Thingiverse
Simple Wi-Fi Car by cpopp
by Thingiverse
Last crawled date: 4 years, 7 months ago
This is a basic RC car that is intended to be straightforward to understand, includes example code to control it via Wi-Fi, and uses centered drive wheels so that it can spin in place.
Suggested Build Instructions
Required materials
8x M2 16mm screws: Home Depot, AliExpress, AliExpress M2 Assortment
Substituting a length from 10mm to 20mm should work
4x 5/16" x 2" Fully Threaded Bolts: Home Depot
Bolt head doesn't matter. Longer is ok but results in axle sticking out from vehicle. Shorter down to 1.5" is ok but the idler wheels will be closer to the frame than the drive wheels.
12x 5/16" Lock Nut: Home Depot
4 of these can be regular nuts (non locking) if it works out cheaper
2x MG946R Servos: AliExpress
These servos (or any digital servo roughly 1.60×0.78×1.69 in) should work as well: MG945, MG945R, MG946R, MG956R, MG995, MG995R, MG996R
ESP8266 Microcontroller: Amazon, AliExpress
Print the following
1x frame.stl
2x wheel_drive.stl
4x wheel_idler.stl
PLA or your preferred material is fine for the frame and idler wheels. A softer material like TPE/TPU is better for the drive wheels but PLA would still allow it to drive on flat surfaces.
Assembly
Slide the 5/16" bolts into the holes on the frame so the threads are sticking out. Secure the bolts with two 5/16" lock nuts on the outside of the frame for each bolt. (The inner nut is just a spacer so the idler wheel is even with the drive wheel, you can use a plain nut for this or omit it entirely if you happen to have a shorter bolt.)
Slide the idler wheels onto the threads. The idler wheels will be a tight fit on the threads at first so just spin them all the way in and slide them back and forth a bit and it will wear away enough material so the idler wheels can spin freely without climbing on the threads.
Put a final lock nut on the threads to hold each idler wheel in place. The nuts should be tight enough to prevent the idler wheels from sliding side to side but loose enough to ensure they spin freely.
Modify both servos so they can spin continuously. Here's an example guide: http://www.instructables.com/id/How-to-hack-a-servo-for-continuous-rotation-Towe/
Screw each servo to the frame. The servo should be placed so that its shaft is halfway between the idler wheels. The servo should include four screws that screw into the holes in the frame.
Take the servo horn that looks like a plus. The drive wheel has a slot for the horn with holes to screw it in. You'll need to drill four of the servo horn holes slightly larger so the M2 screws can slide in...this should be the third hole from the inside, but to verify place the horn in the drive wheel slot to see which lines up.
Place the horns in each drive wheel and screw them in with the M2x16mm screws. Make sure the horn is facing such that it will be able to slide onto the servo once screwed in.
You can now mount the drive wheel onto the servo. Use a screwdriver through the hole in the drive wheel to screw it in.
Wi-Fi Control Setup
Install the latest MicroPython firmware on your ESP8266: https://micropython.org/download
Hook the brown/black wires of the servo to the ground pin on the ESP8266.
Hook the red wires of the servo up to your 5V power source (on the nodemcu board this will be the Vin pin).
Hook the orange/yellow wire from the left servo to GPIO5 (D1 on NodeMCU)
Hook the orange/yellow wire from the right servo to GPIO4 (D2 on NodeMCU)
Make sure wifi is configured on your ESP8266 so you can ping it
Place servo.py on your ESP8266
Place the attached main.py on your ESP8266.
Power it up. If it works, you should be able to go the IP address of you ESP8266 in a browser and control your RC car.
Alternative Build Instructions
If printing the full frame is difficult because of your printer you can print 2xsubframe.stl instead of frame.stl. The instructions are very similar but instead of the 4x5/16" bolts you'll want 2x5/16"x12" (or shorter) threaded rods with 4x5/16" lock nuts.
Suggested Build Instructions
Required materials
8x M2 16mm screws: Home Depot, AliExpress, AliExpress M2 Assortment
Substituting a length from 10mm to 20mm should work
4x 5/16" x 2" Fully Threaded Bolts: Home Depot
Bolt head doesn't matter. Longer is ok but results in axle sticking out from vehicle. Shorter down to 1.5" is ok but the idler wheels will be closer to the frame than the drive wheels.
12x 5/16" Lock Nut: Home Depot
4 of these can be regular nuts (non locking) if it works out cheaper
2x MG946R Servos: AliExpress
These servos (or any digital servo roughly 1.60×0.78×1.69 in) should work as well: MG945, MG945R, MG946R, MG956R, MG995, MG995R, MG996R
ESP8266 Microcontroller: Amazon, AliExpress
Print the following
1x frame.stl
2x wheel_drive.stl
4x wheel_idler.stl
PLA or your preferred material is fine for the frame and idler wheels. A softer material like TPE/TPU is better for the drive wheels but PLA would still allow it to drive on flat surfaces.
Assembly
Slide the 5/16" bolts into the holes on the frame so the threads are sticking out. Secure the bolts with two 5/16" lock nuts on the outside of the frame for each bolt. (The inner nut is just a spacer so the idler wheel is even with the drive wheel, you can use a plain nut for this or omit it entirely if you happen to have a shorter bolt.)
Slide the idler wheels onto the threads. The idler wheels will be a tight fit on the threads at first so just spin them all the way in and slide them back and forth a bit and it will wear away enough material so the idler wheels can spin freely without climbing on the threads.
Put a final lock nut on the threads to hold each idler wheel in place. The nuts should be tight enough to prevent the idler wheels from sliding side to side but loose enough to ensure they spin freely.
Modify both servos so they can spin continuously. Here's an example guide: http://www.instructables.com/id/How-to-hack-a-servo-for-continuous-rotation-Towe/
Screw each servo to the frame. The servo should be placed so that its shaft is halfway between the idler wheels. The servo should include four screws that screw into the holes in the frame.
Take the servo horn that looks like a plus. The drive wheel has a slot for the horn with holes to screw it in. You'll need to drill four of the servo horn holes slightly larger so the M2 screws can slide in...this should be the third hole from the inside, but to verify place the horn in the drive wheel slot to see which lines up.
Place the horns in each drive wheel and screw them in with the M2x16mm screws. Make sure the horn is facing such that it will be able to slide onto the servo once screwed in.
You can now mount the drive wheel onto the servo. Use a screwdriver through the hole in the drive wheel to screw it in.
Wi-Fi Control Setup
Install the latest MicroPython firmware on your ESP8266: https://micropython.org/download
Hook the brown/black wires of the servo to the ground pin on the ESP8266.
Hook the red wires of the servo up to your 5V power source (on the nodemcu board this will be the Vin pin).
Hook the orange/yellow wire from the left servo to GPIO5 (D1 on NodeMCU)
Hook the orange/yellow wire from the right servo to GPIO4 (D2 on NodeMCU)
Make sure wifi is configured on your ESP8266 so you can ping it
Place servo.py on your ESP8266
Place the attached main.py on your ESP8266.
Power it up. If it works, you should be able to go the IP address of you ESP8266 in a browser and control your RC car.
Alternative Build Instructions
If printing the full frame is difficult because of your printer you can print 2xsubframe.stl instead of frame.stl. The instructions are very similar but instead of the 4x5/16" bolts you'll want 2x5/16"x12" (or shorter) threaded rods with 4x5/16" lock nuts.