3-Axis CNC Mill Project

[JAZZCNC]

The base is not so much an issue and easily sorted with bracing or like Robin suggested stiffening with panels.

The tall narrow gantry is the biggest weak area I see and is where all the action takes place. It's also where all the other machines of similar design fall down.!

If your having a single central screw then you need a wide bearing footprint to help counter racking when cutting at the outer edges. The wider the better but obviously this loses travel so it's always a compromise.!

The other area that is often over looked and is THE most important part of the machine IMO the Z axis. It does all the work so if this is flimsy then it don't matter if the rest of machine is carved from one lump of granite the finished result will be shite.! . . . Obviously this is fastened to the Y axis and again if the gantry is flexing around because it's too tall or narrow and under braced then so will every thing attached to it.!. . . . It's also what Robin was pointing out.!

It's really just a case of make the X axis bearing foot print has wide as you feel you can spare and make the gantry only has high as you really need. If you need high then build very rigid with loads of bracing.

Don't under estimate the inertial forces of the gantry and Y/Z axis they can be quite high and will easily rock and flex a high narrow gantry at half decent cutting and rapid speeds.
This is what plagues the Merchant dice type offerings because the motors and Ball-screws are capable of so much more than the frame will allow and the finished cut is drasticly reduced if run too high.!! . . . So therefore the machines run feed rates well below there components potential to give anything like a decent finish and stop the frame from falling apart.!! . . . . This soon becomes very limiting and restrictive and why most sell them shortly after buying.!

My suggestion is you Stand back a little have a think and look about at other machines and throw a drawing or two our way for checking over. Has you've probably seen already where all more than willing to help and advise with honest opinions.