NOSFET Electric Dreams Posted March 5, 2020 Share Posted March 5, 2020 So back in the day most everyone of us rode the Ninebot One E+. No matter how hard I pushed the device at it's top speed despite the tilt back I was never able to get it to cut out. I did however manage to overlean the device by accelerating too hard. Was it my lack of skill back then to push my E+ beyond the max speed or is it that modern wheels don't have the same protection for riders to not reach cut out speed? Why can't the wheel just not permit the rider to go beyond a certain speed? Quote Link to comment Share on other sites More sharing options...
Chriull Posted March 5, 2020 Share Posted March 5, 2020 12 minutes ago, Jack Frost said: No matter how hard I pushed the device at it's top speed despite the tilt back I was never able to get it to cut out. I did however manage to overlean the device by accelerating too hard. How do you differentiate "cut-out" and "overlean"? Every wheel can be overleaned by going fast and/or accelerating hard enough. Every wheel cuts off at lift cuts off speed. Ninebot E+ BMS did also cut off at some max current, which modern wheels do not do anymore (or at much higher currents). 15 minutes ago, Jack Frost said: Why can't the wheel just not permit the rider to go beyond a certain speed? If one leans forward the wheel has to accelerate or one faceplants... 1 Quote Link to comment Share on other sites More sharing options...
NOSFET Electric Dreams Posted March 5, 2020 Author Share Posted March 5, 2020 3 minutes ago, Chriull said: How do you differentiate "cut-out" and "overlean"? Every wheel can be overleaned by going fast and/or accelerating hard enough. Every wheel cuts off at lift cuts off speed. Ninebot E+ BMS did also cut off at some max current, which modern wheels do not do anymore (or at much higher currents). If one leans forward the wheel has to accelerate or one faceplants... I differentiate cut out to be: wheel tells you "NO MORE" with it's continuous beeps and you continue to push it. Overlean is you pushing the wheel with sudden acceleration that cant allow the motor and motherboard to react fast enough and you either fall from losing balance because the wheel cant accelerate fast enough or the wheel doesn't rotate forwards. 7 minutes ago, Chriull said: Every wheel cuts off at lift cuts off speed. Ninebot E+ BMS did also cut off at some max current, which modern wheels do not do anymore (or at much higher currents). I haven't experienced cutting out on my E+ and off memory I pushed my E+ hard, I know I was able to find cut out speed by lifting the wheel off the ground but I ride it to it's cut out speed. 6 minutes ago, Chriull said: If one leans forward the wheel has to accelerate or one faceplants... I don't think you understood my questions. Obviously a wheel has to rotate, but why not maintain the wheels speed at 34km/h when cut out is at 36 km/h. Shouldn't the firmware be protecting the hardware from pushing itself further? Quote Link to comment Share on other sites More sharing options...
Chriull Posted March 5, 2020 Share Posted March 5, 2020 7 minutes ago, Jack Frost said: Overlean is you pushing the wheel with sudden acceleration that cant allow the motor and motherboard to react fast enough and you either fall from losing balance because the wheel cant accelerate fast enough or the wheel doesn't rotate forwards. The wheel cannot accelerate fast enough only because one reached the wheels limit (motor &battery) limit. The motherboard is always fast enough. The alarms you mentioned for your cut out definition are mostly not directly correlated/corresponding to the wheels limit. So there are mostly some speed/load/acceleration/etc combinations possible to reach the wheels limit without any alarms. 11 minutes ago, Jack Frost said: I don't think you understood my questions. I did. 11 minutes ago, Jack Frost said: Obviously a wheel has to rotate, but why not maintain the wheels speed at 34km/h when cut out is at 36 km/h. Same answer - if one leans forward at 34km/h and the wheel does not accelerate one faceplants... 11 minutes ago, Jack Frost said: Shouldn't the firmware be protecting the hardware from pushing itself further? The hardware does not suffer from reaching the limit. Just from the faceplanting rider bringing the wheel out of balance causing it to crash The best try manufacturers do is letting the wheel tilt back - that's a very decend sign for the rider, it's harder to keep leaning forward. But still no 100% solution - one can still ride the tiltback and go for the limit. Theoretically tilting the pedals straight up could hinder the rider from further leaning forward. ... but quite most riders will not stand this most presumably ... Quote Link to comment Share on other sites More sharing options...
LanghamP Posted March 5, 2020 Share Posted March 5, 2020 1 hour ago, Chriull said: but quite most riders will not stand this most presumably .. I saw what you did there. Quote Link to comment Share on other sites More sharing options...
NOSFET Electric Dreams Posted March 5, 2020 Author Share Posted March 5, 2020 1 hour ago, Chriull said: The wheel cannot accelerate fast enough only because one reached the wheels limit (motor &battery) limit. The motherboard is always fast enough. The alarms you mentioned for your cut out definition are mostly not directly correlated/corresponding to the wheels limit. So there are mostly some speed/load/acceleration/etc combinations possible to reach the wheels limit without any alarms. I did. Same answer - if one leans forward at 34km/h and the wheel does not accelerate one faceplants... The hardware does not suffer from reaching the limit. Just from the faceplanting rider bringing the wheel out of balance causing it to crash The best try manufacturers do is letting the wheel tilt back - that's a very decend sign for the rider, it's harder to keep leaning forward. But still no 100% solution - one can still ride the tiltback and go for the limit. Theoretically tilting the pedals straight up could hinder the rider from further leaning forward. ... but quite most riders will not stand this most presumably ... To me the limit of the hardware is face planting the rider... so why don’t these manufacturers make a calculation the motor is stressed by the weight(also factoring battery level) and to not prevent a wheel from getting close to face plant speed. by the sounds of what ur saying I didn’t push my e+ hard enough for cut out and that was probably because of the aggressive tilt back then. Quote Link to comment Share on other sites More sharing options...
Chriull Posted March 5, 2020 Share Posted March 5, 2020 1 hour ago, LanghamP said: I saw what you did there My english knowledge does not enlighten me - feel a bit blind Hope the meaning of my sentence at least somehow expressed my intentions and its only some amiguity.... 1 hour ago, Jack Frost said: and to not prevent a wheel from getting close to face plant speed. It's just no possible. An old, often and well discussed topic here. Every speed restriction leads to a facplant. Sorry that i am not able to explain this in an understandable way. Quote Link to comment Share on other sites More sharing options...
Planemo Posted March 5, 2020 Share Posted March 5, 2020 4 hours ago, Jack Frost said: Why can't the wheel just not permit the rider to go beyond a certain speed? 57 minutes ago, Chriull said: It's just no possible. An old, often and well discussed topic here. Every speed restriction leads to a facplant. Sorry that i am not able to explain this in an understandable way. OK I'll have a stab at trying to answer the OP A wheel cannot 'speed limit' because in order to do so it would then be unbalanced by default. A wheel needs to be able to constantly accelerate and decelerate to keep you upright. If you take either of those away by limiting the wheelspeed then the only direction you are going is down. All the manufacturers can do is WARN you that you are getting near to max wheel speed. Either by tiltback, warning beeps or both. Some wheels under max tiltback are very difficult to ride, but it can be done. I have no doubt that if you were able to physically deal with the angle of the pedals on your E+, you could have ridden faster until the wheel eventually couldn't keep up with your demands, the max wheel speed would be reached and the wheel would cut off. You would then go over the front (faceplant). Some people (me included) don't like tiltback as it can be un-nerving or it can (on some wheels) come in like a hammer blow, suddenly and at a large angle. So on the MSX I turn it off and rely solely on the 80% (final) alarm. When I hear this I know it's game over for pushing any harder. As Chriull said, it's just not possible to 'speed limit' a self balancing device 2 Quote Link to comment Share on other sites More sharing options...
pst Posted March 6, 2020 Share Posted March 6, 2020 4 hours ago, Planemo said: OK I'll have a stab at trying to answer the OP A wheel cannot 'speed limit' because in order to do so it would then be unbalanced by default. A wheel needs to be able to constantly accelerate and decelerate to keep you upright. If you take either of those away by limiting the wheelspeed then the only direction you are going is down. All the manufacturers can do is WARN you that you are getting near to max wheel speed. Either by tiltback, warning beeps or both. Some wheels under max tiltback are very difficult to ride, but it can be done. I have no doubt that if you were able to physically deal with the angle of the pedals on your E+, you could have ridden faster until the wheel eventually couldn't keep up with your demands, the max wheel speed would be reached and the wheel would cut off. You would then go over the front (faceplant). Some people (me included) don't like tiltback as it can be un-nerving or it can (on some wheels) come in like a hammer blow, suddenly and at a large angle. So on the MSX I turn it off and rely solely on the 80% (final) alarm. When I hear this I know it's game over for pushing any harder. As Chriull said, it's just not possible to 'speed limit' a self balancing device I had a discussion along these lines a year or two ago in the safety section, and I recall a few folks giving this same answer. Certainly - physics being what it is - you cannot simply spin the wheel at a slower speed and expect the rider-wheel unit to both slow down AND stay balanced. I don't think that's what people mean when they say this (or at least the ones who think it through). SOME measures can be taken (adequate/consistent warnings, adequate design guardband, redundancy/diagnostics) and from what I gather reading some of the tales, either people disregard the warnings a lot more than they say, or in reality very little regard is paid to the safety of occupants in corner-case situations. For as much as we supposedly "can't slow down an EUC", I have never had my (sometimes painfully slow) S1 cut out on me, during my couple years of fair-weather 10-mile commutes. No problems on steep hills, no problem losing track of speed next to fast-moving traffic, etc. Sure, a couple times going down a hill I had to quickly swerve to avoid something... that's where that "adequate design guardband" comes in. In the DIY thread, which is actually what I'm back to check on (hope springs eternal), there may be opportunities for experimenting on ways to improve safety, and I would love to see this. But commercial designs would get pretty costly, and - as I was told in my safety board thread - basically the market wants speed more than safety, especially when it comes to Chinese engineers marketing a product to a bunch of not-always-wealthy, not-always-seat-belt-wearing . Unfortunately work controls most of my personal life right now as well as daytime life, so I don't have much time for tinkering, but maybe some day! Quote Link to comment Share on other sites More sharing options...
LanghamP Posted March 6, 2020 Share Posted March 6, 2020 (edited) 7 hours ago, Chriull said: My english knowledge does not enlighten me - feel a bit blind Stand has two meanings, one of the physical act of standing (upright), and the other meaning tolerance. Since EUC riders stand up to ride,and since the context of your sentence also implies a tilting wheel that dumps the rider, either/both meanings can work. Edited March 6, 2020 by LanghamP 1 Quote Link to comment Share on other sites More sharing options...
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