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

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

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.

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

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

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

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

I started with a couple of MT3 finger collets as I was on a tight budget. I rarely use them though since I bought an ER32 collet chuck. If you’re buying an ER32 chuck buy yourself a “bearing nut” for it as it makes tightening easier.
ER32 is a good choice as there seem to be lots of other fixtures and fittings in that size. You can also get over size collets for the ER32 up to 1”.

SillyOldDuffer

Thats an impressive list of things to put in an ER collet. I have a brace of nice Albretch drill chucks to deal (more) quickly and easily with most of those. Tramming device (Burk Co-Ax knock off) goes in a direct spindle collet. Slitting saw arbor and fly-cutter are direct to spindle shanks. The idea of futzing about with a collet to hold drills almost makes my ears bleed. I have done it with oversize straight shank drills for one off "why did I agree to do this" types of job and hopefully won't be revisiting the experience.

The Stevenson blocks, spindexer and work holding in a lathe possibilities are the best arguments in favour of a comprehensive ER system. But my main lathe is native 5C spindle taper and I have full sets of 5C by 1/64" and 0.5 mm so ER has no attraction there. Obviously my spindexer, hex block and square block are 5C. All get regular use. Great thing about 5C is being able to get hex and square collets when needed.

To my mind, except a lever action closer on the lathe, popping a native arbor out of a spindle is always going to be faster and less hassle than mucking about with collets for everything. Been mimbling whether or not to fit my lever closer for ages!

One great thing about this hobby is that there are many ways of doing things with considerable overlap between methods. What you do is always constrained by what you have. Given most folks budgetary limitations the art is to get what you need now and for the foreseeable future without exhausting todays funding. No point in overspending on tool holding and tooling in early days leaving no money to get materials and actually use the stuff.

In retrospect I spent far too much far too early in anticipation of what I might need! When an absolute "must have now 'cos I shall surely need it" sits in a cupboard for 30 years before triumphantly emerging to save the day its possible the need was overstated! Hope is fading for some 40 year and counting cupboard queens. I shall use my Edgwick (Cincinnati copy) dividing head one day. I will, I will! Got the wide range plate set too, how cool is that!

Bargain prices tend to have undue influence on me too.

If I were to do it again starting now I would go with several end mill holders, a good keyless chuck, direct to spindle arbours for slitting saws and flycutter, possibly a direct to spindle collet for the tramming device and wiggler / edge-finder too. Actually I'd ditch the edge finder and buy a Huffam type wiggler, more spendy but they work properly, always. I'm unconvinced about collet blocks unless your mill is small. 5C spindexer and 5C mount chuck could cover all collet block duties for me. The blocks only tend to come out when I can't be bothered to fit the spindexer or when I have vice set ups going on at the same time. Clearly if you eventually do decide that an ER or whatever collet set is your future way forward then starting out with a collet set will probably be cheaper.

One place I would spend out on is a good machine vice. If the size is appropriate for your machine the Vertex VJ400 is a decent vice with much larger opening capacity than the normal 4" jaw vice. Spendy at £250 (ish) from Rotagrip but I'd find an ordinary vice limiting.

Clive