ER32, ER25 or Direct R8 collets ?

Hi Chris,

using R8 collets will give you maximum height between milling machine table and the cutter. To use ER-32 colleets you need a collet chuck, this will reduce the maximum height between table and cutter compared to using R-8 collets. However each ER collets have a 1mm range, so you need fewer collets.

Regards

Thor

Edited By Thor on 19/10/2012 18:20:12

I would use the er32 setup as you can use metric collets to hold imperial cutters, so less collets needed

ER32 has a wide clamping range but you will lose around 2" of "daylight"

Paul

Chris,

I have an Sieg SX3 with an R8 spindle I have a set of R8 collets and an R8 ER32 collet chuck. I started off using the ER 32 but soon found that for me working with R8 collets is so much easier. They grip up with far less tightening effort and release easily too. I fitted a spindle lock to the mill which makes the whole thing so much easier. The ER32's do come in useful but they mainly get used on my lathe.

Tony

I use ER32 x 3mt as both my of mills and my lathe have 3MT spindles so it is a universal fit .

I don't know of a hobby lathe that runs R-8 in the spindle .

Ian

I need to obtain a new set of collets for my mill (3mt) from reading the above posts I see I have a choice of mt3 'finger' collet or an ER32 collet and nut.

Given that the ER32 takes up work space below the spindle what advantages / disadvantages do they offer over the finger collets?

(sorry I'm new to this! any recommendations appreciated)

regards

Paul

The downside of the er32, is the limited length of the larger diameter tooling that it can handle. I chose er25 which holds up to 16mm, and we have a full set of R8 collets which will hold longer tooling deeper, except for the 20mm one which is limited by the size of the R8 design. Above that diameter I have a 25mm indexable with 3 APHT 16 inserts with the shank turned down to 20 and 18mm in steps according to how much projection is needed. Then its shell mills, 40, 50, 63 and 80mm.

I am like XD351, but have five metric collets that go direct in the Mill taper, for when headroom becomes important.

I use ER25 and ER 32 collets on the mill and with a Backplate, allowing material to pass through, on the lathe.

Facemills and Flycutters are on 3MT arbors for the mill.

But you need to use whatever suits your circumstances the best.

Howard

Range and flexibility. Other collets have much smaller clamping range, whereas ER32 can cope with a full millimetre. 18 collets gets from 2 to 20mm. Modern design (1973), they hold well and are accurate, I use them for work-holding on my lathe as well. Recommended for use with an MT3 mill. (Someone's bound to mention R8, but we MT3 owners have to stay loyal to our choices!)

If you get ER32, well worth getting a ball-bearing Nut for the chuck - easier to tighten.

No one ever got fired for choosing ER32

Dave

Thank you for the help.

I think I'm going to go with the ER32 set from ARC with a few MT collets for when space is required.

Regards

Paul

Cutters usually have a limited range of shank sizes so just for cutter holding a limited range of direct collets would be required. To cover all possible sizes if you wanted to hold drills in a collet then ER is very accommodating. I use an ER25 chuck but I have also got quite a few direct R8 collets. One consideration is cutter visibility, with a large chuck and small cutter you tend to see a lot of chuck and not much cutter and the same with small cutters in a direct collet, the spindle nose tends to obscure your view. For small cutter work is can be nice to use a small chuck to maximise visibility. I suppose the answer is that no system is perfect but the ER chuck may be a good place to start. Eventually I suspect most of us acquire a choice of methods. My machine is R8 but I have now got a Clarkson chuck, an ER25 chuck, some direct R8 collets and an MT3 and MT2 adapter which are not overly convenient as you have to eject the adaptor to remove the drill. Other tooling will surely be collected like shell mill arbors, slitting saw arbors, a fly cutter and a drill chuck. Unfortunately there is probably no end to collecting tooling but you certainly don’t need it all on day one.

Mike

As Mike says cutters come in a very limited range of shank sizes so the versatility of an ER system is basically wasted.

If I were starting over I'd go for end-mill holders such as those from Arc **LINK** and either buy cutters with the flat already fitted or set up to fit my own flats.

Either two of each shank size you use so as to have an end mill and a slot drill set-up and ready to go or go all modern and use three flute centre cutting end-mills for both duties. I'd go three flute now.

Although keeping cutters ready to go in shanked holders is thought of as a CNC concept where seconds wasted in tool changing add up to real money the convenience and faster toolchanging is just as valid in the home shop where we need to make the most of the valuable workshop time eaked out around other responsibilities.

Generally ready flatted end mills appear a little more expensive than the plain shank versions but this is somewhat spurious as true economy range cutters don't seem to be made with flatted shanks so you end up buying a better cutter.

Like Mike I have lots of choices ER, direct R8 collets, a Clarkson chuck and end mill holders. All got for what seemed good and sufficient reason at the time. As I have a good stash of screw ended cutters the Clarkson (Posiloc actually) is my normal go to. The ER system has turned out be the unloved step child. Pretty much never used.

Clive

Not necessarily so. Carbide cutters are increasingly affordable. These from Cutwell come in shank sizes the same as the nominal diameter **LINK**

Rod

There is also the fact that you can hold drills in ER collets so saving the time having to remove MT collets or an ER holder to be replaced by a drill chuck which takes up even more head room.

More so on a moving head mill you will find you spend less time cranking up the head or moving the table to one side when you want to change ER collet size than you need to when removing and replacing a MT or R8 collet

It's worth considering your wider tool and workholding requirements ... e.g. I did the me-math and have er40 standardised across my mill (MT3 - chester's version of the sieg sx3), lathe spindle (sieg c6b), rotary indexer (5c spindexer with adapter), and square and hex (stevenson) blocks. My logic is that I can accomplish workholding and toolholding with one system - and I have two sets of collets ( up to 26mm) and one set of oversize collets which go up to 30mm.

The downside is the mill looses height and rigidity with the additional collet stickout!

I'm trying to workout how I can set up my lathe to have front lever action collet closer that works with er collets, and also a quick-change lever action mt3 toolholder for the mill (a bit similar to the tormach system - but manual) - but those are challenges for another day

Edited By jann west on 05/10/2020 19:33:09

As always depends on what you're doing! I put a DTI, wiggler, edge finder, fly cutter, slitting saw, miniature drill chuck, tramming tool and imperial and metric twist drills in mine. Also use ER32 for work-holding in the lathe and a Stevenson Block. The whole set's been used, though it's true some of the larger ones haven't seen much action.

Dave

There is no law to enforce the buying of the complete collet range. Just buy the chuck and the collets you need.

regards Martin