Good advice thanks for that. I hear what our saying about the machine build. Ideally i'd just rebuild the the machine but no time for that. I do have a larger rack and pinion machine but I don't have time or inclination to go down that route again at the moment.

I have however got a complete set of chain, sprockets, idlers and tensioners for Y and X, which I think I bought as the original upgrade to the belt machine but never fitted. How about I replace the T5 belt with chain and keep an eye on the tension (cant quite remember what type of chain it was but prob the same stuff used on Mechmate builds. 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?