wlpuah / RUMBA32 - History

Initial microcontroller changes

Remove 2560 and 16u2, add F446 in similar pinout to PicoPrint.

Change to RUMBA32

Change project/file names, remove output files

Tidying for v1.4

Updating images
Removing old files

Change 16U2 from AU to MU package

Smaller, better stock availability

Initial v1.4 changes

Move fuses upward slightly, make room for deeper screw terminals, adjust silkscreen labelling.

Change diode D8

D8's forward voltage is the limiting factor in 12V regulator current capability, currently gets uncomfortably hot running 12V 40W heater cartridges. Changing D8 to SSB44-E3, lower forward-voltage than previous part to reduce heating.

Update MOSFETs

Change heater and fan MOSFETs to BUK9Y21-40E - cheaper, improved gate-capacitance, logic-level, still very good RDSon. No loss of performance or significant heating at heater or fan current levels.
Leave bed MOSFET as PSMN1R8 for maximum current capability.
Change MOSFET numbering to make BOM tidier.

Improve 5V regulator

Change diode D5 to DB2W40200L - higher current capacity + smaller + easier footprint
Improve routing of power and ground, add vias to improve thermal conductivity to ground plane