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Van Norman 1/2 Bearings

Seth Quarrier

Plastic
Joined
Jul 19, 2011
Location
Berlin, NH USA
Hi,

I have a Van Norman 1/2 mill, not sure the date but late 19'th to early 20'th century, post Springfield move anyways. It was in service in a shop as of a couple of years ago making tooling for a jewelry wire factory in RI. Anyways when I pulled it home a couple of years ago, I greased the bearings with axle grease, not realizing the issues of grease compatibility etc, I see no evidence of separation or heating so I think they where compatible and I just got lucky. Anyways, I recently noticed some end play in the spindle and decided to clean out the grease, inspect the bearing etc. I also wanted to double check I was removing the end play the right way, so I pulled it apart. It has two opposing tapered bronze plain bearings to support the spindle. The upper bearing is in beautiful shape, looks brand new and perfect and the lower one is visibly ridged and worn, but comparing to some other bearings I have seen you all have, I think by no means shot. It looks like thrust was provided by both the tapers and by a flange running along the end of the bushing, which has significant wear, I expect it has lost at least a 1/16" over the years judging by the worn lip. I thought you all might be interested in seeing some pictures of the machine and bearing and I was also wondering if anyone has lubrication suggestions, it was originally greased, but I have wondered about rigging an oilier (it would have to be based around flexible tubing to handle the head tilt), if grease, what grease do you recommend. The original literature mentioned a top spindle speed of 300rpm but that might have been due to it's countershaft setup, not its bearings. I haven't run it over 270, but in vertical mode the faster the better, so I was wondering what speed people would run it to under very light load with a small endmill (I have never experienced any heating) or if there are any other modifications, repairs that you all would make. It also has some wear on the bevel gears, but I think it is more cosmetic then functional. It is a neat old beast and it would be fun to get it in tip-top shape.

Thanks for the input,
SethBottom_journal.jpgHead_Rear.jpgSpindle.jpgTop Bearing.jpgBottom_bearing.jpg
 
The bad news... I don't think that bearing wear is easily fixable.

The good news... You will probably only get another 200 years out of that bearing before it fails, if you just run it.

On the grease vs oil thing, I have NEVER seen an old machine tool like this that was designed to run on grease. Most used Gits cups which provided an oil reservoir when running. The oil system was total loss. The oil just ran out all over the place. Messy, but it provides a constant oil change, where grease gets packed in there and hardens to a coal like material. This is practically the identical bearing system to a Hendey lathe of this same era. I'd treat it as such. Lots of info on them with a quick search of the site.

Your cutter head has definitely had the lubrication system modified. Old as this machine is, if it had used grease fittings, they would be of the old Zerk style that had a tube with little pins on either side. The grease gun fitting had mating hooks that engaged the pins and locked in place with a slight turn. The fittings on it are modern Alemite fittings. Somebody probably took the oil cups off and pumped it full of grease so it wouldn't leak oil and require constant oiling. You are lucky to have caught it before the grease ruined the bearings.

There are a bunch of us here with Van Norman machines, but few will have anything old as your 1/2. I have had in my shop or places I worked, a VN6, 12, 22L, and currently a 1960 model 1R-3-22 with metric leadscrews. I also have a 2G bridge mill, but it's a weird thing unlike the VN ram type machines.
 
Thanks for the reply, yeah there is no way I can think of to fix the wear, just live with it, and the tapered bearings make it very easy to adjust away. While you are right, the zercs where definitely changed, I suspect it may have always been greased though because the vn0.5sheet.pdf advertisement for the 1/2 on the VN Yahoo group doesn't show oil cuts (although the fact it is an engraving means that it is suspect at best) and I haven't seen any photos of machines with oil cups. I think an oil cup would be difficult with a tilting cutter-head without using flex tubing but I would also think total loss oil system might do a better job and allow for a bit faster speeds (maybe 400 - 450 rpm) which would be a lot more useful in today's day of modern cutters then when the machine was made.
 
Admittedly, every VN ram type mill I have owned or been around has had grease in the spindle bearings. Maybe it's a hold-over from days of yore. I'd sure want to know exactly what to use in there, though. I have seen way too many machines ruined by some well meaning moron putting grease fittings on in place of the oil cups. Most tapered bronze bearings use oil, though.

As for spindle speed, keep it low. Yes, it makes it more difficult to keep from breaking small endmills, but you don't want to exceed the max spindle speed for any reason. If you overspeed the plain bearings, they'll gall and then they are totally shot. It'll ruin the bronze bearing bushing and the mating steel spindle seat.

If you want high spindle speeds, keep a look out for a small Bridgeport head. Mount that to a bar to go in place of the overarm and use it for fine endmill work. You'll still have your VN head for big cutters and horizontal work (swapping out to the overarm) and you'll have the powerfeed.
 
Its good to understand tapered bearings - the lower one in your case will get "tighter" the more the thrust component wears. Old Hendey lathes are notorious for wearing away their thrust faces and allowing the tapered components to literally run out of running clearance and drag or stop dead. Yours has the necessary floating upper taper that can be adjusted up and down to suit the situation of the lower bearing. Get the thust components at the bottom to to be metal to metal at the same time the tapered components down there are and it will literally run forever - but never with grease. I would run Exxon Mobil Velocite #10 in such close fitting high class bearings. Its is thin oil MADE for such bearings.

Hendey used a separate steel thrust ring behind the spindle flange and you could shim this or not as needed - or grind the ring thinner, or just make a thinner one.

Cinicinnati used tapered plain bearings in their mills to about 1928.
 
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Hi John,

Thanks for the reply, I think that makes sense, I wonder what the best way to shim it would be. It seems that the thrust portion of the bearing would need to be machined down to make clearance for a ring in order to be able to adjust the clearance, as the spindle has no such ring currently and a new one would make a lot of clearance. Also it wouldn't hurt to regrind the thrust on the spindle flat, both of which would be probably out of the realm of my competence ;). I am not trying to be difficult, just hoping for suggestions. It is too bad it doesn't have a ring, that would make things simpler. Do you think it is important for the ridges on the tapered portion of the journal and bearing to line up, fitting hand in glove, or do you think adjusting a clearance is more important? Do you have any idea as to what the clearance should be? A half thou or so maybe? To switch the spindle (back?) to oil, would you try to machine in a well for felts, or rig a drip oiler off of rubber tubing. A regular oil cup wouldn't work, as it would dump when ever the head was moved from vertical to horizontal position, a very strong point for grease in terms of simplifying design of a duplex mill, and why I suspect grease might be original spec. With a dedicated horizontal or vertical mill or a lathe, the bearing orientation is fixed, so oil cups become far simpler. This is also the only reason I had asked about increasing spindle speed if I converted it to oil a hair, as I thought grease might make the bearing be under rated, the wear should put a stop to any such tom-fool ideas anyways. I suspect that until I figure out a way to set the clearance, I should leave some end play in the spindle to provide a rough clearance, seems better then locking the spindle. I like Mike's idea of a M head for light vertical milling in addition to the horizontal cutters, I'll be on the lookout.

Seth
 
A possible approach would be:


Oil Stone ridges and forget about matching them to bearing - the aim being only to remove raised metal if there is any.
Recut thrust face nice and square
If stock is available, recut thrust face on bronze to square it up and flatten it and also make room for thrust ring

A way to determine thickness of thrust ring is to set spindle into bearings so spindle taper is solid metal to metal against bronze, and then measure gap you have created by above steps.

Make ring .003 thicker than this gap.

Assuming 4 degrees on a side like Hendey used, pulling the taper .003 away from bronze will make a clearance of .0002 on each side. This is because the tangent of 4 degrees is .0699 and .003 times .0699 is .0002"

Before all this you would have blued the taper (whisper thin) and used it to do enough work with a bearing scraper to cut down the bronze ridges if any.

Hendey pinned the ring to the spindle so there would be no steel on steel relative movement

"oil stone" in this context is a medium or fine India used with solvent
 
I like it, makes sense and sounds doable explained like that, I'll let you all know how I make out. Be nice to get the old beast running right again. I may need to get creative cutting the thrust face, as the spindle appears very hard, might be grind-able or could be filled between the face and the ring with JB weld or the like, crude but might work.The bearing definitely was running metal-on-metal in the taper, it should be happier with a proper thrust bearing.

Seth
 
Entirely possible the original oil system was just holes in the casting that got a shot of oil every few hours. It was a different world back then. None of this touchy feely job stuff. If you didn't oil and properly care for your machine, you were out the door before you knew what hit you. I;ll bet my 1918 L&S had fourty oillin locations, all total that are suposed to be oiled every day. Except for one that got covered up in pounded in chips, they must have all been properly attended. Old beast is still in pretty amazing condition.
 
I like Mike's plan. Slightly fancier would be closed top oilers you could fill for that attitude during set up.

B & S used open grain wood pugs being fed by a chamber surrounding bearing in some of their grinders - the wood plugs extending thru the walls of the bearing. Such an idea would seem to be effective whatever the attitude might be.
 
Yes, John.. my first thought was Gits 90 degree oil cups with the felt wicks in them, left only finger tight. You just rotate them upright for whatever position the head is in.
 
Good thoughts, I can't do much until I visit my folks as it turns out it is hard to work on a mill with itself, but my father has a B&S #2 light type which should reface the thrust bearing without an issue. When it's back together I'll play with lube, but it sounds like the resounding consensus is oil, no grease, to keep it happy for another hundred years.
 
Seth, I was hoping you may be around to help answer a question. When you took your spindle apart, was there a threaded section in the middle of the housing where the bevel gear sits?

I have a very similar VN sub head that I am trying to take apart and cannot get the tapered cones out of the bronze bushings. The picture is the area I am concerned with.

Hopefully, someone with more knowledge about these heads can chime in.
Screenshot_20210808-065752_Samsung Internet.jpg

Here is a picture of my sub head, partially taken apart
20220223_080457.jpg
 
Also, does anyone know how old these sub heads with bronze bushings are? I only found one reference to these in an accessories catalog on vintage machinery.org. The catalog did not have a date on it.
 
Where would a flat steel thrust bearing ride? Which part of the bronze taper bearings would it fit to?

From 20 feet away it would appear that all thrust in this assembly is taken by the opposed tapered journals riding inside tapered bronzes. The upper tapered
journal obviously slides along the shaft, key visible, and is pushed downwards by the nut at the top. Is everyone sure that the nut (apparently adjusted via a
pipe wrench....) isn't the thrust adjustment for this setup?

Amazingly cool milling machine BTW.

Another point to consider is some of the old zerk-type fittings were designed to be serviced by an oil gun. This may be such a case given the adjustability of the head.

There was an older bridgeport in the staff shop here with original zerk fittings on the ways. After using it, in a fit of helpfullness, I took the grease gun (which I might
add was right on the shelf by the machine!) and gave each fitting a brief shot of grease.

Locked the table up solid. Had to be completely disassembled. No good deed goes unpunished.....
 
Jim,
Yes, there is a visible key way that runs the length of the top adjusting nut to the bevel gear inside the head. I just cannot figure out how to get that steel sleeve out from the bronze bushing. I have tried everything to get it out:

1. Heating with a heat gun on high setting
2. Pipe wrench in a twisting motion
3. Took the adjusting nut off and forced grease with a grease gun into the fitting (hoping this would work like a pilot bearing on a clutch and hydralicly force it out).
4. Last resort is using a shop press, but I don't want to use extreme force if something like a threaded nut is holding it in the inside.

Here is another picture from the top
20220223_080514.jpg
 
I had a VN 20 and I believe the oilers for the spindle were were the type that are on my tie bar Hendey to check oil level in the spindle. They are brass with a sleeve that covers the oil hole which is perpendicular to the axis of the oiler assembly. The sleeve is not oil tite by any means so I assume there was a cavity in the casting that contained oil and wouldn't let it leak through the oiler in vertical nor horizontal position. I looked through my photos but none showed the oilers clearly.
 
Looks like I may be the only one who has taken one of these heads apart. I'm going to try to press it out tonight. I sure hope I don't break something. ��
 








 
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