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Smart and Brown 1024 VSL lead screw engagement problems.

Abmeboy

Plastic
Joined
Sep 16, 2017
I have a Smart and Brown 1024 VSL square top lathe after cutting some threads and using the micrometer stop to dis-engage the lead screw I have found that on subsequent operations that the lead screw lever (round cooker type knob) will not engage either x or y feeds? Have I knocked something out of alignment that requires a total apron strip down or is there an easy fix?

Any fix suggestions will be greatly received.

Thankyou.
 
I'm not entirely clear about the problem you now have. You say that the lead screw lever will not engage either X or Y feeds. X and Y is confusing - lathes generally have X and Z. The leadscrew lever is only used to close the half nuts on the leadscrew for screw cutting. It is not used at all for sliding/surfacing feeds. Those feeds are engaged with the 'drop worm finger' which is the rectangular control sticking out of the bottom of the saddle. The feeds are driven by the feed shaft. The selection of the direction of the feed is by means of the selector knob on the front of the saddle.

A few things to check -

Make sure you have the leadscrew /feed control in the feed position. Start the lathe and check that the feed shaft (not the leadscrew) rotates as normal. Engage the feed using the drop worm finger - check that you get the feeds. Disengage the feed.

Now with the lathe turned off try turning the leadscrew by hand. If you can turn it try engaging the half nuts gently while you turn the leadscrew. If they engage does the saddle move? Now disengage the half nuts, select leadscrew on the leadscrew/feed control, start the lathe and engage the half nuts. Does the leadscrew rotate? Does the saddle move?
 
I have a Portass lathe which has a dog clutch on the leadscrew, a lever will disengage the leadscrew. Also I have a Drummond "Knee planer" lathe, and it has some kind of mechanism too, not sure.
Now then if you set the stop so it opens the dog clutch the thread would end in a stress riser V groove. Easy to get it aligned again too, as there are only two positions.
 
I have a Portass lathe which has a dog clutch on the leadscrew, a lever will disengage the leadscrew. Also I have a Drummond "Knee planer" lathe, and it has some kind of mechanism too, not sure.
Now then if you set the stop so it opens the dog clutch the thread would end in a stress riser V groove. Easy to get it aligned again too, as there are only two positions.

Dog clutch leadscrews are a very handy feature, however the S&B 1024 doesn't have one. It does of course have a lever that selects between screwcutting and normal feeds - just like most lathes.

Until the OP gets back to us with a bit more diagnostic detail it is difficult to give him any definitive guidance.
 
The micrometer stop only disengages the feed shaft which has an adjustable overload clutch. The screw cutting shaft has no overload protection. If you have been screw cutting and hitting the micrometer stop to stop the feed there is a fair chance that at best, you have busted a shear pin in the gear train in the L/H end of the lathe. I am surprised that the first time you ran the saddle into the micrometer stop there was not a loud bang and loss of drive!.
 
I agree Peter F. Unfortunately the OP appears to have gone away, so without more diagnostic feedback from him it is hard to give any useful help. I really hope that serious damage has been avoided - a very nice lathe that deserves to be kept in good condition.
 
I have a Smart and Brown 1024 VSL square top lathe after cutting some threads and using the micrometer stop to dis-engage the lead screw I have found that on subsequent operations that the lead screw lever (round cooker type knob) will not engage either x or y feeds? Have I knocked something out of alignment that requires a total apron strip down or is there an easy fix?

Any fix suggestions will be greatly received.

Thankyou.

Did you fix this problem? I have the exact same problem and would like to know if and how a fix was achieved?
Thankyou.
 








 
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