# ER40 Collets on a 13" South Bend Single with 1 7/8 8 TPI Spindle?



## Janderso (May 8, 2018)

Has anyone figured out a way to adapt their early Single gear box,13" South Bend Lathe with a 1 7/8 and 8TPI?
I would like to use ER40 Collets.
Bob Korves is working with me (thank you Bob) and I thought I would put this question out there for ideas. Bob thinks it's a MT4. If you have done this or know of a way, Please let me know!
Thank you.
Jeff


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## T Bredehoft (May 8, 2018)

I only have an Atlas/Clausing MK2, but I made a mounting that would hold an ER40 collet . I bought a piece of 4140, threaded one end to screw on the spindle, machined the other end to be an ER40 holder.


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## dlane (May 8, 2018)

I’m using 5c collets in my SB 10L but it has the larger spindle bore , I had Miller machine Shop make a mt3 adaptor for my spindle that can take my er40 mt3 chuck but haven’t tried it.


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## Janderso (May 8, 2018)

I'll contact Miller. I don't know if I have the skill level yet to make an adapter.


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## magicniner (May 8, 2018)

ER Collet Chucks are available for lathes, all you need then is a back plate, and to machine it to accept the chuck.
You get good through capacity that way


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## Tozguy (May 8, 2018)

Janderso said:


> I'll contact Miller. I don't know if I have the skill level yet to make an adapter.


 
I think that you might enjoy the exercise. Why not give it a try. We can coach you along.


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## jdedmon91 (May 8, 2018)

magicniner said:


> ER Collet Chucks are available for lathes, all you need then is a back plate, and to machine it to accept the chuck.
> You get good through capacity that way



Yes that’s what I did on a Grizzly, find or machine a backplate then fit the ER collet chuck to it. 


Sent from my iPad using Tapatalk


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## blaser.306 (May 9, 2018)

I made one for my King 10x22 , and if I can make one anyone can make one!!! There are plans and drawings available on " projects in metal " that are well drawn and explained through the entire operation. Some dimensions may need adjusting, but at worst it is a learning experience and an opportunity to be in the shop making chips, with the side benefit of satisfaction that every time you use it in the future knowing that you accomplished the job yourself. good luck and post pics along the way.


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## dtsh (May 9, 2018)

Janderso said:


> Has anyone figured out a way to adapt their early Single gear box,13" South Bend Lathe with a 1 7/8 and 8TPI?
> I would like to use ER40 Collets.
> Bob Korves is working with me (thank you Bob) and I thought I would put this question out there for ideas. Bob thinks it's a MT4. If you have done this or know of a way, Please let me know!
> Thank you.
> Jeff



I am in the the process of (slowly, oh so slowly) machining one to fit the spindle of my lathe, 1-7/16 12 TPI. I had considered one with a taper, but I didn't want to sacrifice the ability to chuck longer stock through the spindle and collet. In the interim, I have an ER40 block which I can chuck up when I need to use the collets (haven't actually used it that way yet). We will see how well it works when it's done (eventually).


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## Janderso (May 9, 2018)

dtsh said:


> I am in the the process of (slowly, oh so slowly) machining one to fit the spindle of my lathe, 1-7/16 12 TPI. I had considered one with a taper, but I didn't want to sacrifice the ability to chuck longer stock through the spindle and collet. In the interim, I have an ER40 block which I can chuck up when I need to use the collets (haven't actually used it that way yet). We will see how well it works when it's done (eventually).



How about some pics??


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## mksj (May 9, 2018)

Turning your own out of solid stock is doable, but takes some skill and tooling. You would be best to cut the spindle thread, mount the stock and then proceed to cut the collet taper and ER nut thread which is metric.  You also need someway to hold the chuck when unding the ER nut, I machine sume wrench flats into my ER40 chuck that I made. Alternatively you could get a back plate, mount it and then machine a registration step so you can use a set-tru mount ER chuck similar to what Alan did on his PM-1340GT.
https://www.hobby-machinist.com/threads/shars-er40-chuck-on-a-pm1340gt.68998/
http://www.shars.com/5-er40-zero-set-fine-adjustment-collet-chuck


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## dtsh (May 10, 2018)

Janderso said:


> How about some pics??



I'm taking pics as I proceed; it just takes a long while as I have precious little time to commit to projects in general and machining is but one of many facets. When it's done or at least near done; be it good, bad, or otherwise I'll make a thread about the process and what I've learned, but it's not likely to be anytime soon, unfortunately.


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## Janderso (May 24, 2018)

Da da!
Thank you Bob.
I found I have a mt4 spindle, bought a mt4 to mt3 adapter so now I can use my mt3 centers, drill chucks etc.
I found the lathe dog driver with my spindle threads on eBay. These are getting quite rare as I had but few choices.
Some people think the old dogs are worth their weight in gold.
Shoot, if I have to I’ll buy a few from Grizzly.


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## Bob Korves (May 24, 2018)

Janderso said:


> Da da!
> Thank you Bob.
> I found I have a mt4 spindle, bought a mt4 to mt3 adapter so now I can use my mt3 centers, drill chucks etc.
> I found the lathe dog driver with my spindle threads on eBay. These are getting quite rare as I had but few choices.
> ...


Glad that it works for you.  I have three mt3 reamers, but no mt4 reamers, and I have precision ground flat stones that do a great job of cleaning up burrs on mt taper OD's if you want to try to clean some of them up.  Also have Prussian blue.  We could test them for runout and fit.

I have a bunch of dogs, but they never seem to fit the job and the machine at the same time when I need to use one, so I end up making one for the job or cobbling something together to get it done.   I was going to make a dog driving plate and I have the metal and a D1-4 back plate for my lathe, but the more I thought about the design for it, the more I remembered how nothing seems to fit when I need it.  So, I am just going to make it to fit the first project that needs it, and then modify it as needed for every subsequent job...   In some ways I prefer cutting a soft center in place in a chuck and then using the chuck jaws to drive the dog.  Seems to go faster, and is inherently accurate.


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## Janderso (May 24, 2018)

I am familiar with what you are saying, using the chuck jaws to drive, it seems like a popular/efficient choice.
You would think the weight of a cast iron dog would be hard on the spindle bearings, but, this method has been used for a long time.
I look forward to using this new option on my lathe.
Thanks for everything Bob!!


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## Bob Korves (May 24, 2018)

Janderso said:


> You would think the weight of a cast iron dog would be hard on the spindle bearings, but, this method has been used for a long time.


The dog just pushes against the jaw or catch plate.  It only pushes as hard as the cutting tool does, and the dog does not normally bounce against the chuck jaw.  They just turn together, staying in contact.  The dog does not mark up the chuck jaws at all, in my experience.


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## Figor (Jul 1, 2018)

Making one for my Sheldon. Threaded the bore for the spindle and put it on to finish up.


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## Janderso (Jul 2, 2018)

I configured a draw bar for the M4 taper-ER40 Chuck.
The next thing to do is to make a backing plate for the, through hole ER40 chuck.


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## Janderso (Jul 2, 2018)

Figor said:


> Making one for my Sheldon. Threaded the bore for the spindle and put it on to finish up.


Cutting the internal 8TPI thread on the Dura-Bar is giving me night twitches. That and addition to getting it exactly centered.
Good job on the Sheldon.
I like your work light


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