Understanding the real world considerations and implications of Speed VS Torque models

[on one]

fyi flying monkey means:

When people discuss narcissists, they sometimes use the phrase 'flying monkeys. ' Flying monkeys refer to people who carry out the work of a narcissist or an abusive person, and it comes from The Wizard of Oz, in which the Wicked Witch of the West puts flying monkeys under her spell.

[on one]

1 hour ago, Rawnei said:

It's a weak wheel with speed based tiltback.

@Rawnei, please don't misunderstand me, I'm not suggesting that you are a narcissist, just that the other comment you made was narcissistic in nature.

But I have noticed that I get tilt back a lot sooner on a lower battery, so it can't be speed based tilt back in the 14D.

[Rawnei]

37 minutes ago, on one said:

@Rawnei, I don't want to be your flying monkey, not fall victim to your narcissistic comment,

If it's a low power, weak, wheel, then can you help me understand why that makes the King Song 14D unsafe?

It's safe if the rider knows the limits and stays within them, you are talking about hard acceleration, that is your whole thesis, King Song 14D is not the wheel for hard accelerations, in this context the wheel is not safe for that type of riding.

The point is that you are doing all these mental exercises without having the experience of riding a powerful wheel, it becomes some weird form of theorycrafting for what reason? You don't even have the correct frame of reference to start with, a lot of things have happened since the Ninebot Z10 which is not even remotely comparable to something powerful like a Lynx, ET Max or other powerful modern wheel in terms of power and safety margins that comes with that.

And speaking of ego you are asking page after page for people to take the time to explain things to you which they are trying to, yet you are not content and want more and seem to get annoyed by the replies you get, so don't get me wrong I'm not calling you a narcissist but.

[on one]

1 minute ago, Rawnei said:

You don't even have the correct frame of reference to start with, a lot of things have happened since the Ninebot Z10 which is not even remotely comparable to something powerful like a Lynx, ET Max or other powerful modern wheel in terms of power and safety margins that comes with that.

Wheels are always being made faster and more powerful, not really safer. Sometimes as in the motorcycle sport akin to euc, more powerful is more dangerous. That's why kids get low power bikes to learn on.

3 minutes ago, Rawnei said:

You don't even have the correct frame of reference to start with, a lot of things have happened since the Ninebot Z10 which is not even remotely comparable to something powerful like a Lynx, ET Max or other powerful modern wheel in terms of power and safety margins that comes with that.

I am hoping to learn and adjust my frame of ref, that's the point.

[on one]

Ninebot Z10 is an extremely powerful wheel, especially with @MRN76's firmware mod.

[on one]

The manufacturing organizations and dealers are always pushing the "by another wheel that's more powerful" because they want to sell more wheels. I'd rather spend $2000 on a graphene battery 14d than 5000$ on a sherm L

[Rawnei]

4 minutes ago, on one said:

Wheels are always being made faster and more powerful, not really safer. Sometimes as in the motorcycle sport akin to euc, more powerful is more dangerous. That's why kids get low power bikes to learn on.

I am hoping to learn and adjust my frame of ref, that's the point.

People already explained to you, more power = more safety, higher top speed = more safety, less risk of you overpowering the wheel coupled with dynamic PWM tiltback.

You won't be able to figure this out in theory, you need to ride a more powerful wheel to understand it.

1 minute ago, on one said:

Ninebot Z10 is an extremely powerful wheel, especially with @MRN76's firmware mod.

By today's standard it's not really.

Just now, on one said:

The manufacturing organizations and dealers are always pushing the "by another wheel that's more powerful" because they want to sell more wheels. I'd rather spend $2000 on a graphene battery 14d than 5000$ on a sherm L

At this point your posts are kinda pointless.

[on one]

You'd rather insult me than address the wheels.

[on one]

13 minutes ago, Rawnei said:

People already explained to you, more power = more safety, higher top speed = more safety, less risk of you overpowering the wheel coupled with dynamic PWM tiltback.

I don't follow agree with that statement. That's not what people are saying, and if it really is what they are saying then I disagree from an engineering perspective.

[EUCzero]

Ronnie is saying:
 

• Ride any EUC at 30 miles/hour! Witch one will be safest?
  • The one that have 31 miles/hour top speed (you only have 1 more to go  )
  • or the one with 65 miles/hour top speed. (you have 35 more to go)
• Do hard acceleration. Witch one will not "pedal dip/overlean cut out"?
  • The old 14D
  • or the way more new and powerful Lynx?

Soooo..... is stronger and faster EUCs safer to ride or not? No one tell you to ride at their max speed or max acceleration. So witch EUC do you think will most likely fail and hurt you if you use them in the same way?

The EUCs has become WAY safer as long as you use them the same way. And EUC can only be used safely if you use them below below their speed and power limit. And if these limits are very low, you will get hurt more often.

PS... even if the 14D reacts at a lower speed at low battery, the pedal tiltback is still speed based. Lower speed at low battery yes, but still based on speed. Not available power as PWM tiltback does. So the 14D will not help you is you use the power for acceleration hard or going uphill. Then a speed based tiltback will often tiltback too late. Therefor the more modern PWM based tiltback is what all new models use ( or should use).
PWM based tiltback calculate how much extra power resources you actually have left, and then gives you a warning if you are getting close to the limit.
The beeps have been PWM based for a long time, but PWM based tiltback is a quite new but important safety feature.
 

Edited July 29 by EUCzero

[on one]

Thank you @EUCzero for the quite rational and coherent explanation. Sometimes I am a little autistic in my thinking, for good and ill.

PS... My KS14D has some kind of strange springy mechanism, maybe you know what it is. When I do a jump and land too far forward or too far backwards, my wheel doesn't cut out, and I weigh 245 lbs, way over the limit, the pedal springs down and up again. What's up with that?

[Duster]

2 hours ago, on one said:

Thank you @EUCzero for the quite rational and coherent explanation. Sometimes I am a little autistic in my thinking, for good and ill.

PS... My KS14D has some kind of strange springy mechanism, maybe you know what it is. When I do a jump and land too far forward or too far backwards, my wheel doesn't cut out, and I weigh 245 lbs, way over the limit, the pedal springs down and up again. What's up with that?

If I'm understanding what you're describing, that's a normal thing that all wheels do when there is a big, sudden torque on the pedals/body of the wheel. EUCs work by reacting to the body being tilted forwards or backwards, but there is only so much energy a wheel can dedicate to keeping itself upright when a lot of leaning weight is applied at once (like when you hit a bump or land hard and far forwards/backwards), so it takes a split second for the wheel to put in the energy to become upright again. Imagine like someone tossed a bag of potatoes into your arms: you would not be able to be completely rigid, you'd sag down for a second, and then you would be able to stand straight again.

That's my best attempt at explaining this.

[on one]

follow up question: Why can't the firmware always stay ahead of the cut out by regulating the power provided if the request is too high and would result in a cut out. This seems like an extremely no-brainer part of firmware.

[Duster]

Just now, on one said:

follow up question: Why can't the firmware always stay ahead of the cut out by regulating the power provided if the request is too high and would result in a cut out. This seems like an extremely no-brainer part of firmware.

Well, it's not exactly that simple. If the wheel were to give you less energy, and you were still leaning forward, you would likely fall over because the wheel isn't helping to keep you upright while you lean forward (I've almost fallen forward by expecting my wheel to accelerate faster than it actually did). To see what this would feel like, lean forward like you would on an EUC, but do it while standing on solid ground (please don't do this as you might actually fall, and I'm just trying to describe why the firmware idea wouldn't work).

Also if you want an explanation for why wheels cut out (it used to be strange to me that wheels "protected themselves" by shutting off), there's only so much energy a wheel can give to keep you upright, and if you surpass that capacity, then the wheel can't keep you upright. Another way of imagining the cutout scenario is: if you jump out of a moving car that's going, say, 15mph, you could probably start running and be able to keep yourself from falling (this is a crazy hypothetical, but stick with me). BUT if you jump out of a car that's going 25mph, you'd likely fall because you can't run fast enough. When we run, we're using our legs to keep our bodies upright. Likewise, EUCs use their wheels to keep their frames (with the pedals that we stand on) upright. It's all about physical limits.

[on one]

I'm processing what you said, but my intuition is, I don't buy it. Here's why: the control board always knows the amount of acceleration that the rider is requesting and the control board always knows how much power it has to work with, thus it should be able to incrementally provide the rider with just a little bit less and less power instead of just shutting off or even tilting back, let alone, God forbid just cut off.

[Duster]

16 minutes ago, on one said:

I'm processing what you said, but my intuition is, I don't buy it. Here's why: the control board always knows the amount of acceleration that the rider is requesting and the control board always knows how much power it has to work with, thus it should be able to incrementally provide the rider with just a little bit less and less power instead of just shutting off or even tilting back, let alone, God forbid just cut off.

What we have for that is tilt back, where the wheel tilts itself (and thus the pedals) backwards, effectively forcing you to slow down. Not all wheels have this programmed in, and I think the King Song 14D may be too old to have had anything like that programmed in except for when the battery is too low to safely go above 5mph. But newer wheels are getting tilt back for that power limit (called "PWM tilt back"). I think that's what a lot of people on here are suggesting should be an industry standard to have as an option.

Believe me, if EUCs didn't encourage you to lean backwards as they slow down, then you'd just keep leaning further forwards, with greater speed too in fact. It'd be like if someone pulled your feet backwards while you leaned forwards: the wheel would be actively trying to trip you.

[techyiam]

1 hour ago, on one said:

Here's why: the control board always knows the amount of acceleration that the rider is requesting and the control board always knows how much power it has to work with, thus it should be able to incrementally provide the rider with just a little bit less and less power instead of just shutting off or even tilting back, let alone, God forbid just cut off.

The "hands" of the controller are tied.

The controller can only go up to 100% duty cycle PWM to generate enough counter-torque to counterbalance the rider's lean-generated torque.

Beyond that, the wheel will not be able to balance the rider adequately.

Dynamic tilt back must start tilting back before the controller has reached 100% duty cycle PWM.

Without dynamic tilt back, the rider will find the pedal dips or gives maybe a fraction of a second before cutting out. Depending on implementation, the rider may have to be very advanced and experienced to make the save.

[on one]

There seems to be a general consensus here that motor watts is too ambiguous of a concept to have use as a method of determining wheel power. I don't see how @Jason McNeil and @Forwardnbak and other dealers can possibly agree with this because motor watts is always used as a measure on their sites describing electric unicycles that are available. I really wish our dealer members and our liaison from King Song who has been participating and the member from EUCO who is a member here. I would be so grateful if those members could chime in here about power using their official accounts so that we could get some credible answers who have viewpoints that could really help here.

[Punxatawneyjoe]

56 minutes ago, on one said:

see how @Jason McNeil and @Forwardnbak and other dealers can possibly agree with this because motor watts is always used as a measure on their sites describing electric unicycles that are available.

Jason is the owner of ewheels and forwardnbak is a you tuber that has affiliate links to eriderz and shredlights etc.  FYI

Motor watts is just another specification amongst many others listed that "some" people are interested in. I don't feel it's listed to manipulate you into thinking it's the end all factor in how fast and powerful an EUC is. It's just another spec and a meaningful one in conjuncture with others to understand the speed/power of a wheel. It's obvious that a motor/control setup that can consume 900w continuously is far weaker and slower than one that can consume 4,000w so the people who say it means "nothing" are not being entirely honest about it.

[alcatraz]

This might seem irrelevant but in cycling we have something called FTP functional threshold power. It's often just one number like on these specifications "354 watts" but in detail it's a graph. 

The number is the maximum power output a cyclist can keep for 1 hour.

The graph however (which I suggest eucs should all have) shows something like this. 

It would clear up a lot of the confusion when comparing wheels.

It shows the maximum power output that can be sustained at different durations. A 1 second max power is WAY different than 10 seconds (or longer). How much different when talking about eucs? Well, we don't know because we don't have these kinds of graphs. We can only speculate. In cycling they don't speculate. If a 1 minute effort is coming up during a race, every rider knows exactly how many watts they can push to arrive at the end of it "at the redline".

Obviously eucs are more complicated because power output changes depending on rpm. You controller can handle 20.000W but if your motor is at 50% rpm you have a fraction of the motor's max power available.

Edited July 31 by alcatraz

[on one]

11 hours ago, alcatraz said:

Obviously eucs are more complicated because power output changes depending on rpm. You controller can handle 20.000W but if your motor is at 50% rpm you have a fraction of the motor's max power available.

Interesting, but that doesn't explain why controllers are currently not programmed to use their multitude of inputs to eliminate over lean failure.

[alcatraz]

11 minutes ago, on one said:

Interesting, but that doesn't explain why controllers are currently not programmed to use their multitude of inputs to eliminate over lean failure.

I'm sorry. This graph appears to point out that we have max power at ~50% rpm. So if free spin speed is 120km/h you have max power at 60km/h? Past 60km/h your power budget starts to shrink.

I don't think you can eliminate overlean. There's a third party firmware for begode wheels that attempts to do that. It seems quite good at solving the problem with many positive reports. It's been out for a few years and I'm sure begode are aware of it. I wonder why they haven't adopted it. I believe it's like a wheel internal "minimum safety margin" value like in eucworld, but perhaps better?

I've got four Gotway wheels but non are supported. 

[EUCzero]

On 7/31/2024 at 4:35 PM, alcatraz said:

I'm sorry. This graph appears to point out that we have max power at ~50% rpm. So if free spin speed is 120km/h you have max power at 60km/h? Past 60km/h your power budget starts to shrink.

I don't think you can eliminate overlean. There's a third party firmware for begode wheels that attempts to do that. It seems quite good at solving the problem with many positive reports. It's been out for a few years and I'm sure begode are aware of it. I wonder why they haven't adopted it. I believe it's like a wheel internal "minimum safety margin" value like in eucworld, but perhaps better?

I've got four Gotway wheels but non are supported. 

Begode HAVE implemented PWM tiltback. Not sure why you belive they have not.
That is also one of the reasons why Ronnie say moders EUC are more safe than old like 14D.

PWM tiltback is the sollution fro overlean cutouts. But for it to work the riders MUST use the function, and they MUST respect the tiltback.
There is only one more way to eliminate overlean cutouts, and that is to make the EUSs infinte powerful.

Not sure why "on one" seems to think preventing overlean is as simple as a programming thing. Overleaning is done by the rider, but by the machine.
WHEN the rider overlean it means that the rider continue to lean forward even if the EUC already is at 100% power. And then the EUC can't accelerate more to keep the rider in balance, and the rider will tilt more and more forward until the EUC has to cut due to it believing the rider has fallen off (angle to high).

 Not sure if "on one" actually understand what happenes during overlean. As others have written allready. Only thing the EUC can do is to try to tiltback the rider before reaching 100%. And that is what 80% PWM tiltback is. But remember, sometimes the time between 80% and 100% is too short for the tiltback to actually kick in.
 

Edited August 1 by EUCzero

[Chriull]

7 minutes ago, EUCzero said:

"on one"

 

[on one]

11 minutes ago, EUCzero said:

Not sure why "on one" seems to think preventing overlean is as simple as a programming thing.

I hope over lean wheel failure can be prevented with firmware and hardware solutions. I know not how to do this, but am optimistic.