Those of you with 3d printers may be interested in the new Nova Labs Fan Board. Read on to learn how the board was created, and how you can get your own!
The Nova Lab Fan Board is a PCB that I designed with a lot of help from Ted Markson, in order to power and control a bunch of fans and other accessories on RAMPS-based 3d printers, such as the MendelMax printers built by Build Group #4.
Ted and I started by coming up with a circuit diagram in EAGLE. The initial design (see schematic below) did most of what we needed, using standard through-hole components. At it’s core, the board receives four PWM inputs (spare outputs not used on the RAMPS board) and uses them to modulate a larger input power voltage. This allows you to turn the fans on and off using G-code commands.
We then took the schematic and designed a corresponding board in EAGLE. In order to prototype the board, we exported it into a set of tool paths using an EAGLE plugin called pcb-gcode. The g-code was used to mill a test board on the Lobo CNC machine at Nova Labs. It took several tries to get the tool height correct and even through-out. Here are a few of the misfires:
Once assembled, the test board was fully functional:
Emboldened by our prototyping success, I then expanded and iterated the design a few times by submitting it to OSH Park, a great place for hobbyists to order small number of PCBs. They operate by combining many orders onto a single panel, greatly lowering the entry cost of making your own PCB. The final board has some additional outputs, and even a few “always-on” outputs, by popular demand.
The board is now ready for a bigger production run, and I’ll be ordering all the components and hardware in bulk to create kits that contain everything needed to put together and use one of these boards.