Cutting metal shapes

[RoboCutter]

Something like this maybe: https://www.stepcraft-systems.com/

[jmac80]

Something like this maybe: https://www.stepcraft-systems.com/

hi
that does look a nice build, looks a lot nicer than the cheap Chinese ones.
would it basically been a router not mean it would make a mess of 1050 grade aluminium ?

[Jonathan]

Something like this maybe: https://www.stepcraft-systems.com/

Judging by the photos on this page, the machine uses simple brass rollers on a (possibly?) aluminium extrusion to guide the X-axis. Although it looks like the rigidity of that system is adequate for engraving, I'd be concerned about the longevity.

The German word for 'ballscrew' is 'kugelrollspindel', but they've instead used 'Rundgewindespindel's, which are leadscrews. This means the machine is likely to have higher backlash, especially once the leadscrew nuts have worn a bit. This is confirmed by the 'Wiederholungsgenauigkeit' (positioning repetability) being +-0.05mm. That's enough to show up on a detailed engraving.

Interestingly they have given some measure of stiffness. Although it says torsional, the units imply linear stiffness hence I think they are saying that the machine will deflect by between 0.1mm and 0.14mm if a force of 20N is applied, so the stiffness is between 143N/mm 200N/mm. Unimpressive, though might be adequate as your requirements are small. The thing to do would be to ask someone who'se got one of the cheap machines from eBay (e.g. CNC6040, CNC3020) to measure its stiffness, then we can make an objective comparison.