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VN 22LU lower saddle removal

Brandenberger

Hot Rolled
Joined
Sep 19, 2017
Hi,

I'm working on my VN22LU, attempting to remove the lower saddle. As the nut and power feed spline shaft housing is screwed into the lower saddle with unreachable screws, I assume the only way to remove the lower saddle is first to remove the two shafts.

Opening the knee:

knee - 1.jpg

Removing the next level of plate holding the various bearings
and shafts:

knee - 2.jpg

Note for anyone else doing this, there is a ball bearing and spring
detent for the saddle feed stops in the top left corner, assume the
bearing will go flying:

knee - 3.jpg

Now, I am attempting to remove the shaft which has the acme thread
to the saddle nut, which is the top shaft second from the right. However
there is a shifting fork, to remove that the rear saddle feed needs
to be removed and the internal cross-shaft needs to be pulled out:

knee - 4.jpg

So now I can unscrew the acme thread shaft, up to the point one of the
gears is blocked by the remaining internal plate.

I'd prefer to not have to extract those several shafts, etc. If anyone
has done this before and has some pointers that would be great!

-Phil
 
I determined the front and sub-plate probably come out together, so I
re-affixed the two with the 3 central hex bolts, and put threaded rod
into the bolt holes that would affix the outer plate to the knee.

knee shafts - 1.jpg

then, carefully align the front feeds speed gear tumbler so the teeth
are not obstructing the movement of any shafts coming forward, this is
hard to see up into the knee from below.

carefully cranking the saddle crank, together with tapping / prying carefully
at the locating pins and other locations, keeping the fork for the saddle
power feed central to avoid engaging the other gears.

knee shafts - 3.jpg

At some point almost ready to come out, the entire package would come no
further, so I separated the front plate with the 3 bolts, and removed it.

knee shafts - 6.jpg

with the outer plate removed, the two top shafts (acme thread and spined
shaft for driving the saddle) can come out.

knee shafts - 7.jpg

throughout this, carefully watch the clutch plates, as they seem very fragile. One section of the frontmost clutch plate was cracked and broke out on mine.

Finally I'm left with just the sub-plate in the knee, which is loose but the clutch plate assembly is too large a diameter to exit through the front.

knee shafts - 9.jpg

Anyone know how to separate the rear clutch plates, other than removing the nut holding the parts together?
 
Removed the lower saddle finally after removing gib.

Underside of saddle has some fairly deep (probably .010"?) scoring.

dovetail wear - 2.jpg

The dovetail top surface had been badly scored, and some previous "repair"
had installed a .025" sheet, pinned into the dovetail itself.

dovetail wear - 4.jpg

Removed that, and stoned flat the pins and the whole surface.

dovetail wear - 3.jpgdovetail wear - 1.jpg

So now, with saddle back on the badly scored ways, nevertheless,
indicating against the underside of the ram, I get somewhere around
.001" over the entire knee! So interestingly when the sheet metal
was still on, the saddle movement indicated .005" front to back, but
it seems most of that variation was the sheet, or debris under it, etc.

dovetail wear - 5.jpg
 








 
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