My second router design

[Joe]

I have now changed the design slightly and I have beefed up the gantry more, well I hope so anyway!

It is now made from box section steel, the biggest wall thickness I can get, probably 3mm. It is the part in blue just so that it can be seen more easy. The plan is to weld 2 sections of 50 x 25 together with a piece of 25 x 25 to create a sort of I beam shape. The frame would be clamped together and then spot welded to try and retail some squareness before it is fully welded but I know this process will put the whole part out of square and distort it, so it will then be fly cut flat on all faces so it can be mounted square to the rest of the machine. The idea behind this was that steel is far cheaper and I have the facilities to then make it flat after, but I am still not sure if that structure will be stiff enough to cut aluminum at reasonable speeds.

As for the z axis I have reversed the bearings and rails so that the rails are now on the dropper plate but because I can not mount the bearings back to back the ones on the z axis are much closer together with only 80mm separation between centers, do you think this will be a problem?

Any thoughts would be greatly appreciated :)