So, does the LSS arm rely on springs like the AL5D? If not, how does it keep its balance? Can it be driven from an RPi in the same way as the AL5D? Is there any feedback from the motors, and if not, what is the accuracy in repeated movements over time? What other improvements over the AL5D might there be?
Thanks.
LSS Articualted: https://www.robotshop.com/en/lynxmotion-smart-servo-lss-articulated-robotic-arm-kit.html
AL5D: https://www.robotshop.com/en/lynxmotion-al5df-kt-robotic-arm-flowbotics-studio.html
Q1) Does the LSS arm rely on springs like the AL5D? If not, how does it keep its balance?
The AL5D uses Hitec’s 805BB in the shoulder, which was one of the largest available at the time. Unfortunately for an arm of that length, the maximum dynamic torque from the servo was at its limit when the arm was stretched far forward. The springs were added to help reduce the load on that servo.
Q2) Can it be driven from an RPi in the same way as the AL5D?
The AL5D doesn’t really have direct compatibility with a Pi other than a USB connection, which is the same case for the LSS Articulated Arm.
Q3) Is there any feedback from the motors, and if not, what is the accuracy in repeated movements over time?
The AL5D uses Hitec RC servos which do not offer any feedback nor onboard intelligence, and take RC PWM signals, whereas the LSS Articulated Arm uses Smart Servos which, although they can be set to RC mode, work best in serial. Main differences include:
Unlike motors with optical encoders, the accuracy does not build up over time since the built-in magnetic encoder is absolute. The accuracy is best when close to the base, and decreases as the arm is oustretched and load is added. The accuracy is also affeced by the holding stiffness value. The angular accuracy of each servo, combined with the mechanics, ends up around ±1 degree (average based on tests).
Q4) What other improvements over the AL5D might there be?
