Machine Mill nod correction

[Larry_C9]

Some time back, by careful measurement, I found that the head on my Craftex CX601 mill had .003”nod across the table. I did some calculations and decided that if I were to put a .002” shim across in front of the two front bolts that hold the column to the base I should be able tip the column slightly back to remove the nod. In preparation I machined a solid lifting bracket from some 3/4” plate to bolt to the top of the column. So today was the day to see if my calculations were correct. I connected my engine crane to the top of the column via the lifting bracket and place a block I had previously made, under the head on the table. I lowered the head onto the block and took a little strain on the crane then loosened off the four bolts that secure the column to the base. By putting a little down pressure on the head the column raised a little off the base. I slid a .002” shim in ahead of the bolts and torqued the column back down. By using my Edge tramming tool I determined that there now is less than .001” nod across the table. I think we can call that a success

 

[David]

I think I may have the same problem. Thanks for the tips!

 

[Dan Dubeau]

Good fix Larry. That will certainly be noticeable.

 

[Larry_C9]

I think I may have the same problem. Thanks for the tips!

Just one thing to keep in mind. Make sure all your gibbs are locked up before you try to take measurements, just in case there are some slight movements there.

 

[David]

Just one thing to keep in mind. Make sure all your gibbs are locked up before you try to take measurements, just in case there are some slight movements there.

Good pointer.

 

[trevj]

I have a Milltronics CNC mill, and when I pulled the head off it for my last move, I found a shim under the lower edge of the face that the head mounts to. A strip of .005" shim stock.

This is not a new idea.

Glad it worked for you!

FWIW, I'd rather have a side tilt than a nod, but either can be worked around, once you are well aware of the presence.