FunTech4Real Posted May 13, 2021 Share Posted May 13, 2021 I have some questions as I am trying to understand my wheels better (S18, EX.N, and mten3): What exactly is PWM? What does it stand for? From what I can tell it is some sort of percentage measurement of the maximum power of the EUC? When I disable the speed alarms on my EUCs because they seem to be useless and annoying, that is not going to disable alarms (and tilt back) that would normally go off when the EUC is being overpowered, right? There is some sort of hard coded alarm (beep) and tilt back that cannot be disabled when the EUC is being pushed too hard and its going to cause it to fail, right? If I am correct about number 2, then what is the point of the speed alarms? Why should I care to have something beep at me at a certain speed if its not going to overpower the EUC? Quote Link to comment Share on other sites More sharing options...
Popular Post meepmeepmayer Posted May 13, 2021 Popular Post Share Posted May 13, 2021 12 minutes ago, sevin7 said: What exactly is PWM? What does it stand for? From what I can tell it is some sort of percentage measurement of the maximum power of the EUC? No, it's irrelevant for EUCs. PWM means pulse width modulation, which is a technique to get smooth signals from a device that can only be on or off, by switching it on and off rapidly in a way so the average is the desired signal curve. That's just digital technology (the mosfets on your board can just be on or off) instead of much more complicated and expensive analog circuitry. That's just how the motor input is controlled behind the scenes. What defines the possible power output of your EUC is the battery and its configuration (that mostly means battery size), as well as possible firmware interference (current limit or whatever). And the cabling and electronics (board) must not fry, of course. 16 minutes ago, sevin7 said: When I disable the speed alarms on my EUCs because they seem to be useless and annoying, that is not going to disable alarms (and tilt back) that would normally go off when the EUC is being overpowered, right? There is some sort of hard coded alarm (beep) and tilt back that cannot be disabled when the EUC is being pushed too hard and its going to cause it to fail, right? All EUCs have some sort of alarm that can't be disabled. Beeps, tiltback, or both. What exactly happens depends on the wheel. Gotway: only beeps at 80% max motor speed (that speed depends on the battery voltage = charge state), S18 I don't know, something a bit more sophisticated I believe). Because demand on your EUC can vary rapidly (fast acceleration, pothole, ...), these alarms can (on paper) only be trusted if you go fast but with no acceleration. You can overpower any EUC by going near its top speed (beeps/tiltback) and then accelerating like crazy. Building a EUC that realiably warns you in any situation is unworkable, it would have to beep at 20kph just to be sure. The faster (and heavier) you are, the more careful you need to be with hard accelerations (braking is never a problem). The way to be safe on a EUC is to buy a fast and powerful one and happily ride away from its limits. 21 minutes ago, sevin7 said: If I am correct about number 2, then what is the point of the speed alarms? Why should I care to have something beep at me at a certain speed if its not going to overpower the EUC? Some people just want speed alarms so they know. Could be for any reason. Speed limit (external or self-imposed), because they weigh 250kg and they need to give a bigger safety margin than the usual emergency beeps, ... any reason. 4 Quote Link to comment Share on other sites More sharing options...
Chriull Posted May 13, 2021 Share Posted May 13, 2021 12 minutes ago, sevin7 said: I have some questions as I am trying to understand my wheels better (S18, EX.N, and mten3): What exactly is PWM? What does it stand for? From what I can tell it is some sort of percentage measurement of the maximum power of the EUC? Pulse Width Modulation. With EUCs this is used to chop the DC battery voltage into pulses with varying duty cycle. As these pulses go to the motor coils, their inductivity flattens the current. https://forum.electricunicycle.org/topic/7549-current-demand-versus-battery-voltage/?do=findComment&comment=104078 This works like a normal DC/DC step down converter. Battery voltage is transformed down to suit the needed voltage at the motor for the wanted speed and the current for the needed torque. And these for all three coils to form a rotating magnetic field turning the tire (rotor). By the varying duty cycle of the PWM signal not only voltage and current at thr motor is controlled, but also the right commutation waveform (mostly sinusodial?) for the bldc motor to not emit high pitched sounds. (As older wheels did very annoyingly) 12 minutes ago, sevin7 said: When I disable the speed alarms on my EUCs because they seem to be useless and annoying, that is not going to disable alarms (and tilt back) that would normally go off when the EUC is being overpowered, right? There is some sort of hard coded alarm (beep) and tilt back that cannot be disabled when the EUC is being pushed too hard and its going to cause it to fail, right? There is some "80% alarm" depending on battery voltage and speed with GW wheels. https://forum.electricunicycle.org/topic/13209-speed-reduction-graph-rider-info-needed/?do=findComment&comment=226677 KS have an 88% alarm really showing overlean limit. https://forum.electricunicycle.org/topic/7855-anatomy-of-an-overlean/?do=findComment&comment=307699 Tiltback is always at a fixed (choosable) speed. 12 minutes ago, sevin7 said: If I am correct about number 2, then what is the point of the speed alarms? Why should I care to have something beep at me at a certain speed if its not going to overpower the EUC? Speed alarms were with the first wheels and stayed. Some new better alarms are used with some wheels, but the historical beeping stayed. At least it can be disabled! 1 Quote Link to comment Share on other sites More sharing options...
Tawpie Posted May 13, 2021 Share Posted May 13, 2021 1 hour ago, sevin7 said: There is some sort of hard coded alarm (beep) and tilt back that cannot be disabled when the EUC is being pushed too hard Kingsong has a factory set non-changeable max speed tiltback that cannot be turned off, that’s set at around 31mph for all their “fast”wheels, lower for wheels with smaller batteries. I’m not brave enough to see if the overpower alarm (“the wheel is overpowered”) still sounds if you turn off voice prompts—I’m guessing it’ll at least beep at you. Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 13, 2021 Author Share Posted May 13, 2021 thanks for the replies but I'm still pretty confused. The wheel log app shows 'PWM %' and max PWM %, what does that mean? I knew PWM stood for pulse wave modulation but I thought it must mean something else in this context (PWM % and max PWM %). What I'm most concerned about is overpowered my EX.N while accelerating hard (face plant!). Will it beep at me to let me know I'm about to overpower it? I won't ever be hitting the top speed on the wheel (I doubt I'll reach 40 MPH). I ride up very large and steep hills and I like to go up them around 30 MPH (and I'm 210 lbs). On my S18 the wheel beeps at me if I try to accelerate too hard even at low speeds (the lower the battery state, the easier it is to make it beep at me). My S18 won't take me up the large hills I go on at more than about 20 MPH (it starts beeping if I try to go faster going up these hills, but I'll easily do 30 MPH going down them). So it would seem that my S18 has something built in that warns me that I'm going to overpower it (however, I have overpowered it a few times at low speeds and it happened so fast that I didn't even notice beeps - one time it even happened while breaking too hard). I'm riding my new EX.N and trying to figure out how hard I can push it in acceleration and I have not heard any beeps yet, but I have reached 98% PWM in the wheel log app, and I've noticed that my S18 seems to beep at me if I go above 80% PWM in wheel log (max PWM % stays below 80% normally, but if I push hard accelerating up hill and it beeps the Max PWM will show something over 80%). I don't want to find out how much acceleration is too much on my EX.N by overpowering the wheel and faceplanting. I'm pretty sure I will be able easily to overpower the EX.N when trying to accelerate very hard up a 25* incline once I get my power pads (in 2 days). Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted May 13, 2021 Share Posted May 13, 2021 1 hour ago, sevin7 said: The wheel log app shows 'PWM %' and max PWM %, what does that mean? I don't see it in my Wheellog app? Where is it? Do you have a screenshot maybe? @SebaDo you know what "PWM %" and "max PWM %" are in Wheellog? 1 hour ago, sevin7 said: Will it beep at me to let me know I'm about to overpower it? As far as I know, there's only the 80% alarm beeps (five/continuous beeps) on Begodes/Gotways. They beep at 80% (supposedly) of the max speed, which depends on the battery voltage. So unless your voltage drop from the power demand is high enough to trigger these, no beeps as far as I can tell. Might be too late anyways if you accelerate hard. Difference between the S18 and EX is a 3p battery vs. a 6p battery. 3p is "can be overwhelmed", 4p seems to be extremely fine (RS, V11, all the 1800Wh wheels are 4p), 6 is better naturally. So you have far less voltage drop on the EX. I believe the "small" battery is why the S18 is so careful to quickly warn you of all kinds of things - little reserves. Typically all "big" wheel (MSX, RS, etc.) overlean cases have been due to going too fast, not 10+mph below where the beeps would even appear. But of course I don't know how hard you plan to accelerate, going how fast, and how steep your hills are. You can always overdo it. Your intuition that the power pads might be dangerous is spot on. TLDR: no "overwhelm" beeps on the EX afaik, but 4+p wheels don't seem to overlean unless due to speed. Unless you really push them hard. Rest is for you to find out. Maybe use Wheellog to watch your voltage drop going from 40mph to faster on flat terrain vs. going from 30mph to faster on your hills. Maybe something gives you an indication. Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 13, 2021 Author Share Posted May 13, 2021 8 minutes ago, meepmeepmayer said: I don't see it in my Wheellog app? Where is it? Do you have a screenshot maybe? @SebaDo you know what "PWM %" and "max PWM %" are in Wheellog? As far as I know, there's only the 80% alarm beeps (five/continuous beeps) on Begodes/Gotways. They beep at 80% (supposedly) of the max speed, which depends on the battery voltage. So unless your voltage drop from the power demand is high enough to trigger these, no beeps as far as I can tell. Might be too late anyways if you accelerate hard. Difference between the S18 and EX is a 3p battery vs. a 6p battery. 3p is "can be overwhelmed", 4p seems to be extremely fine (RS, V11, all the 1800Wh wheels are 4p), 6 is better naturally. So you have far less voltage drop on the EX. I believe the "small" battery is why the S18 is so careful to quickly warn you of all kinds of things - little reserves. Typically all "big" wheel (MSX, RS, etc.) overlean cases have been due to going too fast, not 10+mph below where the beeps would even appear. But of course I don't know how hard you plan to accelerate, going how fast, and how steep your hills are. You can always overdo it. Your intuition that the power pads might be dangerous is spot on. TLDR: no "overwhelm" beeps on the EX afaik, but 4+p wheels don't seem to overlean unless due to speed. Unless you really push them hard. Rest is for you to find out. Maybe use Wheellog to watch your voltage drop going from 40mph to faster on flat terrain vs. going from 30mph to faster on your hills. Maybe something gives you an indication. dang that sucks. Basically your saying the only way to find out how hard I can accelerate up at 25* incline that is 100 ft long is to face plant...... Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted May 13, 2021 Share Posted May 13, 2021 23 minutes ago, sevin7 said: the only way to find out how hard I can accelerate up at 25* incline that is 100 ft long is to face plant That's really steep! But because speeds will be low, you'll feel pedal dip and likely be able to react without stepping off the wheel. And if you fall, falling 'uphill' is about as gentle as it gets 2 Quote Link to comment Share on other sites More sharing options...
..... Posted May 13, 2021 Share Posted May 13, 2021 (edited) 1 hour ago, sevin7 said: dang that sucks. Basically your saying the only way to find out how hard I can accelerate up at 25* incline that is 100 ft long is to face plant...... Standard testing proceedure. You have to cross over beyond a machines ability, to know exactly where the failure/limit is. Edited May 13, 2021 by ShanesPlanet 2 Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 13, 2021 Author Share Posted May 13, 2021 25 minutes ago, RagingGrandpa said: TBut because speeds will be low, you'll feel pedal dip and likely be able to react without stepping off the wheel. And if you fall, falling 'uphill' is about as gentle as it gets So the EX.N will attempt to pedal dip before giving out due to me pushing it too hard (at a speed much lower than its top speed)? Thanks for the video, it was useful to watch. I also have a mten3 and I'm pretty certain it beeps at me if I lean forward too hard on a hill (at low speed, around 10 MPH). The S18 seems like a much safer wheel because it at least will tell me when I'm overpowering it (all though its so easy to do that it can be kind of dangerous, especially when the battery is less than about 70%). I don't understand why all wheels would not have something programmed into them to beep at you when you are pushing it too hard (at a speed that is lower than top speed). I don't see how it is too hard to figure out. The wheel knows what the peak current it can handle is (I understand all the factors of battery, ESC, and motor and how peak current will be lower when battery is low). The S18 clearly has this feature and it seems to me that it would be a critical safety feature in all wheels. To only beep when I'm close to top speed is absurd if that top speed is a hard coded number that only changes based on battery remaining. The wheel's actual top speed will be much lower with a 210 lb rider going up a 25* incline than it will be with a 160 lb rider on a flat road. With the EX.N on a full charge the battery is capable of putting out way more power than I could possibly use accelerating up a huge hill as fast as I can, so the ESC or motor are really the limiting factor (likely ESC). Did anyone ever figure out if the EX.N has the same ESC (control board or what ever you want to call it) as the RS 19 high speed? I've seen the threads that show it has the exact same motor as the RS 19 high speed. Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted May 13, 2021 Share Posted May 13, 2021 10 minutes ago, sevin7 said: So the EX.N will attempt to pedal dip before giving out Yes. It's not a deliberate action... the controller will already be at max output, and if you keep leaning and exceed this output, the pedals start to dip. If you relax your stance (stop leaning) you can recover from it. I bet you've already experienced this with your MTen3: a sudden 'kick' at low speed will cause the pedals to dip, and as long as you don't sustain the kick, you can recover and keep riding. 14 minutes ago, sevin7 said: EX.N has the same ESC (control board or what ever you want to call it) as the RS 19 high speed The controls are the same, but the heatsink assembly is totally different and not interchangeable. Quote Link to comment Share on other sites More sharing options...
Seba Posted May 13, 2021 Share Posted May 13, 2021 1 hour ago, meepmeepmayer said: @SebaDo you know what "PWM %" and "max PWM %" are in Wheellog? No, I don't know, but I don't think it's a value that is read from Gotway/Begode wheel, because as to my protocol knowledge, this information is not sent by the wheel. 3 Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 13, 2021 Author Share Posted May 13, 2021 1 minute ago, RagingGrandpa said: Yes. It's not a deliberate action... the controller will already be at max output, and if you keep leaning and exceed this output, the pedals start to dip. If you relax your stance (stop leaning) you can recover from it. I bet you've already experienced this with your MTen3: a sudden 'kick' at low speed will cause the pedals to dip, and as long as you don't sustain the kick, you can recover and keep riding. The controls are the same, but the heatsink assembly is totally different and not interchangeable. To be clear, when you say pedal dip, are you talking about tilt back, or they will dip forwards? If the controller is at max output then I'm not sure how it would have power to tilt me back. If the pedals dip forward then I'll likely face plant as I'm already leaning really far forward just to make it accelerate fast. Quote Link to comment Share on other sites More sharing options...
..... Posted May 13, 2021 Share Posted May 13, 2021 (edited) 22 minutes ago, sevin7 said: To be clear, when you say pedal dip, are you talking about tilt back, or they will dip forwards? If the controller is at max output then I'm not sure how it would have power to tilt me back. If the pedals dip forward then I'll likely face plant as I'm already leaning really far forward just to make it accelerate fast. dip forwards. Give it a try on your mten. Soft grass and a slight hill is all you need. Just give it some oompf. I can get mine to momentarily dip and then ride right along. You are right, pedal dip while leaning into the wind is what lands us on our faces. As stated before, doing it uphill and slowly, youll likely run it off. Edited May 13, 2021 by ShanesPlanet 1 Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted May 13, 2021 Share Posted May 13, 2021 4 minutes ago, sevin7 said: I'll likely face plant as I'm already leaning really far forward just to make it accelerate fast. Right. We're recommending to command acceleration in some other way than 'leaning really far forward.' Other ways include: Inertia (sudden 'stomp' or 'kick' of toe pressure) Power pads (relaxing your stance makes it fast and easy to stop shoving the pads with your shins) Always better to experiment at lower speeds- grass hills are ideal. 1 Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted May 13, 2021 Share Posted May 13, 2021 30 minutes ago, sevin7 said: Did anyone ever figure out if the EX.N has the same ESC (control board or what ever you want to call it) as the RS 19 high speed? I've seen the threads that show it has the exact same motor as the RS 19 high speed. Should be the same hardware (just some current revision of the Begode board), but the firmware is adapted to every wheel model. No need to be worried about the board being damaged for your scenario. Nothing will break from an overlean crash (except possibly you). You merely momentarily overwhelm the capacity to balance you with some combination of speed (meaning limited reserves) plus a sudden acceleration. The EX motor is the same as in the Monster Pro, the RSes have other motors - Begode's older ones from the MSX (speed) and MSP (torque). I guess the summary of the answer is: as the wheel can't know how crazy hard you might accelerate at any time, choosing a safety margin to warn you is tricky - you could always out-crazy any margin, at least on paper. Begode seems to say "our usual warning must be enough", while King Song attempts to tell you "don't try anything now please, you're getting towards thin ice" - that's how I interpret the S18's warning behavior how you described it (also at lower speeds). I find pretty cool that they did this, btw. I suspect they partially also implemented it due to the smaller battery making it more important, whereas the EX will be really really hard to overwhelm from anything but top speed (but you can out-crazy every wheel). There's no guarantees, such is EUC life. Gear up and don't overdo it. And don't worry too much, too, modern performance wheels are really strong. 1 Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 14, 2021 Author Share Posted May 14, 2021 4 hours ago, meepmeepmayer said: Should be the same hardware (just some current revision of the Begode board), but the firmware is adapted to every wheel model. No need to be worried about the board being damaged for your scenario. Nothing will break from an overlean crash (except possibly you). You merely momentarily overwhelm the capacity to balance you with some combination of speed (meaning limited reserves) plus a sudden acceleration. The EX motor is the same as in the Monster Pro, the RSes have other motors - Begode's older ones from the MSX (speed) and MSP (torque). I guess the summary of the answer is: as the wheel can't know how crazy hard you might accelerate at any time, choosing a safety margin to warn you is tricky - you could always out-crazy any margin, at least on paper. Begode seems to say "our usual warning must be enough", while King Song attempts to tell you "don't try anything now please, you're getting towards thin ice" - that's how I interpret the S18's warning behavior how you described it (also at lower speeds). I find pretty cool that they did this, btw. I suspect they partially also implemented it due to the smaller battery making it more important, whereas the EX will be really really hard to overwhelm from anything but top speed (but you can out-crazy every wheel). There's no guarantees, such is EUC life. Gear up and don't overdo it. And don't worry too much, too, modern performance wheels are really strong. Thankyou for the information. However I have the EX.N, which has been confirmed to be the same motor in the RS high speed. The EX has a different motor than the EX.N.j I just got home from riding and I found a hill that was about a 30* incline and 50 feet long and covered in mulch and I tried to ride the wheel up it a couple times and it almost made it which is massively better than my S18 so that was good. The wheel was on 25% battery when I tried it so I think I could make it if it had more battery life. So far the battery life has been epic, I just plugged it into the charger for the first time after 40 miles of riding it got down to about 23% battery. Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted May 14, 2021 Share Posted May 14, 2021 9 hours ago, sevin7 said: However I have the EX.N, which has been confirmed to be the same motor in the RS high speed. The EX has a different motor than the EX.N. You're right, I forgot that (now that you mention it, it rings a bell). The EX.N inexplicably being a secret RS (and not like the EX) is funny. Glad you like yours! 10 hours ago, sevin7 said: and I tried to ride the wheel up it a couple times and it almost made it For the purposes of this topic, what do you mean "almost made it"? Did you fall off (overlean)? Or was the wheel just so sluggish that you had to stop? Beeps? Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 14, 2021 Author Share Posted May 14, 2021 13 minutes ago, meepmeepmayer said: For the purposes of this topic, what do you mean "almost made it"? Did you fall off (overlean)? Or was the wheel just so sluggish that you had to stop? Beeps? A lack of speed, power, and traction all worked together to stop me (this hill was very uneven and mulch doesn't have much traction). There were no beeps. I'm going to try this hill or a similar one (that is not a road so that falling won't hurt) and do a lot more testing when I have more battery and more time (it was getting dark) so that I can really understand when the wheel is going to be overpowered and how it is going to respond to it. 1 Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 18, 2021 Author Share Posted May 18, 2021 On 5/14/2021 at 6:31 AM, sevin7 said: A lack of speed, power, and traction all worked together to stop me (this hill was very uneven and mulch doesn't have much traction). There were no beeps. I'm going to try this hill or a similar one (that is not a road so that falling won't hurt) and do a lot more testing when I have more battery and more time (it was getting dark) so that I can really understand when the wheel is going to be overpowered and how it is going to respond to it. I confirmed today that the EX.N will just cut out without any beeps or tilt back of any sort if you over power it and its actually very easy for me to overpower with powerpads on it (clark pads). The lack of safety features on this wheel is astounding to me. How can the engineers at gotway just hard code beeps at a certain speed based on battery life and think that is acceptable? The amount of power needed to keep the wheel from being over powered at say 30 MPH is massively different for a heavy rider on a steep incline than a light rider on a flat road or a decline. I confirmed this by trying to ride up a roughly 30* hill that is covered in mulch a few times and the motor absolutely runs out of power (I can hear the sounds the motor makes when its out of power) and then it just lets you face plant. I didn't get hurt doing it but I don't trust this wheel or any gotway wheel that has idiotic hard coded beeps. The beeps have to be dynamic (based on known power load that the wheel can handle, and by power I mean watts or amps, not a ridiculous hard coded speed based on battery life remaining). I also discovered I can overheat the wheel in less than 5 minutes of riding in the hilly area that I live in while the ambient temperature is 73* F. If the ambient temp was 90* F (which it will be very soon) then I could likely overheat the wheel in about 2 minutes. At least the wheel does tilt back when you reach 175* F. I'm not impressed by this wheel or gotway/begode. 1 Quote Link to comment Share on other sites More sharing options...
btl Posted May 19, 2021 Share Posted May 19, 2021 https://youtu.be/lUW5xab9T-A?t=628 "it can go up to like 35° incline and then it beeps" ... with proof of it a few seconds later. Did you go that steep and then torqued it? Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted May 21, 2021 Author Share Posted May 21, 2021 On 5/19/2021 at 7:36 AM, btl said: https://youtu.be/lUW5xab9T-A?t=628 "it can go up to like 35° incline and then it beeps" ... with proof of it a few seconds later. Did you go that steep and then torqued it? I watched that too. I've found WrongWay often says things incorrectly. I like his videos a lot but sometimes he is not accurate. I don't believe the thing beeps unless its the high speed beeps; at least it would not for me and others are saying the same. WrongWay is also a lot lighter than me. Quote Link to comment Share on other sites More sharing options...
FunTech4Real Posted June 4, 2021 Author Share Posted June 4, 2021 I have now confirmed that the V11 does NOT have a "overpower alarm" as I'm calling it (what the S18 has). I tried some low speed hill climbs that were extremely steep and eventually the motor just gives out just like the EX.N. I'm disgusted by the lack of safety engineering in EUCs and shocked that even Inmotion wheels are lacking such a basic feature. I just watched a video of a EX.N and Sherman being overpowered on a steep hill at low speeds and both of them fried their motherboard!! 1 Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted June 4, 2021 Share Posted June 4, 2021 3 hours ago, sevin7 said: I tried some low speed hill climbs that were extremely steep and eventually the motor just gives out Be grateful that the EUC protected itself from damage, instead of allowing you to melt it! Quote Link to comment Share on other sites More sharing options...
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