Ah yes, sorry, you're right, I meant Mach4. Ok, that's cool then, I'll stay with the parallel port. Glad I kept that old IBM Thinkpad now :D

On Q6, well, I didn't know - I was just after any thoughts/opinions. Sounds like it's just not worth it, so that's cool.

Digital drivers is a new one on me - guess some more reading to do - do they need different motors, presumably? No problem if it's a complex answer, I'll do some reading on the forum, just curious.

I guess any upgrades to the electronics can be considered an investment, assuming the drivers and motors remain matched..... maybe I can keep the motors and spindle, if nothing else, if/when I do make my own.

Am I right in thinking the main thing I need that's really lacking is the rigidity in the gantry, the quality of the runners, lack of support on the Y and just general strength/"trueness" in the aluminium extrusion approach...

Here's the crux question then - for the PCB work and aluminium work (slow, hobby, prototyping stuff, low volume, 0.1" through-hole and SMD designs) is the extra £400 on a 6040 worth it over the 3020? The only real differences I can make out are the crappier spindle, the crappier ball screws and the smaller working size. The latter I couldn't care about :)