Is it possible to convert a 1968-71 model Myford Super 7 to metric

Hi

I have 2 early teenage grandchildren who are showing an interest in engineering and in particular using my myford. I am a ft and inches person, and when I talk in imperial they look at me as if I am mad.

The question is- Is it possible to convert my Super 7 fitted with a gearbox to permanent metric measurements. If so what do I need in addition to the new dials. I hope I have explained this properly.

I already have a metric wheel thread cutting set for the gearbox.

Thanks

Tom

Back in the 1970's when this country pretended to turn metric the school workshop where I taught metalwork had 4 Boxford lathes and 2 Colchesters, all were of course imperial. To promote metric teaching I was provided with metric "conversion" dials for each lathe. This was fine for small increments but as soon as the dial turned greater than a full revolution things became totally confusing.

After a chorus of complaints across Hampshire we were eventually supplied with new metric feedscrews, nuts and dials. They didn't provide new leadscrews so metric screwcutting wasn't possible.

This is really the only way to convert an imperial lathe to metric and I suspect it might be quite pricey to do now.

It's some time since I used a Myford, but if I recall correctly, some have a dial at the end of the leadscrew. In your case it would be hard to convert this without changing the leadscrew too.

There must be examples of people converting Myfords so maybe there is a conversion kit available? Others may know more than I do.

Been asked before see **LINK**

The parts to convert are or seem to be available from Myford Ltd but could prove expensive, may be easier to teach them feet and inches only cost is time.

Personal the vital bit of kit in my workshop is a calculator as my machines are metric and the locomotive builds are imperial so if it says 1.25" I simply convert to metric 31.75mm in this case.

Bob

Edited By Bob Brown 1 on 14/09/2015 12:09:34

Metric Super7s came with metric cross and topslide screws and dials, the leadscrew and gearbox remained Imperial, the metric conversion set being used to cut metric threads (clasp nuts to be kept engaged). This is why you need to be able to reverse your lathe. Probably cheaper to buy the young ones a metric mini lathe.

Dave

You may like to have a chat with Myfords (or eMail them) regarding a new lamps for old refurbishment.

The last show I was at, they said that many people trade in their old Myford for a reconditioned one. They may be willing to go to a metric rather than like for like.

If you are going to replace the leadscrew, leadscrew handwheel, cross slide screw and nut + micrometer dial, topslide screw and nut + mocrometer dial, you are already in for some reasonably serious dosh.

If you change the leadscrew presumably you are going to mess up all your gearbox ratio's too which will need to be addressed.

regards Martin

. . . . or you could just fit DRO's and ignore what the lathe micrometers say.

Martin

I am fairly certain that Myford Ltd. supply metric feedscrews and nuts as well as new dials, and fitting is a doddle. Look at http://www.myford.co.uk/acatalog/Myford_Super_7_Carriage_Assembly.html to see part numbers and also on the site there is a history page that may help to check exactly what parts you need for your model. Or give them a ring. They are quite pricey, so an alternative would be to make your own as trapezoidal feed screw stock and nuts are available e.g. from Zapp Automation or Marchant Dyce. I've made a total of 3 cross slide feedscrews in my cnc conversion, the last one being a ballscrew. (I don't bother with a topslide except for tool setting.)

Alternatively you could keep the imperial screws and fit a cheap DRO system based on capacitive scales, for example from Allandale Electronics.

As for the main leadscrew, as someone said even on the metric version this stayed at 8 tpi which confused me at first. If you have a metric gearbox it won't be an issue for you, but anyway most fixing threads can be cut to an acceptable approximation using the standard imperial gears. I've kept the leadscrew for the moment but I don't care as the computer sorts out the conversion!

Thanks all. I had not thought of the DRO route, will need to explore this option and at least as an interim option find out how to source and fit these.

Almost 100% they will find DRO's easier to understand. It is the main way or working now in teaching colleges etc. and industry and all my peers that I learned with (not being much older really) found them much simpler and more useful than the dials. And my regards and best of luck to them and yourself for teaching them , there are not enough young people in this hobby!

Edited By Ralph H on 14/09/2015 13:29:15

Rather than converting the lathe and making it more difficult to use yourself, perhaps buy a small metric lathe for learning on, which could, ultimately, be given to one of the youngsters when they get their own space?

INeil

That's my plan, except they will learn the English way as well I have found it very useful at work to have a good understanding of both.

Before DROs became generally available I had a set of Top slide and Cross slide leadscrew and nuts for one of my Myford Super 7s.

Once DRO was fitted, that was it. Now full DRO and metric/imperial screwcutting is the order of the day.

It would be good I they learn imperial working as well as metric, in industry it is often required that new workers have to be taught about feet and inches because a lot of stuff out there is pre metric, and a small workshop may only have an imperial lathe that's been there for the last 60 years or more.

Ian S C

Teach them to use a calculator. More trouble than it is worth to convert lathe to metric.

Hello Tom,

I would also endorse the DRO route, it adds enormously to the versatility and I for one would never go back to dials and counting. You and the grandchildren can then both feel happy with just one switch to alter the 'language' as and when you feel like it. There are other advantages too, such as instant resetting on stepped work. and zeroing the tool on the chuck jaws or face, to then cut work to length from those references with complete confidence..

It may well be a cheaper alternative to rebuilding the lathe with new feed screws, nuts and calibrated collars, the youngsters might even take an active interest in fitting the system as well and learn something of how the lathe works while doing so..

Regards

Brian

Hi Brian

I think your suggestions are the route I will take. You are probably right that they will take an interest in the fitting of the DRO system

Now all I need to do is source the best system to fit.

Any ideas?

Rgds

Tom

Hi. I have done this.

Myford supply all the required parts though they are not low cost.
You need:
Top and Cross slide feed screws and Nuts.
2 X new Dials.
Tailstock Quill

You can cut Metric Threads on an Imperial Myford with the addition of a few Change Gears. There was a series on this in ME / MEW.

Alex

Hello Tom,

Far be it for me to tell you what is best, that is bound to be inflammatory! All I can do is describe my own system and why I chose it.

Having had some industrial exposure I saved hard and bought the expensive Newall Microsyn system; it is rugged, supremely accurate and traceable to national standards with performance test records for each scale and reader. I took the view that industrial users will chose kit that has a good reputation and I believe Newall are as good as you can buy.

Both the scales and readers are fully sealed and immune to coolant, swarf and other such contaminants, they will operate fully submerged if necessary.The guarantees were also impressive, lifetime on the scales. I don't know how that compares to other competing systems that are a lot cheaper.

So, as in all things, you get what you pay for---I have no regrets. I also equipped my mill from the same stable.

Regards

Brian

Edited By Brian Wood on 14/09/2015 18:36:34

You can't beat magnetic encoders Brian but sadly most folks can't justify the cost.

I'd love that Spherosyn system on my mill!