ER40 collet chuck D1-4

[jim’Participant @jim11037]

[jim’Participant @jim11037]

I'm thinking about fitting a D1-4 ER40 collet chuck to my Chester Crusader.

Has anyone tried one?

I'm thinking about making up a large hand closer to fit on to a bearing type nut. similar to this type used on jacobs rubber flex

Any thoughts or advice please

Cheers Jim

[jim’Participant @jim11037]

**LINK**

the image didn't work in my opening post

[Roderick JenkinsParticipant @roderickjenkins93242]

Bearing in mind that my experience relates only to ER25: a hand closure might work OK on larger diameter collets that are holding work close to the nominal size of the collet e.g. 20mm diam in a 20-19mm collet but otherwise I think you are going to need more leverage to hold e.g. a 1/4" bar (6.35mm) in a 7-6mm collet.

HTH

Rod

[Nick_GParticipant @nick_g]

.

I was only the other evening watching on youtube a short video about the Jacobs one. I found it quite interesting.

I am left wondering though if it was the cost of these or them not working as specified that has not made them more popular.

Here is the link to youtube :- **LINK**

Regards, Nick

[Gary WoodingParticipant @garywooding25363]

I have a set of ER32 collets for my mill, and purchased the square and hexagonal collet holder (John Stevenson) blocks from Arc Euro. They are great for holding delicate items in the lathe, and the square one can set to run very accurately in the independent 4-jaw. They are also quite useful for quick 2,3,4 and 6 sided dividing in the mill. Maybe they do ER40 versions.

Just a thought.

Gary

Edited By Gary Wooding on 23/07/2014 17:03:23

[John HaineParticipant @johnhaine32865]

Yes they do er40 versions.

and no, you'll need a wrench to tighten ER 40 collets in my experience.

[jim’Participant @jim11037]

That's my thinking John.

I was thinking about something 6 inch dia and either pressed on or locking screws to prevent movement.

Thank you everyone for the input

[Oompa LumpaParticipant @oompalumpa34302]

This would definitely work. However, I did notice, looking at the video linked to above that the collet nut/wheel thing was left hand thread. I don't think this is a deal breaker but you would have to be careful not to touch the wheel when in use or it could turn into an exciting afternoon.

Please let us know how you get on as I am going to put this on my (very long now) list of future mods.

graham.

[Michael GilliganParticipant @michaelgilligan61133]

Jim,

Given that your original picture didn't post correctly … this should be a useful reference for anyone interested in what you are planning.

MichaelG.

[Neil WyattModerator @neilwyatt]

'Official' closing torques for ER collets are scarily high, much higher than most of 'us' use. We've been this way before…

Neil

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Michael Gilligan on 23/07/2014 20:52:39:

Jim,

Given that your original picture didn't post correctly … this should be a useful reference for anyone interested in what you are planning.

MichaelG.

Hmm. The "Hammer Blow" is interesting, together with the "internal stop mechanism". Suggests that this mechanism is not just "hand tight"

Rod

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Roderick Jenkins on 23/07/2014 21:59:25:

… Suggests that this mechanism is not just "hand tight"

Rod

.

Quite so, Rod … and let's not forget that the RubberFlex collets [presumably] have a "softer" action than ER40.

It would probably be worth digging-out some of those patents listed at the end of the instruction leaflet.

MichaelG.

[jim’Participant @jim11037]

I had never seen figures for closing torque before, 130 ft/lb is a hell of a lot to do with a 6" dia hand closer,

here are the figures, i now see why we use sidelock holders!

**LINK**

Thank you for further thoughts

[Roderick JenkinsParticipant @roderickjenkins93242]

To be fair, ER collets were designed as tool holders. ER40 can hold a 1" diameter end mill. Hard steel in a hard collet takes some gripping! As a collet system for a lathe the required torque to hold a job with adequate force will be considerably less. But……..

Cheers,

Rod

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 23/07/2014 23:04:57

It would probably be worth digging-out some of those patents listed at the end of the instruction leaflet.

.

John,

Do you class this as "trying to drag peoples ideas through the mud" ??

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

If you are work holding as opposed to tool holding then forget the torque figures.

I'd love to put a set of strain gauges in a conventional 3 jaw chuck and measure them when tightened using the standard supplied 5" or 6" chuck key.

I'll bet it's far less than a collet chuck.

It also depends on the design of chuck.

I have a 5" Pratt chuck on my dividing head that is very high geared compared to other chucks and you have to really lean on this to get it to hold without sliding the work back in.

I also have two of the Jacobs Rubberflex and yes they work and work well and from what I can see they will work the same way with any collet in. In fact the Jacobs collet is far weaker in design.

Depending on size they have different numbers of steel fingers, less on smaller sizes, more on larger seperated by the bonded rubber.

All the rubber does is hold them apart, so on say a 1" collet you have a maximum of 12 fingers with an average width of 65 thou max so maximum gripping area is 12 x 0.065 = 0.78"

A 1" ER40 collet has a gripping area of 1" x Pi = 3.142"

I shall leave you to work the maths out on that one.

[jim’Participant @jim11037]

As you point out the surface area of an ER40 collet will be far greater.

This is my thoughts on trying ER40, as they are going to have far more area than hard jaws, (many times i reckon).

I usually just bore soft jaws to hold stuff if it matters.

I will await any more feedback before deciding weather to have a go at this. (most likely will)

Thanks again for all the advice given so far

[Anonymous]

Posted by John Stevenson on 24/07/2014 09:42:39:

I shall leave you to work the maths out on that one.

Hmmmm, according to my maths the calculations given are linear dimensions, not areas?

Andrew

[John Stevenson 1Participant @johnstevenson1]

Ok so yes linear because I don't know off hand the length to get area but form memory ER40 and rubberflex are about the same, rubber flex might be a tad more.

So for the pedantic we will say 2" for the Rubberflex and 1.5" for the ER40 to give it a fighting chance.

So Rubberflex is 0.78" x 2 = 1.56 sq in.

ER 40 is 3.1412 x 1.5 = 4.7118 sq in.

Ipso Facto – case rests.

Go for it Jim…………………………

[Neil WyattModerator @neilwyatt]

O ye of little faith!

I have a full set of these and use them ALL the time

**LINK**

<edit> it's interesting that the max torque for many of them is less than other manufacturer's recommended closing torque…

Neil

 

Edited By Neil Wyatt on 24/07/2014 11:00:24

[John Stevenson 1Participant @johnstevenson1]

I fully agree Bog's

John Stevenson MBE [ Motor Bike Engineer ]

[Michael GilliganParticipant @michaelgilligan61133]

John and John,

I have absolutely no problem with the "give it a go" attitude, but, given that Jim asked for comments, I think the Jacobs instruction leaflet and [potentially] the patents must be a very "good value" way of learning from others' experience.

MichaelG.

[jim’Participant @jim11037]

Thanks everyone.

Think I’ll order a chuck and collet ser over the weekend.

I’ll post my results, when I have some

[John HaineParticipant @johnhaine32865]

Just to repeat I've got an er40 chuck without a ball bearing closer and it needs a lot of wellie with the collet wrench and a tommy bar to properly clamp, at least when the collet is being significantly closed down in diameter. Life could be easier with a ball bearing nut but actually using a wrench is easy enough, so I don't see any reason why I would want a hand closer or spend yet more money on the special nut. Your mileage may differ.

Oh and JS's square and hex er40 collet blocks are very nice.

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