hi all
I was wondering if anybody could suggest a way to turn on an M200 manually other than a Thruster Commander where the M200 is at full power instantly. Ideally, this would be a switch. I am not sure what the detrimental effects would be to the M200 if this was done repeatedly of alternatively if there is a better motor for this. Hoping somebody has some ideas.
Hi @johng -
What is your specific application?
You could setup a BasicESC with M200, and connect the signal line to an arduino. You could wire a switch to the same arduino, and make some simple code send full speed (in whatever direction) when the switch is closed. You may want to ramp up the speed over a couple of seconds to extend the life of the M200, yes, depending on how rapidly you are switching it on and off!
The transient requirements here will likely drive what motor and/or controller technologies are appropriate.
If the latency of a speed controller like the Basic ESC isn’t a problem then there are various microcontroller-based approaches you could take to convert your switch signal into appropriate PWM ESC control signals (e.g. ordered by convenience: using a Thruster Commander, Arduino-like breakout board, or a small basic PCB), but if your application requires the fastest possible switching then an oil-filled brushed motor or similar may be faster, because the switch can directly apply or remove the voltage that makes it spin.
Hi Tony and Eliot
Thanks for the suggestions. Much appreciated. The M200 is powering a cutting disc or a drillI for as a trial for culling invasive urchins. The small ROV I am using for the trial has very limited capabilities and I am unable to access the electronics so I am using the claw actuator on it as best I can. I have found a crude and unfortunately probably ultimately destructive to the M200 way to turn the M200 on a speed. I ended up connecting a Thruster Commander to the ESC and motor and setting the potentiometer to half revs or so. I then placed a momentary switch which I can depress with the claw actuator on the blue potentiometer wire which allows me to turn it on and off that way. This all takes place in 50 mm watertight enclosure tube with custom endocarps. I ideally I would have liked to be able to use the claw actuator to turn the potentiometer but the amount of actuator movement to get useful speed from the M200 wasn’t enough.
The whole thing is really just a proof or concept thing and will just a starting point to try to find an ROV based solution to the problem. Eliots suggestion regarding the possibility of an oil filled brushed motor is likely to be a good direction to go in but in all probability the best solution, if the tools work, is to mount them on a BR2 where I can run it all from the main electronics.
Attached is a photo of my ham-fisted work around.
John
Hi @johng -
If you’re using the M200 with an ROV, I assume it’s not running BlueOS? It would be trivial to control the motor from a BlueROV2… and not require the interesting re-use of the newton gripper!
I believe the thruster commander is somewhat ramping the throttle signal even in your use of it, and would think the M200 can handle it ok. How well does the M200 work when attacking urchins? I think we’d all love to see some of that mayhem!
Hi Tony
A BR2 would indeed make light work of doing this and the end goal is to have a range of powered tools (of which the rotating cutter is just one) mounted on a BR 2 that can cull urchins.
For reasons of convenience in traveling ( airport s etc ) I am putting this particular unit in a common toy grade ROV just to offer a tool option at the lowest possible price to anyone attempting to use an ROV for this.
I am launching a Kickstarter campaign for those tools this week. As many people are now aware, catastrophic kelp loss from explosions in urchin populations in California and many other places in the world is of major concern. I hope to be able to come up with an ROV based solution to that problem.
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