Choose an ESC or VESC

EFOIL.builders Electronics (ESC, remote, batteries)
21

I killed my Flipsky 75200 on the workbench as well, when I plugged in the comm port and the bare wires touched one another. It went into error mode, then turned off altogether. Now only the 3 blue indicator lights show and it won’t boot (no green light, no red light), nor is it recognized by USB. Flipsky says the only thing I can do is send it back to them. I was able to pull it off the power board and put another logic board on the power board, which is a nice feature. Still it’s very frustrating that a $300 device (what I paid in May) dies from a couple of wires touching one another. And whether that’s warrantied or not is a question that remains to be seen, but the process of sending back the board to China and waiting for a replacement is even more frustrating.

It’s amazing to me that there isn’t a good stock of ESC or VESC in the US…

22

Maytech has a 30 days warranty, thats a joke for a 250-300$ product. Now I need to find someone that can replace the driver chip.
I guess it’s still a niche product and it’s hard to make profit in high salary countries like in europe or the US with it and they are quite likely ro fail.

23

Its not super hard to replace the DRV if you have a hot air station and good flux. And those are cheap in Amazon. Its a very useful skill to learn. There are a lot of hot air rework videos in youtube. Preheating the entire board in an oven helps. Just be patient, you dont want to rip off the small pads so wait for the chip to move easily while applying heat.

24

After some extensive searching for additional ESC/VESC that could be easily acquired, I stumbled on oDrive Robotics, which is $149 for a dual 56V, 120A peak (appears to be 90A sustained with proper cooling) per channel VESC:

After searching this forum, I didn’t find any references to it, so I thought it was at least worth posting it and see if anyone has any experience or knowledge about it.

Also I posted on their forum already to ask if the 2 channels could be combined into 1 channel to take advantage of 240A peak instead of 120A peak. No response yet…

Last, here’s the schematic for anyone smart enough to make sense of it:

I liked that they have
a) stock ready to go in US & Europe
b) a robust support community
c) python based tools
d) $150 price tag…
e) other interesting bells & whistles on the board

DC power voltage input range:

  • 24V version: 12V to 24V.
  • 56V version: 12V to 56V.

Current:

  • Peak current 120A per motor.
  • Continuous current depends on cooling: Details.

A board without connectors looks like the last picture, which makes it easier to fit into small enclosures and apply custom cooling, but you must solder your own connectors or directly to the board.

Starting from this version, the firmware comes already flashed on the board. You can install firmware upgrades over USB from a PC. This board is hardware-ready for all of the features listed on the features page. Currently the firmware supports the following:

  • Position, Velocity, and Current control modes.
  • Automatic identification of motor parameters (Inductance, Resistance).
  • Realtime USB communication (>4000 floats/sec) to Python host program, which you can interface to your own application.
  • Live-plotting of many variables, including position, speed, current, control effort: extensible to expose your own variables.
  • UART communication with an easy to use Arduino Library.
  • Step/Direction input, for replacing stepper motor drivers.
  • Trajectory generation and tracking.
  • Hall effect sensored motors (instead of encoder).
  • PWM input.
  • Encoders with Index pulse.
  • USB Bootloader.

Features that will become available with free firmware upgrades:

  • Absolute encoders.
  • Commands over CAN.
  • Automatic identification of mechanical system parameters and tuning of position and velocity feedback gains.

This listing Includes the ODrive v3.6 board, a power resistor (for brake energy dissipation), a USB cable, heatsinks, and some nylon standoffs. The pictures show older versions, but you will receive a v3.6.

Getting started guide Is available here, and the ODrive forums are also available, for posting support queries, showing off your project, and connecting with the rest of the community.

1 Like
25

Sad story, from oDrive developer:

“ODrive does not support running both motor channels in parallel. The output FETs are PWM’ed and the channels are not synchronized. It’s likely that, even if both channels were “50%”, they would not be in phase. That will definitely blow up the output stages!”

I suppose it’s not trivial to put the output stages in phase…

"ODrive v4 is in development and it will be single axis at a similar power level to each ODrive v3 axis. It is feasible to do some firmware modifications to get v3 to run both axes in parallel, but it would be kind of crappy on our part to get this up and running for you only to have it be discontinued (I don’t really have a timeline for the v3->v4 switchover, but eventually v3 will be discontinued). In other words, it would be an unintentional bait-and-switch which is not something we are willing to do. Bad for us and bad for ODrive users. I have made a note with the team that a higher power level ODrive v4 is desired.

It is, however, feasible to run two motors in parallel mechanically, each one going to a different channel. This would be forwards compatible with the single axis ODrive v4. Torques on a shaft sum through the shaft, so there is no synchronization issue. ODrive typically requires an encoder, but there is a sensorless velocity control mode. I imagine this would be better for something in use underwater."

But wait, I’ll make the efforts to put the channels in phase…

"Our lead firmware dev estimates that it would take 2 days to make it work, so I’d estimate 3-5 days of work for a developer not familiar with ODrive.

On the hardware side, there are some other considerations. ODrive v3 supports a maximum modulation magnitude of 70% as a consequence of how we do current sensing (v3 only measures the currents of two of the motor phases. This is valid mathematically due to KCL, but also means that we require a certain amount of off time to measure both shunts in a single cycle). There’s also a limit on commutation speed of around 600Hz electrical due to the control loop rate and PWM frequency. For that motor, that works out to a 6000RPM limit from commutation ((600Hz / ) * 60) and a 4704RPM limit from modulation magnitude (56V * 0.7 * )

By my math, that works out to 6kW still being possible with both channels in parallel, but at a max speed of 4704RPM. It’ll be a bit slower due to battery voltage sag at high current draw."

26

So what I gather here is that the $150 ESC (fully open source, with tons of support and lots of cool features, and readily available supply…) can be turned from a dual ESC to a single ESC capable of 240A peak, 56V, 180A sustained, but only 4.7k RPM theoretical maximum, with about 60 hours of development time to sync up the two phases and not blow out the output stages. The group says it won’t be forward compatible. I can’t see how that is an issue relative to the current options.

2 Likes
27

Great find! How can we as enthusiasts help to encourage them that this is a good idea? :slight_smile:

Too bad there isn’t a 6 phase inrunner esurf motor option available like the hubmonster of the ebike world!

28

The 60 hours of dev time shouldn’t be an issue, as I am happy to fund that. I think the main concern is the theoretical max RPMs and voltage sag. If we get the two channels in sync, there’s still a ceiling on the RPMs. Is there a workaround?

29

Probably a faster mcu… I have been following oDrive for years

30

Any updates on reliability / performance of the Swordfish 300A ESC for 120Kv motor? Good idea or should I stick with flipsky? Looking for something that works for efoil setup - not looking to mess with tons of settings or to log data. Opinions?

31

Hello
I installed a flypski 75/200 vesc on my new board, I never managed to get it to work properly, I want to take another one but I am unsure of the model and the brand, can someone help me advice, thank you

32

Did you cancel the order?