I am looking at ordering my first cnc (primo version). I have some projects that will be cut from a 1/2 sheet of plywood.
If i use 24"x48" as the working area that would make the side rails 60 inches long. I was told that that would be insane.
I would appreciate your thoughts on the maximum lengths. Should i consider a different approach?
Also, i am very new to this. I would imagine there are ways to put markers in the design that i could use to move wood and resume the cutting if i went with a smaller footprint. Is this doable?
Conventional wisdom here on the forums is if you want to cut 4’wide material, you should consider a LowRider rather than a Primo.
You can certainly move the workpiece part way through the process, but it requires care to build in appropriate alignment methods (placing a couple of pins or dowels into fixed points in the spoil board is a common approach) and breaking the cutting into multiple jobs. You’ll also want to build and place your machine so that the work can pass through, and be appropriately supported beyond the machine’s operating envelope.
What Tom said. The “ideal” MPCNC size is about 24"x24" (tube length, not work area, BTW), and rationally tops out at around 36" on either X or Y. If you know you need to cut half sheets of plywood, you really do want to go with a Low Rider. I’m sure you could build an MPCNC with a work area of 24"x48", but I’d suggest using SS tube instead of EMT, and look at using mid-span supports along at least the long edges (which would still leave your gantry sagging).
But you should really look into building the LR2, not the MPCNC. You’re not going to lose any accuracy or precision, or any other metric, versus the MPCNC. It’s just a different set of maintenance routines, troubleshooting processes, and tuning checklists.
Not only are they right about sizing, but the lowrider has another advantage. The table can be used as a work bench when not using it for cnc (because there are no legs or rails in the way) and for somtbing that size its a nice bonus.
