Fun toy for in the car...

Each summer when I was a kid in the early '80s, my father would carve out of wood what he called a “Virevent” in French (windswirl). Hours of fun involved putting your hand out of the car window and letting it spin... facing the danger of snapping your fingers onto it, causing a lot of pain, or accidentally touching the side of the car and scratching it. 

This time, it's reborn in plastic and with a ball bearing to make it spin even faster... use at your own risk!  (don't exaggerate.   for at least 14 years and older!)

Warning: this can spin seriously fast and will be extremely painful if you touch the wheel while it spins.  So try/use at your own risks - you have been warned!

Extra Material

• 1x Bearing 608
• 1x round head screw 4mm diameter, 35mm length (30-40 mm will fit)  (I used a wood screw but there's no thread in the pastic.  The thread must be a bit bigger than 4mm.  Round head is better but I suspect a any screw that has a tight fit will do.  Just test that it bits inside the smaller hole in the bigger hole of the propellor!
• A metal ring (washer) (if the head of the screw is too small to stop in the bearing hole

Instructions:

1. Print at 0.2 mm.  PLA is fine.
2. Print the handle with at least 50% infill and 4 walls for robustness.
3. For the propeller, print with 4 walls and 25% infill.
4. Assembly: 
   1. Glide the metal washer onto the screw. 
   2. Place the 608 bearing onto the screw, followed by the plastic washer.
   3. Carefully screw this assembly into the handle, ensuring not to overtighten to prevent plastic damage. Make it flush. 
   4. For the propeller, place it hole-side up on a table.
   5. Gently position the bearing in the hole; avoid using excessive force.   (DON'T PUSHI IT USING THE HANDLE!  Read #6)
   6. >> Use a screwdriver to gently tap the bearing from both sides to fit it snugly into the propeller hole. Repeat the process gradually until the bearing is fully seated.