Always FOC, since I only run FOC on my boards wouldnât it be more relevant than a âreal kvâ still? Like if the motors clock in at 151kv when benched, theyâd behave like 151kv motors on the road?
@ZachTetra FOC is limited to a sinusoidal waveform, so the motor only sees the full battery voltage at the peak of the waveform, which means in FOC the max RMS voltage the motor sees is significantly less than the battery voltageâŚ
in BLDC, the motor can receive 95% of the battery voltage because the vesc maxes out at 95% duty⌠so even in BLDC mode on a vesc, the no load speed would measure at least 5% lower than the true KV value.
FOC will measure significantly below the true KV value.
The best way to measure is use a controller that can do 100% duty cycle in BLDC mode, and then spin the motor faster than it will turn on its own at no load, and when the motor current reads 0 amps, that is the no load speed. it is the speed at which the back emf voltage generated by the motor equals the applied voltage from the battery.
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no because the torque per amp depends entirely on the actual KV. so if you are estimating your torque per amp based on an under-inflated KV value, you will predict that you have more available torque per amp than you actually have.
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If I just want to know the speed, is it correct? This is the personal calculator I use for all my boards
Hi.
I build a firefly custom remote, and ppm is working but i have no idea how to get the data about speed and battery voltage. If im right the tx and rx pins on the receiver connect to rx and tx on my vesc6. But what now, because nothing shows up on my remote. Do i need to set something up in vesc tool?
Thank you for the anwsers.
Donât have one but you need to enable uart and ppm in the application settings in the VESC tool, think most things use 115200 baud rate but might need to fiddle with that as well then write app config and check.
1:4 gearing is the highest gear ratio I would go with for light offroading. Iâm at 1:5 and like it for a board that is majority on road but likes to get dirty in the woods and BMX park. Id go even lower on gear ratio if I wanted a true mtb but I have yet to ride something where my setup wasnât enough.
@olsyke go with the larger 6374. Not sure if youâre aware that 6374 means 63mm diameter motor can that is 74 mm long. They will run cooler.
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Justin if you could go over to my thread on speed vs torque you could edit it a bit and make it cleaner with all your knowledge. It is a WIKI btw.
yes im aware of that, only the fact that the bigger motor had the lower wattage value made me think that its still weaker than the shorter one for unknown reasons (quality / windings)
thanks for enlightening me on this guys 
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thanks⌠I learned a new word⌠goal attained for today, Iâm gunna go skate!
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what setting stops the studder when trying to accelerate slowly.
You mean the chatter right at 0.00km/h? Thats called âcoggingâ because without back EMF the controller doesnât know how fast the rotor is spinning. Sensors telling the controller what position the rotor is in can eliminate cogging, but also increase failure rates, especially around water.
Or just a small hip flick and you will figure out how to make it not a problem as you get comfortable with the machine
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thx bruhâŚiâve been doing the hip thing as well as kick offs to get around it alreadyâŚthought it might be a setting for it somewhereâŚ
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Why donât I see dual diagonal MTBs?
It seems like there would be better traction and weight balance than dual rear.
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Braking on dual diagonal means you can completely lock up both drive wheels and still retain steering ability. I also donât know why, but I suspect itâs for aesthetic reasons.
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I upgraded my 4.12 esc to a 6.x. It is a little bigger and does not fit in the back of my enclosure. Any concerns with stacking it on top of the battery. I may have room for a small standoff to minimize the direct contact with the esc, but I am not sure how hot the outside of the aluminum housing gets and if it is an issue for the battery. Thoughts?
Sometimes redoing motor calibration if youâve adjusted any wires or connections can help to reduce the cogging but otherwise like Brian said sensors will eliminate it and can run âhybridâ mode where sensors are used below some erpm since the back EMF is good enough at speed and the hall sensors could be worse, but at low rpm the sensors can basically eliminate any cogging which is nice (particularly on the pneumatic build)
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You not only need TX and Rx, but also a common ground for the devices to communicate.
TX --------------- RX
RX --------------- TX
GROUND ------ GROUND
Also, try 9600 and 115200 bauds.
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What about a pair of lower kv motors - 130/150kv? Or is it just the gear ratio that will makes a difference.