Quote Originally Posted by Boyan Silyavski View Post
Using 100x100 profile or any = no problem. But the key is in the welding. Welding no more than 2 inch at a time from different sides and checking with laser thermometer for the temperature of the beam overall not to rise more than 60 degree C will do the trick. It must be done with patience and cleverness.

If you read my building log you will see that it took me some time to weld my big machine, but it was worth it.

And as i said many times before, 100x100x3 is the ideal material for big strong CNC.
I did not check but I guess the moment of inertia will be higher for the steel 100x100x3 compared to aluminium extrusion 90x90, even thought 90x90 has a larger cross-sectional area?

What about skipping the welding and bolting the steel frame together with angular plates or plates? That would also make it possible to disassemble the machine if you need to move it around (hopefully not) at some point.

What kind of epoxi should be used for the leveling? I have never done that before. By the way, thanks for all the answers!