Thread: assessing wear of Van Norman 22L

Some more pictures:

Back of knee.



Guiding dovetail, somewhat scored and little if any evidence of scraping left.



Lightly stoned off highs of scoring marks, then blued with 3ft camelback. Straightedge vertical, in several bluing passes left to right.



Column similarly blued with straightedge, which does span the entire height of the column.



It looks like the central portion of the knee was scraped but probably relieved by a few thou, so only the top and bottom 2-4" were bearing on the column?

The worn areas on the rear of the knee (top and bottom) are .001-.002" low relative to the immediately adjacent areas where blue shows.

Finally removed the ram from the mill. I already had the knee off, so did the
reverse of Paolo and took it off the back. This was easier particularly because
the engine hoist's legs don't straddle the machine base well too.

I had already removed the motor, motor base, cutterhead and overarm. So with the
right strap arrangement I was able to get pretty good balance and force the ram
off the back with a long woodworker's clamp. As more and more weight was taken up
by the engine hoist, some playing with the height of the hoist was necessary to keep
some freedom of motion.



After some cleaning out of 80 years of chips...

The original scraping is in pretty good shape, with what looks like some scoring and
perhaps .0005" wear toward the front.



There is also uneven wear on the guiding dovetail, mostly toward the front. This
seems to make sense, possibly explaining why the ram twists to the left (viewed from
the front of the machine).

-Phil

Flipped the VN22L on its back, in preparation for scraping the column face.

Used two engine hoists for controlled tipping process.

Brandenberger, while you have yours on its back like that, would you take and post a bunch of photos showing the cast-in coolant reservoir in the base and how it meets up with the coolant pump sump? I've got a really sludgy #28A to clean out at some point and I'd like to see what you can reach from where. Much appreciated if you have the opportunity!

Hi,

Sure thing, I can do that. So far what I see is that the bottom portion of the machine is one casting,
including the coolant sump and the pump at the rear (I have the pump off at present). Then the column
of the machine is actually a separate casting, bolted on from the bottom.

I'll post some more pictures, but for now, this one shows a bit of detail:



If you look at the underside of the machine, you can see 3 through holes for in 3 corners-- those are the leveling / lagging points (the right rear has no lagging point). The face at top is the front of the machine, and you can see the coolant sump goes across the whole front except a through-hole for elevation screw. And then the coolant sump runs straight to the back, and the coolant pump on the 22L mounts on the left rear. The coolant sump is NOT present under the column area. Below the column you can see in the picture some of the large SHCS that bolt the column casting to the base casting.

The beige colored piece in the center is a separate casting, again bolted on, which is the housing for the feed sprocket, gears, and bearings for the vertical splined shaft transmitting power to the knee. The round cap covers the lower bearings. Interestingly on mine the seams of the housing for these gears to the base casting were filled with lead to seal them, and also sealing the gear housing cover. I'm now trying to remove that cover to get at the bearings, since when I tool the lower plate off the bottom had a volume of metal flakes. Makes me thing the bearings might need replacing... and the splined shaft is inconvenient for scraping anyway.

The other detail I noted is that the model plate (front center of base) also comes off, meaning there are 3 ground-level entries into the coolant sump: the pump, the cleanout, and the model plate. The model plate cover is small but I think would give access to the front left corner of the sump which otherwise is hard to reach with a brush or whatever.

When I cleaned this one out I filled the sump full of degreaser for a week or two, then wet-dry vacuumed out the contents. Then I packed in sawdust to absorb, then vacuumed out that too. Not as clean as I would want, but not too bad so far.

-Phil

I took apart the splined shaft cover and shaft today. Some pictures might
be helpful for anyone contemplating this in the future.

First, the splined shaft holds the cover captive on the base of the mill. The
cover can't be removed until the splined shaft is released by removing the nut and
lockwasher from the underside of the machine.

This is what the shaft end looks like under the cover (from the underside of the machine base):



removing the lockwasher and nut:



The shaft slipped out easily, with a woodruff key that goes into the gear.

The cover can be removed now.



Underside of cover with the shaft protruding.



And the gears, still in the machine. The bearings for the splined shaft
are still in the machine, and it seems like the gear itself has a hollow
stub shaft (with a keyway).



It isn't clear whether the gear can actually
be removed without also removing the horizontal shaft with the sprocket which is
driven by the feed motor itself. Originally I wanted to replace the bearings as
the splined shaft had a fair bit of play, but now at least I've got enough access to
flush out the bearings and they seem OK for this purpose.

And finally the splined shaft, removed.



The splined shaft sleeve and the housing cover form a sort of labyrinth seal,
and then there is an oil seal below that (Victor 60346). This seal is unobtainable, but
seems like a close match could be a Garlock 21158-9342... I will try that.

Got some Victor 60346 seals from ebay, unfortunately the rubber is very stiff so maybe not
usable. However, easy to measure without removing the original:

OD 1.878"
ID 1.115"
thickness .362"

So not a good match for the Garlock previously mentioned. It looks like Garlock 21158-0357 is
the best alternative.

Originally Posted by Brandenberger

Got some Victor 60346 seals from ebay, unfortunately the rubber is very stiff so maybe not
usable. However, easy to measure without removing the original:

OD 1.878"
ID 1.115"
thickness .362"

So not a good match for the Garlock previously mentioned. It looks like Garlock 21158-0357 is
the best alternative.

Maybe a Timken 472475?
https://media.timken.com/SealSelecti.../BM-606038.pdf

Originally Posted by reggie_obe

Maybe a Timken 472475?
https://media.timken.com/SealSelecti.../BM-606038.pdf

Possibly, the ID of the original seal measures 1.113". I think I've found SKF 11585 might work too.

I've also found another curiosity... the original setup actually
has a wear sleeve on the shaft. I assume it is original...

Here's an annotated picture:

Not sure if this helps or not, but
I have a VN 22LU.
My cross slide on top of the knee is a bit different.
But no matter.
The scores or scratches in the flat part of your way...
I know you are scraping things in to spec,
and I know people love to use those 2 part epoxy type products
that stick to metal. Yes those can work, Better living through
chemistry as it were.
Anyhow, I have had good luck soft soldering scrapes and gouges
in cast iron ways with Lead-Free plumber's solder.
It has 2 tenths of a percent silver in the alloy.
It sticks much better than 50/50 or 60/40 solder.
The silver helps the tinning process so it all sticks.
I use a propane or MAPP torch, (it takes a while, but
the best bet),oxy-ace has too much temperature.
Maybe this is not a road you wish to go down, and that
is cool. Maybe the scraping guys think I am nuts.
But if you are only filling in scratches or scores,
soft solder works pretty well.

--Doozer

Hi,

Thanks, I am probably committed to scraping the top of the knee, however there are some more
minor scores on other dovetails which I might fill with solder, since scraping down the dovetails
just to eliminate small scoring would be removing a lot of metal.

I'm assuming you'd

1) scrape out the score to clean raw metal
2) flux (or use flux-core solder?)
3) heat localized casting area to melt solder freely
4) leave solder high of area
5) flatten down to flat plane

In your experience does this work for even small scores (maybe .010" depth, .030" wide)?


-Phil

Hi,

An update...

I measured the ram dovetail across pins with calipers.



From front to back i get

7.8693 at front
7.8692
7.8686
7.8686
7.8683
7.8682
7.8680 at rear

So, .0013" worst-case difference. I also printed the guiding dovetail with a straightedge
and each end is high, with wear in the center. No surprise here, the ram probably spent
most of its life being moved near the midpoint.

Laying the ram on its side and measuring the bearing surface for the cutterhead versus
the ram flat and dovetail ways:



So at 5 different points I measure the pin diameter +

0.8413" (rearmost, no-wear area because cutterhead can't reach this point)
0.8409"
0.8415"
0.8409"
0.8414" (frontmost)

I printed this with a 12" SE and indeed a "hole" is clear at the center and the SE hinges on each end.



And with a precision square with one inside leg on the two flat ways (on 123 blocks):



So it seems the motion of the cutterhead swung through the 90-degree arc over time resulted in a .0015" or so tilt acute to the ram flat ways. (there is one other possibility for this I need to check... the gibbed ram flat receives only wear on the outer 50%, as can be seen in the first picture in this post (right hand side), so the 123 block riding on that could create this seeming acute angle, will check how much wear differential there is on the gibbed flat).

The cutterhead swings through an arc centered on the helical gear, with the rear clamping bolt swinging between the two tops in the picture.

For flux I used zinc chloride flux with a vehicle of petroleum jelly.
(this is typical plumber's solder flux, Nokorode or Oatey#5 comes to mind)

Shallow scratches, no problem.
I have even scratched with a scriber, inside the molten puddle of solder
to abrade the underlying surface to promote adhesion. You might get some
solder sticking to you scriber, but no biggy.

I have used a gasket scraper ground razer sharp to get the bulk of the
solder down. This works well.

--Doozer

I will be interested to hear how well the solder does after a few years. My gut reaction is that solder makes a terrible bearing material and a worse way material. I'd also think that chips would embed in it easily. But willing to learn from your experiences.

On at least one machine, I have (regretfully) left deep scoring marks alone, and just paid extra attention to keeping them cleaned out.

Originally Posted by sfriedberg

I will be interested to hear how well the solder does after a few years. My gut reaction is that solder makes a terrible bearing material and a worse way material. I'd also think that chips would embed in it easily. But willing to learn from your experiences.

On at least one machine, I have (regretfully) left deep scoring marks alone, and just paid extra attention to keeping them cleaned out.

I guess i might try this only on places where chips won’t get to,
Ie the underside of the knee / saddle dovetail.

Or maybe the ram dovetail.

But not the column dovetail, face, knee top, or anywhere
Chips would fall and potentially embed.

Phil

Flipped the ram over, stoned the flats of the ram dovetail that mates with the Top of the column casting.

In the picture above the top is the gibbed side,
The guiding side is bottom.

Note the gibbed side inner 50% never sees wear, since the
Gib makes no contact with the flat.
So the gibbed side inner area can be considered virgin, except for
Scoring which must be from packed chips.

You can see the Ram probably lived in the middle 50%, so most
Wear is there, and VN had no lubrication mechanism for these
ways.

Measuring with an indicator the difference on the gibbed side
Shows .0005-.001” wear at the worst point. The heavy printing job with
The 36” camelback Above confirms that.

Confirming planar agreement between the two sides, I put a solid 123
Block on the guiding and gib flat, then printed with a straightedge
As per Connelly. Full contact on each side confirms planarity.

All of this seems to suggest a light scrape to improve bearing but no
Need to change geometry of the flats.

Phil

Hows the project going?

I need to machine or buy some Roton nuts for mt table. But this has me thinking ahead and will be a great reference for when I learn how to scrape in ways.