My new shop is pretty cold, about 17-18C most of the day. I couldn’t rely on my prints sticking without a heated bed. So I had to modify the firmware (should do an update but it changes the D8 to D10).
Used some springs and screws to make it an easy level platform like most printers are. Level this buy moving the extruder nozzle to each corner and adjusting the screws, do each corner at least 2 times or until it is right.
I was also getting a funny texture in my prints, solved this by turning up the extruder driver to .9V.
Easy way would be 2 beds side by side with 1 sheet of glass over it. The other option is aluminum with custom wired resistors and a large power supply.
Why not use multiple beds wired into a single ssr and control them from the single output on the ramps board. the only issue will be where to place the thermister and how reliable it will be with that much surface area
Controlling it with a spare arduino seems the best way to go. Put thermistors on each bed and slowly heat them up until they are within a couple degrees of each other. It wouldn’t be hard to use a rotary encoder to change the temp setting and have a small Hitachi HD44780 based display read out the set value and the temperatures of each bed. On the slicing side, just set it up like there is no heated bed. Doing that might change a few of the more advanced settings, but I don’t think that should really be an issue. Just heat the beds up before starting the print with the ramps board.
Yeah but you only need the bed to stay warm it doesn’t have to be dead accurate. as long as there aren’t huge temperature differences between the boards. You could mill down into the table add the 4 plates and using some thermal tape, adhere them all to a thin sheet of aluminum then the glass bed on top.
