ER collets - history

A question prompted by Alan's current thread: When did ER collets turn up in the model engineering world? I've been reading a pile of old MEs and I've got to 1997 and there's still no mention of them so when, and why, did these incredibly versatile collets suddenly spring into the ME conciousness?

cheers,

Rod

**LINK**

ER system originated in 1973 according to this, guess modellers would have picked up on them quite quickly.

Edited By V8Eng on 13/01/2014 20:22:11

My guess would be that as the patent was dated 1973 cheap copies would not have been created until the patent ran out so that would be +20 years, then allow a few years for the traders to wake up to the opportunities and for us to start asking for them.

I am personally surprised that the, in my view, far superior DA collet system is not more widely used in our model making.

Jo

One of the first things I found on Google, "DA Collet chucks are not designed for milling and can crack at the nose when over- tightened or radial load is applied. Don't know much about collets of any sort, but maybe this could be part of the answer Jo. Ian S C

There are a number of different types of DA collet chucks, most are designed to be used in industry CNC machines. Some are relatively thin around the collet so I would guess that they are designed to be used in the (capstan) tailstock or down cavities where the space for the tool is limited and as you say Ian they are not designed for high axial loads and one I have has a hair lined crack where someone has abused it. But I also have numerous with integral 30 Int tapers.... So clearly designed for use in the nose of milling machines.

The latest Cowells collet chuck uses the DA200 collets and is excellent.

Jo