Runout between machines

[Tuba Dave]

I have two lathes with the same spindle nose thread, a Maximat7 and a Logan 1825. I would like to use ER collets on them, as I have a lot of them for the milling machine and they would be useful for the work that I do. Before I buy a collet chuck, will I be able to move it from one machine to another, with the part still in the collet, and expect reasonable concentricity between the two lathes?

The next option would be a through the spindle system like 5C or something like that. I assume this would be pretty repeatable, but would also require purchasing all new collets and fixtures, which is a quantum leap in the price tag.

I know I could test it out with gage pins, but I am just collecting info before purchasing anything. Right now I only have an ER collet chuck for the milling head of the Maximat, which is MT2. The lathes are MT3.

Thanks for your help.

 

[Firebrick43]

I highly doubt that they would be concentric to each other, which is why the backing plate of a chuck on an external thread spindle is always recommended to be final machined installed on the lathe it will be used on. If they do end up concentric it would be a fluke.

How about an ER40 collet chuck mounted on a 5c shank?

ER40 chuck

I make no assurances if that brand is a good one or not, it was just to illustrate what is available. Of course you loose thru spindle ability for long objects.

 

[markba633csi]

I would never have guessed those two machines have the same spindle thread
I expect you wouldn't be able to move between them; why would you need to?

 

[Tuba Dave]

I would never have guessed those two machines have the same spindle thread
I expect you wouldn't be able to move between them; why would you need to?

They are both 1 1/2 - 8 . Convenient to not need multiple chucks, etc.

The Maximat is very precise, but has nylon and phenolic gears, as well as aluminum shear pins and don't ask me how I know that. The Logan is much beefier and has a longer between center dimension, but has a badly scarred spindle taper and I have not yet overhauled the gibs, etc to make it more rigid. (I won't have a free week or so from work until this fall) Until I can tear it down and rebuild it, I trust the Maximat for closer tolerances, but not for heavy duty. Plus, the Logan has a QC gearbox (woohoo!)

I just got the Logan this winter (it was free!) and am still finding ways to work it into my shop. This question is more exploratory right now, but it would be good to know what realistic expectations I should have.

 

[stupoty]

Are you trying to put it in the taper or mount it on the flange so you can put work through the chuck?

Stu

ER32 Lathe Collet Chucks - Arc Euro Trade

ER32 Lathe Collet Chucks: will fit any lathe with a suitable spindle flange or backplate. They are ideal for SC2 & SC3 mini-lathes and larger SC4 and SC6 lathes

www.arceurotrade.co.uk

 

[Jim F]

I would put a 3 jaw on the Logan and a 4 jaw om the Maxi.

 

[Jimsehr]

Your Logan will not take a 5c collet thru the spindle. My Logan lathes will and I often use 5c collets and emergency collets and expanding collets and 5c step collets on 11 inch Logan Lathe then move collet and part to the mill or drill press for next operation. But you need indexing fixtures that take 5c collets to do that.
You could use a 5c collet chuck to do the same.
Don’t know if ER collets have indexing fixtures like that.
It’s nice to change from lathe to mill and have parts run true.

 

[stupoty]

Your Logan will not take a 5c collet thru the spindle. My Logan lathes will and I often use 5c collets and emergency collets and expanding collets and 5c step collets on 11 inch Logan Lathe then move collet and part to the mill or drill press for next operation. But you need indexing fixtures that take 5c collets to do that.
You could use a 5c collet chuck to do the same.
Don’t know if ER collets have indexing fixtures like that.
It’s nice to change from lathe to mill and have parts run true.

ER collet blocks are a thing, they can be very handy.

Stevenson's ER32 Collet Blocks - Arc Euro Trade

Square and hexagonal ER32 collet blocks. Accurately ground faces on all 4/6 sides. Accurately ground back face so the blocks may be used standing upright.

www.arceurotrade.co.uk