Quote Originally Posted by WandrinAndy View Post
Last query on the limits of thread in 5mm thick aluminium... When attaching the supported round rails on top of the beam on the X-axis is it then necessary and best to run a length of thicker flat bar through the box section to take the bolts?
To be sure then Personally yes I would.! . .BUT. . If you use M5 bolts then with smaller pitch and keeping the centres closer together with the higher quantity of bolts you could get away with it.?
I've done this with steel 4mm box section and it's worked ok.! . . It's just with softer Ali @ 5mm could be marginal.?

At the worst you can just add the thicker bar through at a later date if it doesn't feel right or causes problems.?

The Angle gantry sides should be ok because of the squat nature and the fact it's driven from both sides.! The thing to watch out for is that the Angle both internal and external are close to 90deg.? The round rail bearings will handle some discrepancy but you don't want too much.!! . . . Bracing will help absorb any resonance and can only help.

I've noticed from the pics you have 2 plates on the bearings and cutaways in the gantry sides for what looks like access to the bearing bolts.?
If you use 2 plates then you don't need access to the bearing bolts and can bolt the top plate direct to the bearing plate so no need for access slots. The beauty and point of 2 plates means it makes gantry squaring easier without having to worry about bearing bolt access.