Quick and dirty fix.

[toolman]

Hey guys, I just thought I'd pass this along. A few nights ago, I was at the shop trying to get a parts list together for my old 12x36 lathe and trying to figure out how I could make/repair some of them. I came up with some ideas, then started putting the carriage back together and remembered that the cross slide nut was really loose. I didn't want to put it back together that way, so I got the bright idea to tighten it up. I used my bandsaw to slice it lengthwise all the way into the bottom part of the threads, then I clamped it in my vise to close the gap back up. I filed a V along the split and then brazed it back together, after test-fitting the screw. Afterwards, the screw was extremely tight due to a bit of brass that flowed down into the threads, so I used some 220 grit lapping compound and lapped it in. I don't know how long it will last, but right now, there is no discernible play in the cross feed at all and it's slick as glass. The whole process took maybe minutes and saved me over $40. )

 

[iron man]

I made a tap out of drill rod and made a brass nut twice as long as the original works great and should last twice as long too. It was kind of hard to get the tap through a piece that long but it just took time.. Ray

 

[toolman]

Oops, I meant 20 minutes.

 

[Restorer]

Splitting and squeezing the nut is a good idea and will work as a temporary fix to reduce backlash.

However if the thread has worn reducing its tooth thickness, this method dosn't address that issue.
Also it is not a good idea to put lapping compound in a bronze nut. The grit will imbed into the softer bronze and wear the steel screw for years.

A better solution is to make or buy a replacement nut. Be certain to clean any trace of lapping compound off of the screw prior to reassembly.

 

[Restorer]

Splitting and squeezing the nut is a good idea and will work as a temporary fix to reduce backlash.

However if the thread has worn reducing its tooth thickness, this method dosn't address that issue.
Also it is not a good idea to put lapping compound in a bronze nut. The grit will imbed into the softer bronze and wear the steel screw for years.

A better solution is to make or buy a replacement nut. Be certain to clean any trace of lapping compound off of the screw prior to reassembly.

 

[Dranreb]

I made a tap out of drill rod and made a brass nut twice as long as the original works great and should last twice as long too. It was kind of hard to get the tap through a piece that long but it just took time.. Ray

Hi Ray, I'm sure you know this and make allowances in use, but just to make others aware of a potential problem with using a longer nut.

On Atlas lathes with power feed to the cross slide, at the apron end there is an inch or so of screw turned down to the minor diameter, this uncouples the lead screw before the nut hits the casting and causes damage.

Luckily I noticed this before anything happened, when I fitted a spare nut that came with my lathe which was a little longer than standard.

So best to check any aftermarket nut for length before fitting.

Bernard

 

[sniggler]

A dirty fix in the same vein. Many times in steel construction we have anchor bolts cast in concrete that the column bases are bolted down with. No surprise the threads get mangled some times. The bolt are long to allow for shimming. So running the die down can be a pain so we use an impact gun with a field fabricated deep socket usually wobbly. Of course thats no way to treat a die nut and it fractures. The company doesn't want to keep sending out 40 dollar die nuts (big anchor bolts cost even more) and we can" wait anyway so you take a regular nut for the anchor bolt and cut a slot right through to the threads on one flat costs a buck fifty and lasts ten times longer than the die nut. Hell of a thread chaser if you are in a pinch.


Bob

 

[toolman]

Splitting and squeezing the nut is a good idea and will work as a temporary fix to reduce backlash.

However if the thread has worn reducing its tooth thickness, this method dosn't address that issue.
Also it is not a good idea to put lapping compound in a bronze nut. The grit will imbed into the softer bronze and wear the steel screw for years.

A better solution is to make or buy a replacement nut. Be certain to clean any trace of lapping compound off of the screw prior to reassembly.

I didn't think to post the clean-up process. I washed the screw in my parts washer, then chucked up a bronze-phosphor 12 ga. cleaning brush on a section of cleaning rod in my cordless drill. I submerged the nut in the parts washer and ran the cleaning brush forward and backwards through the nut several times.
I wouldn't recommend this as a long-term fix, but it is worlds better than living with a quarter turn of slop in the crossfeed, plus 20 min. trumps a week waiting on parts every time in my book. I'll try to keep everyone updated as to the longevity of this little experiment. Building a new nut was the first thing that crossed my mind, but it's hard to do when your carriage is scattered all over the bench...)

 

[iron man]

Hi Ray, I'm sure you know this and make allowances in use, but just to make others aware of a potential problem with using a longer nut.

On Atlas lathes with power feed to the cross slide, at the apron end there is an inch or so of screw turned down to the minor diameter, this uncouples the lead screw before the nut hits the casting and causes damage.

Luckily I noticed this before anything happened, when I fitted a spare nut that came with my lathe which was a little longer than standard.

So best to check any aftermarket nut for length before fitting.

Bernard

Yes I knew about that when I replaced the cross feed screw I elliminated that feature as well I found it to be an irritating feature and no other lathe I ever run had that you just have to watch what your doing. Ray

 

[wa5cab]

The problem in this case is that you quite literally can't see what you are doing. Fortunately, running the power cross feed in reverse isn't done much. I wonder what part would break?

Robert D.

Yes I knew about that when I replaced the cross feed screw I eliminated that feature as well I found it to be an irritating feature and no other lathe I ever run had that you just have to watch what your doing. Ray