Ninebot One Z : Z6-Z8-Z10

[Vikas]

6 hours ago, esaj said:

Hardly, there are real electronics engineers in these forums that would run laps around me and could likely point out a gazillion mistakes in my logic and designs     But this is getting really off-topic, so let's stick to the Ninebot Z's.

Well that's very humble of you. You are a stellar individual with a crackling personality indeed ?.

 And Yes you are absolutely right esaj we must stick to the ninebot Z topic.

Edited June 30, 2018 by Vikas

[esaj]

15 hours ago, nte said:

The three metal pieces where the motor phase wires attach to - are they attached to the board using surface mounting techniques? If so, how will this handle heat compared to the "thru hole" soldered wires?

It comes down to the surface area touching the board, with wires through holes and soldered to the board, it's harder to say, depending how the wire is placed and how much solder there is. For those "SMD"-pieces, the result is more consistent, but the screws holding the connector in place should be screwed pretty tight. The connection is likely somewhere in the milliohm or fraction of that range, so I don't think it's an issue either way.

[esaj]

13 hours ago, fryman said:

So, the theory that a higher voltage wheel (84 vs 51.8 Z10) is better; is not true?

 

12 hours ago, mrelwood said:

Nothing is that simple. Voltage is just one part of the equation. It is easier and cheaper to make a high powered wheel operate at a higher voltage, but saying one is better than the other is a bit like saying that blue is better than red.

 

(It’s not. Red is better. )

It depends, using higher voltage, less current is needed to transfer the same amount of power (power equals current times voltage). Electric cars use 400V (I think, there might be other voltages, but they're still likely hundreds of volts), because they need to transfer much higher power to the motors than EUCs. Big transfer lines from power plants use 400kV RMS here (400000 volts), otherwise they'd need to use very high current, which would lead to huge power losses (and maybe wires melting ).

Whether it's cheaper/better to build a high-power wheel with higher voltage, again there are tradeoffs. Mosfets capable of withstanding higher voltages usually have higher internal resistances. Higher voltage step-down circuitry needs to be used in the mainboards to power the MCU and other low-voltage (3.3V usually) parts, and usually the higher voltage versions of the parts needed are more costly and larger, but then they can cheap out on the wiring diameters and connectors etc. don't need to withstand as high currents.

For a (more or less) constant resistance in the connector, the voltage drop with same current stays the same, but with higher voltage, not as much current is needed. If a connector would have, say, 0.5 milliohm (0.0005 ohms) resistance, pushing 40A through it would cause a voltage drop of

U = R*I   =>   U = 0.0005 Ohm * 40A = 0.02V or 20 millivolts.

The power loss in the connector is 

P = U*I  =>  P = 0.02V * 40A = 0.8W

It could also be calculated directly from the connector resistance and current without calculating the voltage drop in between:

U = R*I,  P = U*I,  substitute the equation for U into P = U*I  =>   P = (R*I)*I   <=>  P = R*I²

So, for the same current, the voltage drop and power loss in the connector is the same, but, when using higher voltage, not as much current is needed to transfer the same amount of power.

Using nominal 60V (for 16S), the power would be around

P = 60V * 40A = 2400W

With 74V nominal (for 20S), the power with 40A would already be higher:

P = 74V * 40A = 2960W

To transfer 2400W with 74 volts, current needs to be

I = P/U  =>  2400W / 74V = 32.432432... A

Now, the power loss (and voltage drop) in the connector with the same 0.5 milliohm resistance is

P = 0.0005 Ohm * 32.432432² A = 0,52593... W  (vs. 0.8W for 60V)

So the connectors (and wiring etc. resistive parts in the circuit) don't heat up as much with higher voltage for the same power, as the current needed for same power is lower. That's why connectors are rated by maximum current. There's also a voltage-rating for the connectors with 2 or more pins, with high enough voltage the connector might arc over (ie. the electricity "jumps" between the pins), but they're usually rated for a several hundred volts or over 1000V, so hardly an issue with the wheel voltages.

 

Edited June 30, 2018 by esaj

[Scatcat]

On 6/30/2018 at 12:22 PM, esaj said:

 

It depends, using higher voltage, less current is needed to transfer the same amount of power (power equals current times voltage). Electric cars use 400V (I think, there might be other voltages, but they're still likely hundreds of volts), because they need to transfer much higher power to the motors than EUCs. Big transfer lines from power plants use 400kV RMS here (400000 volts), otherwise they'd need to use very high current, which would lead to huge power losses (and maybe wires melting ).

Whether it's cheaper/better to build a high-power wheel with higher voltage, again there are tradeoffs. Mosfets capable of withstanding higher voltages usually have higher internal resistances. Higher voltage step-down circuitry needs to be used in the mainboards to power the MCU and other low-voltage (3.3V usually) parts, and usually the higher voltage versions of the parts needed are more costly and larger, but then they can cheap out on the wiring diameters and connectors etc. don't need to withstand as high currents.

For a (more or less) constant resistance in the connector, the voltage drop with same current stays the same, but with higher voltage, not as much current is needed. If a connector would have, say, 0.5 milliohm (0.0005 ohms) resistance, pushing 40A through it would cause a voltage drop of

U = R*I   =>   U = 0.0005 Ohm * 40A = 0.02V or 20 millivolts.

The power loss in the connector is 

P = U*I  =>  P = 0.02V * 40A = 0.8W

It could also be calculated directly from the connector resistance and current without calculating the voltage drop in between:

U = R*I,  P = U*I,  substitute the equation for U into P = U*I  =>   P = (R*I)*I   <=>  P = R*I²

So, for the same current, the voltage drop and power loss in the connector is the same, but, when using higher voltage, not as much current is needed to transfer the same amount of power.

Using nominal 60V (for 16S), the power would be around

P = 60V * 40A = 2400W

With 74V nominal (for 20S), the power with 40A would already be higher:

P = 74V * 40A = 2960W

To transfer 2400W with 74 volts, current needs to be

I = P/U  =>  2400W / 74V = 32.432432... A

Now, the power loss (and voltage drop) in the connector with the same 0.5 milliohm resistance is

P = 0.0005 Ohm * 32.432432² A = 0,52593... W  (vs. 0.8W for 60V)

So the connectors (and wiring etc. resistive parts in the circuit) don't heat up as much with higher voltage for the same power, as the current needed for same power is lower. That's why connectors are rated by maximum current. There's also a voltage-rating for the connectors with 2 or more pins, with high enough voltage the connector might arc over (ie. the electricity "jumps" between the pins), but they're usually rated for a several hundred volts or over 1000V, so hardly an issue with the wheel voltages.

 

I always read your walls of text with pleasure  

This is by far the most eloquent and clear explanation of the advantages/disadvantages of higher voltage. For me it pointed out a couple of things I had not thought about, the difference in resistance between parts rated for different currents, and the step down circuitry problem.

Higher voltage solutions to the power problem require more expensive parts. But given a good design, it has the potential of higher usable power with a lower power loss. That part seems pretty clear. I tend to think that in the end, the manufacturer that accepts the extra costs of high grade parts. The manufacturer that do their homework in electrical safety and thermal solutions, will earn back the extra costs and research in no time flat.

Consider a Gotway that made a 100V Monster where the thermal solution would easily, and with a temp margin, carry it to the top of Backes "Overheat Hill"...
Consider that at the same time it had margins of mechanical and electrical error (shafts, shims, wires and so on), as well as good internal design providing resistance to water and general ruggedness.
Even if they had to charge $3000 for it, it would probably sell pretty well.

Or to not deviate from the NBZ too much, consider a 100V NbZ10, with the parts and quality to match. That would be something.

Edited July 1, 2018 by Scatcat

[london ontario robert]

I ride a v8 .... in Canada and im 200lbs but my primary use is for golf the golf bag is another 70lbs  .This machine handles great...I carry the bag on my shoulder ..18 plus holes on a single charge.. When is the ninebot one z10 available to Canada

 

 

Edited July 2, 2018 by london ontario robert

[Keith]

3 hours ago, london ontario robert said:

I ride a v8 .... in Canada and im 200lbs but my primary use is for golf the golf bag is another 70lbs  .This machine handles great...I carry the bag on my shoulder ..18 plus holes on a single charge.. When is the ninebot one z10 available to Canada

@london ontario robert, welcome to the forum.

I cannot help you with when the Z10 will be available in Canada, but you have pointed out an excellent reason for its wide tyre. It will make it perfect for golf courses ?.

In fact I am kind of surprised that you haven’t had the golf course complain at the ruts a V8 will make with its thin tyre and nearly 300lbs weight on it (including the V8 itself!)

[Harold Farrenkopf]

4 hours ago, london ontario robert said:

I ride a v8 .... in Canada and im 200lbs but my primary use is for golf the golf bag is another 70lbs  .This machine handles great...I carry the bag on my shoulder ..18 plus holes on a single charge.. When is the ninebot one z10 available to Canada

 

 

Good luck waiting. I’m in Sarnia and wanted a Z10 since last year when I first saw it on the web.  Just couldn’t wait anymore because of the constant hitting the tilt back of my NB1 C+.  Bought a V10F from the USA. Where in Canada would you be buying a Z10 from? I couldn’t find anyone selling here. 

[Turbocharged]

I was trying to make the One Z turn better, naturally I pump up the tire pressure very high. It does improve responsiveness and agility, but it is very stiff, feel like riding on a rim painted black on the edge... Now I find my self enjoying a low pressure setting a lot more, I was curious about how the tire look with different level of pressure, and made this video.

 

[RoberAce]

Final versión with protections installed

[houseofjob]

@Turbocharged very interesting! 

May I ask what your rider weight is for reference?

Also, you don't feel the wheel pulls right & left too much at 25PSI? When I let out the air the most testing the Z, it pulled too much left and right and I was subconsciously fighting / correcting. I eventually settled at ~30 PSI, not the cushiest, but no artificial pull (I'm 175-180 lbs rider weight).

[Adel]

1 hour ago, RoberAce said:

Final versión with protections installed

@RoberAce can you please post more pictures especially.showing.the protection pads. Thanks.

[Turbocharged]

1 hour ago, houseofjob said:

@Turbocharged very interesting! 

May I ask what your rider weight is for reference?

Also, you don't feel the wheel pulls right & left too much at 25PSI? When I let out the air the most testing the Z, it pulled too much left and right and I was subconsciously fighting / correcting. I eventually settled at ~30 PSI, not the cushiest, but no artificial pull (I'm 175-180 lbs rider weight).

I weigh 82 kg (180 lb). At 25 psi, it’s significantly more difficult to turn at high speed, the wheel just wants to stay upright. Other than that, it’s quite good overall.

For better performance, opt for mid to high tire pressure. I’ll choose comfort over performance every time.Tubeless tire is just too stiff for my knees. Riding a 60 psi Z over brick surface is torturous.

[Marty Backe]

7 hours ago, Turbocharged said:

I was trying to make the One Z turn better, naturally I pump up the tire pressure very high. It does improve responsiveness and agility, but it is very stiff, feel like riding on a rim painted black on the edge... Now I find my self enjoying a low pressure setting a lot more, I was curious about how the tire look with different level of pressure, and made this video.

 

Fantastic video  

[Turbocharged]

3 hours ago, RoberAce said:

Final versión with protections installed

I remember you ordered a Z10, this look like a Z8 to me...

[RoberAce]

Hace 15 horas, Turbocharged dijo:

Recuerdo que ordenaste un Z10, este parece ser un Z8 para mí ...

No es mío, esta foto está tomada del foro chino de Ninebot. Todavía estoy esperando el mío

http://bbs.ninebot.cn/forum.php?mod=viewthread&amp;tid=164231&amp;extra=page%3D1

Edited July 4, 2018 by RoberAce

[Turbocharged]

20 hours ago, houseofjob said:

@Turbocharged very interesting! 

May I ask what your rider weight is for reference?

Also, you don't feel the wheel pulls right & left too much at 25PSI? When I let out the air the most testing the Z, it pulled too much left and right and I was subconsciously fighting / correcting. I eventually settled at ~30 PSI, not the cushiest, but no artificial pull (I'm 175-180 lbs rider weight).

I let more air out, drop the pressure to little above 20 psi, and I get what you mean by pulling left and right all the time, it is weird... pump it back to 28, and all is well again.

[houseofjob]

33 minutes ago, Turbocharged said:

I let more air out, drop the pressure to little above 20 psi, and I get what you mean by pulling left and right all the time, it is weird... pump it back to 28, and all is well again.

Yes, actually, when I first went below 30psi, I didn’t notice the pull until one of our NYC riders told me. (I was adjusting without realizing!)

[RoberAce]

could someone tell me what it is "Milk Waves"?  Chinese dudes say this frequently 

[Turbocharged]

15 hours ago, RoberAce said:

could someone tell me what it is "Milk Waves"?  Chinese dudes say this frequently 

If you can copy and paste the exact word in Chinese, I maybe able to tell you... "Milk Waves" does not make any sense to me 

[EUCMania]

"Milk Waves" is similar in sound in Chinese to "NineBot". It refereed to female breast shape. Civilized Chinese will not use it. 

[Scatcat]

On 7/4/2018 at 12:47 PM, houseofjob said:

Yes, actually, when I first went below 30psi, I didn’t notice the pull until one of our NYC riders told me. (I was adjusting without realizing!)

The pull is pretty easy to explain. I experienced it when I got a slow leak. When you lean a bit, the tyre gives, which amplifies the effect of leaning, which amplifies the give in the tyre and so on.

[houseofjob]

2 hours ago, Scatcat said:

The pull is pretty easy to explain. I experienced it when I got a slow leak. When you lean a bit, the tyre gives, which amplifies the effect of leaning, which amplifies the give in the tyre and so on.

Um, yes, I know the phenomenon ?

I was saying with everything new about the Z and focusing on how to improve th cushioning, I did not notice I was adjusting to the pull, subconsciously attributing it to the new experience.

[Esash]

I was a huge skeptic of the Z series, right up until seeing Chooch deflate the wheel and get a much better riding experience on it. Then he rode it on that little beach, and it did great. 

Now I'm thinking that a Z6 might be my next wheel, and the Z series might be the ultimate snow wheel. A lot of us live in arctic-like climates where there's snow on the ground 4-5 months a year.

I'm starting to think the Z series might be a real game changer for snowy/icy conditions. And because I don't like riding for more than 20-30 minutes when it's way below freezing, I'm thinking the Z6 will be just fine for me, and it should come at a great price too. Still getting the Z10 form factor and build quality, but for half the price and perfect for my winter around-town needs.

Can't wait to ride up and down the streets in the middle of a blizzard with 3+ inches of fresh snow on the streets.

[Scatcat]

On 7/6/2018 at 1:32 PM, houseofjob said:

Um, yes, I know the phenomenon ?

I was saying with everything new about the Z and focusing on how to improve th cushioning, I did not notice I was adjusting to the pull, subconsciously attributing it to the new experience.

Sorry for stating the obvious.  

[Turbocharged]

2 hours ago, Scouts Honor said:

I was a huge skeptic of the Z series, right up until seeing Chooch deflate the wheel and get a much better riding experience on it. Then he rode it on that little beach, and it did great. 

Now I'm thinking that a Z6 might be my next wheel, and the Z series might be the ultimate snow wheel. A lot of us live in arctic-like climates where there's snow on the ground 4-5 months a year.

I'm starting to think the Z series might be a real game changer for snowy/icy conditions. And because I don't like riding for more than 20-30 minutes when it's way below freezing, I'm thinking the Z6 will be just fine for me, and it should come at a great price too. Still getting the Z10 form factor and build quality, but for half the price and perfect for my winter around-town needs.

Can't wait to ride up and down the streets in the middle of a blizzard with 3+ inches of fresh snow on the streets.

I would not recommend a Z6 which has only a single battery, So it does not has the same safety redundancy as the dual battery system in a Z8/10. Also a Z6 is almost as heavy as a Z10 (23+ vs. 25),  The performance to weight ratio isn’t as good.

I love riding around on a One Z, but I have to admit it is not as smooth or comfortable as its competitors, some cases does not turn as well as its competitors, the performance isn’t much better in most scenarios if not worse... but the riding experience on a One Z is just so much different from any other wheel I have tried, totally unique! Consider the way I use EUCs, I should be better off choosing a V10F, but after I tested one for a few days,  I find myself bored very quickly.

Although I am seeing a lot of quick reviews giving praises to Z‘s performance. Personally I still consider the Z more as a fun wheel instead of a performance wheel. Like riding a Ducati Monster for years and now adding a Harley Davidson to your gaerage.

And anyway I think using an electric unicycle on snowy or icy environment is not a good idea...