MadModder

The Shop => Tools => Topic started by: HalifaxHerbert on January 03, 2019, 09:34:53 AM

Title: Cross slide nut for EDGWICK lathe
Post by: HalifaxHerbert on January 03, 2019, 09:34:53 AM
Hello,
The cross slide nut and possibly the  lead screw are worn on my Edgwick lathe.
I have no machining facilities left and all of my engineering contacts have either retired to the Bahamas or gone to heaven/hell.
One of the forum members did make some lead screws and nuts some time ago but his details can not to be found.
Can any one help or point me in the right direction.

p.s. I have decided to keep the lathe after 2 close scams on Fleabay.

Title: Re: Cross slide nut for EDGWICK lathe
Post by: hermetic on January 03, 2019, 10:11:41 AM
Check out the thread to see if it can be bought ready made, or at least one with the same pitch to keep the dials correct, and then see if you can modify a standard nut to fit, or make a nut using your lathe as it is. I did this fix on a DS&G by sawing off the worn thead, boring the splined handle end, turning down the thread to fit the bore, and securing with a roll pin, then filed up a nut out of a hunk of bronze and drilled and tapped it. There will be some wear in the centre of the thread, and you could make an adjustable nut to get virtually zero backlash, but with a worn thread an adjustable nut will be tight at the ends and slack in the middle, always swap both if you can! There is a chap in Hull who advertises on Ebay, who makes nuts for various Colchester lathe, depends if he has the taps, try contacting him. he is Boffin53
https://www.ebay.co.uk/itm/Colchester-Student-Feed-nuts/292899074863?hash=item443225332f:g:LwwAAOSw8zdaAF3B:rk:1:pf:0
Title: Re: Cross slide nut for EDGWICK lathe
Post by: HalifaxHerbert on January 04, 2019, 01:49:00 PM
Hello HERMETIC,

Thank you very much for the info, much appreciated.
I will give this a try when the weather gets a bit warmer.
Decided to keep the EDGWICK and give her a lot of TLC.

Will keep u posted on progress.
Title: Re: Cross slide nut for EDGWICK lathe
Post by: AdeV on January 05, 2019, 09:36:44 AM
Glad to see you're staying in the Edgwick club! I've got a lot of wear on my cross-slide nut too (tons of backlash), TBH I just put up with it.  I suppose I should fix it one day.
Title: Re: Cross slide nut for EDGWICK lathe
Post by: hermetic on January 05, 2019, 10:39:10 AM
If you do an image search on "anti backlash nut" you will see some examples that would be fairly easy to make, and as they are spring loaded, would compensate for at least some of the uneven wear in the thread. This is a problem that affects all lathes, and a certain amount can be put up with, till you start to get chatter and poor surface finish, then you gotta fix it!
Title: Re: Cross slide nut for EDGWICK lathe
Post by: Pete. on January 05, 2019, 01:50:39 PM
You shouldn't suffer chatter from a worn not or screw, chatter comes from worn or burred ways and mating faces. Fitting a new screw and nut often improves chatter merely because the closer fit adds rigidity to the assembly - it masks the problem but doesn't cure it. The down-side of course is that your new screw and nut wear faster.
Title: Re: Cross slide nut for EDGWICK lathe
Post by: HalifaxHerbert on January 09, 2019, 07:04:17 AM
Thank you to every member who contributed, much appreciated.
I decided to keep the old girl after 2 close scams on fleabay, when I tried to sell her "as is with wear etc".
The Denham lathe is still missing its cast iron cabinet and end leg, another story (thread) and job for the future.
Ade, how is the "MAZAK" ?

A happy and prosperous new year to you all.