Hi,

I am building a CNC platform in my head, which will hopefully come out some day.

Aiming for something that will mill steel with a precision of around 10 my pr 10 cm. This is a hobby thing, so I cannot just buy the solution.
The platform should support 3D printing and EDM as well, but the milling is the hard part, even though the EDM requirement means that moving the subject is not an option, which means that a moving gantry is the ticket.

Since I cannot afford precision mechanical parts, I will try to make up for this by employing a closed loop design based on DRO's (MESA 5i25/7i66/7i85).

The usual way of doing this, would be having two ballscrews on the gantry moving axis. This conflicts with my closed loop/DRO design, since this design cannot possibly compensate for two crappy ballscrews at the same time.
So I am considering having only one ballscrew driving the gantry, and this has to be placed at the side of the gantry, to avoid collision with the tool.
Youtube has a lot of DIY cnc machines, but I have not found anything like this.

Has anyone tried this? And if not why?

BTW: I have bought a chunk of granite 1500x700x50 mm, and is planning for a for a work area of 750x350x150 mm.
The main consequence of this will be, that the gantry will be heavy, but given the 350 mm width, I can probably keep it below 25 kg.

Kind regards
Henrik