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Step movement of the T100?

(Richard) #1

@Rusty-For use in an actuator application, is it possible to “step” the T100/ESC in 1/4 turn or 1/2 turn increments through PWM signals? Maybe a firmware setup in the ESC? It would be nice not to have to fool with a geartrain.

(Richard) #2

The first use I would make of such a simple actuator is to release a weight to yield neutral buoyancy at the ocean bottom depth of interest. This would save a lot of battery power used to get down to depth.

(Richard) #3

Never mind, dumb question. Won’t work without a gearbox because the motor will not generate useful torque being pulsed for incremental movement.

(Rusty) #4


You actually can do this, although the current motors are not optimized for it at all. Using a brushless stepper driver, you can make individual steps. Since these motors are meant for high power, that will take a lot of current and the motor will heat up very quickly.

We’ve actually made a few prototypes of an M100 with different windings so that it has decent holding torque (13 oz-in) at relatively low holding power (10 watts). That’s not enough to act as a real servo but it’s enough to do some useful work.



(Richard) #5

Great Rusty. For my selfish purposes, I would like to see the following products developed by BR, in order of priority:

  1. External 8-pin connector.
  2. Externally accessed mechanical power switch.
  3. Reasonably priced 8-wire tether, say $1/foot.
  4. External actuator.



(TCIII) #6


Definitely some good suggestions.



(Rusty) #7


Great suggestions. I think you’ll be happy with the direction our new product development is going.



(Ole Hermann Godø) #8

Here is a crude test I did for my ROV build.
Brushless outrunner with 3D printed gears. Adjustable magnetic clutch that slips to protect the motor and removes the need for limit switches.
Plenty of power!

Actuator test