Crossfeed Problem

Rick_B · Nov 26, 2012

Today I noticed that the cross feed body on my heavy 9 is loose - more specifically there is up/down movement of the cross feed to the saddle. I'm not sure what the adjustment would be for this - I tried tightening the gib but that didn't help. I know the lathe came to me with a shim in the gib. Any thoughts on where to start with this problem?

Thanks
Rick

kitno455 · Nov 26, 2012

The gib should tighten both lateral and vertical movement. If it does not, then the gib must be at the end of its adjustment. That means gib replacement, or a thicker shim on the back.

allan

steve-l · Nov 26, 2012

I think you mean Gib not gig. On the SB you will find the gib on the right side of the cross feed casting that bears on the dovetail. This fits loosely. It is tightened by 3 set screws on the right side of the slide casting. The setscrews seat on spot drilled recesses on the outside surface of the gib. Those setscews adjust the slide to apron clearance. Ideally, the gib is adjusted to a light drag, which will be the same across the entire length of the slide's travel. It's an old machine and will be worn, so a compromise of tightness will be the best you will acheive.

iwananew10K · Nov 26, 2012

yes, the common fix is to use a shim between the gib and the cross slide casting.

on a side note, this is probably the(or one of) source of your parting woes.

Rick_B · Nov 26, 2012

Chad - I think your are probably right in terms of impacting parting - and maybe surface finish as well.

Steve - on my machine there is only one adjustment that I think exists for the gib - it is a screw in front of the cross slide and the screw head fits in a not in the gib to drive it further back. The only set screw is to lock the adjustment screw in place.

Allen - I'm going to pull the gib and shim and see what I can do with that.

Rick

johnoder · Nov 26, 2012

Another encouragement to correct to GIB

Rick_B · Nov 26, 2012

I just pulled the gib - it is tapered in two directions. The height tapers front to back and the thickness also tapers front to back. The adjustment screw head fits in a notch in the gig which pushes the gib in or pulls it out. There currently is a .019" shim with the gib. It tapers in height to ,match the gib but does not taper in thickness. I'm thinking its the height taper is what adjusts the vertical movement of the cross slide.

I'm going to pursue a proper gib before I try to "create" a shim for the height..

Rick

kitno455 · Nov 26, 2012

There should be no variation in the vertical dimension, and that might be the source of your problem. The gib is supposed to be somewhat 'free' inside its pocket. If there is enough wear on the cross-slide casting that the gib touches on both its upper and lower surfaces, then you will not be able to adjust it far enough inward to take up the slack. IOW- the gib must have a shorter installed height than the height of the dovetail. If not, just kiss the top with a file.

allan

Cole2534 · Nov 26, 2012

johnoder said:
Another encouragement to correct to GIB

and another

Rick_B · Nov 26, 2012

Spelling corrected - dang E pad auto fills with words it understands - gib isn't a word it understands :-)

Rick

Cole2534 · Nov 26, 2012

Rick_B said:
Spelling corrected - dang E pad auto fills with words it understands - gib isn't a word it understands :-)

Rick

Lol, I can relate to that. Stupid things knows who lady gaga is but not ANSI or ASME.

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