Hi Lee

Thanks - none taken as criticism - it is a learning journey.

You are right, to have two rails per side adds complication, effort and a notable level of frustration during assembly. I had the rails available and wanted to err on the side of rigidity so thought it a good idea to use 2 per side. I first set the left-most rails and then spent hours ailing the rail and ballscrew to an inside reference of the aluminium profile. At some point I also changed the reference line on the profile to try and check for errors (I still questions the flatness of the profile as a reference but didn't have another option). I then aligned the other rails to the first andI probably spend ±10 hours aligning all 4 rails and the 2nd ballscrew. It was quite an effort to get the exact distance between each rail and then between Y1 and Y2, constantly rechecking and testing the resistance.

This is where I realised that I didn't allow for enough adjustability (despite reading about it and being told to add adjustability - lesson learned - I did allow some, but not enough). Next time I will add forwards/backwards adjustment on the left horizontal plate (the one that connects the gantry to the Y-rails) and left/right adjustability on the right plate. Also, if I had to do this again, I'd machine a number of exact template plates to fit over the rails and profile to set the initial positions.

I still need to square and tram it, so I may find a few more issue to solve but am looking forward to using it!

Ian