Posts Tagged With: Fan

Upgrade: Mod your POWERWASP to support variable fan speed

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:

Ultimaker shield rev. 1.5.4

Ultimaker shield rev. 1.5.4

Power Wasp Shield


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.

Step 1:
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 ūüėČ

Step 2:
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.

PowerWasp shield update for variable speed fan

POWERWASP shield modified to use pin 7 to control a variable speed fan. Sorry I took this picture upside down compared to the others…

Step 3:
Solder the transistor BD679 in the right position (see picture “number 1”) (Q4 in Ultimaker pcb schematics) Continue reading

Categories: 3D Printer, Improvements | Tags: , , , , | 4 Comments

Add variable fan speed using an Ulimaker shield & Marlin firmware

Using¬†a fan to cool the extruded plastic helps a lot to get better prints, but having it at a fixed speed it’s not the best way at all.
A variable speed fan can be used more¬†efficiently¬†during different moments of the printing process: first layers, bridges, small layers…

Variable speed fan

My variable speed printing fan at work ūüôā

THE PROBLEM: on my board the pin dedicated to regulate the fan speed (via pwm) gets its current from an unregulated source. The Ultimaker board uses pin 7 to control the fan speed, but this pin has not a 12v maximum tension, instead it gets it power directly from the power supply  (in my case a 18v transformator).
If I had used this feature out of the box my fan would have received a voltage of 0/18V not suitable for the popular 12v fan commonly used for this task.

POSSIBLE SOLUTION 1: Use a 24v fan, but this would also have been impractical since at 18v (maximun voltage of my transformer) the fan would have worked at a very low speed.
In fact, computer fans have a working range that’s not 0 to 100% volts since you need to kick in some power to make it turn first, for instance my fan can effectively operate in the range of 5 to 12v. Under 5v my fan doesn’t even start turning. But once it does you can lower it a little more, I will discuss it later on this post about this.

POSSIBLE SOLUTION 2: in your slicer program limit the maximum fan speed to a value safe for your fan.¬†It works, but it’s not really¬†practical¬†nor intuitive and if you are¬†using¬†a controller (like the utilpanel, ultimaker controller ecc.) it’s not safe at all since you coul¬†easily¬†burn your fan using some functionality these controller provide.


Testing the pwv tension before attaching the fan.. safety first ūüėČ

MY SOLUTION: I modified the firmware and set a parameter to define the maximum voltage suitable for my fan. Now I can safely use any slicer/controller in their full range of 0/100% fan speed. The firmware will then handle all the conversions for me.
Continue reading

Categories: 3D Printer, Improvements | Tags: , , , , , | Leave a comment

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