Utter Tosh, they are for holding nominally round items, tool or stock makes no difference!

I have a Myford Super7 headstock with native ER40 and it's a joy to use – 1m lengths of 30mm bar? – no problemo!

– Nick

Edited By JasonB on 05/09/2016 12:44:46

Yet the radial loads on milling cutters are far greater than the axial ones…

Edited By JasonB on 05/09/2016 12:45:31

Sorry Raymond but how do you work out that a collet tightened up onto work one side and two tapers the other side cannot accept radial loads ?

Surely the limitation will be the collet holder or machine bearings and as Neil has pointed out milling loads in the axial plane are far higher.

I do so hope this is not one of those urban legends that gets repeated over and over with no fact.

Edited By JasonB on 05/09/2016 12:46:07

Found the video on you tube, It is called "Guhring Diver Tool smash". In it the guy from Guhring mentions that the ER system is at its best when the loads are Axial, not so good at Radial forces. Which is what I said. We as hobbyists don't need to consider such things There are better end mill holding systems than ER ,and there are FAR better workholding collet systems than ER . They are great for our needs, very versatile,I like them.

Edited By JasonB on 05/09/2016 12:47:03

None that would cover the range of each ER collet., but for a specific Ø then some of the "C " Series or The B42 series all these are available in round hex and square [ and depending on which size ] can cater for larger Ø's than the ER system which max's out at 34 mm Ø also the mentioned series can all be bought as Blanks There are also a range from Micro centric [ I think thats the name ] that are also available in Round , Square and Hex I've yet to see an ER in square or Hex. I think the ER system is the jack of all trades but is the best at only one thing and that is Drilling / Reaming.for which it was originally designed for. But like I said I like them and use them a lot and i'm certainly not knocking them.

cheers

Edited By JasonB on 05/09/2016 12:48:04

I did that and the video didn't have any commentary, just video of the end mill in action. Nor did it mention collets of any sort?

Andrew

Edited By JasonB on 05/09/2016 12:49:04

John, If the company you mention does work for Airbus AND Boeing then there is NO WAY they will be using ER for workholding. AND I would willingly put money on it. [and money means a lot to me ]

Edited By JasonB on 05/09/2016 12:50:12

Taking part of a statement out of context and calling it "tosh" isn't really helpful. ER collets were designed for toolholding, and workholding is only a by-product that happens to suit our needs. If you read back in EIM in 2003, you will find that I described how to make an ER32 collet for the Myford lathe, so I can hardly be accused of preaching Thou Shalt Not Use ER collets for other purposes!

Thanks Jason for moving this to it's own thread. I have e-mailed Rego Fix Re, the ER collet system and what it's primary purpose was. as soon as I hear back it will be posted in this thread.

John, You say that the ER collets are used in a production environment for Workholding ?? Thats where they are even LESS suited . [ Production workholding ] although, I will happily eat humble pie if i'm proved wrong.

cheers.

Thanks Jason, thats the Video.

I watched the video, not by Guhring, although one of their employees is being interviewed. It's interesting that the hydraulic chuck comes out far worse than the ER collet chuck. The 'high performance' chuck shown isn't specified as to type.

Andrew

OH MY !!!, I made a mistake and the video is NOT by Guhring. but to get back to the jist of the debate, the lad does say what I already said, the ER is NOT at it's best with Radial loads. because it was originally designed for Axial loads. The high performance chuck is I think similar to the ones made by Schunk. and also Albrecht. There is another video about the HPC which I will try to locate to get the title. it also touches on the Schunk shrink fit and the Albrecht hydraulic

cheers.

Ok some Herbert saying it’s not good for radial loads but where is the proof ? Most modern VMC can put that much radial load on they can swipe vises off beds and snap 20mm cutters like carrots but the collet cannot handle a radial load. ?

Sorry I need to see proof from a respected source first.

Milling which is what they were designed for handles more radial load than axial