A controllable fan (on/off and speed) it’s a nice feature that really improves your prints and, once setup, it can operate without any assistance.
In the POWERWASP, fan is directly connected to the regulated 12v output that’s always on. Since this printer it’s really well made you can attach or detach you fan anytime, also during the print, basically turning it on and off as you like. For example you can add the fan after the firsts layer, but still you need to assist you printer and… is just off or full power. To take advantage of the features of your slicer software (like cura or slic3r) and your Marlin firmware, just follow this tutorial.
After your hardware upgrade you may want to update your firmware to support this feature in a better way, but I will tell you about this later on.
SKILL: some confidence with your printer and ability to solder trough holes components
TIME: 1h (actually I don’t remember how much it took, but it’s more than reasonable)
TOOLS: nothing special, just scissors, screwdriver and a soldering iron
COMPONENTS: one BD679 transistor and one 1k resistor
The POWERWASP printer comes with an Utlimaker shield clone (rev. 1.5.4) that uses a dedicate pwm pin (D7 on Arduino) to operate the fan to cool the hot-end.
You can find more info and schematics here: http://reprap.org/wiki/Ultimaker%27s_v1.5.4_PCB
As you can see from the pictures above the two boards are identical except for one thing: the POWERWASP shield has all the components needed to run the printer and not those unused (in perfect WASP style ;-)) so to run this feature I had to add them by myself. A really easy operation if you know how to solder trough hole components.
Open the cover on the bottom of the POWERWASP and disconnect all the wires from the shield (I suggest you to mark them carefully to easily put them back on the right places 😉
Cut the power supply wires that are directly soldered on the pcb. Once terminated the mod, instead of solder them back, I added a connector just in case I will ever need to remove the board again, but that’s optional: you can just solder them back to the pcb without any problem.
Solder the transistor BD679 in the right position (see picture “number 1”) (Q4 in Ultimaker pcb schematics) Continue reading