I cannot remember ever in need of use of that clutch for the last 40 years, so if you can make the drive permanently you probably have solved your problem. Niko.

Joe,

I had one of these, the clutch was dodgy, but I still wish I hadn't sold it!

The clutch was a very crude expanding shoe and was basically just a ring of metal with a wedge cut out of the top. As you operated the handle, a rod was driven down the centre of the rotating drive shaft (the rod spins with the shaft, there is a bearing in the handle if I recall correct)

This rod has a ramp cut in to it, and a dowel pin rides up this ramp, and pushes the wedge in to the cut out in the clutch, expanding it.

My rod was obviously not sufficiently hardened or was damaged by improper adjustment or use, so the ramp had a notch, and this notch made it very difficult to actuate the cluch, all I needed was a bit of medium carbon steel the correct length, and machine this simple ramp in it, I'd case harden the ramp locally and that would have sorted it.

Failing that, making an entirely new shoe wouldn't be difficult as it didn't have any sort of friction material on it. You could also sleeve the corresponding bore in the pulley?

As Niko said, worst case scenario, do away with the clutch, the ML7 version doesn't have one, and you don't really need it. It does prevent you having to stop and start your motor all the time, to quickly check dimensions which is handy, plus as I understand it, stopping and starting can be very harmful to most single phase motors depending on the type!

Until fairly recently I had a Mk1 S7. I only sold it because a low milage PCF machine came my way at a reasonable price.

When the Mk1 first arrived the clutch was awful. After a little investigation I concluded the inner face of the "brake-drum" was well worn. There being a large step in the friction surface. (So far as I could ascertain the "brake shoe" was OK). At the time I acquired my Mk1 I was fortunate enough to still have my ML7. Having dismantle the lay-shaft assembly by driving the shaft out towards the tail-stock (important that) I bored the brake drum out to increase its diameter by about 3/8" over what was the original size.

Before boring the brake drum I was able to determine the original I/D by measuring the unworn part of the drum surface. I made an insert from a chunk of continuously cast iron (c/o College Engineering) with about 0.002" clearance. I then loctited this in and bored it to final size having carefully clocked it to run concentricly..

More recently, shortly before I sold it, I did further work on the clutch by making a new actuating shaft from unhardened silver steel and replace the ball-race in the actuating lever.

The only real complaint I have about the Mk1 machine is the ability of the layshaft bearings to spray quite a lot of oil about. Although I never did carry out the modification myself I have heard many people have tamed their Mk1 layshaft by changing the 4 needle roller bearing to sintered bushes.

I should add that I had my Mk1 machine for about 20 years and still believe the sight feed lubricated headstock is a better arrangement than the later under-fed wick system.

Edited By Brian Oldford on 31/08/2017 22:03:37

Joe

My S7 Mk1 is on a Myford Industrial cabinet, and I would guess the top of the belt guard is roughly just under 5 feet or 1.5 metres from the floor. Adjustable feet on the cabinet raises it a couple of inches from normal. This means the clutch lever falls conveniently to hand for me, being over 6 ft tall.

However, having moved several Myford lathes, I/we have always removed them from the cabinet for reasons of stability. On the cabinet they are very prone to falling over unless tightly restrained from all 4 sides. The lathe is easily unbolted from the cabinet, the tedious part is removing the wiring from the motor and remembering to note where to put it back.   On no account just push it into a van and drive off – a recipe for disaster!

The lathe itself always wants to fall over backwards, so bolting through the feet into a length of timber at right angle to the bed will stop this nasty habit

Edited By Robbo on 01/09/2017 09:42:43