Hello David

The "reverse gear" is done electrically and involves the swapping over of some contacts within the switch unit. It's quite possible that the previous owner has not wired it up that way, or has been obliged to omit the reversing facility as some of the contacts have burned out. If it's the usual Dewhurst affair then that's a common failure. It may even be that the motor itself doesn't have the necessary wiring in place.

I would look out for a ML7 Manual. I think I've seen one in pdf format on the web somewhere, but they're readily available. You ought to have one for setting it up and for routine maintenance.

Reversing an ML7 is also a bit worrying on occasion as the chuck can unscrew, which can lead to a furrowed brow as you examine your broken workpiece and the dents in the lathe bed. It's very rare that you should need reverse anyway.

Look out on the usual auction sites for a copy of Ian Bradley's book on the Myford lathes – a lot of good stuff in there too.

Oh – one other thing that occurs to me; did you let the motor come to a complete standstill before reversing it? If you simply flick from forward to reverse, it probably won't, but just carry on in the same direction.

You may be right about reading the advice, but I do not think it applies to a Myford or any lathe where the chuck screws on.

Perhaps you read (I'm guessing) that parting works better with the tool behind the work and the cutter upside down – as this allows the swarf to fall out more readily. And there may be other reasons … The point is, though, that this method still relies on the lathe going round the conventional way.

Hope this helps

Regards, Tim

The Myford drum reversing switch supplied by Dewhurst cannot reverse a single phase ac induction capacitor start motor when it is running!

To reverse the motor it must first be switched to OFF and when it has completely stopped then the motor switch can be moved to Reverse. If you switch over whilst running forward it will continue turning in the same direction. The reason is that the Start winding has the centrifugal switch in series with it. So when running at full speed the start winding is locked out of action. The same argument holds for running in reverse, changing the drum switch to forward has no effect.

However, if you have a 3-phase ac induction motor, which the Dewhurst drum reversing switch can also control, then changing the direction whilst running can damage not only the motor but also the drum switch contacts and is not recommended. Always switch to OFF and then wait for the motor to come to a dead stop before switching to the other direction.

Edited By John Fielding on 16/02/2016 10:50:39

I have used a friends Myford S 7 with a Dewhurst swtich, but it also has a push button off on switch, the only time the Dewhurst switch is touched is for changing from forward to reverse after first pushing the OFF button, and the lathe stops. Normal OFF ON by push button only.

My own lathe is by push buttons with interlocks, top forward, middle OFF, bottom reverse, it's done 22 years starting a 1.5hp Sph motor.

Ian S C