ER-32 Retention Nut - This is Bad - Right?

That's not a bug Wally, it's a feature. A feature whose purpose is to retain the collet in a properly seated condition while you tighten the nut. A properly seated collet will be paralell to the face of the nut. If it isn't, snap the thing in properly...

Read the manual that came with your collets. Snap the collet into the ring - it only goes in one way - then it should be fine.

GWE

Check these links for a proper way of inserting collets into nut:

And now the reason for that excentric: It is for pulling the collet out.

Nick

I feel like such a dope...

Thanks guys, Wally

snipped-for-privacy@hotmail.com wrote:

========== No foolish questions on this NG, but you may get a foolish answer from time to time. And you are not out any money for a new nut....

Unka George (George McDuffee) ============================= When you give power to an executive you do not know who will be filling that position when the time of crisis comes.

Ernest Hemingway (1899-1961), U.S. author. "Notes on the Next War: A Serious Topical Letter," in Esquire (New York, Sept. 1935; repr. in By-Line Ernest Hemingway, ed. by William White, 1967).

Chuckle...dont feel bad..a bunch of folks have made that mistake..including me with my first ER in 30 taper on my Gorton Master mill. I think I had .05 runout the first time I stuck it in there and spun it up..."WTF!!!??????!!!!"

Gunner

"If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around."

"Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion).

-Buddy Jordan 2001

Actually, that "feature" is to break the taper when you want to loosen the collet.

Matt

I didn't know that. I've customers that remove them entirely and that would explain why thy smack the nut with the wrench once the nut is loose.

Well, you can do that on the larger ER's without causing any damage (as long as you don't hit it too hard), but do that on the smaller ones and you'll have runout problems. All they really need to do is turn the nut a little more, with the wrench, and the taper will break loose.=20

Now, that little tab inside the nut does come in handy for holding the collet when using ER's in a lathe, where the holder is horizontal. Some sizes don't actually 'snap' into the nut. Like the ER 20's I use in my Swiss. You have to hold the nut so the tab is in the 12 o'clock position, which will hold on to the collet until you insert it into the holder. Otherwise, it will fall out. But that's not the real purpose of the tab.

Matt

According to :

That is *precisely* the way it should be.

You put the collet into the nosepiece hook the groove in the collet under the part of the lip closest to center, tilt the collet to upright, and screw the combination into the adaptor.

When it is time to loosen the collet, that eccentric lip pulls on the collet to start it out of the closing taper, so you don't have to run a rod down the spindle and bash on it to loosen the collet as you do with R8 collets. (And the drawbar would be in the way if you did try that.)

Absolutely *plenty* of reason to not turn it concentric. You'll destroy the designed behavior of the collet closer.

I'll bet that your eccentricity came from not first hooking the groove of the collet under the lip of the eccentric in the nut.

Good Luck, DoN.