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VN universal sub head disassembly

Cbrbt

Plastic
Joined
Jul 29, 2021
Has anyone taken a VN sub head apart before? This specific one has bronze bushings in it. I have found a picture of a similar one disassembled, but I am stuck at pushing the spindle out of the housing. The first picture is a similar one I found on this forum. The other pictures are my sub head.

I have tried pressing it out, heating it up with a heat gun, lots of wd-40, and compressed air in the oil ports. It won't ​budge. Is the center ring gear threaded on the spindle shaft? That is the only thing I can think of that would be holding it on still.

Screenshot_20210808-065752_Samsung Internet.jpg
 

Cbrbt

Plastic
Joined
Jul 29, 2021
If it does need to press out (and I'm just not using enough force), how do you hold the ring gear inside the head so the teeth don't hit the housing? That is what I've been battling in order to get a good press on it.
 

Brandenberger

Cast Iron
Joined
Sep 19, 2017
If it does need to press out (and I'm just not using enough force), how do you hold the ring gear inside the head so the teeth don't hit the housing? That is what I've been battling in order to get a good press on it.

Aren't those jam nuts to the left of the ring gear?
 

Cbrbt

Plastic
Joined
Jul 29, 2021
Brandenburger, that is what I thought they might be, but I don't see any threads above or below them. They did have set screws in them. One set screw in the ring gear, and another in that ring to the left, that could potentially be a "jam nut." How would you even get a spanner on that jam nut if it was one? It would have to wrap around the body of the head to grip it.
 

Brandenberger

Cast Iron
Joined
Sep 19, 2017
Brandenburger, that is what I thought they might be, but I don't see any threads above or below them. They did have set screws in them. One set screw in the ring gear, and another in that ring to the left, that could potentially be a "jam nut." How would you even get a spanner on that jam nut if it was one? It would have to wrap around the body of the head to grip it.

Do they have dowel holes in the jam nuts?, or just the setscrews?

I have some VN stuff but no subhead so never seen one myself.
All of the stuff I’ve seen has threads on the spindle but that is 1940’s era.

Usually they seemed to stack up 2 jam nuts together. Maybe no threads would protrude. Usually they would have some way of establishing the gear backlash.

The setscrew in the ring gear might be pressing on a key?
 

Cbrbt

Plastic
Joined
Jul 29, 2021
So, this head is definitely 1940's Era. It has bronze bushings instead of roller bearings, so it is definitely an early van norman type. I think I found a good representation of how my head is designed, albeit a later type with taper roller bearings.

In this diagram, it looks like there are two threaded jam nuts on either side of the bevel gear. Mine probably just has that one on the left side (second picture in thread).

I will try to use a pin headed spanner to turn it when I get home tonight. I'll let you guys know how it goes. Cross your fingers for me.Screenshot_20220301-083738_Drive.jpg
 

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
So, this head is definitely 1940's Era. It has bronze bushings instead of roller bearings, so it is definitely an early van norman type. I think I found a good representation of how my head is designed, albeit a later type with taper roller bearings.

In this diagram, it looks like there are two threaded jam nuts on either side of the bevel gear. Mine probably just has that one on the left side (second picture in thread).

I will try to use a pin headed spanner to turn it when I get home tonight. I'll let you guys know how it goes. Cross your fingers for me.View attachment 343246

The line drawing you posted looks like the threaded collars are there to set lash on the gears. The photo way up there, of the disassembled head with gray paint, does not seem
to have any threads on the spindle at all, indeed it seems to have been polished clean so the gear would slide on easily. That gear may have been retained with a setscrew, a
dowel pin, along with the drive key.

Be sure to undo all the setscrews you see, and remember some manufacturers put a lock setscrew on top of the real one. So look into the threaded hole to be sure there is not another one lurking under there.
 

Cbrbt

Plastic
Joined
Jul 29, 2021
The line drawing you posted looks like the threaded collars are there to set lash on the gears. The photo way up there, of the disassembled head with gray paint, does not seem
to have any threads on the spindle at all, indeed it seems to have been polished clean so the gear would slide on easily. That gear may have been retained with a setscrew, a
dowel pin, along with the drive key.

Be sure to undo all the setscrews you see, and remember some manufacturers put a lock setscrew on top of the real one. So look into the threaded hole to be sure there is not another one lurking under there.

Jim,

Thank you for the nugget of wisdom! I will look to see if there is another set screw under the first one. I didn't even think about that.

On the "jam nut" above the bevel gear (in this picture), there is a hole for a set screw (which I removed already), and another blind hole that didn't have anything in it. Before it was mentioned that the "jam nut" could potentially be a "jam nut" by Brandonberger, I had not paid any attention to it. I did not think about the possibility that it could be for a pin headed spanner to turn it like a nut. The reason I didn't think it could turn is because there is a keyway that starts at the top of the milling head by the drawbar and another keyway on the bevel gear, inside the head. I just assumed that keyway (and a long continuous key) ran that entire length.

Something else I noticed while staring at the pictures on my phone is... do you think these holes have anything to do with holding anything in? They are not threaded like the holes next to it that fasten the cover plate on the center section. These holes had so much grime in them that I could not tell what was underneath it. I will clean them really good tonight and see if any set screws are lurking in them.

20220223_080457.jpg
 

Cbrbt

Plastic
Joined
Jul 29, 2021
Well,

I just wanted to say thank you all for your help! Every time I have a question, someone on this forum has either had the answer, or has led me down the path to the answer!

Big thank you to Brandenburger for the tip about there being a jam nut next to the bevel gear. That is exactly what it was. All I did what hold the milling head with a clamp to my work bend and took a roll pin punch, giving the blind hole a soft tap. The jam nut instantly turned, and the whole assembly was basically self explanatory after that. The spindle was tapped out with a rubber mallet, making sure the bevel gear slid off the keyed shaft. Here is a picture of the shaft and all the components for any lucky person in the future.

Now that I see how the shaft is assembled, it really is quite a simple design.

Cheers!!
Van Norman Milling Head.jpg
 

Cbrbt

Plastic
Joined
Jul 29, 2021
Closer up picture as well

2.jpg
 

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