CNC design for consideration?

[jonbabbz]

Hi all, i'm a long time reader, first time poster. I have experience in CNC and own an A3 sized desktop one and want to upgrade with a new home build. Basically i just want to cut mdf and ply with it, speed and really tight accuracy are not really that important and I have yet to calculate my motor requirements except that I'm going nema 23 for size.

I just wanted maybe a more experienced builder or anyone in the know really to have a look at my design and see if there is anything obvious that might hold my design back before I commit to ordering the parts.

The goal was to create it as cheap as possible but try and keep rigidity. I've used 16mm multi-start trapezoidal lead screws on x, y and z. Fully supported 16mm rails on x and y and 16mm round rail on z. My main concern is the lead screws on x sagging?? The machine is 1500mm x 1000mm at the rails.

Any advise would be greatly appreciated. Thanks

[podolskiy]

Why not use steel square tubing? That material is a lot cheaper.

[ger21]

Personally, I'd try to move the screws down and out of the way, unless you want oil and or grease on your arms all the time from reaching over them.

[HorridHenry]

I'd use 30mm or better for the bottom X-axis rails,keep with the 16mm as guide rails.

[podolskiy]

I would make the machine with a consideration that all moving parts can be covered in nylon fabric sleeves.

That will keep the abrasive dust off the bearings and make the machine run better/longer.

So I would hide the screw underneath metal guides so it won't touch the fabric sleeve.