Would this work for a frame?

[amd7000]

Hi again. Excuse the crappy drawing. But you should get an idea of what I mean.


O.k. I'm planning on using 100x50mmx3mm steel for the main frame, this will be welded by a friend. External dimensions would be 1200x900mm.

I would like to use 20mm square rail with a singular block bearing on each rail,should I use 2?

Could I mount the rails on the side of the frame instead?

This line through the middle is meant to be a ballscrew,haha. Would 16mm be o.k and would it be o.k through the middle of the machine?

I'm hoping to make the gantry out of 80mmx40mmx2mm to keep weight down. Would this be ok?

Will a 4nm stepper be o.k to move the gantry nicely?

What would the likely working space be if the design works?

Sorry if this doesn't make much sense, it's been a LONG Day.