This is my simple solution for mounting a 50mm radial fan to the mainboard of my Anycubic linear plus printer. I was experiencing steps being skipped after installing TMC2130 drivers. I am running my drivers in standalone stealthchop mode. Only the X, Y, Z drivers. The extruder is still on the original drivers.
Running the TMC2130 in stealthchop is easy.. Just connect nothing to the CFG pins. :-) In my case I bought drivers with the CFG pins on the bottom, so I just had to cut these pins.
I am using the stepperdrivers as a fanduct.. Since they are so close to each other on the PCB.
This solution is easy to print and easy to install (you need two 3mm bolts.. a short one and a longer one).
I used this firmware: https://www.thingiverse.com/thing:2803527
Connected the fan to FAN1 and reduced the speed of the fan to 180 in the firmware: