ML7 – Zeroing the Topslide?

[Martin KyteParticipant @martinkyte99762]

When machining to a shoulder I set a carriage stop just shy of the end of the work. Face off the end so the stop is exactly registered to the end. Wind the tool clear and advance the top slide to the length of the shoulder. Machine the shoulder to size with the crosslide and saddle taking a final indeed cut to square the shoulder. If the top slide is within a degree the shoulder length will be accurate to our purposes as has been mentioned. I tend to only use the topslide for short tapers where often a matching reamer can be turned at the same setting to finish the female component so again bang on setting is not required. Admittedly I have a Super 7 which I can set to better than 1/4 degree by eye but mostly that’s unnecessary as I say. I do have a micrometer carriage handwheel too which gives me other ways to skin the cat.

Topslides on Myford are not terribly good for turning I have found mainly due to the short dovetail slides. Turning the handwheel tends to produce a slight rocking which varies the cut. I did make George Thomas’ retractable topslide which has a bigger micrometer dial and a gear interposed between the handwheel and the lead screw which eliminates some of the rock and is much easier to set.

For very accurate spacing down a shaft when using limited or less than perfect kit I would make up a series of accurate spacers to use a stops.
Sometime we have to spend a bit of effort to achieve accuracy rather than just relying on the built in capability of the machine tool.

You could of course just throw money at the problem and buy more expensive kit but it’s not always possible or even justified.

One of the reasons why I find Model Engineering so interesting is learning how the engineers of the past achieved high precision without the modern high tech equipment. Old George Thomas said it’s amazing how much high quality work can be done on antiquated and worn machines provided you understand their limitations.

Happy Machining

Martin

[Dave HalfordParticipant @davehalford22513]

Posted by JasonB on 14/03/2023 07:01:03:

I mounted Dti on some part of the lathe and run the saddle up and down.

I use mine all the time to know how much of a cut I have put on or to position the tool as the saddle handwheel is not accurate and you are guessing anything much less than 10thou.

Not having any kind of a handwheel on my saddle I used mine to set a sliding cut length. Since getting a DRO I use it to make cuts right up to the chuck by locking the saddle where the tool just misses the jaws at full travel of the top slide. Stops all those crashes.

[JasonBModerator @jasonb]

This is how I do it on my flat sided topslide, just loosen the bolts and give it a gentle tap until it reads the same at both ends, far quicker than doing similar to a vice, etc in the mill as the carriage moves a lot faster. Less that half a thou over 7" is good enough for most things

[Dr_GMJNParticipant @dr_gmjn]

Posted by JasonB on 14/03/2023 12:13:13:

This is how I do it on my flat sided topslide, just loosen the bolts and give it a gentle tap until it reads the same at both ends, far quicker than doing similar to a vice, etc in the mill as the carriage moves a lot faster. Less that half a thou over 7" is good enough for most things

That's exactly what I want to be able to do.

[Hopper]

 

On Hopper Said:

At some point in the future at the editor’s leisure, there will be an article in MEW on making your own quite simple resettable top and cross slide dials for the ML7. Absolutely worth their weight in gold. The best mod I have done on the ML7.

As for setting top slide and measuring lateral distances etc, I am big fan of the graduated carriage leadscrew handwheel. The drawback on the ML7 is disengaging the change gears to use the handwheel. So a lead screw dog clutch is in the works too, at some point when i get around to it. There was a handy design reprinted in MEW last month too, disengaging the gear on the end of the leadscrew which is good too.

Meanwhile, another way of doing it is set your topslide as best you can by lining up the machined straight front edge on it with the edge of the cross slide. Use the topslide to take the first roughing cut or two, but accurately up to the shoulder where you want it. Then take the finishing cut/s up to that shoulder using the carriage feed to ensure the diameter is parallel along the job.

I looked at drilling and reaming a dowel pin hole to keep the top slide set parallel when wanted but there is not a lot of meat there where it is easy to access so have not bothered.

Replying to this helpful post because I am planning to fit a resettable dial to an ML7-style topslide (actually from the ML8 attachment). Did the article appear in MEW, please?

I am, of course, aware of designs for ML7 cross slide dials but there seems less scope for improving the original Myford topslide dial and their replacement dial seems to be available only in metric (that said, there is an impressive list of other spares available from Mytholmroyd).

I find the leadscrew hand wheel on my S7 very useful; you would need a long arm for this on the long  bed lathe, of course. There is a Hemingway kit for fitting the end bracket with thrust bearings with incidental provision for zeroising the dial. Also, I have experimented with a digital attachment to the saddle for the same purpose.

Like Martin Cleeve, I commend the use of a simple saddle stop combined with distance pieces.

[Nigel Graham 2Participant @nigelgraham2]

I gave my ML7 a leadscrew handwheel but found I don’t use it very often!

However, I’d also fitted a second-hand, early-type gearbox that uses the shortened leadscrew, and of course this makes manually rotating the leadscrew smoothly, more awkward.

To solve that I cut a keyway in the plain end of the screw where it enters the gearbox, long enough to allow sliding its pinion (on the saddle side of the gearbox) out of mesh. In practice I found it easier simply to lift the gear selector lever and let it rest on the surface of the slot along the top of the gate.*

 

Re machining the flank of the top-slide; Myford was selling replacement machined-all-over slides but these have not been listed for a long time now.

 

*(I have wondered about copying a fellow club-member who reverted his Myford to change-wheels. He says this gives more flexibility at little cost of convenience as he is not cutting threads all that often. )

 

[ega]

On ega Said:

 

On Hopper Said:

At some point in the future at the editor’s leisure, there will be an article in MEW on making your own quite simple resettable top and cross slide dials for the ML7. Absolutely worth their weight in gold. The best mod I have done on the ML7.

As for setting top slide and measuring lateral distances etc, I am big fan of the graduated carriage leadscrew handwheel. The drawback on the ML7 is disengaging the change gears to use the handwheel. So a lead screw dog clutch is in the works too, at some point when i get around to it. There was a handy design reprinted in MEW last month too, disengaging the gear on the end of the leadscrew which is good too.

Meanwhile, another way of doing it is set your topslide as best you can by lining up the machined straight front edge on it with the edge of the cross slide. Use the topslide to take the first roughing cut or two, but accurately up to the shoulder where you want it. Then take the finishing cut/s up to that shoulder using the carriage feed to ensure the diameter is parallel along the job.

I looked at drilling and reaming a dowel pin hole to keep the top slide set parallel when wanted but there is not a lot of meat there where it is easy to access so have not bothered.

Replying to this helpful post because I am planning to fit a resettable dial to an ML7-style topslide (actually from the ML8 attachment). Did the article appear in MEW, please?

I am, of course, aware of designs for ML7 cross slide dials but there seems less scope for improving the original Myford topslide dial and their replacement dial seems to be available only in metric (that said, there is an impressive list of other spares available from Mytholmroyd).

I find the leadscrew hand wheel on my S7 very useful; you would need a long arm for this on the long  bed lathe, of course. There is a Hemingway kit for fitting the end bracket with thrust bearings with incidental provision for zeroising the dial. Also, I have experimented with a digital attachment to the saddle for the same purpose.

Like Martin Cleeve, I commend the use of a simple saddle stop combined with distance pieces.

MEW issue 328.

[Andrew CrowParticipant @andrewcrow91475]

For accurate length setting I would also agree that a saddle stop is essential. There are a couple of designs for multi position stops, one from Hemingway and another was published in MEW afew years ago which mounts at the back of the lathe. In either case a set of slip gauges are a very useful addition, they also have multiple uses and are a worthwhile investment.

Just a word of warning about using bed stops, unless your lathe has automatic cut off for auto feed be very careful particularly with Myfords.

Andy.

[alecs]

On alecs Said:

On ega Said:

 

On Hopper Said:

At some point in the future at the editor’s leisure, there will be an article in MEW on making your own quite simple resettable top and cross slide dials for the ML7. Absolutely worth their weight in gold. The best mod I have done on the ML7.

As for setting top slide and measuring lateral distances etc, I am big fan of the graduated carriage leadscrew handwheel. The drawback on the ML7 is disengaging the change gears to use the handwheel. So a lead screw dog clutch is in the works too, at some point when i get around to it. There was a handy design reprinted in MEW last month too, disengaging the gear on the end of the leadscrew which is good too.

Meanwhile, another way of doing it is set your topslide as best you can by lining up the machined straight front edge on it with the edge of the cross slide. Use the topslide to take the first roughing cut or two, but accurately up to the shoulder where you want it. Then take the finishing cut/s up to that shoulder using the carriage feed to ensure the diameter is parallel along the job.

I looked at drilling and reaming a dowel pin hole to keep the top slide set parallel when wanted but there is not a lot of meat there where it is easy to access so have not bothered.

Replying to this helpful post because I am planning to fit a resettable dial to an ML7-style topslide (actually from the ML8 attachment). Did the article appear in MEW, please?

I am, of course, aware of designs for ML7 cross slide dials but there seems less scope for improving the original Myford topslide dial and their replacement dial seems to be available only in metric (that said, there is an impressive list of other spares available from Mytholmroyd).

I find the leadscrew hand wheel on my S7 very useful; you would need a long arm for this on the long  bed lathe, of course. There is a Hemingway kit for fitting the end bracket with thrust bearings with incidental provision for zeroising the dial. Also, I have experimented with a digital attachment to the saddle for the same purpose.

Like Martin Cleeve, I commend the use of a simple saddle stop combined with distance pieces.

MEW issue 328.

I should add that the dials described in issue 328 by Pete Barker fit both top and cross slides. Both are the same. The design works well and is simple to make. I made a couple of extras for my two vertical slides , which also use the same dials.

[Author]

Posts