# ER collets in South Bend lathe



## Mosey (May 9, 2012)

Decided to get some ER 32 collets for my 10K lathe, which has an MT3 spindle. What kind of drawbar should I use? Some ER's are available with 1/2" thread on an MT# shank. Is that the best I can do?


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## pete (May 9, 2012)

Mosey,
If it were me? I actualy wouldn't go with that type of chuck. It's then only good for short pieces. Personaly I think a piece of steel screwed, or camlocked to fit your lathe's spindle nose is a better system. And then just cut the ER internal taper and the threads for the ER nut. That's probably a much more usable setup.

And to even get good accuracy with a MT type collet chuck, You'd need to spotlessly clean your lathes internal taper every single time before using that type of chuck also.

Pete


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## techonehundred (May 9, 2012)

I built my own. Just bought a nut and made the taper to fit. I went with er 40, because I have a 2 1/4" threaded spindle. here is the 
thread.
http://www.homemodelenginemachinist.com/index.php?topic=17925.msg184976#msg184976


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## Mosey (May 9, 2012)

Maybe I should say that I have no capacity for metric threading, so I want to buy a holder with a thread that I can make for a drawbar. Hopefully, I can get some through hole into or even though the drawbar. So, if the through hole is no bigger than what I have now (5/8") why don't I just get an ER 25 x MT3 holder, and use the ER 25 collets I already have on the mill? Or, get an ER 32 x MT3 holder, new collets, and take advantage of the extra size for short workpieces that can't go all the way through the holder? Or, is there an ER holder that screws onto the 1-1/2" x 8tpi spindle?
Sorry for being so confusing.


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## pete (May 9, 2012)

Mosey,
There are a few dealers around for the type Of collet chucks I mentioned. It may require a threaded backplate to fit your lathe. Due to a few newer accesories coming out, I kind of wish I had gone with the ER-32's instead of the ER- 40's I did go with.

Pete


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## moconnor (May 9, 2012)

Hi Mosey,

Arc Euro Trade has a backplate mounted type of ER-25 and ER-32 collet chuck. See this page: http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks

They are great to deal with and every order that I have purchased from them arrived very quickly.

This type of collet chuck mounting will allow you the full 5/8" through you spindle and because you mount it just like a plain-back chuck where you must machine the register diameter in-situ on your lathe spindle, you can expect very good accuracy. However, it wouldn't be difficult to incorporate an 'adjust-tru' feature into the backplate if the T.I.R. when mounted isn't up to your expectations.

Regards,
Mike


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## Mosey (May 9, 2012)

So, what must I do, machine an adaptor plate to fit my spindle, and then bolt the ER plate to it? Then the issue would be that I must get the 2 plates accurately positioned on the spindle, correct?


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## pete (May 9, 2012)

Mosey,
You should be able to buy prethreaded chuck backplates. Just thread it onto your lathes spindle, Machine the backplate to fit the collet chuck. Then just bolt the two parts togeather. Since I don't own a South Bend lathe, I just can't be more specific on what you'll need. I'd buy the collet chuck first and go from there as far as what size of semi machined backplate you'd need.

Pete


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## Mosey (May 9, 2012)

Got it, thanks. I'm off to find a chuck in the USA.


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## pete (May 9, 2012)

Maybe try Tools4cheap? For some reason I'm thinking they sell them. I'd swear I saw them on their website last year anyway.

Pete


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## moconnor (May 9, 2012)

Hi Mosey,

Pete is spot-on. Tools4Cheap has them.

http://www.tools4cheap.net/proddetail.php?prod=er32plate

Regards,
Mike


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## Blogwitch (May 9, 2012)

Mosey,

This is how I made the drawbar for when I converted my lathe to a Myford nose instead of the D1-4, which allowed me to make and use Myford chucks and fittings on both lathe and mill.

http://madmodder.net/index.php?topic=1993.msg20641#msg20641

And if you do find a way to cut metric threads, this is how to make an ER 32 collet holder.

http://madmodder.net/index.php?topic=2249.msg23587#msg23587


John


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## Mosey (May 9, 2012)

I'm speechless at this incredible work! I'll go back to my humble beginner stuff sand keep chugging away. I hope to make a backplate, and to fit the new collet chuck to it, and get them all clocked in to something like accuracy.
Thanks for the ride.
Mosey


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## Paulsv (May 9, 2012)

If you have a threaded spindle nose, you can get an ER32 chuck that threads on to the spindle, such as this:

http://www.bealltool.com/products/turning/colletchuck.php


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## Mosey (May 9, 2012)

Wonderful source for collet chuck. It's ordered and saved me all of the work making backing plates, etc.


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## steamer (May 13, 2012)

To quote one of our most esteemed members

",,,,,,Are you laboring under the grave misconception that you can do this without showing us the pictures??? Get serious, man!......"

 :hDe: ;D


Dave


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## lazylathe (May 13, 2012)

Mosey,

Did you order the Beall collet chuck and collets?
Would love to know how they work out, their products are very highly regarded in the woodwork side of things.

Andrew


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## Mosey (May 13, 2012)

Yes, and they will be on the brown truck Monday. I will let you know how they perform.
The collet set is waiting patiently on my bench. They will also be evaluated.
I bet I'm more impatient than you!


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## Mosey (May 14, 2012)

Boo Hoo.
Brown truck arrived with the collet chuck. Chucked it up after carefull cleaning of spindle threads. Spindle TIR .0002 max. Chuck exterior TIR .007". Cone inside where collet seats .006". 1/2" ground test bar at nose of collet .006" Chuck person says the will either find one with better runout (.oo3"?) or refund $.
We'll see.


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## Blogwitch (May 14, 2012)

Mosey,

For a collet chuck, 0.003" is way too much runout, it has to be at most a tenth of that figure otherwise it is not worth fitting, you can get better results using your normal 3 jaw.

There is really only two ways to go about it to achieve the required accuracy, and I have used both methods.

The first is to attack a commercial one like you have already bought with an internal toolpost grinder, and true up the taper whilst it is fitted to your spindle. I have done this with four of my own 5C collet chucks and two ER collet chucks for friends who own Myford lathes that had the same problem as yourself with commercial units (I can convert my lathe to a perfect running Myford nose rather than the D1-4 that it normally is). 
I would not recommend trying to true up the taper with tungsten tooling because so little has to be removed, you could almost guarantee that the taper would get buggered up trying to do it, grinding is really the only way.

The second method is what I have already shown you, make your own. 

You say that you can't do metric threads on your machine, but I will bet you that you can. With combinations of change wheels, you will be able to cut metric threads close and good enough to use for this job. I used to do it all the time on my old all imperial Atlas 10F, it's operating manual came with all the threading charts in there for doing pseudo metric. You just need to be able to screwcut by the permanently closed half nuts method.


John

PS, have a look at my signature line, I swear by it.


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## Mosey (May 15, 2012)

Bog,
You are correct on all counts, of course.
I don't have the metric gears as yet, and someday, maybe. I know the method of cutting them, just haven't done it.
If the chuck maker thinks that .003" runout is acceptable, I should cancel the order and return what he sent, as this is not good enough.
I have no grinding capacity either, but as a small-time hobbiest, I am happy to buy these things instead, provided they are of sufficient quality. I wonder if a Dremel in the toolpost would do the job? Not very rigid or precise. And I risk ruining what I have. Likely.
Thanks for your thoughts.
Best solution me thinks, is to buy better quality stuff, though I haven't seen it offered, and the quality USA guys don't appear to have it. 
How about the 2 plate method? Buy a small face plate to fit the SB. Buy an ER 32 collet plate from anyone. Bolt the 2 together with alignment by me using the indicator.
Mosey


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## lazylathe (May 15, 2012)

Thanks for the update Mosey!

Like i said earlier these are better known on the woodworking world.
0.003 run-out is nothing to worry about when making wooden pens.
As for metal working it is way too much.

Any ideas on what you are going to do?

Andrew


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## Mosey (May 15, 2012)

Yes, the Beall is going back. If they can furnish one with <.001" TIR, then I will accept that. Otherwise, I will keep looking, either for a 2 plate assembly, or an affordable USA one. Keep you posted.
Bog, Are you aware that SB shows a metric 4 disk threading dial in their old catalog? Has anyone ever seen one? Couldn't I make one?
Mosey


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## arnoldb (May 15, 2012)

> Bog, Are you aware that SB shows a metric 4 disk threading dial in their old catalog? Has anyone ever seen one? Couldn't I make one?


Hi Mosey. The metric threading dial is for use on a metric pitch leadscrew, so unless you replace your leadscrew with a metric one, it would be a worthless exercise to make the threading dial. It's not the dial that determines whether you can cut metric threads; it's the ratio of the change gears and pitch of leadscrew that determines that. I screw-cut metric threads often on my non-metric lathe; this is done by simply selecting a ratio for the change gears that closely approximates the metric pitch needed.

Kind regards, Arnold


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## Mosey (May 15, 2012)

Your'e right! I jumped the gun.
Now I just need a metric lat...........


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## Blogwitch (May 15, 2012)

Mosey,

I do have to apologise for taking tooling as a normal possession, I have been collecting now for over 40 years, so can cover almost any eventuality, it just totally slipped my mind at this time as I wanted to help you so much.

I have seen people use Dremel tools for grinding tapers such as this. It would entail making a decent rigid two position holder for it, but once done, it would be a tool for life, whenever needed.

As for cutting metric threads on your imperial lathe. I only ever had one extra gear for doing metric, and I think that was a 63 tooth one, I know I didn't buy any extras from the normal set that came with my machine, so the previous owner must have bought it. If you have a full set of change gears, then at least some metric pitches should be easily within your reach. For a thread length to fit the ER collet nut, I reckon your pitch could be around 1 or 2% out, and the nut would still fit. But usually when cut on an imperial machine, they are only fractions of a % out.

I don't have any charts for your lathe, but I am sure there must be a member on here that can let you have a copy of their metric threading charts for your lathe. In fact, I think Marv has a program that will do the calcs for you.

BTW, I have a metric machine, so I have to do the same sort of thing for imperial, on the other hand, I do have a true conversion gear that gives me exact imperial, but I still have to do it with the half nuts closed. In fact I do my metric the same way, I find it a lot easier than a drop in dial when using a swing up toolholder.


John


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## arnoldb (May 15, 2012)

> Your'e right! I jumped the gun.
> Now I just need a metric lat...........


  Mosey, no need to get a metric lathe. From what I've observed you will most likely usually work in imperial, so it might be better for you to stay with the imperial lathe.
What lathe do you have, and what change wheels do you have available for it, or do you have a quick-change gearbox on the lathe ?
Given that information and the lathe's leadscrew pitch, I'm sure the members can come up with an idea for you to cut a close-enough 1.5mm pitch metric thread for the closer nut. The threads for the closer nut does not need not be super accurate; it's the taper in the chuck that provides the accuracy. If you have a single-point threading bit, you can use that, as being from the US, it will already be 60o.

I didn't respond earlier with a link to my own collet chuck build, as the ones presented give a lot more detail. But if you're interested, here is mine. I built that when I was a lot more inexperienced than I am now, so it was right at the limits of my capability - if not over those. There was a bit of heartache in that build, but the finished chuck has much more than made up for it; I use it nearly every shop session and it was worth every bit of effort. As it was built on my lathe for my lathe, it's much more accurate than a purchased one will be.

 ;D Well, John beat me to the reply - but I wasn't going to throw away a lot of typing. What John Said Thm:

Kind regards, Arnold


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## mklotz (May 15, 2012)

> As for cutting metric threads on your imperial lathe. I only ever had one extra gear for doing metric, and I think that was a 63 tooth one, I know I didn't buy any extras from the normal set that came with my machine, so the previous owner must have bought it. If you have a full set of change gears, then at least some metric pitches should be easily within your reach. For a thread length to fit the ER collet nut, I reckon your pitch could be around 1 or 2% out, and the nut would still fit. But usually when cut on an imperial machine, they are only fractions of a % out.



You probably have a 63 tooth gear because

80/63 = 1.2698... [only -0.0125% error relative to 1.27 = 2.54/2]

It's one of the best approximations to this value using only two gears.



> I don't have any charts for your lathe, but I am sure there must be a member on here that can let you have a copy of their metric threading charts for your lathe. In fact, I think Marv has a program that will do the calcs for you.



The GEARFIND archive on my page contains several programs that allow one to find gear trains that yield high accuracy approximations to any input ratio. The 80/63 result above comes from one of those programs.


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## Mosey (May 15, 2012)

You guys are just great!
I will take awhile to digest all of this important intellligencee.
I do not have any metric change gears, but will get some in the nearside, as my lathe has a QC gearbox. I suppose I could make the gears also.
I do have a rather complete SB library of metric threading, parts. accessories, etc., so I am steady in that area.
I have cut one metric thread, approximated, but it was a fine buttress thread, and it was junk. I will try again. I have an ongoing need for metric buttress threads to make collet devices for my F1.
What I am doing right now is buying a threaded backplate, to which I will mount a proper collet chuck to it.
I did think of something else...why not make an Imperial chuck nut and collet holder? As long as the internal taper is done right for the collet, why wouldn't an imperial nut (which I can cut easily) be just fine? I can harden it also.

Marv, thanks for the program.

Not to pollute this thread, but I am smiling from ear to ear today. I re-leveled my lathe and adjusted the tailstock setover. Made a test bar 6" long with no more than a couple of thou. taper. Then made a new crank bearing that has 0.00 measured taper from end to end. I did it in an unorthodox way. I took a pass the length of the bar. Measured the taper. set the tailstock over 1/2, and re-ran the length of it until I got it on the money. That little Last Word indicator didn't even shimmy as it went the length of the bar. I'm happy.




Mosey


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## pete (May 15, 2012)

Mosey,
I doubt there's all that many here that could or are at least setup with the equipment to make a proper collet nut. Since the collets get snapped into and out of the nut. Your looking at some pretty tight tollerances on a hardened blank nut including eccentric grinding, taper grinding to fit the very end of the collet, And even the internal threads appear to be thread ground on my Bison nut. It's not an impossible job, Just very difficult. A pretty high end and rigid toolpost grinder along with a lot of practiced skill would be needed also. 

Pete


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## Mosey (May 15, 2012)

Whoops! Of course. If it were easy, the cheap ones would be accurate. But they are not.


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## pete (May 15, 2012)

Yep, And there's even more complicated ones than the standard type too. A internal ring of Ball bearings inside the collet nut. I haven't used one ................yet. But they really help with getting the nut tight enough. ER-40s for example take at least 80 plus ft. lbs on the nut for proper tightness. Around $80-$100 just for the nut. 

Pete


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## Paulsv (May 15, 2012)

You might give these folks a call, and ask what kind of runout they will guarantee. A bit spendy, but I have heard they do pretty good work.

http://shop.tallgrasstools.com/product.sc?productId=15


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## Mosey (May 15, 2012)

Spendy, right. I'm waiting for their email response.


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## steamer (May 15, 2012)

How about 47/37?

1.27027....not quite as good, but it works just fine on my lathe.

I have extra 16 dp gears cut this way...but I think the SB is 18 dp


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## Mosey (May 15, 2012)

From the factory parts list, 12/1995


The Quick Change Metric Transposing gear set furnished for a SB 10k with gear box included the following gears:
Metric Transposing Gear 27 and 100

Change gears 
48
44
36
32
28
26 teeth.

Plus charts, index plate, etc.

So how does this relate to the ratios mentioned?

Well, I think that they meant 100/127 gear pair, not 100/27, even though that is exactly what their brochure says.


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## steamer (May 15, 2012)

The only problem is the physical size of the gears.  A 100/127 combination is an exact match (1.270000) .   For a thread that usually never exceeds an inch in length....OK 25.4mm length....the error is so small as to usually be ignored

A 47/37 will fit in the gear guard, and has a ratio of 1.27027 or put another way, it has an error of .00027mm per revolution of the leadscrew

.00027 mm is .0000106" per revolution of the leadscrew or about 11 millionths of an inch/rev..........I don't know about you but I can measure that lead error...... period!

I can bet you that your threading tool has way more form error than that.

Dave


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## Mosey (May 17, 2012)

ALERT! ALERT!
Chronos has them but cannot give runout figure. XXXX not interested.

RDG Tools has them. Waiting for runout figures.

Tools4cheap has the adaptor plate and holder style, bolt the 2 together. If single holder doesn't pan out, I will go this way.


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## Mosey (May 25, 2012)

I received the backing plate and ER 32 collet holder today from Tools4cheap. Very quick response. The collet holder is pretty nice, and the backing plate is a nice, fine-grained cast iron. I machined the hub on the backing plate to fit the holder with a tiny amount of play for adjustment. Mounted the holder, and tapped it into alignment. It now has a couple of ten-thousands of runout inside the collet cone. That is OK for a unit that cost $125.00. Now, stop the BS, and make things.


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## steamer (May 25, 2012)

Glad it worked out of you Mosey!

I turned my Bison 5C into an adjust true in a similar way that you did yours and have been glad that I did it.

Dave


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## Mosey (May 25, 2012)

Dave,
There is a nice Aciera F5 on Ebay for yah! I think it would really fill out your shop.
Mosey


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## steamer (May 25, 2012)

How many billions? 8)


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## steamer (May 25, 2012)

13500.   Are you serious!

Not in my budget!


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## Mosey (May 25, 2012)

I only passed it up because of the lousy paint job! I wonder what they are hiding.


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## steamer (May 25, 2012)

:big:


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## abby (May 26, 2012)

My most loved and most used machine is my BCA jig borer , it was built in 1940 and is some years older than me , but still produces very accurate work.
It is , however , limited by the difficulty in obtaining collets , I have a small range of imperial sizes including 1/4" which covers most end mills upto that size but metric ? no chance !
I decided an ER20 collet chuck was the way to go and made this







I decided on the ER20M (mini) nut which gives a bit more clearance and bought the collets , nut and spanner from Cutwell tools.com.
I can now hold metric cutters and imperial with upto 1/2" shanks !
A very useful addition and well worth the effort.


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## Mosey (May 26, 2012)

very nicely done


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## lazylathe (May 26, 2012)

th_wwp

No pictures it never happened Mosey!!!
You should know the drill by now! ;D

Andrew


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## Mosey (May 26, 2012)

Yeah, I know. I thought I might sneak one by.
I can't remember how to get something video onto Utube and then over to here. Any help?
This one shows cutting back the cast iron backplate to make a true register for the holder, which bolts on.


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## lazylathe (May 26, 2012)

The easiest way is to upload it to youtube and once completed there is a box named "Share"
If you click the box it will expand and give you a link, just right click the link and copy it and then past it into your reply here.

Easy as pie!

Andrew


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## Mosey (May 26, 2012)

and here are some more....
these show the total runout after tapping into alignment...about .0004"
The 2 indicator views are the min and max readings when rotating the holder through 360 degrees.


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## iggy (Oct 20, 2019)

I will like to make one for my old S.B. 10K lathe, attached to a backplate with 2 1/4 - 8 thd


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