• Howdy! we're looking for donations to finish custom knowledgebase software for this forum. Please see our Funding drive thread

Search results

Date Relevance Most replies

  1. V

    VESC - NRF implementation losing connection

    The best thing I can suggest is to try to make some space. You can take the antenna apart or use a smaller antenna. You can also remove the sma connector from the PCB and solder a small antenna cable with a smaller 2.4ghz antenna directly to the pcb.
  2. V

    VESC - NRF implementation losing connection

    Are you using a receiver with PA such as this one? http://www.ebay.com/itm/1PCS-NRF24L01-PA-LNA-SMA-Antenna-Wireless-Transceiver-communication-module-2-4G-/221920817637?hash=item33ab82f1e5:g:~D0AAOSw5VFWKapJ They have been working perfectly for me, but the receivers without the amplifier and...
  3. V

    Vedder's Nunchuk RF

    That should be possible with some minor modifications to the code.
  4. V

    Motor reaching 90°C, go 10S?

    If you go 10s AND increase the gear ratio it will help. Increasing the gear ration is what will make the difference. If you are going to use the VESC I recommend keeping the 170kv motor, changing the gear ratio and increasing the voltage. If you keep using 6s, change the motor gearing and...
  5. V

    10S custom skate ESC: testers wanted!

    This thread is getting kind of long and there is information all over the internet about the VESC, so I just set up a forum for it: http://vedder.se/forums/ I hope this makes it easier to get support from me and the community. Let me know if you think this was a bad idea :-)
  6. V

    10S custom skate ESC: testers wanted!

    Nice that you gave the new implementation a try. On a motor with so low inductance you can try increasing the switching frequency to 60 KHz or so. You can also experiment with the time constant for generating the current controller gains. Try 200µS or 1000 µS and see if you notice any...
  7. V

    10S custom skate ESC: testers wanted!

    I think this is solved in FW 2.4 that I pushed just now.
  8. V

    10S custom skate ESC: testers wanted!

    Nice to see that so many people have tried the FOC implementation already :-) This does not matter since FOC works in a completely different way. The FOC code is mostly separate from the BLDC code. This is most likely the temperature protection that activates. There is more switching with FOC...
  9. V

    10S custom skate ESC: testers wanted!

    FOC SUPPORT! I just pushed the first FOC implementation to github with a quite massive commit: https://github.com/vedderb/bldc/commit/ff090fd4e0028f6a8ceb28f5441c1d0cca40af7e This is a screenshot of the FOC configuration page in BLDC Tool: R and L can be autodetected without starting the...
  10. V

    VESC configuration and brake button SK3 6374-192kv

    You can for example use the current norev button setting. Where to connect the buttons and how they work is explained in the text box. You have to divide the ERPM with half the motor pole number. You motor has 14 poles, so you can divide this value by 7. Run detection as explained in my...
  11. V

    10S custom skate ESC: testers wanted!

    I think the three shunt design is worth it for difficult motors such as RC motors. The software is really where I spend 95% of the efforts, making new hardware is not too difficult. The three shunt design would be less compact and a bit more expensive though. Try to disable safe start in the...
  12. V

    10S custom skate ESC: testers wanted!

    Yes, by principle :-) The main problem with low L and high PWM frequency is actually current measurement, especially with two shunts on the low side. The current will be present on the low side shunts only for a fraction of the PWM cycle, especially on high duty cycle, and during this time the...
  13. V

    10S custom skate ESC: testers wanted!

    Regarding capacitors: I haven't really measured and compared different configurations to determine how many capacitors are actually needed, but in general it is better to have more (the downside is that you get a larger spark, but that's what anti-spark switches are for). Having more capacitors...
  14. V

    10S custom skate ESC: testers wanted!

    Increase the Minimum ERPM from the default of 150 to something like 800. You calculate the ERPM with kv * voltage * (motor poles / 2). The problem is that the switching frequency (40 khz) is too low to get enough samples to track the motor at that speed, and the estimator will loose tracking...
  15. V

    10S custom skate ESC: testers wanted!

    I'm still working hard on FOC and made more progress this weekend, but I haven't pushed the code to github just yet. The more I work on it, the more things to fix I find. I hope I will have the first implementation ready to push soon with firmware 2.0. You can increase the min rpm in the...
  16. V

    hubmotor pros/cons

    You are right about that. And if you run on high current vs motor resistance, the resistive losses also become large since they grow with the square of the current. Since the motor resistance for a given amount of copper decreases with the square of KV, and the resistive losses increase with the...
  17. V

    10S custom skate ESC: testers wanted!

    I think these motors should work, but you have to adjust the detection parameters. The default parameters work for most 100 to 500kv 50 to 60mm eboard outrunners, but for these motors you have to change the current a bit. Does the inrunner happen to be a coreless one (you will notice this if it...
  18. V

    hubmotor pros/cons

    This is where you are wrong. Eddy currents and hysteresis losses occur in the stator with the skin depth at the frequency the motor spins at, not in the windings. If they were in the windings themselves, windings can be made with several smaller parallel strands (as is already done with hobby...
  19. V

    hubmotor pros/cons

    This sounds like you think that LEVers hub motors will generate less heat if you ride up a given hill with a given speed when you wind them with lower kv. Can you explain how you did the math? Because that is not true at all. LEVers motors will generate the exact same amount heat losses under a...
  20. V

    hubmotor pros/cons

    Wrong. Some formulas: N = turns I = current R = resistance KV = rpm/V P = power P_losses = I*I*R (square relation) KV = K * N (proportional to N with some factor) Torque = I * (60 / (2*PI*KV)) (proportional to 1 / kv, meaning that half the kv gives double the torque) If the motor has higher...
  21. V

    hubmotor pros/cons

    You are completely wrong in most points. I have explained this quite often before. For the motor efficiency, the kv does not matter one bit. I wrote a bit about that here: http://vedder.se/2014/10/chosing-the-right-bldc-motor-and-battery-setup-for-an-electric-skateboard/ What matter for the...
  22. V

    10S custom skate ESC: testers wanted!

    You are right about that the top speed decreases. I did some quick experiments with field weakening, but I had to add a lot of negative d-axis current to make it go up, so in practice I think you should expect a bit lower top speed. I haven't measured the efficiency yet, but I don't think there...
  23. V

    10S custom skate ESC: testers wanted!

    Here is a video of the first FOC implementation. Enjoy :-) ISzeSLpZWbM
  24. V

    10S custom skate ESC: testers wanted!

    Yes, that should work (unless I misunderstand what a 6 phase motor is).
  25. V

    Instructions: Compiling VESC's BLDC Tool on openSUSE

    Thanks for posting! I didn't knot that suse had a different version of qmake, good to know. I should really make a forum dedicated to the VESC some time. The community is growing all the time and I think when the FOC implementation starts to mature even more people will be interested.
Back
Top