VN Hot Spindle. Greased Wrong?

J

jjj111

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Hi All,
I have a VN R-3. I am a half-fast machinist.
Thanks so much for your help.
John

ISSUE: The spindle is running a little hot.

WHAT I DID SO FAR: I took off the cap to see the rear bearing (in horiz position) and greased it through the zirk fitting in several places until new grease was visible all around. I then added the same amount of grease to the front bearing even though I couldn't see this bearing.

RESULT: Spindle still runs a little hot: About 70 degrees over room temp after 45 minutes at 1100 rpm.
(Manual says 70 degrees over room temp after running 1 hour at 1600 rpm.

QUESTION 1: I followed some other advice to use molykote grease. OK?
QUESTION 2: How can I know if the bearings are overgreased or undergreased? I assume both would cause it to run hot.
QUESTION 3: If I have to do this by looking at the bearings, can I look at the front bearing without having to pre-load the spindle bearings when I put it back together? The procedure for this in the manual looks complicated.
 
Use an NLGI 2 rated grease.

I only give mine a couple of shots every 8 hours or so of run time. If you over grease it, it will get hot, but eventually that extra grease will get flung out. Unless you flush the bearing with solvent, it's unlikely it's under greased.

Yes, you can look at it. There are either 3 or 4 bolts on the bottom of the cutter head, remove them and pull the part off. It will be tight. You will be able to see part of the bearing. This will have no effect on the bearing end play.

Are you running oil in the cutter head? You should be running a gear lube, I think 140 wt, to lube the gears. It doesn't take much, but over filling the gear lube will cause the head to heat up.

My #12 can run all day and the cutter head barely warms up.

Jason
 
In a letter from a Van Norman Service Engineering to the original owner of my 22L he states that on "older" VanNorman mills the heads will get as hot as 170 degrees F and this is normal. He states that "newer" VN mills will run at a lower temperature due to improved materials and lubes.

Good luck with your mill

Mike
 
I have the very first production model 12, it runs nice and cool.

Jason
 
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