Here's the 3d printed toy helicopter in operation.
This requires two motors, two batteries, screws, 3d printed parts and a polymer clay driver. Let's get started!
To convert the servo motor to a continuous rotation metal gear drive motor, first remove the four screws and the bottom motor cover.
Remove the circuit board by cutting the three wires below and two wires above.
Connect (solder) the two wires from the motor to two wires leading out.
The motor should now rotate slowly (and with lots of torque) when 3 volts dc is applied.
Step 6: Tinkercad Work
I've included the Fusion 360 design files as well as some "in process" files that show the development method, but do not need to be printed.
Blade thread and Blade files were imported into Tinkercad and combined to create the Propeller. The blade file was imported twice (once for each end), then twisted 7 degrees and combined to make the Propeller, which was then exported.
Gear and shaft lg gear were imported into Tinkercad. Gear was imported at 22% of the original size, then made "taller" and combined with shaft lg gear to create the printable file, gear shaft combo.
Small gear and gear spacer were imported into Tinkercad. Small gear was imported at 22% of original size, made "taller" and combined with gear spacer to create sm gear combo.
Harness left was imported into Tinkercad and a mirror image file made and exported (harness rt). Both need to be printed.
The servo motor is mounted to the frame using 3mm screws.
The servo horn (ends clipped off) is mounted to the sm gear combo using 3mm screws.
The small gear combo is pressed onto the servo shaft and secured using the servo horn screw.
The two candy cane feet are fastened using 3mm screws.
The tail rotor motor is slipped into the rear motor bracket.
The rear motor bracket is a press fit into the tail section.
A snowmobile bearing is pressed into the gear shaft combo.
The propeller is screwed onto the gear shaft combo.
The two motors are connected to a 3 volt AAA battery holder.
The body is secured to the frame using 3mm screws and nuts.
The rear cover is pressed onto the back of the copter.
The blade small (printed at 98% size for a better press fit) is pressed onto the tail rotor shaft.
The left and right harness pieces are glued into place.
My wife, Annelle, made the elf using polymer clay. Any suitable driver could be used.
The battery holder is attached to the bottom using velcro. Inserting and removing the second battery turns the copter on and off.
As a bonus, this was designed to operate hanging from a ceiling (NEVER in a place where it could drop on a person or animal). Using 30 awg wire wrap wire (two strands wrapped around the round center piece, through the helicopter shaft), this can be supported and powered in a near invisible fashion (from a distance of 15 feet or more).