Van Norman 12 bevel gear engagement/adjustment

[stoneaxe]

Is there a printed instruction for measuring and setting the bevel gear clearance between the cutter head and the ram on a VN12?
I do not know if mine is out of spec, when I went through the machine, it is something that was not looked at. Turning the knob on the right side of the ram, the one that is for jogging the gears to get them to line up, a small amount of lash can be felt between that shaft and the spindle. I have no idea on what is normal there or how to measure it. It does appear that shaft has some provision for adjusting end play, much like the spindle does.

 

[Rick Hand]

I don't have my manual with me but when I reassembled mine, I basically just made sure it didn't bind anywhere in the 360 degrees of rotation and didn't have "a lot" of back lash. I didn't measure it but have worked with gears a lot on the last fifty years and believe I have some what of a feel for back lash. Getting a good measurement is probably not going to be easy. One shaft needs to be locked really good to get an accurate measurement. I don't remember if the book I have gives a spec for that or not.
Rick

 

[Peter from Holland]

Backlash you measure by rolling a solder wire in between the gears and measure tbickness of the smashed wire I have a PDF from klingelnberg for adjusti g cyclo palloid gears if that is what they are PM me if you want it

Peter

 

[stoneaxe]

I am not sure what type of gear it is- I will pull off the head and see.
A product called plasti gauge is or was used on bearing clearances, the plastic "wire" was put on the plain bearing and the bearing cap tightened down, then the width of the crushed plastic was compared to a chart.
I do not want to fix it if it is not broke, but thought it might be a worthwhile check.
Then again, maybe if it is worn in from years of use, it might not be a good idea to change an existing wear pattern, even if it is not perfect.

 

[Brandenberger]

If I recall correctly one of the bigger mills, VN24 or 26, had a procedure in their manual for adjusting cutterhead backlash.

Those manuals are all on vintagemachinery.org.

The procedure may or may not be helpful on the VN12.

 

[Rick Hand]

stoneaxe: have you made any progress on your cutter head?
Rick.

 

[john.k]

if bevels are jammed into mesh to minimize backlash,point breakage of teeth will occurr..........bevels must be set for correct meshing,not for minimum backlash.

 

[Peter from Holland]

So here is the klingelnberg procedure

 

[stoneaxe]

Peter,
Thank you. This is very useful information.
I have been busy with various other projects and have not pulled the VN head yet to investigate.