Giant 20' x 3' x 2' router build

[charlieuk]

thanks for that jazz i can see what you are saying and we did wonder about the third set of blocks and there is plenty of room to fit it all in and i have made the y frame so i can slide one side in to be what ever size it needs.

i was wondering about using 60x60 or 80x80 for the z axis but the 40x80 in a relatively short length seams crazy strong as it is.

i guess what i will do it try and get the x and y rolling and see how that feels and with the way it is i can pretty much just add to it if does look like its not going to be up to the job. I was planing on using rack and pinion for y could i just run a second motor on the other side rather than a ball screw? or possibly even one motor with a shaft and pinion on ether end like a car axel, although that maybe a little more tricky to build

if needed i could actually make the hole gantry narrower if needed just buy shortening a few bits if it would help.


I should say that i am not after crazy speeds for cutting ply or accuracy for that matter as it will be just for stuff that i would normally make by hand so 1-2mm tolerance would be fine to start with.

many thanks for all the advice i am taking it all on board

[JAZZCNC]

i was wondering about using 60x60 or 80x80 for the z axis but the 40x80 in a relatively short length seams crazy strong as it is.

Yes it may seem strong Now but promise you when there's a spindle on the end with cutting forces acting on it then at full extension at this length which you would be while cutting ply it will twang like a guitar string.!!
The Z axis is THE single most important area on a CNC machine and seen as your going to so much trouble and expense using Profiled linear rails etc why spoil the broth for a pinch of salt.?

Regards R&P then yes it would work ok and seen as your using it on other axis makes sense but you would still need drive it from both sides, thou it would be easy enough to run a shaft across the back of profile. As would it to connect ballscrews with a timing belt, which woud be my first choice.

Tip for you if you use the Bosch Rexroth 45 x90 or it's equivlent then the BK/BF12 bearing block hole centres match the slots and make fastening very easy.
This stuff Profile 45x90S slot 10