Thread: Removing a Sheraton compound feed screw

Before removing the nut,can the compound be pulled back and forth,if so how much does it move.

If it dosent move the .300" that you have indicated that would indicate that theres possably not a lot of play in the screw and nut.

You say theres no dial,is the compound screw moving back the thickness of the missing dial before moving the slide,if so it might only be a matter of either replacing the dial or making a suitable spacer to fill the gap.

Remove the handle being carefull not to lose the pin or key locateing it on the shaft.

Protect the OD of the nut with something suitable,rag,cardboard,aluminium strip etc,and remove with multigrips,stillsons or place in vice with soft jaws and give the nut a turn,it shouldnt be overly tight.

Once the retaining nuts removed you can check the compound screw and nut.

Originally Posted by coffeefro

It has three whole revolutions of backlash

Greg

Well, it's (probably) not play in the nut and screw, 3 turns is a bit much.. more likely something has come adrift, or there's a spacer missing..

Regards
Ray

Originally Posted by pipeclay

Before removing the nut,can the compound be pulled back and forth,if so how much does it move.

The movement of the feed screw in the nut is a large fraction of a millimeter, maybe half. Things are a bit worn in there but I can live with with that for a while.

Originally Posted by pipeclay

If it dosent move the .300" that you have indicated that would indicate that theres possably not a lot of play in the screw and nut.

You say theres no dial,is the compound screw moving back the thickness of the missing dial before moving the slide,if so it might only be a matter of either replacing the dial or making a suitable spacer to fill the gap.

For the compound, that's exactly what the problem looks like, the movement is about the thickness of the dial. For the cross slide though, there is about the same degree of slop and the dial IS there.

Originally Posted by pipeclay

Remove the handle being carefull not to lose the pin or key locateing it on the shaft.

Protect the OD of the nut with something suitable,rag,cardboard,aluminium strip etc,and remove with multigrips,stillsons or place in vice with soft jaws and give the nut a turn,it shouldnt be overly tight.

Once the retaining nuts removed you can check the compound screw and nut.

Thanks, once I've had enough coffee I"ll go get started.

Once I've go this sorted, I'll move on to the cross slide. I remember reading someone else describing a similar problem (gigantic amount of play) on both the cross slide and compound with a Sheraton but can't find the reference now. The missing dial on the compound is very likely to be the problem, but my problem with the cross slide is harder to understand.

Greg

Does the Cross Slide have the (large fraction) of mm movement or greater.

Its not uncomon for there to be anywhere from .010" to .050" of backlash in the Cross slide of a well used lathe.

Generally this Backlash is found in wear in the Nut although the Screws do also show wear,but generally not as much.

Sometimes this can be elimanted to a certain extent by putting a shim between the dial faces.

Other times if the wear is not extreme a type of mod can be made to the nut by means of a taped hole and hacksaw cut,(what your doing is squeezing the threads together in the nut to close the clearance on the screw.

As far as I am aware either used or replacement Imperial nuts are available,also used screws.

Originally Posted by pipeclay

Protect the OD of the nut with something suitable,rag,cardboard,aluminium strip etc,and remove with multigrips,stillsons or place in vice with soft jaws and give the nut a turn,it shouldnt be overly tight.

Just to be sure: its a right-hand thread with no grub screw? Its very tight and I want to be sure of it before applying more persuasion.

Greg

Yes its right hand.

Mine ( sheraton AR ) had 20 thou of cross feed play . It's a relatively easy fix once you get it apart . Buy the new LH acme rod from Steve Wells in the USA , but get him to pack it in a $15 flat rate USPS box or whatever is cheapest. Hercus here sell new nuts , both imperial and metric . Mike PS The compound feed on mine was sloppy as well. After removing the nut, I heated the nut and rotated it while melting some solder inside it . After it cooled I used the old screw to tap a new thread in the nut . It took a while to cut the new thread as its a very tight fit with the solder inside it . I also placed a shim under the dial , between it and the spacer. All this made the thing tight , it's actually too tight but I rarely use it .I don't do much taper turning .

Thanks for the comments and advice. It just took a bit more persuasion to get it unscrewed.

I'm now contemplating making a new dial as a first exercise with the lathe. Making the spacer itself looks to be fairly easy (modulo finding sources for the metals), getting the gradations marked and the numbers stamped on it is a little harder and will probably be a version 2 activity.

Next weekend I'll pull the cross slide screw out and see what is going on in there. There is more likely to be something missing inside in that instance.

Greg