If you build or upgrade your printer with/to DUAL-EXTRUSION (2 extruder) including a heated bed all the output ports (D8,D9,D10) will be used. In this case there is
not option to connect a firmware controlled FAN to RAMPS board directly. However in Sprinter/Marlin firmware there is an option already (Marlin: BOARD=34) which
redirects the FAN to RAMPS output D4. But this solution needs a «buffer/driver»in order to work.
The RRD-FAN-EXTENDER is exactly what you need in this case. It is a plug and play solution to mount the FAN for DUAL-EXTRUSION setups with RAMPS1.4. But instead of
adding only one additional output port the RRD-FAN-EXTENDER is equipped with 2 PWM controllabe channels(D6/D11). The second channel can be used for another fan
(e.g. to cool the stepper driver) or for adding light control (e.g. add dimmable LED light to your machine).
Features:
- max 20V
- 2 (PWM controllable) channels (D6/D11)
- max 0.5A per channel (enough for a really big fan)
- flexible output voltage (you can connect the RRD-FAN-EXTENDER to 12V,5V,… in order to support the output voltage you need)
- each channel has a fly back diode
- easy setup (plug and play)
- already supported by Marlin firmware (choose «#define MOTHERBOARD 34»)
- easy to adapapt to other firmware (e.g. Sprinter: just change «#define FAN_PIN 6» in «pins.h»)
You can use it as follow:
