ER Collet choices

I think I may set up camp within the beginners question section. Took delivery of the nice shiny new mill today and going to purchase a few more tools as required. I would like to start with an ER Collet set but can’t seem to locate any information on which one would suit my needs amongst the array of sizes available. The mill is a WM16b.

Many thanks

I chose er 25, it goes to 16mm diameter. If you want bigger, then er 32 should be your choice. If you have a lathe, then you might want to use the collets on both machines, and er 32 would ba the best choice.

Agree with old mart that ER 25 would be the usual choice for a machine of that size with its MT3 taper..

However I'd seriously consider getting sidelock endmill holders like those sold by ArcEurotrade **LINK** .

They are more compact than an ER collet system being both shorter and of smaller diameter. Which can be imortant when doing small work wth small cutters. All too often an ER system forces the use of long series endmills to clear other parts of the job.

Cutters with flats are no readily avaliable at sensible prices so there are few downsides. A not insignificant advantage is that cutters can be left mounted up so you don't have issues with varying stick outs. Its not impossibly expensive to have enough holders that your general use cutters can be kept ready mounted rather after teh fasion of alateh QC toolpost system.

Cli

Ah ok, I think I must have missed the obvious in the fact of diameter capacity. Can’t see me needing more than 16mm but is it another case of run with 32 to future proof possible needs in cutters. I’m quickly learning that so many purchase decisions in this hobby are either unnecessary or wrong type....it’s a minefield to the uninitiated Lol!

Thanks Clive something else to consider. Perhaps purchase both?

ER collets are really useful for work holding too. So a chuck for the lathe is a good idea, plus the square and hex blocks make a lot of jobs quick and easy. Which makes buying ER32 a no-brainer

Clay

Just a quick thought. I bought an ER25 set to use on my WM14. Then thought wouldn't it be useful to get an MT3 ER25 holder for my lathe.

Now realise that yes I can use all the collets but the length is limited so if you are thinking like me then buy an ER25 mounting for a faceplate for the lathe. Then you can take up to whatever your lathe mandrel will take.

Dave

Thank you all very helpful

Another thing yo think about is the ratio of milling to drilling you will be doing. With single size collet holders, each time you want to drill, you will need to swap the holder for the Jacobs chuck. With ER collets you can pick the size and hold drills as well as the milling cutters. I have a much smaller mill, and ER16 collets. I rarely swap out the holder for the Jacobs chuck.

I have a WM16B. I use an ER25 collet holder on it most of the time.

I've put a 1/4" Jacobs Drill Chuck on a home-made3/8" parallel arbour and if I need to use small drills this goes in a 3/8" ER collet. Much quicker than changing collets for each drill size.

Larger drills go either directly into an ER collet or I replace the collet holder with a 1/2" Jacobs chuck.

Access can sometimes be a problem if using std reach cutters, the ER32 collet nut is listed as 50mm diameter, ER25 at 42mm diameter. this is much less of a problem if using throw-away cutters in a holder, especially small sizes.

Emgee

You will find that the price of cutters rises rapidly with diameter. The best value are the 10, 12, 14 and 16mm indexable cutters which use the APKT or APMT 11 or 16 size inserts, either 1 or 2 per holder. The inserts come in steel or aluminium grades and are double ended. The holders can be cut with a hacksaw if they are too long for your Z height.

Edited By old mart on 04/03/2021 20:39:43

Edited By old mart on 04/03/2021 20:41:56

I don't think I've even used the Jacobs chuck. The ER does it all.

I keep on banging this drum, but with a small milling machine you can easily run out of headroom once you put a vice on the table and a chuck in the spindle. Since the range of cutter sizes is quite limited, say 3 or 4 of both metric and imperial, a good option may be to use MT3 collets direct in the taper, once for each size. Not only will you get more headroom but better rigidity.

Agreed. Sometimes though when using small cutters you get more “daylight” around the cutter to see what you’re doing if it’s mounted in a collet Chuck. I chose ER32 as there seem to be lots of fixtures and fittings in this size. The collets get used on the mill and the lathe.

I bought ER32 as my first choice. I do have a Clarkson holder, but it doesn’t get a lot of use these days. An ER32 would not be too big for your mill, but an ER25 would be a good choice, too.

An ER25 would hold as large a workpiece as your lathe will pass through the spindle. My lathe passes 1” easily. Only hold perfectly round stock if you want your collets to properly remain in spec.

I later bought an ER16 set for smaller jobs (I have only used this set on my smaller mill). You might wish to consider a smaller set later, to complement your initial choice. I don’t make so many tiny things so my 32 and 16 sets suit me. YMMV but I would say don’t rush out and buy, without thinking ahead and considering both your mill and lathe.

I would recommend buying at least ‘middle of the road’ sets. I did buy a chuck from bang good and it was absolute rubbish - the taper was not quite MT2, so was unusable.

Choices are always a compromise. Rarely does one size cover all contingencies. I expect your shiny new mill was a compromise of some sort.🙂

My lathe, a Sieg C3 passes 20mm through the spindle. So it has a bolt on ER32 collet chuck, as the biggest ER32 collet is nominally 20mm, although there are larger ones. My X2 mill has a MT3 spindle, so it is fitted with a drawbolt ER32 collet chuck. To maintain this I have a full set of ER32 collets, plus a few high precision doublers. I seldom use anything bigger than a 12mm cutter in the mill, but the collet chuck is on the lathe most of the time. Changing from collet chuck to 3J or 4J only takes approx 2 minutes, the same the other way ( 3 or 4 jaw to collet chuck). The mill collet chuck and all the collets came from CTC in Hong Kong, with no problems relating to quality, accuracy or reliability.

I have a Clarkson Autolock, but have only used it a couple of times, nothing wrong with it, I just prefer the ER32 system.

cheers

Bill

Edited By Bill Pudney on 04/03/2021 23:23:35

So it has a bolt on ER32 collet chuck, as the biggest ER32 collet is nominally 20mm

Not true. I have both 25.4mm (1&rdquo and 28.5mm (1 1/8&rdquo collets which fit my ER32 chuck. The normal range is up to 20mm, but others are available.

I have a Clarkson Autolock, but have only used it a couple of times, nothing wrong with it, I just prefer the ER32 system.

The things that may be considered ‘wrong’, or less useful, than ER are 1). it requires threaded cutters and 2). the individual collets accept only one specific size. Hence my collection of collets (some metric and some imperial) are generally stored with the relevant cutter already screwed in and they can only used for cutters, not workpieces.

As Vic says you can fet other issues if you just use MT or R8 collets, Yes they are handy when you need the head room but depending on your mill's spindle nose can be even worse than a large ER32 or even ER40 nut as vision is poor and that is more of an issue if using handwheels than a DRO or CNC plus any clamps get in the way. Also note in the photo the quill has had to be fully extended to get the cutter below the bottom of the guard which does nothing to help rigidity and eating up any savings in head room.

Myself I generally use ER32 on the manual X3 mill which includes a good 90% of my drilling as well as milling, I have finger collets that get used for when I need the height or for one particular shank cutter and also have a couple of sidelocks but have not used then in the 6months or so since I bought them. Also got an ER16 for Xmas but have not used it yet mainly as collets are in the other workshop and can't be bothered to go and get them but would if the ER16 was really needed due to access.

the SX2.7 I tend to use the ER25 99% of the time and have used sidelocks in anger on that, don't think the finger collets have been used.

KX3 is almost all ER16 as I don't use large cutters on that and the smaller nut makes it easier to get in and clear swarf.

Having 5C on the lathe I'm not so worried about workholding on that but do have ER32 & 25 blocks

So really there is no ideal one item does it all and what suits one person uses and one particular machine may not suit another but my opinion is ER will do most things from the start and then add as and when needed

Edited By JasonB on 05/03/2021 08:27:44

Hi Guys,

I tend to agree with Jason, I bought an ER32 collet chuck for use on my mill, I also have the one that was supplied with it. Both chucks come almost level with the bottom of the perspex guard/shield. So without removing that shield it effectively limits the amount of stick out of the spindle.

So whilst I agree that MT3 collets fitted directly in the spindle will give you more headroom you would have to remove the shield to take advantage of the extra clearance.