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South Bend 9 inexpensive collets: half solved spindle puzzle and a question...

atreder

Plastic
Joined
Jun 29, 2017
OK,
in the desperate search for a cost effective, simple solution to getting "collet" and "South Bend 9 C" in the same sentence I have stumbled across these 2 solutions, both based on ER32 collets which are now very inexpensive:
- Search for "100MM DIAMETER ER-32 COLLET CHUCK " on eBay and you find a backplate mounting chuck. So for under $100 / £100 you get one of these and a backplate, some simple fitting and you are done. Much neater and less expensive than one of those big chucks with the integral draw system;
- Searching for the SB9 spindle taper, I have discovered that it's almost certainly a Morse B24 taper, the same taper angle as MT3 but one "size" bigger, as if it continued from the larger end of the MT3. Check it on Wikipedia. These are used for arbors, like a Jacobs taper.

So, if I could find a B24 - MT2 / Mt3 sleeve I could get a simple, inexpensive, widely available MT2/3 - ER32 collet system... But they don't seem to exist, only arbors, sigh...

BUT, if the B24 is just 2 mm larger in diameter than MT3 why not turn a sleeve? Painful to set up the taper of course...
BUT (my quest for a quick fix continues) what about a sheet of 1mm steel sheet wrapped round an MT3 taper (trimmed to a truncated cone of course), that would take it dimensionally up to a B24?

I don't have any MT3 tools, I need to buy sleeve and give it a try...

Meanwhile, reactions? Improvements?
 
OK,
in the desperate search for a cost effective, simple solution to getting "collet" and "South Bend 9 C" in the same sentence
.
.
BUT (my quest for a quick fix continues) what about a sheet of 1mm steel sheet wrapped round an MT3 taper (trimmed to a truncated cone of course), that would take it dimensionally up to a B24?

I don't have any MT3 tools, I need to buy sleeve and give it a try...

Meanwhile, reactions? Improvements?

First off . .JF FORGET the s**t-sheet shim! Taper is nowhere near "painful" if you have a lathe.

My first few had to be done with files on a Walker-Turner Drillpress to get the LSO (and the DP) into more useful order.

Secondly.. ER is not the only "nose mount" out there, and nose-mounts can carry collets waay larger than the spindle bore. bar-stock is still limited to bore. Pre-sawed slugs or repair work not so much.

Downside is greater hang-out, using up a ration of longitudinal c-to-c daylight as well.

ISTR the "native" SB 9" is a 3C? Even so, you might be better-served with a 5C key-cranker. Lot easier to find internal expanding, hex, and square, collets than for ER system.

Disclosure: I have 5C, 5C step, 2J, ER40, ER20, Rubber-Flex 9XX, and Multisize. D1-3 mount. "Nose actuated", loop/lever, handwheel, key, or wrench closers, every one of them - no drawtubes atall.

YOUR "first one" should be either 3C, (or wotever..) and ignorant handwheel drawtube like most other SB 9, ELSE 5C, nose-cranker.

ER 32 means the shortest slug it wants to hold well needs to be 32 mm long in collet, and not much less. They were meant for TOOL SHANK holding, after all. Not workpiece holding.
 
ER 32 means the shortest slug it wants to hold well needs to be 32 mm long in collet, and not much less. They were meant for TOOL SHANK holding, after all. Not workpiece holding.

ER sucks on the lathe, IMO, and I use it on my mills, just not on the lathe.

The 5C is certainly one of the best as it's common. I consider the 6R I use very similar in style to a 5C, but not nearly as easy to find as 5C and very hard to find squares and hexes.
 
ER sucks on the lathe, IMO, and I use it on my mills, just not on the lathe.
I'm set up to use ER 40 or ER 20 EVERYWHERE (their range overlaps. Just barely).

Lathes, mills, DH, rotab, bench workholding.. Alzmetall AB5/S DP included .. but..
...only as a last choice.

I'm set-up NOWHERE with ER as a "primary" solution.

CNC shop with toolchanger magazines to fill? Not MY bag, but would surely be t'otherway 'round, and perhaps TG over ER, even so.
 
There's always a deep insight to be found somewhere, so thanks!
a) I had not considered that the design of the ER collets dictates the length held, which is obvious once pointed out!
b) My 9C does indeed take 3C collets, which are rare as hen's teeth (especially in UK), and drawbars hard to find, which is why I was looking at nose jobs;
c) I "grew up" using W20 collets on my father's Simonet lathe. He was a precision toolmaker and barely used 3 jaw chucks (or power feed, come to that.) So 5C will feel like "home".
So 5C Nose-cranker it is then, with a 1-30mm (1mm step) set of collets, plus a backplate... Will cost 50% more than what I paid for the lathe! Ha ha.

Thanks again.
 
I use an ER40 /MT3 adapter (with oversize collets up to 1-3/16") as well as a Jacobs Model 50 in the spindle for most of my work. Jacobs allows for through-spindle, but rarely need that as I'm usually just holding small parts or the end of the work so the MT3 holder works just fine for me on my 9A.

Oversize ER40'S:
ER4 Collets Individual Metric and Imperial Sizes - MariTool
 
... 5C will feel like "home".
So 5C Nose-cranker it is then, with a 1-30mm (1mm step) set of collets, plus a backplate... Will cost 50% more than what I paid for the lathe! Ha ha.

Thanks again.

1 mm or even roughly half that - 1/64" steps - in 5C are useful only so long as your stock FITS closely. Fortunately, it most often DOES, as spring collets usually have a seriously narrow effective clamping range.

Stock "extras" in finer granulation only for the sizes you actual WORK with. Many sizes in a set never get used ONCE in 20 years and more, but still - one needs a set or two.

Buying 1/32's, AND 1/16ths, AND 1/8ths as 'sets' was a cheap way to get duplicates/spares on the more common sizes. Even just 3/4" holds several of my straight-shank tools, one of the "mm" size holds another lot, so those get "extras" bought loose.

Also get yerself some "emergency" collets, snap up second-hand ones in steel, brass, even Nylon. Used collets are otherwise a dice-roll I try hard to avoid.

And don't be too shy as to DIY split-sleeving-down a larger 5C down now and then, either.

Useful enough, 5C can be, but they need YOUR help sometimes to deliver a good grip.
 
Yes, I realise that these collets have a very limited clamping range but that's less of an issue for me due the differing philosophy of a toolmaker (which my father was) and a machinist (which I have no need to be!)
Basically it was very rare that he put stock material in a collet to make the piece. First he would put it in either a 3 jaw chuck or the nearest collet that could be induced to grip. He would then machine the end to a precise dimension and then reverse it into the right collet. Precision was more important than speed.
Me, I just prefer collets, they make the machine look nicer (though not these nose job devices!)
But first, I need to finish the repainting job, stripping the bed today!
 
I realize that this is an older thread but could you tell me the designation of this lathe? I recently bought one which I think is identical 2780 YB on the tag with a serial #51889 which puts it around 1933?
Thanks.
Time to start my own thread...
 








 
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