How to limit the speed on flipsky vx3 with ESC (not VESC)

Trying to figure out how to reduce the max speed. When I set the remote to M (medium) gear the speed is slightly too slow and at H (high) it is way too fast. I find that the remote is too sensitive so I find I have best success when I just put in in M and press the throtle to full and hold it there for the entire session. In high gear it is much too fast and the 3 seconds required to set the cruise control makes its pretty useless (for me at least).
Any ideas?
Thanks in advance

Remotes are not the problem, ESC’s are the problem. You need to be adjusting the limits on your ESC.

I think there are a few solutions, but mostly they cost money and work. I only know the more expensive and labor intensive solutions unfortunately:

  • try other ESCs
  • try adjusting the pulse width (going into the ESC) by adding a simple circuit of a few passive components (requires an oscilloscope)
  • increase the speed of the M stage by increasing the battery voltage (adding e.g. 1s, 2s, …it’s easy to try), in that case the H stage will probably be unusable (too high battery current)
  • increasing the speed of the M stage is achieved by replacing the propeller with a higher efficiency, in which case the H stage will be even faster, but with the original battery current, which is an advantage
  • reduction of the H stage speed is achieved by replacing the propeller with a lower thrust propeller, in which case the M stage will probably be unusable (too low speed)

Thanks for the replies. Both pretty expensive as I’ve already got all the parts and it’s working (more or less).

Here’s an idea I think I’m going to try:

Insert a PWM to voltage cct in series with a voltage to PWM cct between the receiver and the ESC. This way I can trim the max PWM signal out to be whataver I want to the ESC after the esc has been calibrated. Thoughts?

Another solution for your ESC (HIFEI SWORDFISH X 300A 14S ESC) can be this programmable box

Hi, I don’t understand how this would help. Can you explain what setting I would change on my Swordfish X 300 A esc to reduce the max speed? I’ve reviewed the docs on the ESC that I can find and have seen no way to control top speed.

I’ve been thinking about trying this. Any advice on where to start with the circuit? Let’s say I want to reduce the PWM signal duty cycle by 20 % for example. Cheers.

Another idea that just occured to me. What if I use a pwm generator circuit to calibrate the ESC. I set the PWM to be 20 higher duty cycle than max throttle on the VX3 for calibration. Then when I reconnect the vx3 it will have effectively reduced the max speed. Makes sense?

I have read but I don ‘ t remember which remote can do this ( Maytech flipsky or ray…) : you can set the throttle max value wanted and the trigger play will be always full at this value

This may works :

Or drill and pin the trigger :crazy_face:

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Figured it out. I ran the calibration routine on the ESC and during th process instead of pulling the throttle to 100%(normal procedure) I only pulled it into about 80%. Now when I pull the trigger to 100% when in M gear it goes about 10% faster than before - which is perfect.


Hi mlab, I know we are 18 months later but I am having the same issue with a VX3 and a vesc ESC. When you say “ran the calibration routing on the ESC” are you talking about withing the VESC software and not just the throttle calibaration on the VX3 - I tried the latter and it seemed to make it worse - that is M was even less useable and H was super “on/off”.

thanks for your help

The maytech MTSKR2005WF remote control has programable 3 speed settings which might fulfill your needs. Though it is labeled for skateboard only, it might work for efoiling. You need to waterproof the remote control more than its IP66 rating.

I have found a solution with the Flipsky VX3 and the v1.0 firmware as Flipsky dont seem to want to upgrade it after several emails back and forth.

In the VESC software I have set an eRPM limit at 18000 (roughly 80% of the maximim with no limit) and the I have also set the duty cycle limit to 80%. Now, in High gear I can be at full throttle and foil comfortably which is much easier for learning and you dont have to manage the trigger while balancing. I guess I will remove the limits later when I am more comfortable so I can get full speed out my set up.

Hope this might help someone with the same issue

As explained here “How to set a motor rpm limit using the eRPM limit parameter”
this 18000 limit is a function of your 120kv motor (6 pole pairs) and 14s battery,
It should be adapted if kv or s number is different.

As (eRPM limit/pole pairs) is a rpm, you’ve selected a 3000rpm motor limit (18000/6)= 50% nominal rpm.
Effective because it is above the max rpm of your motor which is for minimal-nominal-maximum rpm at 100% duty: 5376-6216- 7056rpm [120x14x(3.2-3.7-4.2 volt/cell)].

Right, so I am limiting the actual prop RPM to 3000 which seems to work fine for my setup. Is there a potential problem with this ?

I’m not a VESC expert but it has been designed for this need.

Hello. It is Aug 23 and I am struggling with this exact issue. Would you please explain exactly what you did to address it? Thanks!

Hi, in the end I have switched to using PPM as I have a flipsky bluetooth on the uart1 (uart2 does not work for Bluetooth on my vesc).

From there, after reconfiguring the contoller in the vesc tool, I have set maximum duty cycle to 80%. I can now use it with the L setting and still foil. As I have got better the trigger issue is no longer a problem as I have more control, so I can also it in M or H level with less throttle.

I would also add that I have given up on FOC (even with HFI) as I could never get ut to work without cogging. BLDC sensorless works well for me.

Hope this is usefull

Thanks a ton. I am new to all of this - so I must admit, I don’t follow most of these acronyms. It sounds like you figured this out and I would love to do so as well. I’m mindful of not causing you extra work - what might be the most efficient way to unpack your approach? Thanks very much!

Well, for a start, what is your setup ? - what ESC do you have, which motor, and what battery (total voltage or S number).
I could send you my Vesc settings but they will differ widely depending on your setup.