The Dobson lives

Got PPM to a decent level. Still a lot of glitches. Decided to get as much fabrication done as possible & get U some video of the dobson in action before the next commute.

Motorized Dobsonian mount (1 min 35 sec)

If the counterweight looks familiar, that's because

https://www.rcgroups.com/forums/showthread.php?t=984892

It's the landing gear from the pentarotor.

Camera gimbal dreams

The motorized dobson mount made us think more about camera gimbals.

U could probably do a gimbal with 2 of the tiniest servos & the same friction drive mechanism. Instead of directly tracking an attitude, it would only damp motion, relying on hall effect sensors to maintain an average, fixed orientation. The average orientation would be controlled by manually bypassing the loop & resetting the target hall effect values.

Systems that track attitude with servos have been disappointing. The best systems use video tracking, but moving analog video into a computer is super expensive.


DIY servo control dreams

Instead of sending PWM to the yaw servo, you're better off capturing the servo potentiometer directly & controlling the motor with the main computer. That's right. Completely custom servo control just like Heroinesapien. That's how U get virtual flybars on T-Rexes.

Except for an indoor tri-rotor where the servo is really small & basic, the large tri rotor is stable enough to not need any servo hacking. It has enough yaw inertia to fly manually with no damping of any kind.