Knee Movement on Mill

[ddickey]

I was checking my vertical movement of my knee today. Set up a DTI so taking a reading on the fixed jaw of the vice. There was zero movement going up. On the way down however if moved. It was close to .010" but did not make an accurate check. Just wanted to check for movement.
I adjusted my gibs recently not sure if I did something wrong or not. My mill has always squawked on the downwards path. I'm wondering if the gib is to tight and holding up the knee.
Also the gib really should be replaced. IS this something I could make myself? It is the type that has two screws on either end.

 

[john.oliver35]

Do you mean that the jaw moved away (or towards) the mill column as you lowered it?

My Rockwell 21-100 used to 'shudder' a bit when lowering. I scraped in the gib a bit, and some high spots on the ways. cleaned and lubed well and it improved a lot. Not a full re-scrape mind you (someday I'll get to that).

 

[ddickey]

Pretty sure it moved forward.

 

[Ulma Doctor]

you sure could make your own gib
i don't know what type of mill you have-
but i'm sure you can do it if you have the will and machines available- you can make most anything
the problem is that you will disable the milling machine, perhaps momentarily, to get dimensions to replicate another gib

 

[Alan H.]

I would say you do have the gib too loose. I believe 0.010" tilt at the vise is a strong indicator that the knee is too floppy.

Another question, are you sure you are getting adequate lubrication? From your description, I'd think you have a gib adjustment and a lubrication issue.

 

[ddickey]

I have an oiler but perhaps not. I did feel the lower part of the dovetails and they were oil covered. I'll have to check above the knee tomorrow.