Articulated Arms Stroller Fan

A lovely fan which offers a cooling breeze that can be fully 3D printed (other than the motor, battery, and switch).  Makes use of a snap-ball-joint system to create three articulating arms which can be conveniently flexed in a myriad of ways to wrap around various stroller parts, allowing you to point the breeze in the perfect direction.

Designed to make use of a small hobbyist electrical motor with a body that is 24 mm wide and a 2 mm shaft, such as this one.  You'll also need a basic toggle switch with a body size (i.e the “hole size”) of 8 mm x 15 mm such as this one, as well as one or two 9 volt battery clip connectors.  

The compartment uses a threaded design so that the batteries can be replaced/recharged, and is designed to accommodate two 9 volt batteries.  I setup mine so that the two batteries are wired in parallel to give the fan a longer run time (which works out to around 20 hours in my case), but you could also run them serially to get the fan running faster (if you think your motor can handle the voltage).

Printing tips:

All parts can be printed without supports, although I added a small support in the center of the “Cage Mount” piece - which is designed to be placed top-side down on the print bed.  The cage front and back should be printed with their face-side down on the print bed, and the snap-ball-joint pieces should be placed with the flat-side of the “ball” part down.  Finally, the “Bottom” piece should be placed top-side down on the print bed, so that the mount joints are up when printed.  For your convenience I've also upload a “Stroller Fan.3MF” file which includes all the parts in their correction orientation, and shows the print settings I used to print the one shown in the pictures on my Prusa Mini.

Assembly tips:

1. Glue the “Fan Hub” onto the “Fan”, using the provided slots for alignment.
2. Slide the motor axle into the “Fan”, and optionally use a drop of glue if you think the axle is going to slip (but in my case I didn't need it).
3. Thread the motor wires through the provided hole on the “Cage Back”, and then place the motor into the housing in the center of the “Cage Back” piece.  Depending on how tight your motor fits, you may want to wrap a piece of electrical tape once or twice around the motor body - so that it's nice and snug when you slide it into its housing (I suppose you could use glue as well.)
4. Feed the motor wires through the “Cage Back” and “Cage Bottom” piece, and then either glue or use two M5 screws (16 mm long) to attach the “Cage Bottom” to the “Cage Back”.
5. Attach two wires to your switch (solder recommended), and wire one side of the switch to the red wire of your motor and the other side to the positive terminal(s) on your battery connector(s).  Wire the negative terminal(s) on your battery connectors to the black wire of your motor.
6. After ensuring the wires are all well attached and covered (either using solder and electrical tape or small wire nuts), then slide the switch into its place in the battery compartment.
7. Print two of the provided pegs, place them in the “Bottom” piece, and then use a small amount of glue to attach the “Bottom” piece to the “Battery Compartment” piece.
8. Snap together however many of the “Snap Ball Joint” pieces as you chose to print to create the three arms.  In my case, I found an arm length of about 9 pieces each worked nicely.
9. Finally, when all looks good, simply snap the “Cage Front” piece on and use the threads to twist the “Battery Compartment” into place to complete the assembly.