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Van Norman No. 12 Ram Lead Screw Pitch

swarfmeister

Aluminum
Joined
Aug 29, 2017
So. I've worked with and on machines for most of my adult life. My Dad's first job was as an apprentice at Van Norman, and after WWII he worked as a factory sales rep, while my uncle eventually became a vice president in the 50's before taking another job. In a shop I ran in the 80's and 90's we had a No. 36 which we used to do T-Slotting and as an overflow machine for our boring mills.

So recently I got a chance to intervene in a No. 12's trip to the scrap yard. This was taken out as a favor from a local precision manufacturer where up until the sale of the company some ten years ago, did a credible job of maintenance. Not so much since then and I'm figuring I'll be making a lot of parts as I go. The machine was running, but by no means is it in any kind of condition to run anything other than the one or two jobs it's spent the bulk of it's life on. Yet the bones are good. So I'm going to have questions for you guys in order to save time and effort getting this back to fully operational.

First question is regarding the ram lead screw. I was able to back this off in prep for removing the ram from the machine, but it's rather S shaped and I doubt will be able to be adequately straightened. It appears to be an Acme thread and possibly if it's not too exotic I can buy a piece of Acme threaded rod and machine down the adjusting end. Does anyone know the size and pitch of this screw?
 
Wait, I'm confused. The screw is present on the machine and you are asking a bunch of faceless people on the internet what the diameter and lead of the screw is?

calipers and a 6 inch scale will give you the info is less than 3 minutes.
 
The machine is currently outside in a scrapyard and I have limited time to get it apart and removed. Sure I can measure it later, I just figured I'd get a leg up by asking you fine people.
 
Ah, well, a perfectly good question just for curiosity. However, given that that machine is expected to need moving, repair/restoration, and that you have limited time to devote to it, knowing those things at this point will make a zero change in the completion date.

And you haven't asked for the other parameter, how long this screw is.

Good luck in any case. It sounds like you'll need it.
 
First of all. I've worked in machinery repair/sales/rebuilding for my entire adult life (so far). I figured if it was a standard Acme and I could make the part out of commercially available threaded rod, I could size length to the original once it was out. Since I intend to use the machine mostly as a vertical I could have at least gotten the rod on order and that would save some time up front.

This ain't my first rodeo. I'm aware of the scope of the job!
 
Over the last week I've been taking parts off the machine. It's in rough shape and appears to have spent most of it's production life running only a few jobs. There are a lot of "fix it good enough to keep it in production types of remedy's and a good deal of creative solutions to parts breaking and such. It appears to have been run with flood coolant and the all too familiar varnish of coolant and lube actually appears to have been a blessing in disguise as it created a nearly pickup proof protective film on all the way bearing surfaces. It was a little touch and go getting the table off as the gib had been shortened and the adjusting screws had been replace by some improvised brackets with allen screws to adjust the gib and the small end slipped allowing the gib to tighten considerably before I caught it. This made the last six inches of getting the table off the saddle a bit of an adventure but all's well that ends well, and it came off without too much invective assistance.

The table screw and nuts have been pretty bastardized, but since they were cleaning out the department I have a lightly used if not new set that we saved from the dumpster along with a reconditioned table gib and some handwheels and other goodies.

Yesterday I went to town on the feed gearbox, which was a mess of rusted millings and since this ran a dedicated job everything was frozen in place under a calcified pile of chips. It took a few hours of judicious scraping and cleaning but I got the box back in shape and sprayed everything down with PB Blaster and worked on freeing the shifters up. And it's ready for an oil change and to go back on the machine. Everything works fine now and today I've been working on getting the saddle less full of foreign materials.

Goal here is to get the machine operational and cosmetically acceptable, then use it to make the parts I need to repair it. Planning on a 3 Axis DRO so that the screw error can be directly compensated for, and between that and the lathe I should be able to bang out some good replacement parts where needed.
 
Give me a day or two and I can get you the ram screw dims. I have the same machine fully disassembled, going through a similar degree of reconditioning.

The nut for the ram screw is is pressed into a bore, held by a set screw. It appears to be a simple item to remove and remake if needed.
 
Much appreciated. Yeah the collar set screw is loose but it's going to take some work to get it off. Pretty typical for the shape this machine is in. I won't be starting in on the head for at least a week or more, and have it out in the storage shed, so no big rush as I'm working on the saddle and knee assemblies before I start in on the head. The saddle is full of probably 70 years of accumulated millings and grease. Not pretty.
 
Another question

Also, on the back of the saddle there are three pockets closely approximating the locations of the three bearings for the feed drive shafting. From right to left facing the machine: The first is an oil cup which is still there and in good shape. The middle appears to be a screw or plug of some sort, and the one in the middle of the saddle may be the same, but I'm still trying to gently dig out the chips. So I'm wondering if these were also oilers that were later plugged up after crashes, or if they were cross holes that were drilled to provide lubrication passage to the table drive bearings?

Anyone?
 
Also, on the back of the saddle there are three pockets closely approximating the locations of the three bearings for the feed drive shafting. From right to left facing the machine: The first is an oil cup which is still there and in good shape. The middle appears to be a screw or plug of some sort, and the one in the middle of the saddle may be the same, but I'm still trying to gently dig out the chips. So I'm wondering if these were also oilers that were later plugged up after crashes, or if they were cross holes that were drilled to provide lubrication passage to the table drive bearings?

Anyone?

I believe one of those set screws is a table lock. On my 22L which I am cleaning up at the moment there is a similar allen head screw that when tightened makes the table harder to crank. The y and Z axis have handles for the table locks which I could only surmise is because you would be using the X feed often enough that you would not need to lock the table in place. The simple Allen head instead of a lever makes it a lot harder for someone to forget that the table is locked when engaging the feed.

Took my first cut and the table did not like climb milling so its loose, when I went to conventional it cut like a dream.
 








 
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