I've been following the OX forums for a while now getting ready to start building one myself, and while I really like the concept, I am wondering about the resolution these machines are capable of. I was thinking of looking at ball-screw or rack-and-pinion setups for the X- and Y- axis, but this looks to add considerable cost - especially for me here in NZ the shipping costs alone become prohibitive. I like the simplicity of the belt drive system (and the double belt setup looks like a winner), so my question is: has anyone looked at using a worm drive reducer like this one from Aliexpress: 90 Degree Worm Reducer RV030 11mm Input Shaft Worm Gearbox Speed Reducer for NEMA 23 Stepper Motor Brushless Motor-in Speed Reducers from Industry & Business on Aliexpress.com | Alibaba Group These seem to be available in a range of gear ratios, so what would be the ideal reduction ratio to get a decent resolution without making the thing ridiculously slow? It also seems like this would be an easy mod without having to redesign the gantry plates. I would like to build a mill predominantly for wood & perspex, but would also like to be have the ability to cut aluminium from time to time.