Thread: Cross slide lead screw wear issue

hi i just received a quote of 60 pounds for a cross slide screw on my colchester.. 100 pounds for nut and screw. i thought that sounded ok may be he could do one for you...
aaron

Originally Posted by Oldneweng

I am still trying to source threaded rod to replace the cross slide leadscrew on my Nuttall lathe. You may have noticed my posts LOL. I tried to cut my own but the leadscrew had so much slop that the tool was pulled into the metal which did it no good at all. I guess about 2mm.

I have an idea to stop the slop by fitting a bracket around the leadscrew nut which will hold two halves of a nylon sleeve clamped to the screw. The plan is to have some thread cut in the nylon so it acts to prevent the leadscrew from moving in the nut as per slop, not turning. Any suggestions at all about this idea and possible alternatives.

My thought was to use the existing nut to drive the cross slide towards the rear and the nylon to stop movement allowing the tool to dig in, and it would drive the cross slide return travel as well. More comments re which way around? Which would work best. I thought that I wanted metal to control depth of cut, not nylon.

This would hopefully only be temporary untill I can rebuild the leadscrew and nut.

Dean

Hi Aaron. I presume you are talking about a UK supplier. My Nuttall is made in oz and they may find it hard to find specs etc. For $OZ118.00 + gst I can buy 12 feet of threaded rod and to fit that is not hard. I only need 8 1/2 inches. A nut will cost $16.10 + gst. I have the means to fit it from there. From the money side I would go with that method being much cheaper as I still have an old worn lathe underneath.

One day I would like to upgrade to something with a bit less wear (actually a lot less). Meanwhile I don't want to spend big money on this one. Thanks for the suggestion tho.

Dean

Originally Posted by Pete F

I've ordered through Enco a number of times, they have the acme rod you're after for US$34 for 3 feet. Enco's postage rates are typically very good. Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies

You would have enough left over to make up some Acme taps to cut a new bronze nut. For a one off it may not even be worthwhile hardening it, otherwise it should at the very least case harden ok. Otherwise just go forward a couple of pages in their catalogue and they have the matching nuts there too, just machine down to suit.

Pete

Hi Dean,

I think you might have missed PeteF's post, so I'll bump it..

$34 for 3 feet of 5/8, 8 tpi left hand acme is a price that would be pretty hard to beat.

Enco Shopping Cart

Regards
Ray

Dean
Something else I just thought of. I don't know if you have had your crosslide spindle out of the machine yet but if not, there will be a gear for the power feed attached to the spindle as well. Depending on what method used to fix it to the spindle, it might make it a bit more complicated for you to machine a complete new spindle.
I have seen a cross slide spindle from a Colchester Mastiff 1600 and it had a funny spline arrangement that was used to attach the gear and hand wheel to the spindle. I have no idea what Nuttal used though. It might be as simple as a woodruff key.
Something to consider anyway.
regards
bollie7

Originally Posted by Pete F

I've ordered through Enco a number of times, they have the acme rod you're after for US$34 for 3 feet. Enco's postage rates are typically very good. Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies

You would have enough left over to make up some Acme taps to cut a new bronze nut. For a one off it may not even be worthwhile hardening it, otherwise it should at the very least case harden ok. Otherwise just go forward a couple of pages in their catalogue and they have the matching nuts there too, just machine down to suit.

Pete

Edit: Just one more thought, try the Roton site 5/8 - 8 Left Hand Acme Lead Screws & Nuts for Power Transmission - Roton Products, Inc. I've used their site for data, but no idea what they're like to deal with as i've never bought from them

Read this thread https://www.woodworkforums.com/f65/ro...plying-142633/

I am checking on enco. Thanks for that idea.

Ray. You are correct. I missed it until now. Saw it before yours tho. Thanks anyway.

Bollie7. Yes I have had it out. The gear is actually missing, presumed to be suffering injuries from a crash. A rough cut sleeve is in its place. The gear was connected with a woodruff key. My plan was to cut or buy a length of thread and just replace the thread section of the leadscrew.

I then want to build a brass gear replacement. I have seen a description on how to do this in a lathe using a divider head mounted on the carriage with the axis vertical and a home made single edge cutter in the chuck/tailstock. The divider head is also homemade.

Dean

Hi Dean,
Check your P.Msgs.
Russell

Latest update. I have contacted B & D Machining and got a quote of $470 for leadscrew and nut replacement. That is more than I want to pay for this lathe considering the wear and that I would like to update one day.

At this point I am leaning towards buying rod and nut from enco but have no money spare at the moment. I will post when it is finished.

Dean

Hi Dean,
As far as the tool self feeding, are you sure you are on center height?
All lathe unless they have ballscrews(and I assume taper roller thrust bearings) will have some slop

Do you have a picture on the leadscrew and nut?
As most of the wear will be in the nut(?)
You maybe able to add a nut, if they are spaced correctly the old nut will feed in one direction, the new nut in the other. This would removed most of the slop from the worn nut leaving only slop from any wear in the leadscrew.
Though it may not fix your problem.

Stuart

Centre Height? Yes.

No picture at this point. Nut is cast, screw is ?. I would assume most wear in nut but the wear in the screw is uneven as with all lathes. More wear near main cutting region. As for adding a nut read my first post.

Dean