45°/90° Servo mount

thingiverse

I'm making a Rubik's mixer with my older son instead of being a human assistant for him. We're building it together using the Kas' gripper design, which costs around $20 to $25 depending on what materials we already have at home. The design is almost complete, except for the servo mount, but I had to create an alternative because I don't have access to a CNC machine like in the original design. The main issue with this project is figuring out the final position of the servo mounts, which took me three days to get right. Now it can run for five minutes without any major issues, although it does hiccup occasionally if not aligned perfectly. If the cube isn't rotating correctly, I need to re-seat the grippers in software, which slows it down a bit. To make it work smoothly, we used different plate heights and added a touch of hot glue or thick paper for extra stability. If you have any ideas on how to improve the alignment of the grippers, feel free to share your thoughts here or in the forum. We're using an Arduino Pro Mini with an ATmega168 chip, which works fine with the native servo library, but has issues with the varspeedservo library used in the original code. With the varspeedservo library, the Towerpro MG996R servo tends to spin out of control at the boundaries or stall when trying to set angles below 0°. To solve this problem, I added a 2K resistor to the potential meter on the wrist servo, which helped stabilize it. However, I suspect that customizing the attach call in cube.cpp to set the min/max values for my servos might be necessary to fix the issue completely. Without solving this, you can still use the 90° rotation code to complete all operations, just slower. If anyone knows what could be wrong with this setup, please let us know. You can find more details and instructions on how to build a Rubik's solver using the links below: https://www.thingiverse.com/thing:2800244 https://forum.arduino.cc/index.php?topic=271827.0