Support and motion for huge 100x60 mic8 bed

I am designing a really big printer for my business. The bed is going to be a 100cm x 60 cm chunk of 8mm aluminium which will be the Z axis. I am currently deciding how to
support and move it. I am thinking of 2 x 20 mm linear rails and 2 x 16 mm ball screws or possibly just using 3 x 16 mm ball screws and no other means of support and guidance.
By linear rails I mean the square ones with the re-circulating ball carriages. Or would round guides be better?
Any advice would be most welcome!

Screws are not guides. Using screws without guides is asking for Z-wobble in the prints. If you don't mind z-wobble, it should be OK.

No other means of support? Will the bed be heated?

Linear guides, if used fully-supported (screwed to frame members or plates), are almost always better than end-supported round guide rails, but they are less forgiving of errors in parallelism.

For a plate that size 2 screws might work, but 3 is better.

Don't even think about using 20x20 or 25x25 mm t-slot for the frame. Start at 40x40 and go up from there.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Thanks Dentist!

I figured that 2 or 3 screws with 2 linear rails in the middle of the short sides would be best. I dont want to over do the rails and wind up over constrained. What do you think would be best with 3
screws, 2 or 3 rails I could always have 2 screws and 1 rail on one side and 2 rails with 1 screw on the other side?

The bed is going to be heated, I am printing PETG. It will be insulated with cork on the bottom. I am planning on using 230VAC heaters

For the frame I plan on using 60x20 or 80 x 20 for the frame and either 20x20 or 20x40 for the Y axis.

I am thinking of using 12mm MGN for the X axis and 20mm HGW for the Y axis and bed.

I actually only need about 3cm of build height for my business stuff, but will design for 500mm ball screws so I can use it for other stuff as well.

Why would you want to move the bed instead of the extruder/hotend?

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etfrench
Why would you want to move the bed instead of the extruder/hotend?

The bed is moving in Z. Arguably an easier feat to do then moving an XY gantry in Z.