What could cause a cross slide screw to bend?

[AndySomogyi]

I just spent the last few days straightening the taper attachment half of my cross slide screw (Clausing 5400), and rebuilt the taper attachment block with new bearings.

Now I find out that the other half is also extremely badly bent.

Originally the taper attachment side was bent about 25 thousands, got it down to about 1-2 thousands.

The front half screw is bent about 15 thousands.

I don’t understand how these could get bent so badly.

Someone was clearly in this lathe before as there are vise grip marks on the tail of the screw and were on the threaded section.

Could a screw get bent though normal use or wear?

Sent from my iPhone using Tapatalk Pro

 

[cathead]

Probably was bent with abnormal use... Good job on straightening it to 1-2 thou.

 

[pontiac428]

Think the prior owner might have done a lot of heavy knurling with it?

 

[DAT510]

If you cross-slide has power feed, it could have been crashed while under power.

When I got may lathe, the power cross feed didn't work. When I dug into it, it appeared to have been crashed, as the taper pin for the drive gear had been sheared.

 

[Ulma Doctor]

+1 on CRASH, bad crash

 

[MontanaLon]

Only if normal use includes crashing, likely more than once and probably at high speed.

 

[C-Bag]

Not exactly the same but a demonstration of what can happen. Lead screws by their very construction are weaker than a plain rod in my mind. My old shaper had two lead screw mechanisms that were totally stuck. One was the tool head and it turned out somebody had tightened down one of the gib screws tight enough, along with a lack of oil, to gall the gib and pile up some of the gib material. Both gib and lead screw were bent which I would have thought impossible being the handle being tiny/short and the lead screw being only like 5" long. Somebody really CRANKED on it and something has to give.

The other was the short crank gear screw that adjusts the length of cut. It's very short but the nut slides along the mechanism and all the other parts that interact with it need to be loose to be able to adjust it properly and because it's adjusted with the universal crank that offers a lot of leverage. The nut coupling is offset so somebody decided to crank on it when the rest of the mechanism wasn't loose. Bent it enough where it wouldn't travel it's whole adjustment and totally bind offering only 1/3" of its adjustment.

I was able to use my arbor press with feeler gauges to micro straighten both back to work smoothly again. Something I'd never tried before but through desperation worked. I can only imagine the longer the leadscrew the easier to bend.

 

[cjtoombs]

+1 on the crash theory. The handle end might have been hit by something or the lathe dropped at some point before you acquired it.

 

[Cadillac]

First thing that would come to mind is she fell over. How are all the handles? Check backside of taper attachment for marks. A crash on the cross slide maybe but hard to see??

 

[GL]

+1 for it got tipped over. Kills me to admit it, but I tipped mine over trying to level some adjusting screws. Bent the cross slide screw, broke handles...idiot move, learning experience of highest dumb level. Why yes, they do have a high center of gravity, even if they are "small". New parts, patience, and cursing will get it back. Probably never sell it because of that incident.