FarDriver pole pairs

This video is just to give some details on a tiny fraction of the settings in the FarDriver. Pole Pairs.
This is not a tutorial, its just some tips that a real content creator can use to make a tutorial.

[@user-bw8cn2hy6u]

Thanks a lot! It's the best source for understanding fardriver setup, so far. I have 72800 model and lightning rods big block xl motor which has 5 pole pairs, according to specs, what is interesting I can not change p.p. value in app, as you mentioned in comments, (it's set to 4) and after Autolearn it still remains 4 but max rpm is set to ~7200, not to 8k, it looks like it measures everything right, just skip that pole pairs param for some reason. Also autolearn magically fill in all speed ratios table values, from 100% ... 33% to 3%, that is very handy and honestly was a nice surprise, at least there's no risk to burn the motor if someone don't undestand how this part of settings work.

[@imho7250]

Autolearn can’t detect pole pairs so if you can’t manually change it to 5 pole pairs then the reported rpm will be 20% faster than actual rom. Many older firmware versions and fardriverr clones only allow 4 pole pairs if anything less than 16 pole pairs is used. Ratios in speeds normally come preset at a generic % values and its based on e-rpm so regardless of pole pairs it will automatically scale. The reason it cant set ratios in speeds for a specific motor is some motors have a mechanical rpm limit, especially mid-drive with surface mounted magnets. The fardriver can’t detect this so the one tuning needs to set ratios in speeds. The ratios in speed table can be used in a few ways. Mainly its to pull current down to a safe amount because typically during acceleration it will have 4x max continuous amps, which must be pulled back by the controller, except for those who wish to take full responsibility and release the throttle when they see smoke coming from the motor lol. But you can try to set all ratios in speeds to 100% and run autolearn and its not going to adjust them because it has no idea what is needed. Auto learn will pair the phase and hall wires, and then set correct shift angle, and i believe it can also detect the correct hall sensor 60 or 120 degrees commutation (the first setting). Also ratios in speeds is the rpm limit during boost because MaxSpeed rpm limit gets over ridden in boost. So if you have field weakening on and boost mode activated it will accelerate up to wherever the taper down in ratios in speed sets it. I personally like to taper down to 0% at an rpm that is only achievable unloaded to prevent accidental overspeeding when on a stand or something.

[@user-bw8cn2hy6u]

So if I don't use boost, or set boostcurrent=maxline current , the table only tapers max line current? Also it's not clear, if the setting for some rpm is 100%, does it mean 100% of max line current? Or it means no taper at all, because you said it can reach 4x of continuous current (which is max line curr afaik). Let's say i have 120A continuous, 250A peak for motor specs, and set maxlinecurr to 120, and I want some peak amp for fast start for short period at 1000 rpm i.e., should i set 100% for that rpm or 200-210% to achieve that? In other words how it decides to put 4x or 3 or 2x of continuous current or it takes just everything the BMS can provide to get that rpm even if it's more than motor can handle?

[@imho7250]

@@user-bw8cn2hy6u the ratios in speed table is for phase current. It will indirectly pull back DC current once it’s limited enough. Normally a motor current limit is for phase amps because thats the amps that will overheat the windings, and is independent of battery voltage. If watts are used as the motor rating, then you can use line current but depending on voltage. Normally line current limit is set at the battery peak discharge rate, which also supported by the BMS and battery cables. The phase limits are set for motor/phase wire limits. Lets say your motor is rated at 7200 watts continuous, and you have a 72v battery with 400a peak discharge. The max continuous dc current would be 100a to give 7200 watts, but this would severely limit acceleration. So an OEM would use 200a DC limit and a DIY might use 400a DC limit. But when we allow 4x max continues power for acceleration, we must use RPM limits or ratios in speeds to pull that back down to 100a at cruise. We can use MaxSpeed rpm to do that, or we can use ratios in speeds to do that. If you use the boost feature, a motor protection feature, you can set normal DC limit to 200a and max speed rpm to pull it down to 100a. And then boost current at 400a, and set ratios in speeds to pull that down to 200a, and then use the time limit to set how kong it can run at 200a. You will notice phase amps don’t directly track with dc amps. So setting it to 50% might not limit dc amps to 50%. Your first limit for the motor is max phase amps. You should decrease this below the 800a max until you feel it affect starting torque, then the % used in ratios in speed will be more effective.

[@vfxmora]

thanks for this video. It helped me a lot to understand everything better. I was finally able to get all the power out of my engine as it should be.

[@imho7250]

Thats good news. Glad the video helped.

[@imho7250]

Just be careful that you don’t overheat your motor. The DJB/Nanjing/Yuan Qu/ Fardriver controller can easily be set to give too much power for too long, and overheat the motor. Normally a motor can take 2-3x its rated power for a brief time for acceleration, but after running at that power and heating up to max allowed peak temperature, it will require a cooling period where it is at or below rated power. It seems most of these controllers were programmable to work with the KTY84/130 sensor (#3 on the sensor list), so if your motor has that sensor then the controller can be set to shut down when it overheats. But most people don’t have that sensor. So while testing different controller settings you need to keep checking motor temp with a temperature gun or your hand. The controller has several settings which allows you to run your motor safely. The first is the RATIOS IN SPEED settings. Typically the first few RPM settings will be at 100%, meaning gives 100% of the current you set in current limits. Then as RPM gets higher, the % must taper down. Lets say you have a motor rated at 72v 3kw. That means your motor can run continuously at 80v with 37.5a. And lets say your controller is a 72360 with 170a max line current. Your motor can normally accept 3x rated power for a short time, so about 112a. So you set the current limit of the controller to 112a. In the RATIO IN SPEED you set 100% for first few RPM ranges at 100%, and that allows the controller to send 112a to your motor during acceleration. But its very important that once you get up to speed, amps decrease to rated power or less (37.5a). So at some point in the RATIOS IN SPEED you need to taper down from 100% to 33%. And then later at even higher RPM you should taler down to 1%. There are many variables that affects the current needed to run the motor at each RPM, such as the winding type, tire diameter, weight or vehicle and rider, and going uphill or against the wind. The RATIO IN SPEED table allows the motor to run faster downhill/downwind while protecting the motor and limiting speed and current going uphill/against the wind. I would recommend doing some basic tests to graph the current needed at steady state cruise at various speeds 5,10,15,20,25 up until it requires more than rated ampa to cruise at higher speeds. The graph should use fardriver app motor RPM and current. That will show you where in the RATIO IN SPEEDS you need to taper down. Once these settings give you maximum performance without burning the motor, the other settings to protect the motor are down in low speed and mid speed settings (if you have 3 speed switch). Speed one would normally be set so low (33% line amps) and slow that nobody riding it can overheat the motor. Speed 2 would typically be between 1 and 3 and give short bursts of 2x max rsted power (66% line amps) and a lower speed that is much safer than sport mode (speed 3) but still lively around town. Remember to keep checking motor temperature when testing each increase in power to the motor. That means max current as well as the duration of time allocated to run at max current. The Fardriver can easily burn any motor it’s rated for if set wrong.

[@vfxmora]

@@imho7250 Yes, I just bought the Fardriver for the engine I have. and it's on point

[@danirinaldi1044]

Wow.. a very nice explanation.. would you share a video explaining about flux weakening next?

[@imho7250]

My friend with the Fardriver is away on business so I can’t get more information on Flux Character or FluxResponse settings, but most settings are going to be tuned in RATIOS IN SPEED % settings. Basic idea is the RATIOS IN SPEED table lets you set several RPM current limits for top gear (sports mode), instead of just one like most controllers do. Most DIY just set it such that the motor will burn up if they let someone else ride it. But the Fardriver lets you tune it such that you can lend your bike to somebody and they can hold full throttle in all normal riding situations and not burn the motor up.

[@danirinaldi1044]

@@imho7250 so the flux weakening is automatic feature controlled by software, and we can only limit the overall current from ratio in speed?

[@imho7250]

@@danirinaldi1044 , yes, but you do have two settings for flux weakening called Flux Character and FluxResponse, but i cant tell you exactly what they do. You can try changing those and see what each one does. I believe flux character will be (OFF, SHALLOW, DEEP) and flux response might be how fast it adds in flux weakening current

[@danirinaldi1044]

@@imho7250 thanx a lot, i already have qs hub motor 2KW and nd 72340 paired with lifepo4 72v44Ah. But still doing framework so havent touched any electronics. Your info helped me alot, thanx u my friend, good health to you

[@imho7250]

@@danirinaldi1044 , I made a 60v 30ah LiFePO4 for my 500w ebike with 30a controller. It’s a good chemistry for low power. But for my new project its got to be li-ion because i have limited space and a 2kw motor. Im waiting on items (PVR60 valve stems) to mount my rear tire and then i can see what the original 15a controller does to my 15ah battery. If it sags significantly at 1c discharge rate i need to replace it with something stronger. I expect to need 60a peak for my new motor. My friend had a 12” 2kw he ran with a Votol 100 and a qs138 and 17” 3kw he ran with a 72360. The 72360 was too much for the 3kw motor. Your 72340 is 100a/300a which should be sufficient to reach full reasonable potential of your motor. The 44ah LiFePO4 battery will probably be ok as long as you set RATIOS IN SPEED such that cruise speed current is limited to 44a max. My 30ah LiFePO4 battery replaced 5x 20ah AGM batteries and was same dimensions, half the weight, double the useable energy, safer chemistry, and most important I can maintain them with my phone using the Bluetooth app, and they already paid for themselves in battery replacement costs. But where volume is limited and power requirements are high, it forces you to use lithium ion, and in some cases you need high drain cells like Molicel 42a. Tesla model 3 can get away with LiFePO4 in their short range vehicle because the battery space is big enough for long range lithium ion or short range Lifepo4. But I don’t think they offer performance models with the LiFePO4 cells. This is why im buying one component at a time (motor first) and test it and then gauge what controller and battery i need based on what the 15a from the original controller does.

[@surronzak8154]

3:07 okayyyy that’s why

[@surronzak8154]

I tested but after auto learn the rated rpm jumped back to 8702 with 4 pole pairs (couldn’t change the pole pairs to 5)

[@imho7250]

What I found when getting my friend to test and also looking at every Fardriver video on KZbin is that most Fardriver firmware doesn’t support any pole pairs

[@surronzak8154]

@@imho7250 least I understand now why I couldn’t change the rated rpm to what ever value, it’s like you said’ only the values with the formula will work. I would like to set my contrôler to have the best longevity and rentabilty. I’m currently running 72v 120 amps on my surron, just enough for everyday use, but I know my rated % are off, I try to understand right what you said to dial them in perfectly for my motor. I have rated power 8000w and running 72v so 110 continuous amp ? 8700 rated rpm (with 4 parole pairs) so I could set 100% until like 6000 rpm and after that taper down to 90% ? Until 9000 rpm ? Without damaging and overheating my motor ? You are really a info goldmine ^^

[@imho7250]

@@surronzak8154 , the tuning of the FarDriver depends on many things. If I read correctly, you want rent-ability and reliability, almost impossible to. Lol. But basically thats what every manufacturer must do when they tune a controller. The bike, the rider and the environment also affect the needed tuning. If the rider is 150kg and you have an area with lots of steep hill climbs, you need to ensure the controller will throttle back amps before overheating the motor. Initially you can use manufacture’s specifications on maximum continuous current. Compare that to the battery/BMS capabilities, and set that as current limit. In theory everything will be ok because the motor should be able to use that current continuously. If however you find the motor is running too hot (>70c) then you need to ensure the controller pulls back the amps slightly at the top end so it can cool. You will notice every production bike you can buy will draw peak amps during acceleration, but at top speed will ALWAYS pull current back some. Normally this is just done by setting a speed limit, then the controller auto offloads once it reaches that speed. However this doesn’t work on steep hills, since you never reach the max speed, and the controller will keep sending max current. But normally even max current won’t burn the motor quickly. If you set the RATIOS IN SPEED all at 100%, you basically remove this feature and it acts like a basic programable controller with merely current limits and RPM limit. But this table is the thing that makes Fardriver stand out. Most BLDC motors can use 2-4x rated current, but for short periods of time. Manufactures normally state RATED, MAXIMUM AND PEAK current limits. Lets say for example the motor has 100a rated, 150a max, 200a peak. The RATIOS IN SPEED table lets you use 200a line 400a phase as the current limit , and then the first 1/2 of the rpm range you set to 100% (200a). Then from 50%- where flux weakening begins would set to 75% (150a) and then taper down to 50% (100a, which is the maximum continuous current) as you enter flux weakening zone. And the flux weakening zone will taper down from 50%,40%, 30% as it reaches the end of the range. To imagine what this does, imagine a heavy rider with some steep climbs, long downhill straights and. Anywhere on the track you want to allow peak amps to get moving, then maximize amps to finish acceleration, then pull back amps further to so that the motor always ends up limited to maximum continuous current. So it looks like 100%,100%,100%,90%,80%,75%, 75%, 60%, 50%, 40%, 30% 10% of the 200a/400a current limit. But it’s really the same as 200%,200%,200%, 180%, 160%, 150%, 150%, 120%, 100%, 80%, 60%, 20% if you used 100a/200a in the current limit section. With this, if you get stuck climbing a long hill at top speed with maximum flux weakening, the first thing is does is cuts amps down and lets you slow to below flux weakening range so that all the current is used for torque and makes less heat. Hopefully with these current settings it lets you get up and over a hill sooner so it can go downhill and speed up and cool down some. As you can see, the tune you use for yourself where you the rider must know when the motor is too hot, versus a tune for someone renting your bike, will be quite different.

[@imho7250]

@@surronzak8154, did you make any progress? I see some on your channel asked how to do the Surron BMS bypass about a year ago. Like every production ebike, Surron matched the battery amps, BMS amps, motor amps, controller amps and tuned the controller to ensure it offloads after accelerating. Some people can quickly get a problem by increasing one thing without compensating for it somewhere else. They get a high powered controller, see the BMS trips so they bypass the BMS, then they can raise controller amps and then the big mistake is increasing top speed so the controller never unloads. The RATIOS IN SPEED table lets you set a high top speed but limit current so that you can only do that speed in the right situation, such as downhill or with a strong wind at your back, but when going uphill or against the wind it will still limit amps to a safe amount and your speed will be limited to whatever those amps can give you.

[@mrk_u1352]

FD pole pair setting doesn’t have 15.. as I have 30mag divided 2=15 but doesn’t have 15🤷‍♂️

[@imho7250]

Are you 100% sure it’s 30 magnets? 15 pole pairs. Is weird on a 3-phase motor because the cogging will be terrible. We know all 3phase motors have 3/6/9/12/…..27/30/33 slots. So that it can have 3 phases. But in a 30 coil motor you don’t want 20 coils all acting on 20 magnets at the same time, so the magnets are either 2 extra , like 32 magnets, 16 pole pairs. Then lets the stator coils all pull or push at the same time (because its all the same windings, but the magnets are a different distances so it sequentially pulls on them smoother action. Can you post a picture of your hub motor showing the magnets on your channel?

[@imho7250]

If you aren’t sure and can’t open the motor, you can see its right by measuring your rear tire circumference and looking at the GPS for speed. Is the RPM on the Fardriver dashboard shows too fast, increase pole pairs. If it shows too slow. Decrease pole pairs. This is how I corrected mine because I set 40 pole pairs but it was on,y 20. Lol

[@mrk_u1352]

@@imho7250 yes as per manufacture / 15 poles, the motor magnet has 15x2 =30 pieces

[@imho7250]

@@mrk_u1352 , do you have the link? Thats a very strange motor. You will see 16/17/19/20/22/23/25/26/28 but 15 is very abnormal and would cog severely. Thats why most fardriver don’t waste firmware memory space for those multiple of 3 pole pairs. But use 16 for now, and later we can use math to check. If you need help with that just let me know the rear tire size or circumference, the gps speed, and fhe fardriver digital RPM (not the needle) and ill tell you if pole pairs are correct.

[@imho7250]

I found a motor with 27 coils and 30 magnets (15 pole pair) made by UU motor. If your fsrdriver doesn’t have the latest firmware like mine, it won’t let you set 15 pole pairs. If you try to set 15 and it doesn’t accept it, just use 16 pole pair. The motor will run exactly the same, only the reported RPM will be 6% slower. But you can stil calibrate your speedometer with other settings or inside the speedometer (if it’s a hall sensor type.)