HI Guys
Thanks for the replys, have attached a few photos so you can see the type it is , i would rather buy the complete unit threaded bar bearing nuts the whole lot as the hands are not steady enough now to put together but i could manage to put the whole lot in together already built.
The instructions say it is 1404 double thread trapezoidal screws and about 420 mm long .
There is a bit of backlash on the x axis just now and thats what i want to get rid of as its about 1mm Click image for larger version.  Name: IMG_20200810_193111.jpg  Views: 227  Size: 154.8 KB  ID: 28698Click image for larger version.  Name: IMG_20200810_193049.jpg  Views: 222  Size: 179.2 KB  ID: 28699Click image for larger version.  Name: IMG_20200810_181726.jpg  Views: 219  Size: 163.4 KB  ID: 28700