Thread: Let's talk ER chucks & collets

Do a search for er collets,that will give you the holding range for the er collet chuck,11 being small and the 40 being large.
The lower the number the smaller the diameter of the largest size cutter they will hold.

The size of the collet set will be determined by how big of tooling you want to use. ER32 will go up to 20mm where ER40 will go up to 25mm with aftermarket collets available up to 30mm,
In general 30 taper are suited to ER32's and the smaller sizes are suited to the smaller mills, but that does not mean you can's use them in your machine.
Take a look around CTC tooling and you will see the maximum tooling size each ER number will take.

Dave

Looks like 16mm is the biggest that you can fit in an ER25. ER32 can go to just over 25mm(20mm*) from memory
Stuart



Seems I was wrong. ER32 seem to only go to 20mm, I thought I had seem someone selling up to 25mm on ebay

Hi Ken,

Depends on your mill..

I think ER32 would be about right for you mill, the collets go up to 20 mm ER40 goes up to 26 mm.

I made the mistake of buying both imperial and metric sets, you don't need both. there is enough tolerance for one set to do both. I would just buy a metric set of ER32

Like this set ER32 COLLET SET (19 PCS) #A07

I'm not clear on what sort of chuck the arboga takes, but that's the other piece of the puzzle. An ER32 Collet chuck to suit the arboga...

Not sure what tooling you have with the mill... but...
If you don't have any tooling, I recommend that you get an indexable endmill like this
10MM AKEN INDEXABLE ENDMILL & 10 PCS. MITSUBISHI CARBIDE INSERTS #B32

Just be aware, buying tooling is like a bottomless pit, I'm still in free-fall, no signs of slowing down just yet...

Regards
Ray

EDIT: Looks like we all cross-posted at the same time... All saying much the same thing it seems...

At our age, we've put the kids through school, the house is nearly paid off, the ex missus has settled on $50,000, we are in the clear. She keeps the second car, and both cats. Oh yeh, is that right?

The mill or lathe is one thing, the tooling is something else. It's a drug, we are all tool junkies, if it isn't a bottle of scotch a day, or two packets of fags, what else are we going to spend our dough on? A blow up doll, I think not.

Money spent on a hobby is money spent well. Engineering is a great outlet for us hobbyists.

You could spend $250 on a new ironing board, or the same on a Kenwood Chef, but would you? I don't think so.

What I'm saying is, at our stage in life, live like there is no tomorrow, we might just not wake up.

Nuf said.

Ken

Hello Ken,

You might need to consider how the chuck will be retained in the spindle given that you
do not have a draw bar. I found this discussion on PM. It may be of interest -

Autolock flanged to suit Arboga - Practical Machinist - Largest Manufacturing Technology Forum on the Web

Bear in mind that the discussion is in relation to a Clarkson Autolock chuck.

I have purchased ER chucks and collets from both the sellers Greg recommended and I am happy enough with those purchases.

Bob.

Hi Bob,

Great response, unfortunately the post is back in 2007, and all the photos etc are no longer there.

In any case, I will give it a good read, and try and read between the lines.

Ken

What's up Ken ? Can't sleep because you're thinking about your toys?

On my computer, I'm using my wife's machine to type this, I have a link to a dropbox where a lot of the old PM images are stored. I will have a look in the morning for you.

I guess you're still up because you had a kip earlier this afternoon

Good night

Bob.

Originally Posted by RayG

I made the mistake of buying both imperial and metric sets, you don't need both. there is enough tolerance for one set to do both. I would just buy a metric set of ER32

The "metric" and "imperial" set is actually the same set. The collets span 1 mm so they just put a different label on the box. Indeed the set i have is even marked in both!

For a mill I think ER32 would be the go, if that. At the end of the day consider what it's going to be used for, holding cutters. If it were a lathe one could argue for an ER40 so you can hold larger diameter work, though personally I use ER32.

Pete

Pete and Ken,

This has been discussed at length before but I have an ER40 chuck for my mill because I have a number of 1" and 25mm shank cutters. I bought a 1" collet from Mari Tools in the US and a couple of Rego-Fix 25mm collets on US Ebay. They are the only collets I have for the 40 chuck. That chuck takes up a lot of the vertical clearance I have on my mill. My 63mm diameter face mill is a lot shorter.

I use both ER32 and ER25 collet chucks on the mill. I have an incomplete set of Rego-Fix ER32 collets and a complete set of CTC's ER25's.

I agree that the 32's would be your best bet.

Bob.

They're big shanks Bob! I feel your pain, I put a piddling little 4" vice with swivel base on the mill last night. With an MT3 - ER32 adaptor and a cutter I have no more headroom it all! I'll be investigating some MT3 collets to see if I can win some back. OT, but I guess you've seen the column extension Bob? Think that's going on my to do list.

Pete

Originally Posted by neksmerj

It seems there are many different sizes, eg, ER11, ER25, ER32, ER40 etc just to list a few. What determines what size to buy?

Does the ER number relate to some dimension of the chuck, or collet?

I'm going to need something with an MT3 arbor. I reckon the cutters might range from 3mm dia up to 20mm dia.

As has already been said, ER32 will cover that size range (3-20mm).

As far as the physical dimensions go, here is a photo I posted for Big Shed when he was discussing ER collet chucks, it shows the size difference between an ER32 and an ER40 collet chuck in R8 taper. I don't have an ER25 unfortunately, so I can't show you the difference there...

Originally Posted by Pete F

They're big shanks Bob! I feel your pain, I put a piddling little 4" vice with swivel base on the mill last night. With an MT3 - ER32 adaptor and a cutter I have no more headroom it all! I'll be investigating some MT3 collets to see if I can win some back. OT, but I guess you've seen the column extension Bob? Think that's going on my to do list.

Pete

The vexatious headroom issue is one that haunts me too. I bought some MT4 collets for my spindle...rare as hen's teeth, and expensive too. I only bought the 10, 20 and 25 mm sizes for those tools which are too big or long for ER32's. I think MT3 collets are available at littlemachineshop.

I have the clarkson chuck too, but it sticks out about 5" from the spindle nose. . Those Rego-Fix guys did us all a huge favour back in the day when they invented the ER series.

ER chuck in the Arboga. Ken and I discussed this briefly yesterday. I think the way to do this is to buy the MT3 chuck, insert it into the spindle as far as it will go, then scribe the taper at the spindle nose.

The taper can the be gashed, cut, ground, whatever to leave a flat-bottomed groove on each side. The dimensions from the Clarkson can be copied, allowing re-use of the slotted washer he already has. The chuck can then be retained by the nut and washer combination.

Greg