Myford Super 7 - Convert from Imperial to Metric

So guys, this weeks challenge should you wish to accept it is to talk me through the process of converting the above.

I think I will look to use a DRO of some kind on the top slides but wonder about the screw cutting aspects.

You will need the metric conversion set of change wheels and the metric banjo on which to mount them. When you have set up for a particular metric pitch, whilst you are actually cutting the thread you MUST NOT disengage the clasp nut from the leadscrew which is still imperial. If you machine has a norton type gearbox there are other considerations.

Dear Chris,

I have just read your thread on the ML7 and most of what has been said there applies to your S7 however personally I would not bother converting. But if you do I think the DRO is the way to go and there are plenty people who have done this and very successfully.

I've been cutting metal for over 50 years now and everything I own is imperial and the "on board" computer was programmed in imperial, it even has to do a quick computation of anything metric to give a meaningful value. I realise the younger generation will be all metric and wonder what inches are but for me I will stick to that which I understand. If I get a metric drawing a few moments on the calculator and I have all the dimensions in imperial--Oh joy

Regarding screw cutting, I think you said you have a QC gearbox on the S7 ? If so to cut metric you will need to buy the kit from Myford which consists of a new quadrant and some additional change wheels ---will have to look at mine to see which ones. This will allow you to cut a range of metric pitches just by changing the levers on your QC box but you will have to leave the clasp nut engaged for the duration of the operation and reverse the lathe back to the start point after each cut.

There are several cleaver devices that have been designed to overcome this if you want to cut a lot of metric it will be worth considering building one. look at "screw cutting made easy" on this site.

I also have an Emco Maximat and the conversion for metric threads is much easier on this machine so if I REALLY have to cut metric this where I do it now.

Wishing you success in your endeavours whatever you decide to do.

Regards John

PS where are you located? I am in Lancashire

If you read this post **LINK**, you will see that a good way around screw cutting is shown.

I have these gears for my S7 (with gearbox). It will not be 100% accurate but will be a very good approximation on most of the most common threads. You get a chart with them to show what gear goes with what thread

Here is a picture of my gearbox, not sure what type it is.

I couldn't find the "screw cutting made easy" sadly, brain issue probably.

I'm slowly coming around to the idea that I should leave the lathe alone and work around it.

I do fancy putting some magnetic DRO's on the top slides.

Thanks for the advice guys, it's slow to go in but I'm getting there.

Hi Chris,

Sorry my error it should have been screwcutting simplified -- look at this link

**LINK**

Your gearbox is the standard Myford Quick Change box or a Norton box in engineering parley

Regards John

Brilliant thanks.

I'm in Great Yarmouth by the way.