Lathe collet chuck questions

I am prospecting around for a used collet chuck for my lathe which has a L-0 spindle. It appears that there are at least two types available
which I could use that seem readily available: Sjogren-Hardinge and Jacobs rubberflex. I have only used Sjogren ones previously. Are there reasons to favor one type over the other? I know that the rubberflex collets have a greater range of adjustment and so fewer collets are needed to cover the range of the chuck's capacity. Is the accuracy of the two types significantly different? Do the metal jaws of the rubberflex chucks hold workpiece better or worse than the solid metal collets? Do they leave bite marks? I would appreciate any comments or suggestions about these things. I would be using the chuck mostly for personal projects. I don't know whether a good 3-jaw chuck is just as accurate as a good condition collet chuck. Leo Plas
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wrote:

<snip> Unless you can buy used be prepared to dig deep in your pocket.
If you have a face plate you can get what is called a collet vise that will take 5C collets and bolt this to the faceplate. You want the kind that has a big nut that screws down to compress the collet, not the lever operated type. I got mine with a set of 1/16 to 1 inch collets X 1/16ths from Enco for less than 100$ US.
I find this is quick to set up. Put a 1/2 diameter X inch long piece of tool steel in a collet and chuck up in the tail stock, bolt to the face plate. This will get you within a few thousandths, and with a little dial indicator work you can get it to 0 tir for the close jobs. You can't however feed the stock through the collet.
Alternative is to get a Morse taper ER collet holder and set of ER collets and use in you headstock. You have to use a MT adapter. Be sure to use a drawbar to keep everything secure. I find that a piece of allthread (2$US) works fine and I had enough for another project. Get the set with the big ER40 collets. [stock wont go through these collets either]
If you go with the 5C collets and collet vise, a good purchase is the square and hex tumble blocks. Very helpful if you have a mill, and you can use on a faceplate to machine square and hex shapes.
See following websites for sample offers -- many other available, but I deal with H&H and Enco. Also found WT http://www.wttool.com/ very good to deal with
5C collet vise http://www.use-enco.com/CGI/INSRIT?PMAKA1-6023&PMPXNO905664&PARTPG=INLMK3 http://www.hhip.com/products/product_view.php?ProductID 0-0016-21 [I milled off the vertical pad]
square hex tumble blocks http://www.use-enco.com/CGI/INSRIT?PMAKA#5-7050&PMPXNO0317&PARTPG=INLMK3 http://www.hhip.com/products/product_view.php?ProductID 0-0016-20
5C collet sets http://www.use-enco.com/CGI/INSRIT?PMAKAP5-5021&PMPXNO1494&PARTPG=INLMK32 http://www.hhip.com/products/product_view.php?ProductID 0-0012
MT ER collet holders http://www.hhip.com/products/product_view.php?ProductID 0-0005 http://www.hhip.com/products/product_view.php?ProductID 0-0005-061 http://www.hhip.com/products/product_view.php?ProductID 0-0005-270 [call or email they had some cheaper sets]
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I have been followiing this discussion with interest. I also want to add collet capability to my lathe. A 10" Atlas. 5C collets have square and hex stock chucking capability. I looked for ER collets with the same capability on the internet but didn't find any. Do ER collets have square and hex stock capability? Is this a discriminator in choosing 5C over ER?
Dave Scott
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ER collets are for holding tool shanks (e.g., end mills), thus you will not find them with hex or square bores (and I doubt their design could be made to function with a square bore).
5C collets are what you want. They are designed for holding stock.
- Michael
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Why limit yourself to a solution that will not allow you to pass long stock through your spindle?
Ebay currently has a Hardinge-Sjogren 5C Collet Chuck for L-0 Spindle available (albeit, pricey):
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&categoryA946&itemu25494250
But before laying out that kind of money, I'd see if I could mount a plain-back Bison 5" 5C Collet Chuck to your L-0 spindle using a suitable mounting adapter. You can probably make such a mount, but I don't know enough about the L-0 spindle specs to say for sure.
Enco currently has the Bison 5C collet chuck (Item # 271-5610) on sale for $274.95 (down from $318.95):
http://www.use-enco.com/CGI/INSRIT?PMAKA'1-5610
You can see it at the bottom of this catalog page:
http://www.use-enco.com/CGI/INPDFF?PMPAGE)5
Combined with their free shipping, this is a very good deal!
- Michael
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DeepDiver wrote:

New England Brass & Tool <http://www.brassandtool.com sells a L-0 adapter specifically for the Bison 5C collet chuck (which they also sell). It's not terribly expensive.
Dan Mitchell ===========
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Daniel A. Mitchell wrote:

them for our Rockwell 14" lathe. Perhaps they aslo sell a L-0 adapter ... but I don't know this for sure. You'll need to contact them. I don't believe they list the "L" series adapters on their website ... I had to talk with them directly. Good luck.
Dan Mitchell ===========
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I'm confused. I can use 5c collets directly in my L00 spindle and a L0 is even bigger, so I assume a L0 spindle will accept 5C collets directly in the spindle with a suitable adapter, so why add the extra overhang, possible runout and expense of a 5C collet chuck?
collet chucks like jacobs rubber flex and pratt burnerd allow a wide range with a few collets, so they can hold oddsize stock. I have one, but I really prefer to use the 5c collets directly in the spindle. The primary reason is that the collet chucks will not hold short items.
chuck
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My MSC catalog only shows one Morse taper 5 to 5C collet holder/adapter for close to $600. Do you know of anything more economical? Leo Plas
P.S. thanks to all for the the helpful discussion. I got outbid on a Jacobs collet chuck this morning, alas. The quest goes on.
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Call some reputable used machinery dealers. Dick Tremistra is my favorite. I bought a mint condition drawbar, nose piece and set of royal 5c collets for my rockwell lathe for about 300.
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Leo Plas wrote:

I had a lathe with an L-0 spindle which I fitted with a complete set of Jacobs No. 91 rubberflex collets and a NOS Jacobs chuck. I got all of the items for under $400, maybe well under. They worked very well for me and although I never checked them for accuracy vis-a-vis a 3-jaw chuck, they seemed very accurate.
Another option is to buy an ER-40 5MT adapter, and make a drawbar, and mount the adapter in your spindle bore (assuming you have a No. 5 Morse taper spindle) and get a set of ER-40 collets. That works very well, will also work on much smaller lathes (I have an ER-40 3MT adapter with which I use ER-40 collets on my SB9) but you can't put work through the collet.
Still another option is to buy a Buck Ajust-Tru 3-jaw chuck, about an 8" one, and dial your part in. I've got one of those for sale if you want to go this route, good condition but no backplate.
Only other thing I have left over from my big lathe is a Holdridge 4D radius tool, complete. Anyone looking for one of those drop me a line.
To email me visit http://www.tinyisland.com/email.html - do NOT 'reply-to' this posting as this email address is completely phony.
Grant Erwin Kirkland, Washington
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Do not confuse the Jacobs rubber collets with steel collets. While they are very good for many applications, they have serious limitations. One of their drawbacks is holding short items. Because the steel segments are supported only by rubber, under heavy stress conditions they are known to release the item being machined, often with less than good results. If you're taking a serious cut, you often end up with a broken insert, if not worse. That's true even when you use the rubber plug (support) provided for holding short items.
The other inherent problem with the rubber collets is their ability to produce a given pattern in the work as you're machining. It happens, again, only under heavy machining conditions, and is easily removed when taking finish cuts. As you alluded, they are also capable of leaving a holding pattern where you grip, but more so on short pieces that tend to wallow about a little.
I've used them a great deal, and while I don't have them for my current machine, it's only because I've never landed the right deal. I highly recommend them, but with reservations. They are especially useful for holding hot rolled material, or bastard sized materials. My only caution would be for you to not expect them to replace steel collets. If you expect that, you're going to be disappointed with them. They are an excellent accessory, *along with* steel collets.
If you have soft jaw capabilities with your 3 jaw, you might consider exploring their use. They offer unlimited holding capabilities (within the range of the chuck), and are very capable of repeating within a half thou when properly applied. You can't expect (and are highly unlikely to get) any better precision from steel collets, and they don't offer the rigid stopping and squaring capacities of soft jaws. The added bonus of soft jaws is their incredible ability to hold parts without any trace of gripping damage. Even better than steel collets.
Harold
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The adjustable 3-jaw like Grant has can be more accurate than collets, especially cheap collets, and holds the piece more solidly so it doesn't slip while you are threading and mess you up. I like 5C collets a lot but there are only a few things they can do that a good 4 and set-tru 3 jaw chuck can't match.
Jim Wilkins
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If your stock is slipping in your 5C collets, then I suspect the following problems:
1. Not enough clamping pressure applied to the collet. 2. Collet bore dirty or oily, or chips stuck in the grooves between the collet "fingers". 3. Stock size not correctly matched to the collet bore. 4. Cheap, out-of-round collets. 5. Taking WAY TOO BIG a cut.
Otherwise, they should hold your stock more securely than a jawed chuck (it's all about friction and surface area). Unless of course you are tightening your jawed chucks to the point where they are digging into the stock; then you're changing the rules of the game.
Btw, the same list of problems go for tool slippage in R8 collets.
- Michael
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Items 1 and 4 apply. The handwheel closer was adapted from a different lathe and doesn't take well to serious tightening for several reasons, and the collets are mostly $5.95 from Enco or second-hand and well-used. If I need something to run really true I use the 4-jaw.
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currently on Ebay 6" buck tru adjust $45
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category%292&itemu26132912&rd=1&ssPageName=WDVW
On 29 Jun 2005 16:21:38 -0700, snipped-for-privacy@segway.com wrote:

-
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    Yep -- the only problem is that it is an L-00 mount, not the L-0 that the original poster was requesting.
    If it had two-part jaws, *I* would be bidding on it, as I have the L-00 spindle.
    Enjoy,         DoN.
--
Email: < snipped-for-privacy@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
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Another option is the Pratt-Burnerd collet chuck, which came in lever-type (production) and keyed type, which closed like a drill chuck. The P-B chuck was similar to the Jacobs in that each collet had a range of 1/8", +/- 0.020, I think, but the collets were all metal. I'm pretty sure that both Jacobs and P-B spec'd the runout at 0.0005" or less. Both Jacobs and P-B sold their chucks for a variety of spindle configurations, including L-0. The Jacobs chucks seem to come up more often on Ebay than the P-B types but I don't think that the Rubberflex collets for these chucks are made anymore. The P-B collets were still listed in MSC as of a year ago or so at around $200 each.
Both types suffer from one disadvantage - they don't like stock that is much shorter than the collet jaw length. Jacobs dealt with this by including rubber plugs that could be inserted in the rear of the collets, but I don't think that P-B had anything similar.
There were also at least styles of collet for each brand so make sure you get a match if you the chuck and collets separately.
I've got both Jacobs and P-B chucks and prefer the P-B, though there really isn't much difference in my (hobyist) experience The Jacobs is a little more convenient to open/close since that only requires popping the lock ring and rotating the handwheel whereas the P-B requires the use of a chuck key. For frequent, long-term use the lever-type P-B chuck would probably make the mosty sense.
Mike.
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In all the comotion, I am surprised that no one has mentioned Burnerd. Burnerd makes a fantastic collet chuck. They pop up on ebay all the time I think I paid about 400 for a very nice L00 chuck and collets. The Burnerd is similar to the jacobs rubber flex but uses steel seperators instead of rubber. You can still buy new collets from MSC while you cannot buy new rubber flex collets.
chuck
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    [ ... ]

    Yes you can -- but only in the sizes for tapping chucks. :-)
    Enjoy,         DoN.
--
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