myford leadscrew

When I have tried to use the hand wheel on the end of the lead screw on my aged S7to move the cross slide with the half nuts engaged . it's always difficult to move because it turns the screwcutting gear box as well . Just been cleaning and oiling , and I cant see any way of disconnecting it . I never use it for that reason . Is this the normal situation or am I doing something wrong ? Just what is the use of that graduated hand wheel ?

Regards Phil

On a lathe without gearbox you just remove the gear that meshes with the one on the end of the leadscrew. Presumably not so easy if you do have a gearbox.

If you move the selector lever on the top of the gear box and leave it between two normal settings this will disengage the gearbox gear train and the leadscrew should be free to turn with the handwheel , a bit like a car in neutral !

There have been drawings over the years for a dog clutch -- to bring it up to the standard of a Drummond M type. 😁

Philip,

An alternative to T.B's suggestion is to pick the gap in the selector positions on the front of the gearbox and leave it parked there instead.

Brian

As T.B says, just disengage the gearbox using the selector arm and the leadscrew will rotate freely. The graduated handwheel is invaluable for measuring turned lengths. I use it all the time.

why didn.t I try that before !!

Also, if the Handwheel is tight up against the Tailstock end bearing, it will make turning the Handle hard. You only need just enough clearance to allow it to turn, with minimal endfloat on the leadscrew.

Howard

I find the handwheel on my lathe annoying (ML7) as the graduations don't go up cleanly in tens for each revolution. I can't explain it very well, but I mean the end of the graduations end in a five when it reaches zero.

I know what I mean if no-one else does...

If it's fitted with an 8 TPI lead screw, and I expect it is, the graduated hand wheel will need 125 divisions for each division to show .001" of carriage travel.

So, yes, the last division before the zero would be a five.

As the lead screw is 8tpi you are rather stuck with it moving 125 thou per revolution but you could have a metric version and move 3.175mm, both make life awkward if you have to count past the zero point. Such is life.

Mike