This is a bigger body for the Kame.
I am still working on it, but it should be okay as a starting point for others.
It allows to integrate a 800mAh 2s Lipo, a strong 6A BEC, a pin header or small prototype board and a ultrasonic sensor. There is a hole in the back to to install an on/off switch and a battery chute for easy battery access.
The servo holes fit my generic cheap 12g metal gear servos, but you can set the parameters in the OpenSCAD-file to make them fit your needs. However, try to use tough servos, they are under direct load all the time in this design.
Modified software is in development, trying to make use of the ultrasonic sensor. The sourcecode can be found in the GitHub repository which is a fork of the miniKame repository: https://github.com/Blomdoft/fatKame
So the idea is to have this really non-compliant little web server for issuing commands to the bot. Works fine so far.
About Controller Boards
I am using a NodeMCU Amica Development Board, which basically is a ESP8266-12 with a full pinout board underneath it, there are many like these and they are inexpensive.
Struggles to use the sensor
The ESP8266 boards have the problem that they only offer 8 "real" GPIO pins, so using the ultrasonsic sensor with them is quite tedious. An additional GPIO can be used for sending out data if no interrupt is required (triggering of the ultrasonic sensor works fine). But receiving back the echo requires freeing up GPIO9 or GPIO10, and that means making modifications to the way that the flash chip on the board is wired. Think soldering SMD. Still looking for a better solution to this.
board_pins = D1; // front left inner
board_pins = D4, // front right inner
board_pins = D8; // front left outer
board_pins = D6; // front right outer
board_pins = D7; // back left inner
board_pins = D5; // back right inner
board_pins = D2; // back left outer
board_pins = D3; // back right outer
BIG thanks to bqLabs, this is a supernice bot!
The upper part is a bit ugly to print, I am printing it in natural direction with a lot of support. As the bad surface finish then is on the inside, it does not matter that much.
I took the FreeCAD file from the Kame, failed to modify it and made a new one in OpenSCAD. My OpenSCAD skills are still bad, so the file is definitly not nice.