A simple solder fume extraction fan using:
* 140 mm pwm controlled silent fan (because pwm is fun)
* A microcontroller with suitable pwm control and a simple interface (TBD)
Starting out very simple (off the shelf computer fan, arduino, cardboard prototype) I plan to get something working and then refine until I feel like I'm done =)
My current goals are:
* 3D printed design (my first)
* Table top version
* Articulated arm mounted version (desk lamp style)
* Simple pwm control with rotary encoder/pot
* Software controlled power on/off for the fan
* Custom pcb (my second)
* Presentable code base
Stretch goals/experimentation:
* Automatic on/off using some form of heat sensor or the like
Files
solder-fan.stl
Render of full model, both fan enclosure and filter holder in one piece. Might be trickier to print in one piece.
Standard Tesselated Geometry -
7.07 MB -
12/29/2021 at 18:12
Created a GitHub repo for the files, recreating some of the steps on the way to the current 3D model. Removed the model file in favor of a link to the GitHub repo where I intend to keep working, soon adding some software and electronics info.
Fleshed out my 3D model to include a housing for the fan with screw holes for mounting and a filter holder in front of the fan, with a separating "X" between the two. Also added a hole for the fan cable to exit the fan holder. I plan to mount the controller on the outside of the fan holder, on the top.
I've started out very simple to get going, since I do need a solder fume extraction fan right now, but also to test out some of the things in my comfort zone, putting a bit of throw-away software together to get things rolling. My current hack uses a basic Arduino skeleton, poking directly into the avr registers to get the target pwm frequency of 25kHz. It mostly works but falls down at very low/high duty cycles, since in the current pwm mode I need to update the threshold value in the interrupt handler at each counter overflow. But that's OK since I'm just testing things out. I'm currently running the fan directly off of 12V from a lab supply and the arduino from USB.
I also had some fun with a serial based UI where you can control the pwm speed with the arrow keys and get a nice volume meter style gauge to show you the current duty cycle setting.
Right now I've started experimenting with openscad to make a simple, printable design to replace the cardboard and tape prototype.