[ShellbackBill]

What guide or plan did you use to build your CNC router?

And what one would you use today?

I'm starting to Learn CNC on the China Special 6040 I bought. But my next goal is to build a machine capable of working a 4x8 sheet. Wondering what guide you guys used to build yours.

[cyclestart]

What guide or plan did you use to build your CNC router?

I built mine on the fly with a few rough sketches. This was the result of having an accumulation of parts and material from 'here-and-there' and a determination to make the design fit the parts. The compromises are many but it works okay(ish) . Here's a pic fwiw. See what happens when you don't use a map ?
Attachment 395166
4x8 means the goal is plywood or other soft sheet goods ? If so the design parameters become clear. You won't need much clearance or travel on the Z axis but the long Y span will need the to be stiff.

And what one would you use today?

Honestly I'd probably buy a kit like cncrouterparts and let them do all the cutting and measuring.
Anyway the real reason for replying was to share this link:
CNC Router Source: The Ultimate Information Resource
It's not a plan but it's a guide of sorts and gives a lot to chew on.

[ShellbackBill]

Thanks,You build looks pretty good. Hope mine looks and works as well.On my way to Router source to do a little chewing.

[cyclestart]

You build looks pretty good.

You're much too kind but I'll accept that in the spirit it was intended. Thank you. The main source of flex is the 16mm Z axis rods so not a good place to get cheap.

A less common design has the gantry beam riding near direct on the X axis. It looks very rigid.
Attachment 395234
In fairness to the owner of that image here's a link:
"http://www.kronosrobotics.com/krmx02/"

Good luck. Hopefully someone who has actually built a machine that size will reply.