Hey guys Thanks very much for the replies, Unfortunately I was a silly boy and bought the supported rails kit before I knew anything about the subject from Aliexpress. the plan being I will use what I have for now but then look to either create another or upgrade to rails. I have made it wider also so that I can slide work pieces around a little and work with larger materials and then make a second continued cut although most of the things I do will be sheet material and smaller pieces but I wanted an all-rounder for things like my daughters dolls house I intend to make with the machine and other toys too for her and me !

I didn't even think about the tensioning in all honesty that is a very good point I will make it on a movable faceplate. I couldn't think of a different way for the box for the ballnuts otherwise the other option being the ali route but though this might be better on the strength I might be able to make a silicone hose to the grease maybe although I'm not sure if it would just pop off.

I will have a good think to see if I can make those better

Thanks so much guys.