Thread: Bridgeport Gib Adjustment

I noticed last time I was using my Bridgeport that when reversing the movement the Y-axis, the table was twist sideways a slight bit (few mm at the ends). Assuming this is a gib issue I thought I would have a go at adjusting all the gibs. I need to remove the table first as I have noticed the RHS y-axis oilers are not flowing.

What is the method/theory in adjusting the gibs? Are they tightened such that all slop is removed but not that they make the table harder to move? My ways are no doubt worn so is the adjustment done at a least worn part of the table leaving the most worn bit (and probably therefore the area most used) is a little loose?

Originally Posted by Mk1_Oz

Are they tightened such that all slop is removed but not that they make the table harder to move?

I'd say that's the theory.

You're probably not going to be using the full travel all the time, so I would adjust them to suit the range of movement that you use regularly and just back them off a bit when you need more.

The saddle will wear on both the X and Y sides convex, this is the the X axis side of the saddle but the same principle applies to the Y axis side and the rear of the knee that interfaces with the column.
from factory the area in green is relieved on both the flat ways, fixed dovetail and the center of the gib by at least a thou. doing so means than even as the saddle rears in wont rock or sway side to side however once the area in red wears to parody with the area in green no matter how much you tighten the gib you will still get movement in two planes. with this in mind its very hard to set a gib accurately on a worn machine. if I'm tidying up a mates mill I will usually relieve the middle 30% on all short slides and give it a quick tickle with the biax which allows each axis to lock positively and makes the mill altogether more pleasant to use.

75521685_610464469781042_5808376216192811008_n.jpg
the top face of that saddle is blued up pretty heavily so I could monitor parallelism while I tipped in the Y axis geometry

Thanks mate. Not sure i have the confidence to start scraping it but I dare say I need to.