WM250V – MT4 spindle

[John McCullaParticipant @johnmcculla]

I have a Warco WM250V lathe which I occasionally use for milling with a vertical slide.

The spindle bore of the lathe has a number 4 morse taper. I have been unable to find any endmill holders in this size, so I made my own out of one of these – https://www.rdgtools.co.uk/product/4-morse-taper-blank-end-arbour-32mm-x-42mm/ It works well and takes tooling with a 10mm shaft.

I now want to hold a few different sizes of tooling, but again I can find almost no tooling holders with a 4MT. Is my only option to buy a few more blank end arbours and make what I need, or should I look at using an adapter to 3MT like this? – https://www.arceurotrade.co.uk/Catalogue/Adaptors-Sleeves/Morse-Taper-Sleeves—Open-for-Drawbar-use

I was always led to believe that adapters should be avoided whenever possible, but in this instance would an adapter be a more practical option? Have people experienced increased runout or reduced rigidity while using adapters like this? What about removing that style of adapter with the two spanner flats?

[GazParticipant @gaz13336]

Would something like this work if you were able to make a backplate to suit your lathe? https://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks/ER40-Lathe-Collet-Chucks?gad_source=1&gclid=Cj0KCQiA7NO7BhDsARIsADg_hIZ9ddJZ__HxdZv5Kq4tMKltsp-3nPfyaWM8Mp-byhI1HHrj2E3JorIaAuY8EALw_wcB

More versatile than a blank arbour for a specific cutter.

I’d imagine you’d find it difficult to find exactly what you’re after because I’d assume that manufacturers would presume that anyone with a 4mt lathe has a suitable mill but I could be wrong there.

[DiogenesParticipant @diogenes]

A backplate / flange-mounted ER32 collet chuck set-up would seem a fairly cheap solution with wider usefulness.

You can buy MT4 shanked ER collet chucks (some vertical mills use this size) – Amadeal have a set with collets for £99, a Bison one is ~£55 ‘bare’, or a Chinese one off Ebay for about half that.

A ‘reputable’ 4-3 sleeve would let you use MT3 direct collets, for minimal stick-out and lowest cost.

Of course, might be an ideal justification for buying a 5C collet chuck 😊

[JasonBModerator @jasonb]

When I want to put the odd bit of tooling from my MT3 mill into the 280 lathe I just use a MT3-4 sleeve, make sure you get an open ended one so a drawbar can be used

But if you don’t have any existing MT3 tooling then a backplate mounted collet chuck would be the way to go. This is preferable to a taper mounted collet chuck a syou can also hold longer work in it not just short cutters

[John HaineParticipant @johnhaine32865]

I assume from your first post that the 250V takes full-lengthMT4 tooling?  The Myford big-bore S7 is MT4 nominally but as I found out when I bought an RDG blank arbor it is shortened!  I wanted an arbor to make a lathe tool-setter for CNC so ended up making a short taper myself.

Myford supplied a short MT4 – 2 adapter that is very accurate and has an open back so takes aa drawbar.  I haven’t tried it for milling but I’m sure it would be fine.  Might be worth contacting them to see if it’s still available.

They also supply a screw-on spindle adapter to the old-style spindle nose but not much use for you.

You can buy MT4 finger collets;

https://www.fwt-gmbh.de/en/morse-taper-collet-mt4-539e

But I’d ideally agree with Jason – a backplate mounted ER 40 collet chuck will hold your cutters and stock as well.

[Mick B1Participant @mickb1]

I don’t know what sort of work you do, but when machining in the vertical slide on my WM250V, I’ve always simply held slot drills, end mills, slitting saws and boring bars directly in the 3-jaw. It helps that the 3-jaw happens to have very good concentricity .

If I needed better circumferential grip I guess I’d bore my soft jaws to suit.

I can’t readily imagine what would ever would make me think it worth the work or expense of doing it any other way.

[Pete RimmerParticipant @peterimmer30576]

Milling cutters I would hold in a collet chuck but to answer your question yes MT4 tool holder tooling is not so common and takes patience to find. I myself have bought a handful of blank arbors in order to re-purpose them as required.

[mark smith 20Participant @marksmith20]

Can you not use a osbourne or clarkson collet chuck  with some kind of drawbar. They show up on ebay occasionally cheap  with some collets (usually imperial 1/4, 3/8, 1/2″ etc…)  .I use aMT4 one on my alexander mill.

Such as this, though i only paid £35  for mine and it came with 8 collets

https://www.ebay.co.uk/itm/335568932483

[John McCullaParticipant @johnmcculla]

<p style=”text-align: left;”>Tbh I hadn’t wanted to go down the collet route, it means buying a whole set of collets, but maybe that is the best option. Arc Euro have a stonking deal on an ER32 collet chuck, so I might give that a go and just buy a few individual collets for now. (Although it would involve then making a backplate which is one more thing to add the roun tuit list!)</p>

[DiogenesParticipant @diogenes]

Well, if reducers fit the bill then there’s no real harm in using them – the spanner flats are to ‘wring’ them out, BTW.

Note that ER32 collets only go up to 19mm in the standard range – you used to be able to readily obtain sizes up to 25mm or 1″, but they don’t seem quite so common these days. ER40 will go up to 25 standard.

There are advantages of a collet chuck for workholding; as well as (generally) better concentricity, they have a firmer grip with more even pressure, so work is less likely to ‘spin’ or get crushed, don’t mark the work, and of course there are no whirling jaws if you need to use handtools to finish or form shapes on a workpiece. I use mine a lot.

 

[mgnbukParticipant @mgnbuk]

(Although it would involve then making a backplate which is one more thing to add the roun tuit list!)

Maybe not ?

Depends on the spindle nose register dimensions, but I bought the 125mm version for my Warco GH600 and it fits the spindle nose just like any other chuck. No backplate required, as the register & bolt pcd dimensions of the Arc supplied ER35 collet chuck are the same as the 3 & 4 jaw chucks supplied with the machine. Might be worth a measure-up of your spindle nose / existing chucks ?

Nigel B.

[John McCulla]

On John McCulla Said:

<p style=”text-align: left;”>Tbh I hadn’t wanted to go down the collet route, it means buying a whole set of collets, but maybe that is the best option. Arc Euro have a stonking deal on an ER32 collet chuck, so I might give that a go and just buy a few individual collets for now. (Although it would involve then making a backplate which is one more thing to add the roun tuit list!)</p>

A set???

If you stick to metric you will need 4 sizes though 16mm might have too much bite for a vertical slide.

 

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