I'll tack this onto this thread as it's a similar subject on the same machine...
On the Beaver mill ram there are two Gibs on the right hand side. One at the front and one at the back. Rather than setting a clearance these are used to lock the ram down tight and can be slackened to make any ram adjustments.
It came to my attention that the one at the front wasn't doing anything ............ might explain a couple of things as I'd been chasing traming and a vibration fruitlessly so far. My issues wern't huge, in fact quite slight but all the same an unlocked ram sure wouldn't help anything !!
In this first picture showing the Gib you can clearly see a clearance at position "A".
A 1/2" bolt is inserted in the direction of "B" and threads into the Gib. When the bolt is tightened it pulls the Gib down against the ram dovetail. Except in this case the bottom of the gib is already down due to the side clearance at "A"

I took both Gibs out, front and rear and they are both similar except the rear one is a little shorter. Here you can see where the bolt threads into.

Set up on the mill I decided to remove 2mm/80thou from the bottom of the Gib as this will have the same effect as making it wider.
Using a 20mm dia cutter this was done in one pass as there was nothing critical here making guestimating the order of the day ..


Popped back in for a looksee .... Yup.. that'l do it.....

BTW, these are not the original Gibs, someone had made these .... not too well either ....

