starting from scratch- router 1st project

[Neale]

Many thanks for the details. I had started with 12mm plates but I think that you are using 20mm which allows you to machine recesses for extra clearance, and there are also packing pieces under the rails. Back to the drawing board!

Are you using something like Solidworks for the drawings? The drawings of slides, ballnuts and so on are very detailed and look as if they might have come from the manufacturer!

[idefix]

Yes Neal, using SW for the drawings with some parts already loaded from the web such as rails, blocks and M4 and M6 screws plus the timing belt pulleys. All the rest is own design.

I do confirm that base material thickness for the plates is 20mm (initialy for ridgidity purpose) but helps making the cavities...

[Jonathan]

For a small gain in strength and machining time, you should be able to make the recesses in the Z-axis not cover the whole length, as the ballnut doesn't traverse the whole rail.

[Neale]

That's the kind of thinking that leads to something that looks great in the drawing but is impossible to assemble! In this case, I don't think that that would be a problem but I've painted myself into a corner before now...

[Jonathan]

So think harder! Admittedly I did recently make something that turned out to be impossible to assemble...

Have you checked that the Z-axis belt clears the posts upon which the motor is mounted? If you decide to change the ratio it might not. Also, I wouldn't reduce the thickness of that motor mount beneath the motor, partly because it needs to be strong but also because it adds an extra machining operation which will increase the cost of the part unnecessarily.