myford leadscrew

This topic has 11 replies, 10 voices, and was last updated 9 April 2019 at 22:01 by Mike Poole.

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8 April 2019 at 20:26 #404240
Philip Burley
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@philipburley44197
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
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8 April 2019 at 20:26 #26542
Philip Burley
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@philipburley44197
8 April 2019 at 20:46 #404247
John Haine
Participant
@johnhaine32865
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.
8 April 2019 at 21:09 #404253
T.B
Participant
@t-b-2
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 !
9 April 2019 at 00:39 #404269
Hopper
Participant
@hopper
There have been drawings over the years for a dog clutch — to bring it up to the standard of a Drummond M type. 😁
9 April 2019 at 09:34 #404294
Brian Wood
Participant
@brianwood45127
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
9 April 2019 at 09:37 #404296
Phil H1
Participant
@philh196021
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.
9 April 2019 at 18:18 #404365
Philip Burley
Participant
@philipburley44197
why didn.t I try that before !!
9 April 2019 at 18:57 #404368
Howard Lewis
Participant
@howardlewis46836
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
9 April 2019 at 20:06 #404373
Jon Lawes
Participant
@jonlawes51698
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…
9 April 2019 at 21:56 #404387
Dennis Pataki
Participant
@dennispataki22631
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.
9 April 2019 at 22:01 #404389
Mike Poole
Participant
@mikepoole82104
Posted by Jon Lawes on 09/04/2019 20:06:03:

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…

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
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