I already build my 525 mpcnc and is on use. I would like to upgrade to primo. Can I use 6mm belts with the 10mm non toothed idler pulleys or I require the 6mm pulleys. Ian using 16 toothed 6mm pulleys on the steppers.Later I would like to purchase 10mm belts if required because sourcing now locally the 10mm belts is difficult.
Using wider pulleys should be fine. Belt tension should keep the belt from “wandering” on the pulley, even if you use the 10mm pulley on the stepper. You could use 2mm worth of washers to a side as well to use the 6mm pulleys.
For me, it was sourcing the pulleys that was difficult.