ML 7 – Adaptation for wide ange cones

[Martin DowingParticipant @martindowing58466]

One of awkward issues related to ML7 but no longer present in Super 7 is lack of ability to turn wide angle cones using a top slide. Such cones are useful for example for turning a pulley. I know, pulley grove is often cut with a form tool, but I do not expect ML7 to pull this trick out, so I won't even try.

Initial inspection of task suggests that 4 holes could be drilled in the boring table at 10.30 am, 1.30pm, 4.30pm and 7.30pm or so, then tapped with1/4" tap and then as need arise these can be used for clamping the part on which top slide is sliding (holes must be matched with circular slots used also for usual clamping).

When not in use these holes can be plugged with appropriate setscrews to prevent swarf going in.

Is it how this job should be done or idea is daft and something more clever was worked out long time ago?

Martin

[Martin DowingParticipant @martindowing58466]

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Martin,

I made an intermediate plate that bolted to the existing top-slide tee-nuts and provided a second set of mountings to take the top-slide at 90 degrees to its normal position. You need to lose a bit of space under the tool but that's feasible if the original Myford tool-holder is used with an HSS tool-bit – just discard some of the packing.

I hope that helps.

Best regards,

Swarf, Mostly!

[Mike PooleParticipant @mikepoole82104]

**LINK**

I asked the same question and got plenty to think about.

Mike

[Martin DowingParticipant @martindowing58466]

Many thanks both of you.

Thread from 2013 is very informative.

Martin

[Andrew TinsleyParticipant @andrewtinsley63637]

Not sure if I have misunderstood your comment on machining V pulleys. If you look at an early Duplex article on the subject I think they shows how to do that job using a form tool on an ML7.

Andrew.

[Howard LewisParticipant @howardlewis46836]

Puzzled by this, must have misunderstood the post.

The grooves for Vee Belts are usually about 38 degrees, so only 19 either way off square to machine each side if not using a form tool (A bit like thread cutting).

To exceed the travel on my ML7, I had to go more than 45 degrees off square.

Howard

[Neil WyattModerator @neilwyatt]

Posted by Howard Lewis on 10/03/2018 17:17:56:

Puzzled by this, must have misunderstood the post.

The grooves for Vee Belts are usually about 38 degrees, so only 19 either way off square to machine each side if not using a form tool (A bit like thread cutting).

To exceed the travel on my ML7, I had to go more than 45 degrees off square.

Howard

Ahem 38 degree grove = 71 degrees off square…

Sorry H.

Neil

[John OlsenParticipant @johnolsen79199]

As mentioned in the earlier thread, the top slide can go to 65 degrees to the lathe axis, although the calibrations only go to 45 degrees. You can scribe another mark to allow setting accurately beyond that. However…if you need to get to 71 it won't quite make it. You could probably win the extra by lengthening the curved slot by a bit, although this would weaken it a little and would of course also offend the flat earthers. Just as well they can' see my ML7, which although it has not had that particular mod, is not exactly factory standard. (the tailstock uses the rack out of a small Japanese car, and the 4 speed poly V belt drive is a big improvement over the original.)

Of course at extreme angles you will start to get fouling between the cross slide and top slide dials,but you should be able to get to 71 degrees .

Speaking of poly V belts, I would use them for most drives rather than mess around with ordinary V belts. The ML7 can certainly cope with the form tool to make poly V pulleys. The hardest bit is the awkward distance between the grooves.

John

[Martin DowingParticipant @martindowing58466]

Posted by John Olsen on 11/03/2018 04:59:30:

As mentioned in the earlier thread, the top slide can go to 65 degrees to the lathe axis, although the calibrations only go to 45 degrees. You can scribe another mark to allow setting accurately beyond that. However…if you need to get to 71 it won't quite make it. You could probably win the extra by lengthening the curved slot by a bit, although this would weaken it a little and would of course also offend the flat earthers. Just as well they can' see my ML7, which although it has not had that particular mod, is not exactly factory standard. (the tailstock uses the rack out of a small Japanese car, and the 4 speed poly V belt drive is a big improvement over the original.)

Of course at extreme angles you will start to get fouling between the cross slide and top slide dials,but you should be able to get to 71 degrees .

Speaking of poly V belts, I would use them for most drives rather than mess around with ordinary V belts. The ML7 can certainly cope with the form tool to make poly V pulleys. The hardest bit is the awkward distance between the grooves.

John

As per offending flatearthers – well lets them be offended if there is no way around it. Have done few modifications myself and long time ago when I got machine all original badly damaged paint was stripped to bare casting and much better specialistic abrasion resistant epoxy paints were applied but now machine is in black and red. One flatearther told me that I have destroyed machine by doing so.

As per cutting pulleys for V-belt by using form tool in rear toolpost – in aluminium you will succeed, in steel no. Not for 13 mm belt at least. I have failed with 7 mm wide and 10 mm deep grove on 70mm diameter., rear toolpost or not. If your machine can do it, then I will need to look on my headstock bearing.

As per making topslide more useful – I will go for drilling & tapping 4 holes in crosslide (with care to avoid damage to t-slots). Possibly I will also make "long topslide", perhaps 1/8 inch "thinner" to get more space for tooling.

Martin

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