Collets help

Hi guys" can any one identify these collet please? They came with the mill, great collets & I want some more.

Rob

Just had a look on ebay & found Deckel FP1 George Alexander cutter Grinder Collets item No 29108421473 could these be the ones! My mill is a Deckel FP1

Rob

I finally bit the bullet and have brought myself a ER40 milling holder but without the collets. So now I need to get some collets which I will get as needed. But I have a question, the collets are available in 1 mm increments, So it your milling cutter shank is 12 mm, do you get a 11-12 mm collets or the 12-13 mm collet.

Hi Kenneth' I would say 12/13mm a 10mm will do a 3/8" or it works fine in Al204 ER collets, I thought ER 40 was a little large for a FP1 deckel! ER 32 was the size I looked at, but hay let me know how you get on with them.

Rob

I would always fit the cutter in the smallest collet that way you only have to tighten a little rather than squashing up a whole mm

so 10mm shank goes in a 9-10mm collet

Ian

Kenneth: ER collets were designed for use with cutting tools, although many model engineers use them for work holding too. For maximum grip on a cutter you should use a collet where the larger number is the same as the shank diameter. so for a 12mm cutter shank you should use an 11-12mm collet. Using the collet towards it's lower size significantly reduces the grip on the cutter shank and worsens the runout.

Regards,

Andrew

I agree completely with the 2 posts above. Although ER collets are supposed to have a 1mm range, it becomes increasing difficult to get a good grip on the tool as the diameter of the collet goes down. So, whereas a 25mm collet may well grip a 24.2mm shank OK, a 10-9mm collet can have difficulty securely clamping a a 9.5mm (3/8" ) cutter. A 4-3 mm collet will not grip a 1/8" (3.18mm) endmill shank, even in ER25 size collets. If you are contemplating using imperial cutters it is well worth considering investing in a few imperial collets, or at least some from a range that includes .5mm increments.

HTH

Rod

Edited By Roderick Jenkins on 04/06/2014 13:55:49

How can I tell in a polite and non-aggressive way that something written here is nonsense? Without getting a hit with that proverbial ***?

Naturally it is perfectly possible to hold e.g. a 3.1 mm drill in a 4-3 mm ER collet, - BUT - you have to do it outside of the machine!!! It is necessary to hold the chuck body either in a dedicated holder or, in the absence of such a thing, in your trusty vice. Most (all?) chucks have two flats just for that. Then use the correct spanner for the collet nut and Bob's your uncle.

Regards, Frank

Edited By Neil Wyatt on 04/06/2014 18:23:24

Frank,

Putting such force on the collet nut that you have to hold it in a vice doesn't seem to be very kind to the collet or the chuck. My ER25 chuck has a spanner flat on it and I bought a 30mm spanner especially to fit. Even with a ball bearing nut, I regard the force required to close the collet on a 1/8" endmill as excessive.

Clearly your experiences differ from mine and the polite and non-aggressive way is to not call my experience nonsense.

cheers,

Rod

Edited By Neil Wyatt on 04/06/2014 18:23:03

Are they 5C collets? **LINK**

Correct torque is about 75ftlbs, which normally requires a holding fixture. The bearing nuts are better .

This force goes up for ER32.

Steve

We had this discussion before. Official clamping force is much higher than you might expect - but I use a 4" tommy bar and a C-spanner and have only had a few problems (caused by not using full strength).

The length of ER25 closing spanners is between 140 and 210mm or about 6-8", but you can get heavy duty torque wrenches.

Rego Fix give values between 20-104 n/m, with a ball bearing nut for ER25 (20 for up to .3.5mm, 104 for over 8mm), but just 32 nm (24 foot pounds) for the fine-thread collet nuts.For the record normal is 1.5mm pitch, fine is 1mm. Mine are 1.5mm pitch.

Rego Fix advise using a torque wrench to avoid over tightening by more than 20%.

**LINK**

Remember though , that these are recommendations for a production environment where the endmill is expected to stay put for its working life possible a carbide endmill being used at silly rpm on nasty materials.

On the other points, below 2.5mm the ER25 series have a collapse range of just 0.5mm. As for imperial end mills, I have a 1/4" collet as I prefer not to collapse a 7mm regularly down to 6.3mm and I have a lot of 1/4" shank FC3 cutters, but have had no problems using 10mm for 3/8" mills.

Neil

I don't see why? I tighten my ER collets with the body in the machine spindle. One spanner on the flats of the body and the other on the nut seems to work fine. But then again I always use collets at their nominal diameter, so I don't need to close them down by very much. And I only use ER20 collets, even on a Bridgeport.

Regards,

Andrew

My first set of ER collets was a Rego Fix set purchased when I was living in Europe, circa early 1990s.

ER 25. Still in use almost daily on my lathe and Centec miller. The lathe (Emco) has two little round rods for tightening, and last night I used the 2-3mm collet for 2.3mm shafting, no problem.

I also have ER25s on my Worden (Thanks Rod!) and on my larger lathe, plus ER 40s on this larger lathe, and ER 16 on my CNC mill, and ER11s for fun.

All my other MT based collets and MT-mounted drill chucks are sitting, gathering dust, as these ER collets live on most of my machines.

I do, however, try and purchase very good collets; the Rego Fix ones, for instance, the Schaubin holder on my mill, but most of my holders are home made.

Just a happy camper.

How are precision collets made ?

Does any one know ?

Thanks Neil

Rob,

Yes those are Deckel collet's. As far as I know Deckel still make and sell them. Better be sitting down before reading the price though. I seem to recall there might be some cheaper copies around but can't remember where I saw them for sale. Maybe RDG Tools? And if you haven't seen it yet, going to www.lathes.co.uk and then clicking on the Deckel link will get you a lot of further information. I can't say for sure if those G.A. cutter grinder collets are the same or not. But someone here will know for sure. And it would be hard to find a better mill than yours imo.

Pete

I've just starting using my new ER35 collet chuck, wish I'd bought one years ago. The figures for tightening torques seem very high. I have no prpbs. at all ,for the correct size,eg. 10mm bar in 10mm collet Just hand tightening is enough, no need for C spanner. This is just lathe turning and not holding a milling cutter.

Gordon,

I think you might mean either a ER 25 or ER 32 for your collet size. The main reason I think people have for something like endmill's being pulled out of the ER style collets is they just don't know how high the torque requirement's are. My ER 40's need well over 100 ft lbs of torque on the nut. Almost 130 ft lbs if I remember right. But for tool holding, hand tight or a bit more isn't going to do it. You certainly wouldn't want a razor sharp endmill dropping out of the collet at high rpm.

Pete

Pete, quite right of course, ER32 they are, slip of the old brain. As said I only use for turnig, once had a 3/8 endmill in and no bother in a 3/8 collet, only easy cutting tho'.

No problem Gordon, but I did want to double check as you might have had something I've not run across yet. But one thing you might want to watch for, single point threading put's a fair amount of pressure on the part, so doing something like that without much tightening torque could very easily push the part back into the collet. Just one more little detail to trap us.

Pete