Need Help on Way Gibs

D

ddickey

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Or anti-floaters as my manual calls them. I needed to take them off for a repair to my lathe. My lathe is close to new so no wear. I have the apron off for the moment so I thought I'd get the gibs back in and adjust. They're so tight I can not move the carriage. I have to loosen them up so that the gib screw that holds one side in has only a couple threads.
Is there a proper way to do this?
 
Most likely you have them in the wrong way. Have you checked to see that any divots are oriented correctly? It's easy to get them in upside down so things won't line up properly.

John
 
Are you sure that you have the gib oriented correctly? What type of gib do you have? I have seen two types, one a wedge that is pushed in or out to achieve the proper clearance and the other the has multiple set screws push the the gib against the ways. If the first is inserted backwards, it simply won't work. The second type usually has at least one screw that engages a recess in the gib to prevent it from sliding back and forth. If the screw isn't seated in the recess, it may not be possible to loosen the gib sufficiently.

For the wedge type, a careful inspection will reveal one end having a larger gap than the other and the gib being thinner on one end than the other. The thin end of the gib should be inserted in the wider gap. For the multiple adjustment screw type, I back the screws out and insert the gib to the approximate position. Then I slowly tighten the scre until it contacts the gib and move the gib slightly back and forth until the screw loosens as it settles into the recess. Then I advance the scre another half to full turn , mnaking sure the gib still is free to move. It should now be positioned correctly and you can continue the adjustment procedure.
 
I have the wedge type pushed in and out with large head slotted screws. The scraped side is against the bottom of the lathe. The gibs will only go into the holder or anti-floater one way. The gibs are different lengths, probably so you don't get them mixed up. I left one screw in the holder when I took them off so that I could tighten back to the same point but it is way to tight. I feel a fair amount of sticion at this time.
Also, the gibs are opposite direction meaning on one side the narrow end faces towards the HS and the other towards the TS.
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I've got the narrow end of the gib screwed all the way in. I've still got a thread or two holding the wider end. Feels better but I can't believe the gibs were like this before I tore it apart. Next time I will pay more attention.
 
Took the gibs out yesterday and still have stiction. I do not remember this before I took the apron apart. I also know the gib screws were not all the way loose or the narrow end screwed all the way in. Just use it the way it is I guess.
 
your gibs may not be 100% flat and/or the sliding surfaces may have unknown high/low spots
generally low spots don't cause a lot of problems, but high spots will decrease the clearance between moving parts.
i would be tempted to spot the carriage and gib to find out where and why
 
I don't have a straight edge to spot the underside of the ways so that isn't going to happen. I have the gibs out so could try that. Still odd it was fine before.
 
Is the stiction occurring when moving only in one direction?

Also, from the drawing, both gibs should be the same. Having two gibs to adjust for the same slide must make it tricky.

FWIW My cross slide also has the gib sticking out a bit far for my liking. The screw head on the small end is sunken in the cavity while the screw on the big end sticks out. It seems like they have provided for it to wear some and still have some adjustment. The ends of the gib are notched and the screw head has to fit in the notch or the screws stick out too far.
 
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