Re: [CAD_CAM_EDM_DRO] Aligning Rails (or ways) on CNC router

bob_santa wrote:

> Hello Group,
> Can anyone suggest an accurate method of adustind the height (z axiz)
> of router rails that are 6-1\2 feet apart. Preferably using small hand tools as i dont intend to buy a large surface plate to set up the ways.

I think you can do this with 2 tools, assuming the table is actually flat.

First, you need a level of some accuracy grade. For metalworking machine tools, the
standard is the "master precision level", accurate to .0005 per foot or so. This grade
of accuracy is probably more than you need. Putting a hair under on end knocks it
off by 3 divisions or so. What you want to do is make each rail as level as you can.
If the rail reads level at all stations along its length, it is almost guaranteed to also
be quite straight. If both rails read level, they are by definition parallel.

After this, you then can put a dial test indicator in the spindle and read the height
above the table. The spindle should read the same height above the table at all
positions. I'm guessing that is what you are after. Sag of the rails may cause a
dip in the middle, but at least you will know the magnitude of it.

Jon