Well here goes... Aluminium frame router design

[CharlieRam]

Well, Quite a few views but no reply's so it cant be all bad, either that or everyone's enjoying the weather like I probably should be doing! more than likely though it is because of an incomplete design?
I have completed the basic design minus ball nut attachment and adjustable stepper motor brackets, pulleys and belts but I have some questions.

I was wondering about limit switches, Do they stop the machine dead or do I need to bring them in a bit from maximum travel and if so, how much?

Following on from that I may need to scale the machine up by about 100mm on X and Y, will the design still work or will I need to beef it up on the gantry?

I plan on using 1610 ballscrews for X and Y and 1605 for Z, is this correct.

To mount the 100x50 box section to the gantry sides I have a 40 x 40 bar cut to 90mm long in each end, would I be ok to countersink the box section and fasten with countersunk cap screws? I am assuming I can make adjustments with the cap screws on the gantry sides.

I have included an updated sketchup file, all components are models so it can be pulled apart bit by bit if you like, any feedback appreciated.

Thanks, Charlie