Pros and Cons of the ER collet system

I don't pretend to understand a blind word of any of this, but is there something different with ER11 closing nuts compared with the larger sizes? The two pictures in Neil Lickfold's post seem to show the collet not seated properly in the nut. I have ER25 and ER32 collet systems for the lathe and mill and all my collets are flush with the nut front face when fitted.

John

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Reference ^^^

It seems to have gone rather quiet

Has Mark frightened everyone off ?

or is this the calm before the storm ?

MichaelG.

Edited By Michael Gilligan on 21/09/2016 12:04:32

Above is the e-mail received earlier. I think it is the same chap who sent me the er details for a previous thread on the er's.

I have enjoyed the [sometimes heated ] confab on the subject. I and I think a few others have found it interesting.

and thanks to Mark for doing the FEA.

I will reiterate once more that as a toolholding system for our [hobbyist ] needs it can't be beat. I wouldn't say otherwise.

cheers

Proof of intent is not proof of function or fact, in Law or in Engineering, Engineers know this  

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Dear Sirs,

Can you confirm that the key features and many systems utilised in the Saturn 5 Rocket were initially and primarily designed for the Terrestrial delivery of weapons systems?

Thanks,

Nick

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Dear Sirs,

Can you confirm that your track based, steam powered mass transit system is designed for a maximum speed of 15mph because greater speeds will prove fatal to the human body? 

Thanks,

Nick

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Most innovative systems have evolved from something designed for an alternate purpose or to operate under other parameters, to suggest that proof of design intention is proof of limits of functional capability is instead proof of massive misunderstanding and complete failure of engineering conceptualisation on the part of the author, 

- Nick

Edited By Nick Hulme on 22/09/2016 00:27:33

recognise the limitations and work within them

A friend of mine has several 5 axis Huron machines making parts for the areospace industry to limits that most people could only dream about . They use ER collets for everthing and recon there is nothing to beat them . Good enough for , good enough for me

At the start of this thread a member simply stated that the er system was not designed for work holding only for toolholding, he was met with the reply "utter tosh" . I replied that he was correct. I also stated that they were originally designed for holding Drills / Reamers. again proved correct . I also stated that they were not the best toolholders, I never specified in which scenario that was in. I will concede that I should have specified in an industrial setting. they lack the clamping power for High feed milling. and in our "environment and many industrial scenarios, they are great.

I have proven what I stated in all 3 areas. ie their original design intent , Torque / Rigidity at HPC, and the workholding scenario. As far as I am concerned the case is closed. I have no interest or need to argue this "Ad Infinitum".

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Well said, Raymond

The system 'works' for work-holding, to the extent required by many; and the cheap stuff is very cheap .. So it's a 'no-brainer' that it will be adopted [and, using the word literally; abused] by this community. There is therefore no argument to be had.

What interests me however, is the matter of understanding what goes on inside; so that, on the rare occasions when it matters, we can say "ah, I know why it's doing that ... perhaps I should use this instead"

To that end; the questions to manufacturers; the practical tests; and the Finite Element Analysis, are very welcome,.

MichaelG.

Meanwhile the people that can do, do
And the people who can't, waffle on.

But don't forget the poor beginner trying to learn their trade. If no-one explained I'd be left in the dark. To that end I'm prepared to forgive a certain amount of willy-waving.

I'm off to the workshop for some 'doing' now, I promise!

Cheers,

Dave

John,

Is this ^^^ really necessary ?

You and I have different 'interests' and different motivations ... But surely there is room for both.

I have great respect for what you do, and for the 'bodges' that you share with us ... But I also happen to have an enquiring mind.

Could you perhaps manage a little respect [or at least patience] for those of us who are interested in the 'hows and whys' ?

MichaelG.

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Edit: Dave posted before me ... My comment refers to John Stevenson's post.

Edited By Michael Gilligan on 22/09/2016 10:44:49

Thank you Michael and Dave, If people never tried to understand what causes this or that, then nothing would progress. It is about understanding cause and effect [ or at least trying to ] Marks fine work with the FEA has shown what happens, even though I could'nt even pretend to understand the figures But I certainly understood the graphics. This has proved very interesting for me and I hope you and a few others also.

At the end of the day if certain folks have no interest in the topic then fine, they can ignore it but, there are folks who ARE interested in it..

cheers.

Perhaps the "practical" results from all of this is when using ER collets for workholding make some attempt at using the things close to their original design mode. That being, when practicable, grip diameters close to the nominal size of the collet and ensure that the part is neither tapered to any great extent or off round and that the full length of the collet is filled. Many other collet systems really should be used with ground stock but they probably hardly ever are in our workshops.

regards Martin

Well, I've read the whole 10 pages of this thread and I'm still not sure how the Bank of Scotland figures in all this

but I'm looking forward to the comparative tests of all the other collet systems available . . .

Oh dear,after a couple or so years of grown up discussion I felt encouraged to use the site occasionally but I see that handbags have again been procured. What do you mean we don't have to read it.? Who could resist it ? Now can we get down to something useful ? What is recommended as giving the firmest grip on a handbag strap?

Oh, a useful addition. I intend to use the bag ,speaking technically as a tool.

Edited By alan frost on 22/09/2016 13:19:55

Edited By alan frost on 22/09/2016 13:23:35

But only in self defence,officer

found to be excellent in both holding tooling and work. use er25 and er16.