Demo video of 270-degree servo build.
https://youtu.be/C0HKbcXvxyQ?si=A_heGZqB2mn3dSQJ
Demo of 180-degree servo build.
https://youtu.be/JTk9pedSiHE
Video of the PCB for the robot build. Not required but it does make things nice and tidy.
https://youtu.be/z_aoq63YSlE?si=dFaw1UDYoUnlrRP0
I tried PCBWAY for 3d printed clear resin parts as well. Turned out great.
Link to the clear parts. https://youtu.be/2aUJb5Wtf8o
Link to the demo of the assembled clear Katie 270 robot.
https://youtu.be/mwyVuDuips0
The robot can walk forward, backward, flip end over end and turn.
I have built this programable robot using standard 180-degree servos and 270-degree digital servos. Both will work, but the 270-degree ones are best for performance.
The servos come in plastic gear and metal gear versions. If you use the plastic gear version the splined output shaft will be plastic, and the servo horn lever is held on with a self-tapping screw that will be to short once you add the 3d printed leg part so use one of the 2 mounting screws that come with the servo instead. You do not need the mounting screws to hold the servo in place in this project. In fact, you should cut off the two mounting
tabs from the servo to make it easier to install.
Now if you use the all metal gear servo then you have to buy a 2.5mm machine screw that is 6 to 8mm in length as the machine screw that comes with the servo will be too short. You cannot use the servo mounting screw as they will not screw into the machine threads of the brass splined shaft.
I used a Pololu micro mystro controller.
I use buck boost voltage regulators to convert the 3.7 volts from the battery to 5 volts.
I used pencil erasers on the short legs for surface grip. If you print the long legs, then use something thin like balloons for the foot covers for traction.
Gerber files for making PCB included in a zip file.
Here is a video I did on the PCB low-cost method I used.
https://youtu.be/z_aoq63YSlE?si=6Zsa_o7sLBsRWg6j
| 1ServoBrase.stl | 1.4KB | |
| BodyBasePCB2.stl | 302.4KB | |
| BodyTopPCB2.stl | 124.1KB | |
| Gerber_PCB-Katie-270_PCB-Katie-270A_2024-08-16.zip | 10.4KB | |
| LegLong270DigServo.stl | 408.5KB | |
| LegShortEraser270DigServo.stl | 415.0KB |
