(wrong lathe)

Edited By Ady1 on 27/09/2022 18:11:59

Ady: I think Myford beat him to it. The ML1-2-3-4 mostly had a MT1 taper, but as far as I know the ML7 always had MT2.

Mick: Unless the internal taper is really, really bad I would have thought it was better to reclaim it with a MT2 reamer. For normal purposes the taper doesn't need to make 100% contact, so a few scroops won't matter. It might even be possible to turn a couple of thou off the existing taper before reaming, though you might need to get inventive with your boring bar.

It certainly sounds like a lot less work and money than changing the spindle. Has anybody else ever tried this and can offer opinions?

George

Edit : Some people type faster than me!

Edited By Georgineer on 27/09/2022 18:21:07

Check the spindle diameters on the outside for run out firstly in situ on the lathe. If the outside runs true it is likely that the inside has damage which may be fixed by a taper reamer. If the spindle runns out on the outside it may be possible to straighten it using a pair of V blocks and a press or a large vice. Checking it on the V blocks and a dial indicator. It is possible to grind the inside of the taper with a grinding attachment and small internal grinding wheel. Just clock a Morse taper sleeve with the compound slide to set the angle.

David

Bite the bullet £359.50 incl. VAT and apparently Myford have instock. Alignment and fitting second hand parts a potential nightmare.

Robert Butler

Apart from hopefully securing an undamaged spindle the question of the bearing fit remains. Spindle and bearings were precision hand fitted at the factory, this option attempts to accomodate a used spindle from one lathe and bearings from the existing lathe and we must not forget the shim issue. Unless the OP has significant fitting experience and the means of acturately checking the whole spindle could be out of alignment rather than just the MT2 taper.

Robert Butler

Hello Mick,

I know this sounds very much along the lines of "Bodge it and fix it" but I think it might be worth trying; after all you will still have the other alternatives open to you if it doesn't work.

If you have a 2MT drill with a poor taper fitting that you are prepared to sacrifice if necessary, try a little fine valve grinding paste on it. Run the lathe slowly and hand hold it in a glove, biasing the cutting to reduce the ovality and with it hopefully the runout. Test frequently with a test bar if you have one, having cleaned things up between runs of course!

In my early days with far less equipment and knowledge, I recovered the 2MT socket on an ML4 that had been scored with a boring bar, not by me I hasten to point out. It ran true after this work and still gripped taper tooling and the lathe went on to allow me to build my Dore-Westbury mill, still very much in use 30 years later. I sold the lathe on later, but with a clear conscience.

I feel for you, not a nice thing to recover from.

Regards Brian

The only thing that ever went in the spindle taper on my ML7 was a centre for between centres turning. I always skim them in situ anyway, so as long as the damaged taper holds being eccentric doesn't matter. If it's really bad then you can just use a short bit of bar in the 3 jaw with a point turned on, just loses a bit of overall length between ctrs. I wouldn't fork out half the value of the lathe for this.

Not being familiar as to the utilisation of your collets, I assume they have to be MT2. If not ER32's and a screw on collet chuck may be a useful option.

Robert Butler

Edited By Robert Butler on 28/09/2022 19:59:25

Hoppers method would be the way I would tackle it, but if you are wary of trying to machine the spindle yourself you could get Spindle Services of coventry to re-grind the internal morse taper. They are very helpful and reasonably priced I had the spindle assembly of a Hayes Diemaster straightened, re built, and reground with new bearings at a very reasonable price not that much more than I could have bought the rather rare and costly bearings. If you are willing to let them fit it in between other jobs they will accomodate us amateurs quite happily.

Much , much less than the cost of a new spindle or even a used one from ebay.

Good luck with whatever you decide.

Dave

I always offer cash for any such work, sometimes it helps!

Edited By Dave Wootton on 30/09/2022 13:29:49

Edited By Dave Wootton on 30/09/2022 13:30:51

Mention was made earlier of using vee blocks to support a spindle for straightening under a press. Might be prudent to make sure they are not cast iron as they have been known to split by such use.

Ian