hello
I know this has probably already been covered but for the life of me I can not find it anywhere. How does one square the y and x axis on a cnc machine? My gantry is mounted solid to my tabletop and my y axis is a complete asembly and will pivot so that it can be made square with the gantry. The y axis is a table top and moves independently of the gantry. I will eventualy post pics. I tried using the peg Idea and placing a board on the y axis and drawing a line. Then putting the board on the other side of the pegs and drawing another line. Then measure the distance between and see if the distance is the same.
Next question, what should I paint mdf with. Primer ,enamle or what, does the mdf swell when painted do to absorbing the paint. Does it take a special paint to actually seal the mdf. Could someone point me in the right direction thanks.

Thanks
Shawn