I've had a functional 3D printer for about a month, and this is my first complex construction. I’m entering it in the “Catch the Wind” challenge.
The rotor turns nicely in a light to moderate breeze. The planetary gears provide a 3:1 reduction to the 12 bubble wands dipping into the reservoir, and helps prevent violent splashing in a strong breeze. The fact that the wands go in the opposite direction as the blades gives a nice esthetic.
Additional materials include:
- 4mm Corrugated plastic sheet for the blades and body. After the next election, several hectares of the material should be readily available.
- One Inch 10-24 nuts and bolts: Five are used to hold the rotor assembly together.
- One inch 4-40 nuts and bolts: Three are used to mount the planetary gears.
- 1/4-inch dowel to form the axel.
- brads or other small nails. These are pushed through the holes in the mounting brackets and through the corrugated plastic. They do a good job of securing the printed parts to the sheet.
- cyanoacrylate or other glue to lock the 4-40 nuts, secure the sun gear to the dowel, and secure the wands in the holes around the outside of the ring gear.
- BB's for the ball bearings
It took me some time to convince the printer to work, but the project comes together pretty quickly after that, which is fortunate, since the last part came off 6 hours before the deadline for the
What you’ll need to print:
One of everything, except:
3 planet gears
3 planet gear bearings
12 bubble wands
2 bubble solution basins
Once all the parts are printed comes the assembly. Cut blades from the corrugated plastic. I used 20mm straight blades, but there is still room for experimentation. You’ll need to cut a 20-degree angle at the inner end to get it to fit well into the hub. You can use the base of the hub as a guide. Put all the nuts in the front part of the hub and the nuts in the hexagonal recesses in the back piece. They should be snug enough to stay in. Then you can put the blades onto the front piece. You’ll need to punch a hole in the appropriate place to thread the piece over the nut. Once all the blades are on, put on the back piece and screw the bolts into the nuts.
Ball Bearing Assembly:
Place the base and the core on a flat surface. You can insert the BB’s easily. You’ll need 22. Add Cyanoacrylate around the perimeter and place on the cap. Weight it down until the glue has set. Be sparing with the glue. The grooves in the base and cap are meant to catch any excess, but don’t take any chances. You can always add more later if it seems necessary.
Planetary Gear Assembly.
Put the nuts in the hexagonal recesses of the mount bracket and put it on the table with the nuts down. Put 8 BB’s in one of the toroidal grooves, and put the planetary gear on top. Top that with another 8 BB’s and then with the bearing. Pass the 4-40 bolt down through the stack and screw it down. Not to tight.
Repeat with a second planet, then you’ll have to put on the ring gear before assembling the third planet assembly. At this point the ring should rotate freely. You don’t want the nuts too tight. When you’re satisfied, use a drop of cyanoacrylate to lock the nuts. You don’t want them unscrewing at this point.
Slide the wands into the wholes in the ring gear. You’ll want to use glue to secure them.
Bubble solution Basin
Glue the two halves of the bubble solution basin into the Bubble Basin Bracket. Silicone sealant works great for this.
Bringing it all together.
Cut a nice, fashionably body shape. Make it larger at the back, so that it’ll point upwind. Or you can just plan on mounting it to a ridgid structure if you’ll be pointing it into the wind manually. Position the ball bearing and planetary assemblies on the top edge of the sheet and secure them by driving the brads into the holes and through the sheet. Pass the down through the assemblies. The rotor can friction fit not the front end of the dowel, although some glue will make it more secure. Slide the sun onto the back end and into the planetary gears. You’ll need glue to lock it in place. Mount the basin so that the wands dip well into it. Make sure it doesn’t interfere with the rotation of any of the wands before you secure it.
Fill basin with bubble solution and enjoy the long stretch of warm, completely still weather that will ensue. I can vouch for this effect as I’m still waiting.