be.

Could be M22 x 2mm, but is that a thing? And this lathe looks to be pre British metrication.

 

[J-G]

M22 would be 2.5 or 1.5mm pitch - so 'non-standard' but certainly possible to manufacture. 2mm pitch doesn't appear in the standard 'fine' series until 24mm and the cource series at 14 & 16mm.

20.75mm is very close to 13/16" (0.0044" larger) and the only 'standard' I can find for that dia. is UNEF which is 20tpi - 1.269mm pitch.

 

[John Brown]

M22 would be 2.5 or 1.5mm pitch - so 'non-standard' but certainly possible to manufacture. 2mm pitch doesn't appear in the standard 'fine' series until 24mm and the cource series at 14 & 16mm.

20.75mm is very close to 13/16" (0.0044" larger) and the only 'standard' I can find for that dia. is UNEF which is 20tpi - 1.269mm pitch.

Thanks. I don't really want to manufacture anything, just looking for a definitive answer to the thread size question, in case I ever wanted some sort of adapter for a chuck.

 

[Paul Hannaby]

In recent years, lathe manufacturers have all converged on a handful of spindle threads - perhaps because most of them are made in the far east these days. The days where each manufacturer used a different thread are long gone so you would probably need to get an adapter made or a chuck backplate threaded to suit. Bear in mind that the outboard thread is usually a left hand thread.

 

[John Brown]

Bit tricky to get anything made if I don't know the thread parameters...
I have a couple of backplates(faceplates?).

 

[John Brown]

I mistakenly assumed the OP might be able to help, hence my first post. Looking into it, it seems they joined in March and just made the one post, so I'm unlikely to get much help from that quarter.

 

[Fergie 307]

Bearing in mind they could have made it any size and thread pitch that took their fancy, so for example 13/16 by 13 tpi would be close, but weird. You would need to get a pitch gauge onto it to be sure.
Generally I would expect the thread to be smaller than the nominal diameter rather than bigger, even by such a small amount, especially on an old machine where you might expect the thread to be a little worn.
So could it perhaps have originally been 22mm and 2mm as JG says. Again a weird but perfectly possible combination, although on an old English machine I would expect an imperial rather than metric thread. Again a pitch gauge will help.
Does seem a rather odd combination however you look at it. And a finer thread than I would have expected, metal lathes of that sort of size and era typically have much coarser threads. If you know anyone with a screwcutting lathe it would be easy enough to make an experimental collar in whatever size you settle on, and see how it fits.

 

[Fergie 307]

If you can post a picture of the spindle end then I can let you know what measurements I would need, and would happily make you a collar to try out. But you would need a pitch gauge to get that correct.

 

[Fergie 307]

The alternative, and much simpler, route would be for Jacob or someone else who has one to give you the size, which of course was the point of your original post. If they have any recently made adaptors or back plates, I would have expected them to have the thread size marked on them. The other issue is the thread angle. If it turns out to be metric that's easy, 60°. If it's Imperial then still most likely to be 60, but could be 55. All good fun !

 

[Fergie 307]

Lathes.co.UK says M20x2.5 outboard and M24x2.5 inboard. So how confident are you of your 20.75, if it is M20 then the maximum outer diameter should be 19.96, a long way off. And which end of the spindle are we talking about? I assume if it's the outboard end that is a left hand thread?

 

[Fergie 307]

You might find that a local nut and bolt supplier may stock a M20x2.5 left hand nut you could try. The size and pitch are standard, just a question of whether they would have it as a leftie, depends how commonly used it is, which it might not be at all!
Worth a phone call as it would be a cheap and easy way of confirming it.

 

[John Brown]

Yes, outboard end is a left hand thread. I have faceplates for both inboard and outboard. I have two pairs of cheapo digital calipers and one pair of Mititoyo(sp?) which are pretty trustworthy. So I'm very confident about the diameter, and fairly confident about the thread pitch. Thanks for your assistance!

 

[Fergie 307]

Very odd. I can only assume someone has made a new spindle for it at some point and chosen to use a different thread, quite why anyone would do that is a mystery. Good luck getting to the bottom of it. And a happy Christmas to you and your family

 

[J-G]

With the confidence expressed in 20.75mm OD it would be unlikely to be a 22mm thread which is well 'undersize'. The Pitch dia. of a 22 x 2 ISO thread would be 20.663 - 20.70 so even a cursory viewing would show that the thread was very shallow. 13/16 is also unlikely (though not impossible) being 'oversize'.

If the maker had selected a nominal 21mm OD then 2mm pitch would be 'sensible' (?) but totally non-standard.

@John Brown has not addressed the thread 'form' yet either which may give some further evidence as to the true nature of the thread. A good image taken close-up of a very clean thread would help us to help him.

 

[John Brown]

Very odd. I can only assume someone has made a new spindle for it at some point and chosen to use a different thread, quite why anyone would do that is a mystery. Good luck getting to the bottom of it. And a happy Christmas to you and your family

Happy Christmas to you and yours too, and thanks for taking the time to reply.
The inboard and outboard face plates are original, I would guess, and it also came with a collet chuck that looks to hold a half inch diameter workpiece, and I can't see that being made to order. It is indeed mysterious.

 

[John Brown]

With the confidence expressed in 20.75mm OD it would be unlikely to be a 22mm thread which is well 'undersize'. The Pitch dia. of a 22 x 2 ISO thread would be 20.663 - 20.70 so even a cursory viewing would show that the thread was very shallow. 13/16 is also unlikely (though not impossible) being 'oversize'.

If the maker had selected a nominal 21mm OD then 2mm pitch would be 'sensible' (?) but totally non-standard.

@John Brown has not addressed the thread 'form' yet either which may give some further evidence as to the true nature of the thread. A good image taken close-up of a very clean thread would help us to help him.

I'll see if I can get a clear picture or two.

 

[okeydokey]

As you have faceplates see if you have an engineering workshop near you such as the following which appears to be near you
https://luneengineering.co.uk/gloucestershire/stinchcombe.htmPop in with them and I'm sure they will measure for you, Ive found that with a friendly smile most everywhere will help.