What's new
What's new

1942 Van Norman No. 12 cutterhead ring and pinion destroyed

FULLMONTIE

Plastic
Joined
Oct 9, 2017
Hello,

Bit of long story, but the condensed version is I picked up my Dad's Van Norman No. 12 mill that has sat idle with a burned up motor for 25+ years. Disassembled it to the basic components to move from Oklahoma to Texas, cleaned it up, then painted it while torn down. I replaced the burned up motor with a 2HP Rockwell 3 phase motor, and installed a Dayton variable speed motor on the table feed. Lubed everything, and probably my biggest mistake was not removing the cutter head to give it a thorough cleaning......
I started up the mill and everything sounded good, ran it for a while with no load. I then stared machining some table stops, because the machine had none on it, and I heard a bad crunch sound followed by a low frequency thunk thunk thunk sound coming from what sounded like the spindle area. I pulled the drive motor belts off, and rotated the drive side by hand and you could feel a tight spot and a skip when rotating it. I removed the cutter head, and first thing I see is a very nasty looking pinion gear, and inspection of what I could see of the ring gear was a LOT of broken and chipped teeth. Crap....

I cleaned the cutter head with solvent and what I saw really broke my heart. Lodged in old grease were portions of 3 broken teeth, some smaller bits of munched metal, and some ground/pulverized metal bits. The mill had been used for many years in the Horizontal position with an arbor, and I was using it vertically when the **** storm hit. It appears that someone has been into this head at one point, as the number of missing teeth far outnumber the 3 I found, and there really was not much debris in the grease. I see obvious tool marks on parts inside of the cutter head, and likely someone else had seen some damage, cleaned it up, saw missing teeth, reassembled, and ran it like it was. I finished it off, and I guess that a broken tooth dislodged from grease from old spindle bearings, floated in the oil, and landed in my ring or pinion and wreaked havoc.

There are a lot of chipped outer edges which I'm not to concerned about, but there is 25-30% of the inside teeth of the ring gear missing on multiple teeth, and a couple that are adjacent, and the pinion is rough. I am sure that VN NOS spares for this machine are rare as hen's teeth. I have used this machine since I was a kid, and really like it, but it is to rough to use as is, and I am sure that there will quickly be more damage if I tried to run it. Please see the attached photos, and the photos actually look better than it is.

What options do I have?

1. Find the unicorn NOS ring and pinion set....
2. Find a used but better condition ring and pinion set for an early VN 12.
3. Have a new ring and pinion made....... probably cost prohibitive.
4. Build up teeth with brass, probably won't hold up, and the heat from brazing will affect the hardness of the ring and pinion, not to mention hand dressing the teeth to an acceptable profile.
5. TIG weld up the missing teeth, and hand dress new teeth, again even more difficulties in hand dressing and heat treatment issues.

Help! I am open to opinions and options. It's a handy machine and I hate to see it sit for another 25 years or be sold for parts.
 

Attachments

  • 20191222_170112.jpg
    20191222_170112.jpg
    103 KB · Views: 177
  • 20191222_134020.jpg
    20191222_134020.jpg
    96.9 KB · Views: 159
  • 20200111_153056.jpg
    20200111_153056.jpg
    93.6 KB · Views: 206
  • 20200111_152335.jpg
    20200111_152335.jpg
    99.6 KB · Views: 191
  • 20200111_152558.jpg
    20200111_152558.jpg
    100.9 KB · Views: 181
I have a VN 1R with the same problem, I found a couple off-the-shelf gears from Boston that I think might work with some modification, short story moved shop waiting to get 3ph power so I can get lathe running and try modification, might work, might not.

There is/was a guy on ebay parting one out, forget M#, last time I checked he still had those gears, but could not figure out how to remove the head, at least that is what he told me. IIRC he was somewhere in east Dallas area, maybe that is close enough for you to go see.

Link to his ad, probably only worth contacting him if you can go pull the parts, his last message to me was that he was yanking on it with a forklift and it would not come off. Good luck!Parting out Van Norman Mill Number 38 | eBay
 
The VN 38 is a completely different beast and I have serious doubts that the pinion and ring gear would fit (i.e. much larger cutter head, designed for much more power).

Paolo
 
Hello All,

Thank you for the support and ideas. The ideal is to find a spare, but weighing other options too.
 
Dang reggie_obe, story of my life, a day late and a dollar short;) Thanks, please let me know if you see anything.
 
Ive welded up tractor and truck gears like that......case hardened gears weld OK with stainless rod and a bit of preheat......dress the gear tooth back to shape with an angle grinder...the most recent I did was a diff gear in a 4 ton truck ....two pinion teeth partly broken off,adjoining chipped badly....The repair lasted over a thousand miles in normal use,but when I replaced the gears ,the join of stainless and hard steel had started to crack.
 
I've done a lot of differential repair and sometimes you get the guys that have $200 to their name and just need to get to work...

I've set up differential gears that looked worse than that and they actually ran fine. For years and years and probably still going.

Ring and pinion gears are pretty straightforward to setup if everything is good, however, if you have a real shitshow like this I'd suggest you get someone involved that has plenty of real world experience with setting up differentials to take a look at it and attempt a fix.

I wouldn't bother to weld and file. The contour on those teeth is not something you're going to duplicate. As long as you have some kind of contact on every tooth you should be OK. If there is a spot where a tooth is completly gone, you might get away with it if there's a few teeth in mesh at the same time. You got nothing for power going through those gears compared to a vehicle ring and pinion.

Ring and pinion gears break real easy if they aren't in proper mesh. If they are setup right they are incredible strong.
 
You got nothing for power going through those gears compared to a vehicle ring and pinion.\

Which ties with my thought that maybe there's something like a shaft-drive motorcycle R/P that could be made to work here. The big thing (I'd guess) would be the centerline distance, but if close perhaps an eccentric bearing carrier could be made for the pinion. Honda and BMW make shaft motorcycles, I suspect there's a few more out there.

A bit of time scouring Google Image would let you guesstimate housing size and ring/pinion distance (scale using wheel size, which should be easy to find in online specs). If you find something promising a search for the right used parts would be worthwhile, starting with Ebay or the motorcycle used part market.
 
Hello Gents,

Thank you for the replies and ideas. I will tear into it this weekend after I take a lot of measurements and make some ref marks. I need to count the gears, but I know it is very close to a 2:1 ratio. Boston Gear lists some gear sets, but I need to measure a lot of stuff on mine to see what I can adapt, if it comes to that.

Thanks,
Montie
 
Hello Gents,

Thank you for the replies and ideas. I will tear into it this weekend after I take a lot of measurements and make some ref marks. I need to count the gears, but I know it is very close to a 2:1 ratio. Boston Gear lists some gear sets, but I need to measure a lot of stuff on mine to see what I can adapt, if it comes to that.

Thanks,
Montie

On my machine, if I recall correctly, it was 1.7 to 1 ratio, the boston gears are 2:1, ring gear is is 1/4 or 1/2" smaller in dia, so pinion gear will need to ride slightly further out, I think a custom nut will be required for pinion. I found p#s on boston site, then found nos gears on ebay/amazon at half retail price. Boston gears are bevel spiral, but less teeth.

Correction: Stock ratio was 1.8:1 , not sure if it will help you but here is my thread https://www.practicalmachinist.com/vb/cincinnati-milacron-kearney-trecker-vn-usa-heavy-iron/info-nedded-van-norman-1r-3-22-mill-350205/index3.html?highlight=van+norman
 








 
Back
Top