700x700mm print surface

[kuon]

I am working on a larger printer with heated chamber and I am looking for a high temperature (200°) bed that has a 700x700mm print area.

The heater is not really a problem as I can use a silicon heater with no adhesive and sandwich it between two aluminum plates. I also though of splitting my bed in 4 heating zone with 4 smaller plate, to help with leveling and thermal expansion. But I am very open to suggestion on this too.

My main problem is build surface. At this size, it becomes harder to manipulate. Also magnet based surface, which I love for smaller printers, cannot be used at this temperature as magnets are usually rated for 150°. I was thinking of creating some kind of drawer that can be pulled out of the printer (my gantry moves on three axis).

[dc42]

@kuon samarium-cobalt magnets can be used at temperatures above 200C, so a magnetic bed plate is still possible.

[kuon]

@dc42 Ah, thanks for the name. I'm able to find some. I also considered a vacuum to hold the bed in place and electro magnet but they seem impractical.

Also, is there any build surface, beside glass, that can be used for high temp plastics? As glass is heavy and also cannot be used with magnet base.