# Warped Gib on cross slide and other adventures...



## jduncan (Oct 24, 2012)

*Warped Gib on cross slide SOLVED!*

I am reassembling my cross slide after obtaining a new brass nut for the shaft.  After cleaning, re lubing and attempted reassembly, the crossslide is so tight that I can't get the gib back in unless I push it 3 or 4 inches to the rear (perpendicular to the ways) adn then it will not move back when turning the handle!  I took it back apart, cleaned and inspected it once again, remove a suspected bur from the surface the gib slides on and tried it again.  A little better but still WAY tighter than it was before I took it apart the first time.

I noticed that the gib appears to have a curve in it, is this normal?  I'm trying to figure out why it's so difficult to move the cross slide now vs. before.

:angry:


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## woodtickgreg (Oct 24, 2012)

jduncan said:


> I am reassembling my cross slide after obtaining a new brass nut for the shaft.  After cleaning, re lubing and attempted reassembly, the crossslide is so tight that I can't get the gib back in unless I push it 3 or 4 inches to the rear (perpendicular to the ways) adn then it will not move back when turning the handle!  I took it back apart, cleaned and inspected it once again, remove a suspected bur from the surface the gib slides on and tried it again.  A little better but still WAY tighter than it was before I took it apart the first time.
> 
> I noticed that the gib appears to have a curve in it, is this normal?  I'm trying to figure out why it's so difficult to move the cross slide now vs. before.
> 
> :angry:


No it shouldn't be curved, it should be dead flat.


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## jduncan (Oct 24, 2012)

Great.  Any chance of straightening a curved gib or am I  gib shopping tomorrow?


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## Tony Wells (Oct 24, 2012)

You could try stress relieving it in your oven. Bake it for about 2 hours at 275° F, and slow cool it by just shutting off the oven. If that doesn't do it, try to get a flat plate large and long enough to clamp it down flat and do it again, allowing more time because of the plate. If _that_ doesn't work, clamp it gently with shims to push it past straight a little and bake it again. Even engine heads are straightened this way. If you try to straighten it cold, be extremely careful, or you will be gib shopping. If it's only a little out, some people lap it flat with abrasive paper or cloth. If you do that, start with coarse, and finish with a fine paper, as you want it smooth when you're done.


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## jduncan (Oct 25, 2012)

I'll try baking it.  It's .030 out so it's a bit much to lap I think.  I can't figure why it was working before.  Unless being out on a table for a week or so let the stress warp it.


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## 12bolts (Oct 25, 2012)

jduncan said:


> .... I can't get the gib back in unless I push it 3 or 4 inches to the rear ....



Some gibs are tapered. Are you sure you have it in the correct way, (flip it end for end) and also the correct orientation for the trapezoidal shape?

Cheers Phil


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## jduncan (Oct 25, 2012)

It only fits one way as far as I know, the end has a notch for the adjustment screw.

I tried baking it and the first attempt was not successful.  I'll have to shim it flat and try again tomorrow.


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## jduncan (Oct 25, 2012)

We solved this tonight!

I knew there had to be something I wasn't seeing.  My buddy came over to help me with some parts on the truck I am restoring and we eventually started discussing the issue with the gib.  After an hour of disassembly/reassembly cycles, we finally discovered that the new brass nut was rubbing on the saddle as it moved on the outer end of the slot.  Some time with a file and now the cross slide moves properly and all is well.  Except for needing a "washer" for the inside thrust bearing (really a bearing race) and a roll pin I am satisfied we have fixed the issue.

It was really driving me crazy there for a bit though....thanks for all the suggestions, fellows!


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## Tony Wells (Oct 25, 2012)

Great news! I really wondered if 0.030 was enough to cause a problem anyway. Once the gib is in place, it will be forced straight, and they aren't generally so stiff to cause much drag on their own. A properly adjusted gib will apply an even pressure, and if it's not straight, of course it won't be perfectly even, but it should be fine. Ideally, it should be flat and straight on each side. Some people go to great lengths to lap, grind, mill, file, or whatever to get their gibs perfect, but as long as it does the job it is supposed to, I wouldn't worry about it.


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