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Van Norman 26 - spindle getting hard to turn

leeko

Stainless
Joined
Jun 30, 2012
Location
Chicago, USA
Originally posted this in antique machinery, but was recommended to post here instead.
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Hi everyone,

I cleaned up a van Norman 26 last year. When I first got it, the spindle was stiff to turn by hand and it was tripping the breaker at higher speeds. I took off the head and found it packed full of what I assumed was old dried grease, brown-red in colour and the consistency of clay. I scooped it all out, cleaned the casting out and reinstalled. Before reinstalling, I also cleaned out the oil passage from the ram to the head. There was a little of the same clay around that passage, but the channel itself seemed clean so I felt it unnecessary to go digging into the gear train. After reinstallation, I ran the mill with kerosene in both oil reservoirs (ram and knee) for approx 20 minutes, then drained and filled with hydraulic fluid. The issue seemed better, so I chalked it up as fixed and moved on.

I noticed a few months ago that the overcurrent fault was still tripping on the highest speed. I put it on the to-do list to look into, but in the meantime have been using it at lower speeds. Now, with the weather turning colder, the spindle is significantly harder to turn by hand and the VFD is now faulting even in the middle of the speed range.

I'm now thinking there may be some of the same gunk that was in the head, gumming up the gear train in the ram. I'm waiting for delivery of an inspection camera to take a good look in there. Has anyone been inside the ram of one of these? Or can suggest any other reasons for the stiff spindle? Spindle bearing preload nut too tight? IIRC, I had to play around with it some, because it was originally way too loose, then too tight, then seemed just right (in the warmer weather).

If the same Shmoo is found in the ram, is there a better solvent to use for cleaning it out, than kerosene? Assuming it didn't do the trick last time around...

Thanks in advance,

Lee


Sent from my SM-N960U using Tapatalk
 
Originally posted this in antique machinery, but was recommended to post here instead.
-----------------------------------

Hi everyone,

I cleaned up a van Norman 26 last year. When I first got it, the spindle was stiff to turn by hand and it was tripping the breaker at higher speeds. I took off the head and found it packed full of what I assumed was old dried grease, brown-red in colour and the consistency of clay. I scooped it all out, cleaned the casting out and reinstalled. Before reinstalling, I also cleaned out the oil passage from the ram to the head. There was a little of the same clay around that passage, but the channel itself seemed clean so I felt it unnecessary to go digging into the gear train. After reinstallation, I ran the mill with kerosene in both oil reservoirs (ram and knee) for approx 20 minutes, then drained and filled with hydraulic fluid. The issue seemed better, so I chalked it up as fixed and moved on.

I noticed a few months ago that the overcurrent fault was still tripping on the highest speed. I put it on the to-do list to look into, but in the meantime have been using it at lower speeds. Now, with the weather turning colder, the spindle is significantly harder to turn by hand and the VFD is now faulting even in the middle of the speed range.

I'm now thinking there may be some of the same gunk that was in the head, gumming up the gear train in the ram. I'm waiting for delivery of an inspection camera to take a good look in there. Has anyone been inside the ram of one of these? Or can suggest any other reasons for the stiff spindle? Spindle bearing preload nut too tight? IIRC, I had to play around with it some, because it was originally way too loose, then too tight, then seemed just right (in the warmer weather).

If the same Shmoo is found in the ram, is there a better solvent to use for cleaning it out, than kerosene? Assuming it didn't do the trick last time around...

Thanks in advance,

Lee


Sent from my SM-N960U using Tapatalk

Mine is a 22L not a 26, so yours may differ. I found the same sludge in the cutterhead. I pulled it, cleaned it out, and soaked for a week in a bucket of diesel, spinning the spindle periodically, with the rear bearing cap removed and the front loosened. This seemed to clean it out entirely.

For the ram, it had sludge and old oil, and also in removing the shifting forks and top plate I found lots of sludge on the "roof" of the inside of the ram. Filled with diesel almost full so gears were submerged. As some have suggested I scrubbed all that sludge loose, and used a hand pump to repeatedly rinse all the areas. Then drain and refill with diesel and run the gears for a while. It was nice and clean after another drain.

the 26 looks somewhat different, with the oil passing from ram to cutterhead.

If you put the gears in neutral (does yours have that?) then only minimal gears are meshed and perhaps you can tell where the resistance is? I.e. If the handwheeel then spins the cutterhead with ease? With the cutterhead off that helps to isolate too.
 
Hi Brandenberger,

Sorry, Tapatalk sometimes doesn't notify me of responses, so I only just saw this!

My mill does have a "neutral" on the Spindle gearbox, but selecting it disengages the cutter head - the handwheel spins freely but the cutterhead doesn't. I assumed that was normal?

My inspection camera just arrived in the mail, so I'll need to get out there and take a look inside the ram.

To get inside the ram, is it necessary to remove the motor and overhead? I don't see any big access points, but there is a 4" circular panel on the side bedside the spindle high/low gear selector... Hoping I don't have to mess with the motor - that sucker is heavy!

Lee

Sent from my SM-N960U using Tapatalk
 








 
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