I having been using some M200 motors for a couple of months I had to power small submersible 3d printed pumps I designed. The pumps work very well so I have just bought an M500 motor to make a larger version.
I notice that in the technical details of the M500, it says continuous full-throttle operation at 24 V should be limited to 1 minute or less to avoid overheating.
When using a Thruster Commander with an M500, the Thruster Commander heats up considerably very quickly.
The particular application I have for that the M500 motor requires that it runs more or less continuously at a constant amount of throttle so I have the following questions.
If I was using a 6s battery, what would be a safe amount of throttle to run continuously at?
If I was using a 4s, could I run at full throttle continuously with no harm to the motor?
Can a Thruster Commander handle continuous operation with either the 4s or 6s battery?
The Thruster commander shouldn’t be handling any power, so unless you don’t have a ground somewhere you should, it’s not worth worrying about what temperature it reaches.Power goes straight from the battery to the motor controllers to the motors - the Thruster Commander is just a signal generator.
The safe amount of throttle depends on the power consumption. We don’t have good numbers on that power limit yet, do you have an idea of how much power you need from each motors? The T500 power limits are a good starting point, see below. What the motors can take depends a lot on both this and the water temperature you’re operating in. Are the motors driving propellers or some other system?
The thruster commander has been getting power from a 14.4v 4s battery. I am running the M500 from a 22.2v 6s battery and ideally would like to use the 22.2v battery to power the thruster commander from this is well but the technical details for the product seem to indicate that it can only accept up to 20v. Is that correct or can I use the 6s to power the thruster commander as well?
The M500 motor is powering a centrifugal pump impeller. With regards to motor speed, ideally I would like to operate at full revs to get maximum suction. The pump is part of an apparatus that might be used any where from tropical to polar regions so I am concerned about overheating the motor, particularly when it is used in tropical waters.
The technical details are correct, you cannot use 6S for the Thruster Commander. Do you have thr ground of your 14.4V and 6S battery pack connected together? If not, that may be why you are getting excessive heat…
As for the motor, the amount of power it draws at full throttle will depend entirely on the pump impeller. You should be able to get an impeller designed to your specifications, so that at max RPM you’re using the 400 to 680 watts the motor can safely output, regardless of water temperature!
After a bit more testing, the M500 is at about 700 watts when the pump is sucking up gravel and sand as it designed to do. That implies that the impeller does need re-designing. I had previously made very efficient versions of the pump based on M200 motors that are drawing 140 watts and simply scaled the M500 based pump up based on having read that the T500 was 3 times or more as powerful as the T200 thruster and assumed that as a rough rule of thumb, that might apply to the M500 versus M200 motors. Obviously at least some part of that assumption is not correct so probably a case of scaling the M500 pump down until I hit the sweet spot between 400-680 watts.
is there any possibility that there is a Thruster Commander aimed at M500/T500 users on the horizon?
The thruster commander has no limitations, it is just a signal generator- the ESC is what powers the motor, and Blue Robotics is developing updates to the basic and larger ESC 500. I’ma bit confused what’s leading you to think you need a different thruster commander?
I want to only have one battery being the 6s powering both the Thruster Commander and the M500. For the device I am making, both the battery and the Thruster Commander have to fit inside a 3"WTC so needing to cram a 4s battery in there as well just to power the Thruster Commander with its 20v limitation would be less than optimal.
Understood, you’d like a higher input voltage. That’s not planned, but quite easy to achieve yourself with a dcdc converter, no need for a second battery! They can be quite small and it can be rated for very low power!
