Sears Shultz

posted Jan 18, 2017, 12:19 AM by Hawken FabLab   [ updated Oct 10, 2017, 10:17 AM ]
Final Product

Minor Improvements
Potentiometer is desoldered and switch is soldered on:
9V battery is put under the hopper:

Trigger and Hopper V2
I made slight improvements to the hopper and trigger pieces in Inkscape, such as widening the hopper so darts fall more smoothly and perfecting the trigger pieces.
Gluing it all together:
The hopper is a lot better, but it is still challenging to load darts since they don't always fall in the correct orientation.

Cardboard Trigger V1
Designing the pieces in Inkscape:
Gluing it all together:
Many of the pieces for the trigger are the wrong size.

The Hopper V1
Designing the pieces in Inkscape:
Gluing it all together:
The hopper is too narrow, so darts aren't falling smoothly.

Barrel Addition
Cutting the PVC pipe (I cut it more later):
Designing the barrel holder in Inkscape:
Hot gluing the barrel and holder to the rest:
I ended up removing the barrel because it decreased the range of the darts and did not increase the accuracy significantly. 

Wooden Laser Cut Flywheel Prototype V3 - Smaller Motors Again
Designing the new base and wheels Inkscape:
Printed out:
Assembled again with rubber bands:
Glued onto thick wooden board for stability and wired again:

Wooden Laser Cut Flywheel Prototype V2 - Bigger Motor
Designing the new base, wheels, bottom section, and top section in Inkscape:
Printed out:
Bigger motors hold flywheels crooked, going back to smaller motors:

Wooden Laser Cut Flywheel Prototype
Designing the base in Inkscape:
Designing the wheels in Inkscape:
Laser cutting both:
Wheel fits well on motor:
Designing the sides in Inkscape:
Tight fit with the base:
Designing the bottom section in Inkscape:
Good fit as well:
Designing the top sections and flywheel pegs in Inkscape:
Printed and glued on the pegs:
Good fit:
Wiring again and using rubber bands to hold it together:

Plastic Flywheel Prototype Attempt
Designing the base in Sketchup:
Print wasn't great:
Gluing on both of the motors:

Wiring the Cardboard Prototype
Sketch of wiring (P = potentiometer, M = motor, 9V for battery):
Putting it together, Nerf dart is launched fairly far but flywheels keep coming off: 

Cardboard Prototype V2
The distance between the two flywheels was too tight for the Nerf dart, so I made the holes in the base wider by about 3mm (right is new):
Perfect fit:

Cardboard Flywheel Prototype
Rough sketch:
Inkscape .svg for laser cutter:
For the prototype I will be using this motor:
Trying out the first couple cuts for size:
Cutting out more pieces:
Hot gluing everything together:
The distance between the flywheels is too tight for the Nerf dart. I plan on laser cutting a new base with more spread out holes and reusing the cardboard flywheels.

Initial Idea
My idea is to laser cut a triangle shaped RC car with three wheels. Two motors would power each of the front wheels. On top of the base would be a Nerf turret. Nerf darts would be fed to a piston via a hopper. A motor powers the piston so that it moves back and forth to feed each dart to two spinning motors that thrust each dart forward through a barrel that is aiming upwards. This has already been done with some of the products that Nerf sells:
Very rough sketch: