I recently saw the prusa xl has a modular bed system, and thought it would be fun to design my own. I have no understanding of how the prusa implements this, but im trying to come up with my own. I have an Ender 5 Plus with a Mercury One Corexy Mod. Bed size being 377x370mm.
Most of my prints do not need to utilize that full size, nor use the full power. I primarily print ABS so that means 100C bed temp. Plus I’ve been wanting to upgrade my bed to cast tooling plate. This system, which I’m dubbing “B3D”, has the potential to reduce warping from heating unevenly, however that will be tested.
I’ve drawn up a rough sketch of my intended design, ordered the mini plates, and figured out how to wire up 9 thermistors using an additional MCU flashed with klipper (Adafruit Grand Central was my first stab, looking to move to seeeduino Xiao), and went as far as designing a voltage divider PCB (one with 9, and another with 16 inputs) to help input the thermistors signal.
I ordered 9 x 24V 30W silicone heaters to mount to each of my 120x120x6mm MIC6 plates, and each plate will have 3 point leveling with springs. Each bed gets its own MOSFET. The mini beds will have a 1mm expansion gap between them, and ultimately use a Spring Steel PEI bed to transfer the heat.
Beyond constructing the actual unit, I’ll have to figure out how to implement the intended use case, which I’ve come up with, as follows:
A macro will look at the size of the print in the gcode, and toggle the specific beds to be turned on according to which plates it sits.
To further this idea, it would be ideal to have a slicer plugin (I’m currently using superslicer) that orients the object in the center of whichever plates it needs.
I do know, that initially I’ll be manually turning these beds on and off until I can figure out how to even develop the necessary code.
Over the next few weeks I’ll be looking to figure out how to start developing the code and macros, any recommendations or constructive criticism is welcome.