Thanks for this feedback.
The issues you talk about are things that we also noticed. Those Dynamixel motors are great motors for their price, however they’re certainly not enough to achieve a very robust system.
There are also many other factors that can influence the robustness and precision of the robot: 3D printing elasticity, belts, motors, etc. If you add all the small stuff, the overall precision can become much lower. And that’s why we say this robot is only an educational robot, that can reproduce industrial use cases, but not actually do them. Note, however, that the repeatability is quite good on the robot.
The rise in temperature for your axis 5 (XL-430) is maybe not normal. Can you check your power adapter that we provided with the robot? For some early versions we provided a 12V power adapter, which was too much and sometimes can lead to burn the XL-430 motors. Now we ship 11.1V adapters. If you have the wrong one, please don’t use the robot too much and contact our technical support so we can ship you a new one asap!
We have not changed any parameter on the Dynamixel motors we use. However you can (at your own risks) change them using this script on the robot, and following the Dynamixel documentation for registers (available on the link above)