er 32 collets

Hello all

I need to buy some ER32 collets to fit a work head on my Clarkson Tool and Cutter Grinder, I need to sharpen 1/4,5/16,3/8,1/2,5/8-6mm,8mm,10mm,12mm,16mm. Can anyone tell me the minimum number of collets I need to cover this range.

Kind Regards

Roy

You will need 1/4, 8,10, 1/2”, and 16.

While that is technically correct, I suggest that you consider buying the "exact" size collets, both imperial and metric, as it is generally easier to put a cutter into a close-fitting collet. It will usually grip initially with just a nip up on the closing nut; a looser fit means that you often need three hands and it's just a bit more fiddly. Admittedly my experience has been with my mill and CNC router so cutters held vertically and I realise that a cutter grinder has different geometry but it might be worth a thought.

5 ! 7,8,10,13 & 16. Noel

I'm with Nealeb, Also as many makers only give the accuracy of the collet at its largest nominal size you could introduce more runout by closing one down towards the lower end of it's range so then the tool gets ground off ctr.

I generally don't like to close them down too much typically 0.2 -0.3mm to grip a reaming size drill is as far as I tend to go. For use with cutters than I use the full size collet to suit

I'm with Nealeb too. In theory my metric collet set covers all the Imperial sizes, and it does. However, in practice imperial diameters often require metric collets to be clamped most of the way down. (1/2" is 12.7mm, requiring a 12-14mm collet to be squeezed by 1.3mm) As far as I can tell big squeezes don't affect accuracy, but tightening takes a lot longer and feels wrong especially in small diameters. After a while I decided it was worth buying some common Imperial collets.

That ER32 have a 2mm clamp range is highly convenient on unusual occasions, but using the full range is extra work, annoying if it has to be done a lot.

Dave

That's interesting. My ER32 collets are all marked as having a 1 mm range. Is the greater range a new innovation? I have never had any problems using them on imperial size cutters within that range.

Russell

Ok it looks like the 8 collets are needed, I have 5c collets but no way of using these in my Clarkson, I could also buy square 5c and use the T&C to regrind lathe tools for my shaper, I have never been good at using a hand grinder for lathe tools, I have not noticed any square er32 collets other than tap holders. I may take a look at making a 5c collet holder for the grinder.

Kind Regards

Roy

To be fair I thought that ER collets were advertised as having a 1mm clamping range and I think in some catalogues they are still listed as 1-2mm,2-3mm, and so on.

Kind Regards

Roy

Hi, I agree with Russell, all of my ER32 collets only have a 1mm range, and mine are from 6mm to 20mm inclusive.

Roy, if you really want to buy the bare minimum, I would go with Simon's suggestion myself, you can always add others at a later date.

Regards Nick.

Edited By Nicholas Farr on 22/05/2023 11:16:11

It would be hard to sustain SOD's idea given that ER32 collets are available to buy in 1mm increments.

For interest, ER50 collets have a 2mm clamping range.

My smaller ER32 from 2mm upto 3.5mm only have a 0.5mm range, after that 1mm range but never seen them with a 2mm range

Somebody did post a link a week or two back of square Er32 collets but they were not cheap.

An ER32 chuck will accept an inch through the collar, there could be scope there for making a holder for square toolbits - bearing in mind that a holder for grinding doesn't need to be either as hard or springy as a collet - if it has the correct length and angles, the collar should hold it; if you make it to fit the chuck and not into a collet , then it doesn't really matter if it has an open slot down one side?

Edited By DiogenesII on 22/05/2023 20:17:51

Not trying to be silly but whats wrong with replicating the factory Clarkson system using simple parallel sleeves individually bored to match the shank diameters?

Of if you have a sufficiency of 5C collets that you don't mind covering in grinding wheel dust a square 5C collet block could make a good basis for a cutter holder. Thats probably what I'd do if I didn't have the factory sleeves.

Clive

Not silly at all, I don’t have any sleeves for my Clarkson at present but I do have 5c Collets and I can get them with square holes for lathe tools, the cost of 5c collets really outweighs buying steel etc and time. That said I can just machine some sleeves to fit the current work head. I also own a Boxford VSL which will take 5c collets so I decided that I did not want to add another collet system to my tooling. I have already made the holder for 5c to fit the Clarkson which only took a couple of hours and works really well. With regard to grinding dust, I wash all the collets in paraffin and brake cleaner after use.

Kind Regards

Roy

I had a senior moment! ER32 collets are 1mm, not 2mm range.

Apologies for the confusion.

Dave

Don't worry Dave. I have lots of them now.

Russell

Just for interest the very small sized metric collets come in increments of .5mm range(there are only two or three within that range) that is the ER32 set other sized sized collets have more for example ER11

Edited By Dalboy on 23/05/2023 08:26:26