belt drive to ballscrew drive changeover advice required

[JAZZCNC]

The chain will stretch but is certainly supposed to be better than belt. Any knowledge or thoughts about chain before I go down that route?

Or as your suggesting just replace the belt. I think I used 16mm T5 which has embedded reinforcing wire in it. Perhaps there is something more chunky but still belt I could look at?

I've not used Chain on a CNC machine and never would because to me there must be more backlash in a chain. I use to be a motorcycle mechanic and I've fit enough chains of much higher quality than an industrial chain to know it's not a good choice for a CNC machine. A timing belt is a very low backlash and high efficiency so you won't get better unless you use screws.

I'd just use a wider 25mm belt and good quality. I'd also use the HTD profile.