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adjusting Van Norman 22L ram gib?

Brandenberger

Hot Rolled
Joined
Sep 19, 2017
Hi,

I'm scraping in a VN22LU, and have scraped the top of the column (bearing surface
for the ram).

Has anyone adjusted the ram gib on these machines?

Mine looks mostly like this in the manual:

vn22 ram gib diagram.jpg

The gib looks like this on the machine, it is a double-angle type:

VN ram gib - 1.jpg

The underside toward the front looks like:

VN ram gib - 3.jpg

From the top through the gib, you can only see 5 screws-- in the front, a SHCS accessible
from the top, then the gib locks (front and back) and two 1/2-13 screws that attach from the
bottom.

So it looks like manual isn't quite accurate... from below it looks like there is the eccentric gib lock (largest feature seen from inside), then the 1/2-13 screw accessible from below, and then a setscrew.

The same is replicated at the rear:

VN ram gib - 2.jpg

This one also shows the ram pinion mechanism, but has the same eccentric clamp and screw/setscrew arrangement.

One other interesting point... The gib lock seems to flex the gib, rather than the whole
gib moving up and down? i.e., if I put an indicator on the gib relatively far away from the eccentrics and lock and unlock the gib, I don't see any movement. But the at the gib lock location I see .006-.010" of movement when locked/unlocked.

So in terms of adjusting the gib, my questions

- to adjust the travel of the eccentric, does the whole gib have to come off? Or possibly when the eccentric shaft is removed, the screw (part no 8369) might be accessible from below to adjust?

- the setscrews loosened from below drop the gib, in concert with tightening the fixed screws (two from below and one from above).

It would seem to make sense that the procedure to adjust the gib ought to be possible without removing the ram.

I've scraped about .001" from the column top (ram making surface), and probably an equal amount from the ram bottom, and I'll also need to scrape some of the guiding way dovetail on both ram and column... so I am assuming the gib will need adjustment.

Thanks,
Phil
 
Maybe surface grind (or scrape) the bottom of the gib to tighten it up
and surface grind (or scrape) the side of the gib to make the fit more loose.

I have a VN22LU also. The gib looks like the cross slide gib on my Colchester lathe,
only it has hold down screws AND side adjusting screws. Makes it a bit easier.

-Doozer
 
If the holes in the gib are oversized or slotted, the screws should probably be just snugged up enough to keep the gib from moving vertically, but allow it to be pushed sideways by the adjusters.

Cal
 
Maybe surface grind (or scrape) the bottom of the gib to tighten it up
and surface grind (or scrape) the side of the gib to make the fit more loose.

I have a VN22LU also. The gib looks like the cross slide gib on my Colchester lathe,
only it has hold down screws AND side adjusting screws. Makes it a bit easier.

-Doozer

Van Norman docs certainly say (somewhere) that the double-angle gibs when you
run out of adjustment can be surface ground on the underside to tighten it up,
definitely.

That's easiest on the other gibs (saddle, and knee) where one can pretty easily
remove the gib if needed. This one would seem to be harder to remove.

It may be that if the eccentric shafts (parts 22L-128 and 22L-105) are removed, perhaps
the head of the gib screw is reachable from below to adjust.

-Phil
 
It seems like the gib is pulled down (and thus sideways via the angle) only at the gib clamp locations.

Since the recommended hoisting method of the machine is partly by the ram and partly the knee, it is good that there are several 1/2-13 bolts holding down the gib in addition to the eccentric binder.

-Phil
 








 
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