ER40 vs 5C on 10L with 1 7/8" Spindle

I have a 1939 10H,with the small spindle, 1 7/8"x8. I am pleased with my ER40/32 Collets with an MT3 holder. Why should I have 5C collet envy? Not being facetious, but I don't understand why many owners here with a small spindle convert to larger spindle just so they can use 5C collets? They are way more expensive so why are they better? Maybe easier/quicker to load?

Vandegraaff said:

I have a 1939 10H,with the small spindle, 1 7/8"x8. I am pleased with my ER40/32 Collets with an MT3 holder. Why should I have 5C collet envy? Not being facetious, but I don't understand why many owners here with a small spindle convert to larger spindle just so they can use 5C collets? They are way more expensive so why are they better? Maybe easier/quicker to load?

Click to expand...

3C, 4C, 5C and other, only have a narrow grip range per collet size. But... can utilize that grip on VERY short lengths of uniform OD stock or a "feature" of already-machined complex shaped stock.

And they are fast to "cycle" one after another, UNLESS "key" operated.

Whereas:

The number in ER is the collet LENGTH, not max ID.

Stock any shorter progressivey puts the collet at-risk of permanent damage.

WHEN the stock is shorter in mm that that number, a slug, same OD as the work to be gripped, must fill in the gap to support good grip and not damage the collet. "In theory", regardlesss of collet size.

"In practice", the risk drops as an ER 40 grips diameters at half or less the max id.. because there is a lot more steel in the thicker body of the collet.

Being spanner operated to a required precision of torque? ER are very slow to operate, one part after another.

Not a surprise. They were meant to hold seldom-changed tooling. Not to feed rod or bar stock.

I HAVE ER.. for every spindle under-roof. I TRY to not have to use it!

TG-100 is one of several other collet systems that are just as slow. Same deal. Meant to be holding tooling not feeding stock.

As with ER, Rubberflex, and Multisize, it too has an issue with short slugs of material.

ALL of my other systems have faster cycle times.
MOST are indifferent to short lengths.

Two cents .. . and a dozen or so collet systems... Worth

Per what Bill said^^^^^

ER will grip tighter on bars, but 5c are a *much* more versatile system.
You can machine cheap 5c e-collets to hold very thin discs and work on them right at the face. An ER closer puts even a flush part back somewhat from a straight across facing op, say, among other inconveniences.
If you don't have a suitable collection of e collets on hand or just don't want to machine one for a simple job, you will eventually build up a good collection of back stops/rests including mushroom heads that will served the same purpose. Not an option with ER alone.

Then there are pot chucks and closers. With a suitable closer ring behind it, 5c collets are available up to 7" face diameter, in standard depth, and in deep capacities up through at least the 3" face size. I machine a lot of pot chucks (large face collets) for holding all sorts of non-round (as well as round) parts for repetitive ops. A simple example would be to hold (rectangular) T-nuts for c-drill, tap-drill, tap, chamfer ops in one go with a turret. With closer rings, there is probably nothing conventional that will positively locate and hold a part with the non-distorting force/grip attainable with -c system pot chucks.

OTOH, if neither system can be sunk back in the spindle, your best choice might be the one with the least overhang.
Nonethelss, i'd search for a Hardinge/Sjogren chuck with the Hardinge nose spindle extension, so closers could be used with it when desired. If you don't care about pot chucks & holding thin disks, either a Jaocbs rubberflex 9- series (up to 1-3/8" cap)or a Sjogren 2 or 3 J style would give the most capacity. Rubberflex collet sets come with back up plugs for somewhat short pieces, but the work is still sunk back it from the nose closing ring maybe 3/16" or so. They won't conveniently hold thin disks, though there is always a work-around. I use the stock 6K collets in my 10K lathe, to hold stops and mushroom stops behind the Jacobs chuck for some work. But the collet will collapse and distort with any attempt to crank it down on a disk. (as will ER, mentioned by Bill) Advantage jacobs is the larger capacity and the fact that you might find a backplate with your lathe threads that is an easy match.

smt

Thanks for the insights. I am a hobbyist so speed of loading is not an issue. I only use collets for stock <1" for better concentricity and grip but I use 3 jaw for larger. THanks for the heads up about short pieces.

Vandegraaff said:

Thanks for the insights. I am a hobbyist so speed of loading is not an issue. I only use collets for stock <1" for better concentricity and grip but I use 3 jaw for larger. THanks for the heads up about short pieces.

Click to expand...

LOL! I wouldn't use - nor even OWN - a 3-J scroll at gunpoint!.

It ain't JUST the concentrickery, TIR, or lack-thereof. There are a few "Old Skewl" tricks as far as shimming, pulling one jaw, pulling TWO jaws.. use of pie or soft jaws, dowel pins, fixtures, etc, but still..

.. mostly they do only round shapes and multiple of 3-sides - hex the obvious one.

My "real reason"?

3-J scroll only have half the GRIP of a 4-J independent!

Back to "crawlits"..

I have 5C.. In 64'ths, even ...but don't LIKE them very much, prefer to use my 4-way-split 2J (Sjogren, and Hardinge "loop" lever-operated nose-closer.)

But yah pretty well HAVE to have 5C.. because ..it is the least cost and fastest to get goods as can cover:

- Hex, Octagonal, square, oblong rectangular.. custom EDM-sunk or milled odd shapes.. PLUS lower-cost steel, brass, and nylon soft or "emergency" collets. Of which one keeps a few "virgin" ones in the drawer. And saves ones already bored for a specific "one time" tasking. Because they can be modified AGAIN. With a "step" as well as any larger diameter. No collapse-control pins? Just use three slivers of shim stock.

- INTERNAL expanding 5C are less costly and more easily sourced than 2J, etc.

- Step and pot chucks, as SMT mentioned, can also be sourced, new or used, at more reasonable cost than alt-spurnitives.

"And then.." one has 5C spin indexers, square, hex and round 5C "collet blocks" for use as workholding not ONLY on the lathe. Bench. Mill. Rotab. Indexer. DH. Grinder... 'etc'

I'm jealous of not "wasting" the skinny bore on my 10EE's so I have no "drawtube" collet systems for the lathes at all.

- Both 5C are nose-mount, key operated. No drawtube.

- The 5C step/pot closer is the same, pin-spanner operated on a Hardinge threaded "false nose". Drawtube or "similar".. only "sometimes".

- The 2J are Sjogren or Hardinge "loop" closer. No drawbar (or 2-piece tube).

- Rubberflex 9XX nose mounts, operate off a rimmed wheel. No drawtube.

- Burnerd Multisize is a nose mount, "loop" closer operated. No drawtube.

- the ER, TG, a "dead length" collet system or two, (for the mill) are also spanner operated at the nose. Off a B&S #9 adapter on the mill which DOES have a drawbar. Several drawbars, actually, because there are two mills and a DH/indexer that use #9 B&S here, two more spindles in 40-taper, two lengths. More than one thread. Life finds ways to stay interesting one way or another..



The ONLY "drawbar" collets I have are native 40-taper, native B&S #9 for the mills.... and dividing head, 5C indexer, rotab, etc.

And not the lathe(s).

Plan your spend:

ER can get you operational as low-spend #1.

First thing I acquired besides the several sizes of 4-J chuck and faceplates for the first 10EE, actually. It was blessed with 2-J chuck, 6-J chuck, magnetic chuck, later.

Even so, 5C is a "good idea" for reasonable "spend #2". It gets you value-for-money FLEXIBILITY, mostly.

Damned-near ANY other "spring" collet system costs more than 5C. Usually double or more than double.

....Even if you prefer 2J, 3J, Rubberflex, Multisize if/as/when..... later.

3 jaw scroll chucks - what a crude, ignorant way to hold all but rough work.
4jaw independents are a step up, at least. Much better for grip and concentricity. Faster, too if location & concntricity matter.
On small lathes, jaw chucks significantly increase overhang compared to collets integral to the spindle; however, in your case, even a collet chuck will probably be an extension beyond the spindle unless you go with a small series. ER would seem to have the option to reduce that extension, depending on your plans for the chuck sleeve or system.

Jaw chucks grant lobing problems on parts that are not "substantial" (Purpose bored pie jaws excepted in some cases)

I forgot to even mention 5c expansion collets. That alone should be a big persuasive factor. OTOH if you think the cost of spindle tooling is to be minimized & you don't shop auctions or places like cabin fever, it might not be an option you develop very far.

Compared to ER40, 5c really offers multiple x the facility for people whose craft will develop to demand those enhanced functions. If not, ER40 offers more grip on bars, and might be shorter overhang for spindles that won't swallow 5c directly, "depending" how the ER system is configured.

smt

stephen thomas said:

3 jaw scroll chucks - what a crude, ignorant way to hold all but rough work.

Click to expand...

Huh? They aren't worth a damn on rough work. Not enough grip to 'em before yer puttin' the scroll at risk.

I forgot to even mention 5c expansion collets. That alone should be a big persuasive factor.

Click to expand...

Optional here, actually. Breakheart Tool's website seems to indicate the owner has moved-on. But I bought one if not more of every expander he had in the line.

Same style I've DIY'ed for ages. Straight shank, bar body, slit for expansion by tightening a hex-head screw in the face. I cheated with standard tapered pipe taps & bought-in plugs!



He made them of 12L, so they are waaay easier to alter for a specific task, then also keep machining any used ones to the next SMALLER need.

Cheaper to buy his ones, CNC'ed, than DIY myself one at a time as the need arises and never have a "set" I can just reach for.

Naturally, once you HAVE any given class of "problem solver" tooling? The NEED goes and hides-out for years!

I suspect the Devil runs a mill supply...or at least half of eBay?.. and laughs his ass off at the vanity of tool-hoor packrats?

Wait 'til we are eyeball to eyeball.

Like to be a fly on the wall when he finds out I've named him executor to my Estate and he has to get an extension to eternity so as to find a buyer for all my s**t!

"Payback, is a ..." etc.

For a home shop ER's can work just fine, but as already mentioned they are slow. But, many don't bother to check one small but highly critical detail. Using them sure as hell depends on just how well each collet and the chuck itself was made. I've watched multiple Youtube videos showing what I'd call some pretty horrendous run out numbers using inexpensive off shore ER collets and chucks. I've got (admittedly expensive) Austrian manufactured Emco 3 and 4 jaw scroll chucks and almost all of my drill chucks could easily beat by far the average run outs most of those off shore ER collets and chucks seem to come with. For that reason I spent what it cost for what Bison guarantees on there collets and chucks for my mills ER-40s and for secondary use on the lathe.With what I see on YT there's zero advantage to using anything that inaccurate over a much faster to use scroll chuck other than an increased grip or on thin wall material. So unless you have properly checked what you actually have for numbers with each collet, you could well be losing accuracy over what your scroll chucks already provide or can dial in with a 4 jaw independent chuck.

I'm also surprised at your choice of using a MT spindle mounted ER collet chuck. Other than it being quicker to mount and remove, that deletes one of the fairly expensive to produce and highly desirable built in features most lathes were designed and meant to be used with. That hollow spindle. Further issues are that all female and male MT's will have some measurable amount of run out adding to and almost never canceling out or reducing the work holding run out numbers. A shop made or commercially available back plate mounted ER collet chuck instantly gains you back that hollow spindle for longer work and isn't hard to add 4 set screws to the rear of the chuck body and turn it into a set true type when almost zero run out might be important. The only time I'd ever use a MT shank ER collet chuck on a lathe is in the tail stock to hold tooling much more rigidly than a drill chuck can.

5C's? other than cost for a full set of high quality and therefore low run out collets, they have multiple speed, work shape and collet accessory advantages over anything an ER can ever provide. Even more so as a work holder on almost any other machine tool. If I could afford what I want as a full set up for 5C's I'd always chose those over anything the ER's provide. Compared to 5C's ER's are extremely limited in what they can do. Other than there maximum size capability, about the only other collet system ever invented that just might be anywhere nearly as versatile would be the 8mm WW collets and the watch/clock making machine tools designed to use them.Even then the 5C wins just on size and material shape capability. 5C's are almost a world wide standard today for many good reasons.