This is a minimal fan mounting bracket for the Trigorilla Mainboard on the Anycubic Linear Kossel. I made this as a simple way to mount a 40mm radial blower fan to cool my TMC2100 stepper drivers (not wanting to print a fully enclosed tunnel, because I already have a panel between the hot bed and PCB). The fan is attached by driving a 3mm screw directly into the bracket (cutting its own thread). The bracket is attached to the PCB with one M3 screw and nut.
Here's an example of the fan type:
I connected the fan to the unused FAN1 connector on the Trigorilla board, which is controlled by PIN 7 of the controller board. I enabled this by making the following changes in Marlin "Configuration_adv.h":
#define CONTROLLER_FAN_PIN 7 // FAN1 is Pin 7 on Trigorilla Board
#define CONTROLLERFAN_SECS 60 // Duration in seconds to run after motors disabled
#define CONTROLLERFAN_SPEED 255 // 255 == full speed
This works really nicely as the fan switches on automatically when the stepper drivers are enabled, and runs for another 60 seconds after they are turned off.
It took me a while to get the TMC2100 drivers working well. In an attempt to make it use spreadCycle mode, I started by cutting off the CFG1-3 pins and bridging CFG1 to GND with a wire. It turns out this doesn't have any effect on the particular TMC2100 driver I'm using. The drivers were still in stealthChop and kept missing steps and skewing layers, no matter which Vref I used. Eventually I discovered there are two tiny solder pads under the board which need to be bridged to connect CFG1 to GND and enable spreadCycle mode. Now it finally works well...
0.2mm layer height, 0.8mm shell thickness