Making cut outs impossible

[Altaire.]

Maybe this is a stupid question, but why isn't there a way to make wheel cut outs not possible?

[houseofjob]

Because the wheel does not have infinite power, and the gyroscopic lean principle dictates that the harder you lean, the more power is demanded, into infinite. This is compounded when the wheel battery is at reduced capacity.

So it's either let the motor run until it burns out, possibly catching fire because it's trying to output power well above the rating, or cutout the motor so you can turn it back on to be used again.

The real solutions are to try to get the user not to go above this threshold, hence beeps, tiltback, etc.

Edited October 12, 2020 by houseofjob

[Altaire.]

Why not just make a wheel that has a power threshold you couldn't realistically overwhelm? It doesn't need infinite power

[houseofjob]

35 minutes ago, Altaire. said:

Why not just make a wheel that has a power threshold you couldn't realistically overwhelm? It doesn't need infinite power

They do this, it's called soft mode, but people complain about it, claiming it's "lack of torque" or has too much "pedal dip" when these complaints are false, just requiring a different style of riding.

Most riders want a hard mode, where the wheel has instant torque on first press, pedals don't move, but that doesn't leave you much headroom the farther you lean, because a hard mode brings your starting point closer to that power threshold cutoff.

You can't eliminate this power threshold cutoff, you can only tune it like this. TBF, with this generation 100V top performance wheels, it's much harder to cutout a wheel than it was many moons ago with sub-1kW nom motors.

Edited October 12, 2020 by houseofjob

[meepmeepmayer]

55 minutes ago, Altaire. said:

Why not just make a wheel that has a power threshold you couldn't realistically overwhelm? It doesn't need infinite power

"Realistically" being the key word here: that's mostly what is happening now, at least from the spec side. Big batteries, powerful and well-designed motors.

Now the quality and reliability/size of the electronic components is another thing... even though everything works very reliably, it could be much better and more trustworthy designed.

There are some hard limits, though, mostly battery size and therefore weight, that will limit how powerful a EUC can be, especially small and light ones. A V5F-like wheel with high speed and massive amounts of power will not happen before a serious technological breakthrough (like 10x better batteries).

And electric motors have an inherent top speed, which means you can overpower any EUC just by going fast enough because it gets weaker (approaching zero torque) when approaching this limit speed. That will never change unless someone has a clever idea how to circumvent that.

But overwhelming a big battery, fast wheel other than going too fast is pretty hard already. 99% of no-external-cause crashes seem to be just people going too fast (and accelerating too hard at speed) for the wheel they have and overleaning it.

Edited October 12, 2020 by meepmeepmayer

[.....]

how to avoid the possibility of a cutout. Theres only ONE real way to do it.   are you ready? Here it comes.....    NEVER POWER UP AND RIDE THE EUC. Not being a smartass and maybe Im wrong, but this seems to me to be the ONLY way you can be absolutely sure.

[RockyTop]

I don’t think we need infinite power. We just need 1.21 gigawatts and a flux capacitor. 

[Mike Sacristan]

12 hours ago, Altaire. said:

Maybe this is a stupid question, but why isn't there a way to make wheel cut outs not possible?

There is sort of a way if we are speaking of over leaning the wheel. They tried to implement it in FW 1.06 on the 16X.
What they did was reserve more power to the wheel, leaving us with a lower speed at X% battery. The community complained.

Kingsong implements a soft tilt-back (defeatable) at 80% power. At 88% power there is a beep code and also somewhere around there a hard tilt-back (not realistically defeatable).

A wheel with soft-tiltback at 70% power and hard tilt-back at 80% would be safer. Such as the Inmotion V10/F.

The new problem that is introduced here is that if the Gotway Nikola 100V for instance has a 5 beep 80% alarm top speed of 64kmh at full battery then you would hit soft tilt-back or hard tilt-back instead of five beeps. So in a situation where you are passing a car you would be physically stopped as you are passing.

Riders who ride like donkeys will over lean their wheels regardless.

Now if we are talking about redundancy systems then that is a whole other story. But in the end everything would work out as it is if the wheels only let us access 70% of their power.
Their is still the likelihood of a component failure while riding... but that is very unlikely.
 

 

[mhpr262]

10 hours ago, meepmeepmayer said:

 A V5F-like wheel with high speed and massive amounts of power will not happen before a serious technological breakthrough (like 10x better batteries).

Those batteries already exist, LiPo batteries as they are used in RC sports. There are 8.000mAh packs available that are rated for around 60C continuous and 120C burst (ca 30 seconds) discharge, meaning you can draw 1000 Amperes from those batteries if you have to. When the battery pack of my no-name 350W wheel quit I built my own battery pack out of four 4s 4.000mAh LiPo packs and it worked perfectly fine. Only downside is the price and how fast they age.

Edited October 12, 2020 by mhpr262

[Chriull]

17 minutes ago, mhpr262 said:

Those batteries already exist, LiPo batteries as they are used in RC sports. There are 8.000mAh packs available that are rated for around 60C continuous and 120C burst (ca 30 seconds) discharge, meaning you can draw 1000 Amperes from those batteries if you have to. When the battery pack of my no-name 350W wheel quit I built my own battery pack out of four 4s 4.000mAh LiPo packs and it worked perfectly fine. Only downside is the price and how fast they age.

The limited current rate of the used LiIon cells is not the (real) problem (in relation to overleans).

In contrary using LiPos in your no-name 350W wheel could lead to motherboard getting fried because the design based on the higher internal resitance of LiIon cells as current limiter. And by this leading to a real cut out in high burden situations...

Not to speak of the higher risk for hire hazards by mechanical or "electrical" damage.

 

[pico]

The idea would be to have a "last resort" (pre cutout) short burst of 10sec to give enough time to the rider to get out of harms way...

Those lipos would be encased in a special (shockproof) enclosure with special monitoring circuitry. 

The electronic current paths would have to be modified...

But of course someone would find a way to defeat this arrangement!  to brag 106.66666km/h!  

 

[yuweng]

14 hours ago, Altaire. said:

Maybe this is a stupid question, but why isn't there a way to make wheel cut outs not possible?

Yeah i wonder too, having said that, i do witness one of my friend's earliest generic wheel that you can continue speeding but won't cut off but it will just tilt back until you won't be able to ride it but then again its a low speed wheel  Below video is Adam's friend's Nikola+, it behave exactly the same except this is cause by low battery & not over speed/ over power 

 

[Dgar]

Quote

Maybe this is a stupid question, but why isn't there a way to make wheel cut outs not possible?

That is kind of like asking if there a way to make a motorcycle that doesn't run out of gas. The cut out is basically when power runs out. The difference being that a motorcycle doesn't rely on a gyro to keep you upright. It will just coast to a stop. When an EUC loses power, it loses the gyro balancing you and you either fall forward or backward. If a motorcycle relied on gas to keep upright, you would have the same issue.

[NickNonsense]

Maybe it should be less about mechanical and electrical redundancies and safeguards and more about riders’ attitude. Like other commentors have stated, the likelihood of component failure (even though it is there) is rather small. What we hear often is people pushing these to the limit (often unnecessarily)  

Should these wheels be on the road?
In my opinion, no. (your too vulnerable and exposed)

Do wheels need to go above 30mph?
In my opinion again, no. (If you need a quicker mode of transport then need an alternative to an ECU)

Do wheels need +50-mile range?

No, if you need more then 50miles I would say that you most definitely need an alternative mode of transport for your journey, but hey this is my opinion. (this distance is tiring, just carry a charger and take a break)

So you want to limit the possibility of cut outs? build a wheel vastly over the above specifications and then limit the wheel to these specs and have the wheel preform comfortable at these maximums.

I think this is the evolution that the EUC should take, although I know this is far from the evolution the EUC will take in the future.  

[null]

I’ll agree with part one but part two is a lot of your own preferences you apply to others.

I take a lot of pleasure from doing 100-200km day trips, why shouldn’t there be a EUC for me and all others who ride far? If riding less is a way to avoid cutouts they you can get zero cutout but just not riding EUCs.

As for the road it would exclude a whole lot of people who dont have an evolved cycle network.

Edited October 14, 2020 by null

[NickNonsense]

13 minutes ago, null said:

I’ll agree with part one but part two is a lot of your own preferences. I take a lot of pleasure from doing 100-200km day trips, why shouldn’t I? 🤷🏼

That is a lot of miles. That can be over 100miles.

If you’re doing this in a day that’s fine, but realistically you aren’t doing it in one long continuous journey (or you might be in which case I’m surprised )
For most they won’t be doing this journey and if you was most would need to take a rest or be using another mode of transport in between such as a train. So, you will find a place to charge it.

Edited October 14, 2020 by NickNonsense

[null]

13 minutes ago, NickNonsense said:

That is a lot of miles. That can be over 100miles.

If you’re doing this in a day that’s fine, but realistically you aren’t doing it in one long continuous journey (or you might be in which case I’m surprised )
For most they won’t be doing this journey and if you was most would need to take a rest or be using another mode of transport in between such as train. So, you will find a place to charge it.

I do it regularly, thats why I went from the 18XL to the Sherman.
The group rides we do around Paris are often 80km and sometimes more.
While in the countryside this summer I did several 160km and one 200km. Was great, just a bit stiff in the muscles the day after.

I dont think long distance riders are the ones with cutouts, because you have to keep some battery and you're out the whole day.
(edit: I reformulated my original post a bit but doesn't matter, same point)
(edit 2: To each their opinion anyhow, just had to mention I'd prefer there where still EUCs for long range  )

 

Edited October 14, 2020 by null

[NickNonsense]

The 50 miles is what I would argue is a reasonable range for any modern EUC, I find myself fatiguing if I am riding continuously for this range, so would many others I believe and would have to stop and rest and with more electrical technology advances including the use of electrical cars, you have more stations popping up and with the advancement of quick charge technology do you really need a +100 mile range EUC in the future if you can easily charge it when you become fatigued

If I am on my EUC, it is for a leisurely ride or a small town, city commute. I am not on my EUC to go out on cross county adventures or for shopping in a city that is a 3hr commute away. I find for those distances or scenario then there other, more appropriate modes of transport.

The point I was trying to make is build a wheel that can do these specifications easily, a wheel that has vastly over the top specs that is listed in order for it to comfortable achieve those safe and reasonable specifications. So that the wheel is never at its limits and therefore is not at risk of cutting out.

I don’t take the stance that all EUCs should be like this, but to see EUCs as a viable mode of transport in the future this should be food for thought for manufactures if they wish to continue in the foreseeable future, all it takes is an legislation to outright ban these and hard enforcement upholding this and much like what we seen with the hoverboards and then that’s this business fizzling to nothing.  

I feel we are on borrowed time with this hobby.

Edited October 14, 2020 by NickNonsense

[Rawnei]

1 hour ago, NickNonsense said:

The 50 miles is what I would argue is a reasonable range for any modern EUC, I find myself fatiguing if I am riding continuously for this range, so would many others I believe and would have to stop and rest and with more electrical technology advances including the use of electrical cars, you have more stations popping up and with the advancement of quick charge technology do you really need a +100 mile range EUC in the future if you can easily charge it when you become fatigued

If I am on my EUC, it is for a leisurely ride or a small town, city commute. I am not on my EUC to go out on cross county adventures or for shopping in a city that is a 3hr commute away. I find for those distances or scenario then there other, more appropriate modes of transport.

The point I was trying to make is build a wheel that can do these specifications easily, a wheel that has vastly over the top specs that is listed in order for it to comfortable achieve those safe and reasonable specifications. So that the wheel is never at its limits and therefore is not at risk of cutting out.

I don’t take the stance that all EUCs should be like this, but to see EUCs as a viable mode of transport in the future this should be food for thought for manufactures if they wish to continue in the foreseeable future, all it takes is an legislation to outright ban these and hard enforcement upholding this and much like what we seen with the hoverboards and then that’s this business fizzling to nothing.  

I feel we are on borrowed time with this hobby.

Cutoffs aside, you're making a whole lot of assumptions about riding here, some people might go on forever riding without fatigue it's individual, a lot of people ride seated which is much more comfortable, also you're thinking a one way continuous trip, just because you have the range doesn't mean you just blast from A to B for as long as your battery lasts, higher capacity opens up more possibilities, like cruising around various destinations all day without having to think about battery.

[Altaire.]

On 10/11/2020 at 10:30 PM, meepmeepmayer said:

"Realistically" being the key word here: that's mostly what is happening now, at least from the spec side. Big batteries, powerful and well-designed motors.

Now the quality and reliability/size of the electronic components is another thing... even though everything works very reliably, it could be much better and more trustworthy designed.

There are some hard limits, though, mostly battery size and therefore weight, that will limit how powerful a EUC can be, especially small and light ones. A V5F-like wheel with high speed and massive amounts of power will not happen before a serious technological breakthrough (like 10x better batteries).

And electric motors have an inherent top speed, which means you can overpower any EUC just by going fast enough because it gets weaker (approaching zero torque) when approaching this limit speed. That will never change unless someone has a clever idea how to circumvent that.

But overwhelming a big battery, fast wheel other than going too fast is pretty hard already. 99% of no-external-cause crashes seem to be just people going too fast (and accelerating too hard at speed) for the wheel they have and overleaning it.

So wait, the faster you go the more power it takes? That seems counterintuitive because id imagine it took more power to accelerate than it does to just maintain a speed

[meepmeepmayer]

1 hour ago, Altaire. said:

So wait, the faster you go the more power it takes? That seems counterintuitive because id imagine it took more power to accelerate than it does to just maintain a speed

It's complicated. Power isn't the main issue if you want a wheel you cannot easily overlean and crash. Torque is. The faster you go, the less torque is in reserve. No torque left means you crash on the next tiny bump. You don't want to run out of torque.

Two basic facts:

• A given electric motor has a max speed. You have maximum torque at speed zero, and it goes down linearly to zero torque at the max speed.
• Torque is proportional to current. More current means your zero-speed torque is higher, and that the torque-over-speed curve falls steeper towards zero torque at the the same max speed of your motor.

The first means you want to be far below the motor max speed so you have enough torque reserves if a sudden bump etc. comes along. In other words, you want a fast wheel so you're riding far below its speed limit.

The second means you need a "big" battery if you want a "strong" wheel that you can't easily overlean at lower speeds (every wheel can be overleaned with no effort at the motor's max speed). "Big" battery here precisely means "a lot of parallel blocks of battery cells", because current grows with how many parallel blocks you have.

Now there's another trick in the book to make more "powerful" and faster wheels: increase the voltage. Higher voltage means a higher max speed on the same motor (no loss in low end torque!), and because power = voltage * current, it means an overall more powerful wheel.

That's why wheels went from lower voltages (67.2V) to higher voltages (100.8V), to allow for faster wheels that weren't super lethargic at lower speeds (little torque) and accelerated nicely.

(Also, when you design a motor, it's a balance between max torque and max speed. You lose one, you gain the other.)

I felt like making a quick diagram to make things more confusing (click 4 big)

So TLDR: voltage = speed, current = torque, and manufacturers improved these by increasing voltages and battery sizes. So a fast and big battery wheel is what is "required" to have a wheel that isn't easy to overlean. Because you don't want to run out of torque.

1 hour ago, Altaire. said:

So wait, the faster you go the more power it takes? That seems counterintuitive because id imagine it took more power to accelerate than it does to just maintain a speed

If we look at actual power instead of torque, the main power draw in riding is wind resistance. And that grows nastily with speed. So you need more power the faster you go. You get less range the faster you go.

-

Maybe it's helpful to think about it like this:

Power matters mostly when you are riding at a constant speed.

Torque matters mostly when you are accelerating. This includes a sudden acceleration the wheel has to do when you hit a bump. Your outwards speed may stay the same, but the wheel has to speed up to catch you after the bump. If you run out of torque, that's an overlean (I'm trying not to use the word "overpower" because "power" is in there, but torque is what matters) and you crash.

Of course these two (power and torque) aren't separate, but connected in various ways, but this is a reasonable approximation (I hope... I'm no expert, just trying to make sense of these contraptions we ride).

[Altaire.]

On 10/22/2020 at 7:51 PM, meepmeepmayer said:

It's complicated. Power isn't the main issue if you want a wheel you cannot easily overlean and crash. Torque is. The faster you go, the less torque is in reserve. No torque left means you crash on the next tiny bump. You don't want to run out of torque.

Two basic facts:

• A given electric motor has a max speed. You have maximum torque at speed zero, and it goes down linearly to zero torque at the max speed.
• Torque is proportional to current. More current means your zero-speed torque is higher, and that the torque-over-speed curve falls steeper towards zero torque at the the same max speed of your motor.

The first means you want to be far below the motor max speed so you have enough torque reserves if a sudden bump etc. comes along. In other words, you want a fast wheel so you're riding far below its speed limit.

The second means you need a "big" battery if you want a "strong" wheel that you can't easily overlean at lower speeds (every wheel can be overleaned with no effort at the motor's max speed). "Big" battery here precisely means "a lot of parallel blocks of battery cells", because current grows with how many parallel blocks you have.

Now there's another trick in the book to make more "powerful" and faster wheels: increase the voltage. Higher voltage means a higher max speed on the same motor (no loss in low end torque!), and because power = voltage * current, it means an overall more powerful wheel.

That's why wheels went from lower voltages (67.2V) to higher voltages (100.8V), to allow for faster wheels that weren't super lethargic at lower speeds (little torque) and accelerated nicely.

(Also, when you design a motor, it's a balance between max torque and max speed. You lose one, you gain the other.)

I felt like making a quick diagram to make things more confusing (click 4 big)

So TLDR: voltage = speed, current = torque, and manufacturers improved these by increasing voltages and battery sizes. So a fast and big battery wheel is what is "required" to have a wheel that isn't easy to overlean. Because you don't want to run out of torque.

If we look at actual power instead of torque, the main power draw in riding is wind resistance. And that grows nastily with speed. So you need more power the faster you go. You get less range the faster you go.

-

Maybe it's helpful to think about it like this:

Power matters mostly when you are riding at a constant speed.

Torque matters mostly when you are accelerating. This includes a sudden acceleration the wheel has to do when you hit a bump. Your outwards speed may stay the same, but the wheel has to speed up to catch you after the bump. If you run out of torque, that's an overlean (I'm trying not to use the word "overpower" because "power" is in there, but torque is what matters) and you crash.

Of course these two (power and torque) aren't separate, but connected in various ways, but this is a reasonable approximation (I hope... I'm no expert, just trying to make sense of these contraptions we ride).

Thanks, i still am finding it hard to grasp what exactly torque is in a practical sense or as a concept. I understand what effect you're saying it has relative to the unicycle though.

 

[mrelwood]

EDIT: Dear reader, you may skip this post and jump to the next one. At least@Planemo knows what he’s talking about... (Although, the magic figure he talks about only applies to imperial values.)

 

4 hours ago, Altaire. said:

Thanks, i still am finding it hard to grasp what exactly torque is in a practical sense or as a concept.

My English for math and physics is a bit spotty, but in my language torque is “the amount of rotational force”. I do have hard time following meep’s though of it being separate from “power”. What the motor does is to turn electrical power into rotational force, ie torque.

 If you tighten a bolt, the force you do it with is torque. If you’re tired or your tool is lousy, you apply less torque. Eat a banana and get a proper tool and you can provide more torque to the bolt.

I often think of the torque of the EUC as the amount of power I’d be able to utilize with a bicycle. If I’m low on energy, I can’t pedal as fast, and only up a shallow hill without slowing down. If the EUC battery is low, that’s how I ride, I slow down in situations my bicycle would slow down as well.

Edited October 24, 2020 by mrelwood

[Planemo]

49 minutes ago, Altaire. said:

Thanks, i still am finding it hard to grasp what exactly torque is in a practical sense or as a concept. I understand what effect you're saying it has relative to the unicycle though.

 

Torque is actually far simpler to understand than power, it's just that we have been conditioned to think that power is the primary event when actually it isn't, Torque is. It's simply the twisting force available. Power is calculated by adding nothing more than a multiplier to the torque figure, usually RPM, then dividing by the magic figure of 5252.

For example, my old car made 650lb/ft of torque at 6250rpm. The torque figure is actually whats being read by ANY dyno, not power. The Dyno software then applies the calculation (650lb/ft x 6250 / 5252 and bingo you have your power figure of 773hp.

This is the difference between torque and power - power is a sub calculation involving a time event. Torque is your raw data.

[Planemo]

4 hours ago, mrelwood said:

EDIT: Dear reader, you may skip this post and jump to the next one. At least@Planemo knows what he’s talking about...

Haha not quite! But I have spent a fair bit of time on dynos.

4 hours ago, mrelwood said:

(Although, the magic figure he talks about only applies to imperial values.)

OK to keep things easy for you Europeans just add 1.4% to your HP figure to obtain PS. It will be near enough