Steel framed fixed gantry draw slide build super cheap

[Zeeflyboy]

What has been pointed out is entirely correct.

If you are just looking for a cheap machine to mill e.g. foam or something then this probably works fine, as pointed out though the bearings on steppers are radial bearings designed for radial loads. They will be experiencing axial loads when trying to drive the screws which is something radial bearings aren't particularly great at... That will result in excessive play, premature wear and eventually failure.

Given that the drawer slides won't allow you to machine anything hard anyway, you will probably be ok on the X and Y (although they will still wear out and develop slop more quickly, and are more difficult to replace than in a separate fixed bearing block for the screw), but given the weight of the router being pulled up repeatedly the Z-axis will probably suffer more.

It also means you are relying on a rigid coupling between the motor shaft and screw, which translates vibrations and resonance into the motor, which again isn't great news. With direct drive really the idea is to have a jaw type coupling with a rubber/flexible insert that provides some protection to the motor. You can't do that however unless the screw is supported by its own bearing set.

I know you think people are being negative or crushing your creativity but there's a reason why things are done a certain way, and it's not creative to go and do things the wrong way just for the sake of being different. To come up with a new solution that actually addresses the reason why things were done in a certain way (e.g. the fact that radial bearings aren't designed for axial loads, and vibration decoupling) whilst doing it better/cheaper/differently is what being creative or innovative would be... just ignoring the issues that cause things to be done a certain way and then doing it poorly to save money is not innovative, it's poor engineering.

You clearly aim to create a cheap machine, on that front you are succeeding. Though how anyone on here is supposed to know what your end goals are when you haven't stated them is ridiculous. Hopefully it's just a fun project for you, and you enjoy making stuff - which is great imo. If you are expecting any sort of accuracy or ability beyond carving some foam into interesting shapes then you are probably going about it in the wrong way.

By the way were you actually trying to infer that your creation will be capable of holding 0.001mm over a 12 inch disc or did I misunderstand that?