Myford ML7 headstock diameter

Anybody got a Myford ml7 that can tell me the internal diameter of the headstock shaft? Or what’s the biggest round bar that will pass through the chuck and out of the side of the machine. Thanks for your help, cheers Pauly

I have the super 7 but think they are the same. The tapered end of a 2MT is the size. Unfortunately it is one of the Achilles heals of the Myford.

Steve.

Edited By Steviegtr on 19/02/2020 22:52:44

This thread may prove useful.

less than 5/8 of an inch is how my S7 came, so most likely the 19/32. I have since made a 16 mm carbide tipped reamer and pushed that through the spindle. I did bore it first for the 1st 20 or so mm past the taper of the MT2 when the 10mm starts. I really should have made the reamer 16.2mm oe so to allow for metric bar. I can get 5/8 bar through no trouble, and straight slightly under sized 16mm bar bar stock at a push.

Neil L

The reason for the post was I’ve bought a metric ML10 . But to my dismay I tried to put some 16mm bar thru the chuck but found it wouldn’t go. So I measured it and found it to be 15.7 or thereabouts. I was going to check the chuck end but can’t get the chuck off at the moment. I may have to make a Mercedes star style external key to remove the chuck via the jaws and tap it round. So it sounds like because of the mt2 taper they are both the same size. I’d thought of upgrading to a ml7 but aside from the longer bed I doubt there’s much to gain. Cheers Pauly

The downside of overboring the Myford spindle is that the morse taper starts to get very short, depending on what you may need to mount this could start to be a problem. Even the standard bore does nick a little bit of the morse taper. I suppose now that many of us have a milling machine the usefulness of mounting live tooling in the headstock has rather diminished and there are workarounds that get over the problem.

Mike

The ML7 spindle bore is 19/32" or 15.1mm.

The time-honoured workaround is to use a fixed steady to support larger diameter jobs that are held by the other end in the chuck. EG:

So a large bore spindle is a nicety rather than a necessity.

Edited By Hopper on 20/02/2020 10:27:35

Edited By Hopper on 20/02/2020 10:47:34

I thought of doing that ,but the axle I was making was 16mm dia and 500 mm long so wouldn’t go on the bed.I bought a pair of ball raced wheels with a 16mm bore, then bought some 16mm round to mount the wheels, trouble was the bar came up at 16.25 mm. And I couldn’t machine off .25mm

Ah yes. That's when the extra length of the ML7 could be handy. Or you get real creative about machining down one half then flipping it end for end and doing the other half. Still leaves the two end noggins to be cut off though.

So is there anywhere that makes a headstock spindle for the ML10 without the Morse taper and thus giving a bigger bore size

My first lathe, a well-used 3 1/2" Grayson, had a 19/32" spindle bore which could be irksome. I put a 5/8" drill down it. This gave a useful improvement and I never saw any downside. The 2MT still gripped well if needed

The 2MT bore in the mandrel was the main reason that my ML7 went to a new home.

Opening up the bore will slightly decrease the strength and increase the flexibility of the spindle.

If you are prepared to accept this; do it!

Howard

What did you replace it with?

I would leave the spindle and get familiar with using the fixed steady, the next job along will almost certainly be bigger than the spindle hole no matter how far you dare to push it. Even lathes with large holes have a steady for the job that is too big. If you find that you need the steady too often then perhaps it’s time to change the lathe for one with a bigger bore but one day you will need the steady.

Mike

Long job like that can be mounted on the cross slide, vertical slide or even held in the toolpost if big enough and then just use a boring head in the spindle or make shift tool holder to reduce the diameter of the end.

I’ve never seen a boring head. I’ll look that up. Ta

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Paul Smith 3,

With retirement looming, the original plan was to replace the ML7 with a Super 7 Sigma.

Very many will be horrified to know that having learned the cost of a Myford Super 7 Sigma, with 4MT mandrel, gearbox, chucks and steadies but incapable of power cross feed, I bought a far eastern product.

My purchase was an Engineers ToolRoom BL12 - 24, which is a Warco BH600 / Chester Craftsman lookalike.

It was delivered, complete with VFD, Chucks, and Steadies, with induction hardened bedways, and a separate power for both axes, as well as the leadscrew, for a quarter of the cost of the S7 Sigma.

So far, it. has served me well, with only a few early life minor problems.

It has been fitted with a shop made Four way rear toolpost, and gearbox input gear which halves the minimum feed rate.

Like so many lathes, once acquired, it is unlikely to be changed; not in my lifetime!

Probably an overkill for most of my work, but it dies all that I need.

Howard

Thanks for the reply I’ll have a read up !