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jacampb2
04-10-2008, 07:09 PM
Well, I am starting to look for some tool holders for the new mill, and am finding that the nmtb 30 stuff is more money than I would have hoped, so I will have to go slow, and buy as much used as possible.

I found a 30 taper ER32 collet chuck with 11 er32 collets for about $250. Bison brand. I am kind of thinking about buying it, as it would get me a fairly complete range of holders for my needs. I know opinion varies on using EMs in collets or EM holders, and I can purchase a fairly complete set of import #30 holders from enco for around $200, not counting the current sales or codes... The downfall there is, it seems the import sets are all lacking .25" holders, you can get them in the name brand stuff, but it is about half as much as the set for one holder. I have a lot of .25" EM's I'd like to be able to use.

So, I am mostly looking for advise. I only have the money for one of the two right now. What do you guys suggest.

Thanks,
Jason

SGW
04-10-2008, 07:18 PM
I'd go with the Bison ER collet set, myself. I think cheap import collets may be at least partly responsible for the problems people have with collets and end mills. I've got a set of Hardinge R8 collets and have never had a hint of a problem with them. Bison makes good stuff; I think you'll be fine.

IOWOLF
04-10-2008, 07:25 PM
I would go with the Enco set, I think collets may be nice, but, not much beats a setscrew.

A Professional Opinion.

tattoomike68
04-10-2008, 07:39 PM
I would use endmill holders over a collet every time. A collet is not much better than a drill chuck when it comes to milling.

tiptop
04-10-2008, 07:44 PM
I would have to agree with IOWOL on the statement of nothing beats a set screw. I have NMTB 30 on my mill fortunately I was looking and bought most of my tooling a couple of years ago when things were cheaper on the bay. I use collets a lot and for the most part they work fine. I don't push things to the limit though. I definately would not use roughers or corncob mills in collets. Keep you eyes open you will find quite a bit of NMTB 30 stuff. Jay

JCHannum
04-10-2008, 08:01 PM
30 taper is not common and is usually expensive. 40 is a little better and you can't give 50 away sometimes.

The setscrew end mill holder will provide the most positive gripping power and accuracy. It is a simple lathe job to turn up a 1/2" X 1/4" adaptor to hold your 1/4 endmills until an affordable holder turns up.

jacampb2
04-10-2008, 08:56 PM
I don't think it is so much a question of commonality, but more that these tapers aren't as commonplace in the HSM setting. It seems there is all sorts of stuff out there in the various iso tapers, but not a whole lot of import stuff to drive the price down.

Anyhow, the spindle on the new mill is actually the ericson QC NMTB #30, no draw bar, but a cam type(for lack of better explanation) locking collar. Supposedly some NMTB #30's work, and some don't due to the tanged collar location, and how well the manufacturer adhered to the standard. This makes Ebay pretty dicey, at least if I order from enco, worst case scenario I can send them back.

I have never milled with collets in my gorton mill. I have a complete set, but I always use my EM holders. The main reason being so that I wouldn't wear out the $300 each collets in case the next owner needs them.

I think I will probably go the enco route for now. Their tooling, even their import stuff, seems to be decent quality. If anyone has any other good sources for a reasonably priced nmtb #30 set, I would appreciate hearing it.

Thanks,
Jason

thistle
04-10-2008, 10:04 PM
I bought a bison toolmex 30 taper ER 32 set from penn tool for less than 250

also www.victornet.com has some 30 taper stuff , like shell endmill arbors ect quite cheap- i got a few from them- turned out to be german, but new old stock

Oldbrock
04-10-2008, 11:08 PM
You will NEVER be able to make an endmill slip or move in a Clarkson collet chuck of course you have to buy threaded end mills. For other end mills I use setscrew type holders, never had them slip either.

Timleech
04-11-2008, 02:28 AM
Anyhow, the spindle on the new mill is actually the ericson QC NMTB #30, no draw bar, but a cam type(for lack of better explanation) locking collar. Supposedly some NMTB #30's work, and some don't due to the tanged collar location, and how well the manufacturer adhered to the standard.

Jason

I bought a Bison 30 taper ER32 set quite a few years ago. It doesn't fit my QC30 Bridgeport spindle.
That was a few years ago, it's possible that they're different now.

Tim

JCHannum
04-11-2008, 08:36 AM
I only mentioned 30 taper commonality in reference to it's availability on the used market. It demands a premium there, new it is less expensive than the larger sizes.

Taper tooling should all fit the taper in the same manner. The differences are in the flanges and neck configurations. Drawbar threads might be metric or Imperial, I have seen both. I am not familiar with the Ericksson QC, unless it is a large spring loaded chuck affair that swallows the flange of the taper. In that case, the neck for the drawbar may also present a problem as well as the flange.

You might explore the possibilities of modifying the spindle to accept a drawbar.

Timleech
04-11-2008, 09:13 AM
I only mentioned 30 taper commonality in reference to it's availability on the used market. It demands a premium there, new it is less expensive than the larger sizes.

Taper tooling should all fit the taper in the same manner. The differences are in the flanges and neck configurations. Drawbar threads might be metric or Imperial, I have seen both. I am not familiar with the Ericksson QC, unless it is a large spring loaded chuck affair that swallows the flange of the taper. In that case, the neck for the drawbar may also present a problem as well as the flange.

You might explore the possibilities of modifying the spindle to accept a drawbar.

The drawbar end doesn't present a problem,at least not for my QC30. The flange position and dimensions are fairly critical, though.
I've successfully modified BT30 and one or two 30 INT/NMTB30 items to fit, but a lot of the NMTB30 aren't suitable for modification because the flange is too far from the 'right place'.

Tim

jacampb2
04-11-2008, 10:55 AM
Yes, there is plenty of room for the neck for the draw bar does not seem to be a problem. The one tool holder I have is listed as erickson #30 NMTB. The flange looks identicle to the ISO #30, the NST #30 and the NMTB#30, from my research, the "rub" is quite litterally the distance from the gauge line to the outer face of the flange. All of the above tapers share the same flange diameter, and ear layout, but I guess there is some looseness in the flange thickness dimension, and if it outside a certain range, then the locking collers "cam's" cannot bare against it properly. Erickson published a proceedure for grinding the flange on other tool holders to fit, after it became a problem. I have only found mention of the proceedure, nowhere have I actually found it. I am hoping that it is something I can solve on the lathe, whether it needs a spacer, or a few thousandths off the flange. I can't see the flange as being critical to accuracy, as long as you can seat the taper fully.

As for modifying the spindle, it has no through hole at all. I can't think it would be fun to bore it out, and even if I did, that puts a draw bar 8' in the air, so it will mean rigging a power draw bar, or leaving the ladder out. I will make what I have work somehow.

I decided to purchase the bison collet chuck for now. Realisticly most of my work will be with larger EM holders, and I will just try to piece meal the sizes I need together. I will go with collets for now for testing. Thank you all for your opinions!

Jason

macona
04-11-2008, 02:17 PM
What you are looking for is erickson quick change 30. It is a variant of NMTB 30 where the thickness of the flange is controlled.

Many of the spindle that take the QC30 tool holders still have a bore down the spindle where you can use a drawbar and hold normal 30 taper tooling.

ISO 30 taper has no flange.
BT30 and CAT 30 are the same except BT30 has metric threads for the draw stud. Intended for machines with tool changers. You can make up a little longer drawbar and use them in a manual machine. I do.
NMTB30 has 1/2-13 threads on the spigot on the end for a drawbar. NST 30 seems to be the same as NMTB

FWIW, I have never had a end mill pull out of a ER collet. TG's are supposed to hold even better.

JCHannum
04-11-2008, 03:38 PM
Here is a good link to machine tool tapers I had not seen before. It has some information on the Ericksson QC taper with the NMBT description.

http://www.tools-n-gizmos.com/specs/Tapers.html

jacampb2
04-15-2008, 07:28 PM
The Bison ER32 collet chuck showed up today and it fits the spindle perfectly. Locks down plenty tight, so evidently they fit the NMTB QC #30 now.

Later,
Jason

PaulT
04-16-2008, 11:55 AM
ER32 collets are used fairly widely for milling on VMC's so they will work fine for milling on your machine. I use them on my 3HP BP CNC clone machine, and they work fine as long as you make sure to torque them properly. The recommended torque on these collets is a lot higher than most people realize, and some of the wrenches sold for these collets are shorter than they should be, making it harder to get the right torque on them.

www.maritool.com has good prices on ER collets and other ER related tooling, he also sells some 30 taper stuff. He's a good guy that runs a big shop himself and he'll give you solid advice on any tooling questions you have. I know some users buy his BT30 holders and modify them to use on a NT30 taper machine, so if you are interested in that ask him about it.

Paul T.

AlleyCat
04-17-2008, 01:19 AM
I'm installing a new control on a Bridgeport Boss and having the same problem with tool holders. Most of the 30 taper tool holders I purchased were used and USA made. They have all worked ok in my QC 30 spindle. Then I purchased some import tool holders that looked good but wouldn't fit properly. The flange diameter was too large and the flange thickness was too thin.

These import tool holders are about .020" to .030" short of the correct flange thickness. The tool holders that fit the best all have a flange thickness of .344" and a flange diameter of about 1.825". The flange diameter seems to be less critical. I'm thinking about using a tig welder to build up the face of the flange and then put them in the lathe to clean it up and correct the diameter and flange thickness.

Do you guy's think this will work or will the tig's heat be too much and possibly distort the tool holder? If that Erickson QC 30 spindle was bored all the way through I would get an automatic draw bar and just use that. Has anyone bored a hole to accept a draw bar on one of these spindles? I don't know if it can be done but doing so would sure solve a lot of problems. Any ideas?