This is an easy to assemble toy car made using lots of high-tech tools. Once you 3D print, and laser cut your parts, the rest can be zip tied and bolted together in minutes. I was initially planning on making more of a hot rod. However, thanks to the slow speed of the servos, it turned out to be more of a cruiser. This vehicle has a slow smooth ride, which makes it the perfect motorized platform for all kinds of applications. For instance, it makes a great camera dolly (for silent films and music videos), and a suitable robot base. Nonetheless, it was a fun exercise in state-of-the-art personal fabrication.
I made it at TechShop.
Step 1: Go get stuff
You will need:
(x1) An 11" x 6" laser cut bracket (file attached below)
(x2) 3D printed servo wheel
(x2) Parallax continuous rotation servos modified for direct drive
(x1) 3D printed wheel and pivots (printed at precisely 1/4 the model size)
(x1) 1/4" x 2" stainless Steel rod
(x1) 4 x AA battery holder
(x4) AA batteries
(x12) 4" zip ties
(x8) 12" zip ties
(x2) 4-40 x 1/2" nuts, bolts and washers
(x1) 220 Sandpaper (optional - not pictured)
(x1) Polycrylic stain (optional - not pictured)
Step 2: Sand and stain (optional)
Sanding and staining will ensure your cruiser's frame is more durable and has a longer lifespan.
Sand both sides of your wooden bracket and wipe them off.
Coat one side with wood stain. Wait for it to dry, sand it lightly, and then coat it again.
When the first side is dry, repeat on the opposite side.
Step 3: Drill
Grab one of the servo motors. Widen the outermost hole in each corner of the servo's horn with a 1/8" drill bit.
Repeat on the other servo.
Step 4: Zip tie
Zip the wheels to the servo horn using 4" zip ties.
Step 5: Press fit
Press fit the 1/4" rod firmly into the wheel's hub. Center the wheel upon the rod.
Step 6: Attach the wheel
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Place the pivots onto each end of the metal rod.
Slip the wheel into front fork of the laser cut bracket and zip tie the pivots firmly in place.
Step 7: Attach the servos
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Zip tie both of the servo motors firmly to the back end of the laser cut bracket.
Make sure the servos are on the same side of the bracket as the pivots.
Step 8: Battery holder
Place the battery holder on the same side of the servo bracket that the servos and pivots are zip tied to.
Line up its mounting holes with holes in the bracket and fasten it in place with the 4-40 nuts, bolts and washers.
Step 9: Wire it up
Turn the servo bracket such that the servos are closest to you.
Twist together the red wire from the servo on the left to the black wire of the servo on the right. Connect both of these to the red wire from the battery holder.
Twist together the black wire from the servo on the left to the red wire of the servo on the right. Connect both of these to the black wire from the battery holder.
Solder both pairs of wire together to make a more reliable electrical connection.
Step 10: Clean it up
Zip tie all of the loose wires together such that they cannot get caught on anything and the exposed electrical connections can never touch each other.
Step 11: Insert batteries
Insert batteries, flip it over, and watch it go.
Step 12: Use
Feel free to use it however you wish. I stuck this micro tripod on topn and used it as a camera dolly. It was a lot of fun.
I think it will work well as a generic robot base as well.