NOOB Question about Milling Machine Collets

[lazlo]

R-8 .... only accepts to 7/8" (not real sure on on that...!), will only accept the one diameter, have to use the drawbar to change.

I've got a Western 7/8" R8 collet, and there's not a heck of a lot of meat on the taper. I've even seen 1" Asian R8 collets for sale on Ebay, which is just frightening -- I can't imagine they'd hold anything, especially not a cutter with a 1" shank!

In reference to the infamous Coke versus Pepsi, Ford versus Chevy, Lincoln versus Miller, collets versus endmill holders...
I use R8 collets for less than 3/4", and R8 endmill holders for 3/4" and 7/8" shank cutters, especially corncob (rougher) endmills. My facemills all have integral R8 shanks, so doesn't matter there (where the cutting forces are greatest).

The ER's --- Minuses: As mentioned, the real estate they take up is good bit more than R-8, and probably some loss of rigidity....
...
I'll admit I'm a ER convert, (I love em) and I'm using Bridgeport type mill with work space that can get cramped, but I find that with 95% of what I do the ERs are no problem.

Likewise. I've used R8 collets on my Millrite for a long time, but I've recently converted to an ETM R8-ER40 collet chuck, and it's really convenient.

What's especially slick is that I bought an MT3-ER40 collet chuck, so I can move a tool or workpiece from the mill to the lathe headstock or tailstock.

[clutch]

As far as some b&s being tighter you often see posts on freeing a stuck one.

Clutch

[tattoomike68]

My mill at home takes a morse #2 and if you suck it up tight you might be in for an adventure in sleged hammer boogie you dont want.

rather than torque the hell out of the nose cap or draw bar get endmill holders in some common sizes 3/16, 1/4, 3/8, 1/2.

you can get a 1"+ in an endmill holder in R8.
Its still better than a collet.

Anyone who has endmill holders will say they are better by a mile. you dont need 100 sizes just the ones that do the work.

[karlgabel2]

I sure did learn a lot - now to put it into practice! Thanks a bunch to all of you - it's always a pleasure to learn from everyone's thoughts!

[BobWarfield]

A couple of other thoughts:

- ER's cover a wider ranges of sizes for each collet. If you have an odd size for some reason, they're handy.

- In theory, collets have less runout than the endmill holders. At least I hear that a lot. For the record, I use mostly EM holders, and you have to work to get the air out they fit so tight, but I had to bring up the runout issue out of fairness.

- I've seen various threads in various places about the little keyway on the R8's and whether you can remove the grub screw that mates to it. Turns out you certainly can, but if you then use R8 collets, you don't have much to grab on to down there if you need to get things apart again and it's just spinning!

- If you have a powered drawbar, it's nice to have cutters already in holders, whether you prefer collet chucks or endmill holders. Then tool changes are really quick. I have a powered drawbar, so I like this better than fooling with R8 collets.

Cheers,

BW

[Evan]

I don't have experience with the various collet systems other than R-8 and Morse Taper. I have both R-8 collets to 3/4, Morse taper #2 for my high speed spindle and several end mill holders for weldon shank end mills aas well as a full set of European made MT3 collets. I much prefer the collets, especially the R-8 collets for tool holding. I have never had a tool creep out of a collet on my mill and I have pushed them pretty hard as can be seen by some of the videos I have published here. I tighten the R-8 collets by means of a wrench on the drawbar and a friction collar on the spindle that is hand held only, no spindle lock of any sort. I also use MT collets on my lathe both for holding end mills and for work holding and have never had a slipping problem. I use several different collet chucks that I have made for common small sizes such as 1/8 and 1/4" tooling and they don't slip either. Collet holding systems are standard for high speed tooling as well as smaller tooling in general on machines like spin saws, die grinders and routers.

The average home shop machinist isn't likely to be pushing the sort of power and tooling that needs a more positive locking system for the tools. It's also likely that a more concentric hold will be obtained with cheap import collets than with cheap import weldon style tool holders. As well, when I make tooling that will be held via a collet in either lathe or mill I turn or grind about .001" from the shank for a small distance at the end nearest the working end of the tool. By very slightly reducing the diameter of the shank in this area the holding power of a collet is increased to the point that there is virtually no chance of the tool walking out of the collet.

[HTRN]

What? No Mention of the DA and TG sized collets?

The DA's are/were fairly popular in alot of CNC shops, but the ER's and TG's(better known as "single angle" collets) are taking over, as they tend to be more concentric, relatively speaking.

There is a HUGE variety of collets out there, much of it all but abandoned by industry, who smartly wised up and went with the most common. Hardinge sells alot of the old, oddball stuff at prices that will make you weep.

To make a long story short - If you're mill takes R8, and your lathe can use 5C count yourself lucky!


HTRN

[tiptop]

Well I guess I am the only one left with Erickson 400DA collets. I like the holding power of the DA collets, they go to 1" . I use end mill holders on anything above 3/4" and have NMTB 30 spindle taper, which is tougher in my estimation than r8. Duck now and look out, here it comes. Jay

[doctor demo]

[QUOTE]

Can the R8 tapers be ordered with out all the ubiquity?

Ubiquity is a small town in Arizona, I think ,and they don't sell tapers



Steve