[one more GOTWAY WARNING] ACM died on a hill (it was bad cabling + high stress, final update pg 16)

[steve454]

13 minutes ago, Marty Backe said:

Yes, I understand why the fuse is there. But I return to my point that it's a cheap solution. Power electronics can be designed to withstand over-current without the need of a mechanical fuse. But it takes extra brain cycles to arrive at that solution (and a few additional parts), so they took the path of least resistance and threw some fuses in there.

I fear taking my KS14C to any remote areas because a deeply embedded fuse might blow because I overload the wheel a little. If they are going to use fuses, at least use re-settable ones that can be accessed without any tools.

It still boils down to not blowing fuses, not shutting off ever, only failing if the weight is too much to balance, and that happens so fast the wheel can't keep up.  And that is the fault of the too aggressive rider.

[steve454]

4 minutes ago, Rehab1 said:

hey wear the brace until growth terminates.

She was 16!  Why make her taller?  Oh, I know, basketball coach,right?

[US69]

22 minutes ago, meepmeepmayer said:

I'm really liking @KingSong69's theory atm that it's the motor connectors plus an additional short from that, it would explain everything and it would be an issue under control. Will open as soon as possible and check.

i dont think that you will like the outcome...if this really happened.

Because then your board is destroyed and you will be some days without driving :-(

@Marty Backe

i dont know...sure a fuse is a cheap solution...but it is one!

and this Fuse does not blow on easy beasy situation...An example would be a wheel, that you stuck into mud or against a wall and force it to "run" but in no way it can: there have been several reports of burned boards on GW, when wheel is stuck.

On a KS there is burning a fuse....that even is a solution...

I have brought my Ks14 and 18 to situations on extrem hills where the wheel didnt even have the strenght to go higher and even there the Fuse did not blow...so it doesnt blow because of a little overload

 

Gw:

But this Forum at all lives from different opinions :-)

[Hunka Hunka Burning Love]

20 minutes ago, Rehab1 said:

A bit off topic but @Hunka Hunka Burning Love does it all of the time 

Heeey I'm just multitasking my thoughts, and they spill out quite easily.    No need to finger point.  I can't help it if conventional forum threads aren't designed for multi-tasking brainy ideas!  This linear threading is so 80's.    How can I derail a thread if my server doesn't even have rails?  

I think we're just killing time waiting on @meepmeepmayer to get a roadrunner speed reply from Ian so we can see who wins the bet of MOSFETs versus wire disconnection.  Maybe he just needs to open the side panel and video it to kill the suspense!  I'm sure Ian will probably ask him to do that in any case to take photos.

[Marty Backe]

3 minutes ago, Hunka Hunka Burning Love said:

<snip>

I think we're just killing time waiting on @meepmeepmayer to get a roadrunner speed reply from Ian so we can see who wins the bet of MOSFETs versus wire disconnection.  Maybe he just needs to open the side panel and video tape it to kill the suspense!  I'm sure Ian will probably ask him to do that in any case to take photos.

I know. I wonder if @meepmeepmayer realizes that there's a whole army out here just waiting for his report of what happened inside the wheel. 

[US69]

@Marty Backe

i forgot to say that i would like better solution, also :-) No fuse, or a "setback" fuse, or unlimited power boards....

Or Gotway wheels with qualitycontrol and testing(ironic) :-)

@all

to hijack this thread completly:

first v3s+ with original GW black sidepanels has been sighted :-) :

https://www.facebook.com/linnea.lin.14/posts/1918410931769522

 

[Marty Backe]

10 minutes ago, KingSong69 said:

i dont think that you will like the outcome...if this really happened.

Because then your board is destroyed and you will be some days without driving :-(

@Marty Backe

i dont know...sure a fuse is a cheap solution...but it is one!

and this Fuse does not blow on easy beasy situation...An example would be a wheel, that you stuck into mud or against a wall and force it to "run" but in no way it can: there have been several reports of burned boards on GW, when wheel is stuck.

On a KS there is burning a fuse....that even is a solution...

I have brought my Ks14 and 18 to situations on extrem hills where the wheel didnt even have the strenght to go higher and even there the Fuse did not blow...so it doesnt blow because of a little overload

 

Gw:

But this Forum at all lives from different opinions :-)

Yep, saw that video. Just to be clear, I think Gotway's solution of letting the board go up smoke is crap too. It does not take bleeding edge electronics design to arrive at a solution that does not require a mechanical fuse and gracefully shuts down the power electronics.

@jrkline had his 14C blow a fuse as he was climbing a steep hill. I was there - put a real damper on the rest of the day.

[esaj]

18 minutes ago, Marty Backe said:

Yes, I understand why the fuse is there. But I return to my point that it's a cheap solution. Power electronics can be designed to withstand over-current without the need of a mechanical fuse. But it takes extra brain cycles to arrive at that solution (and a few additional parts), so they took the path of least resistance and threw some fuses in there.

Basically, it is a cheap solution. I believe it's a combination of many things, like keeping the PCB/component costs down, wide tolerances of the mosfets, large differences in the rider weights and climates, as well as the demand for more and more powerful wheels... going higher in voltage (as they've done, by going up to 84V systems), they could lower the currents (or just produce more power), but going even higher could make the wheels downright dangerous (like they weren't already to begin with , but in the sense that with high enough voltage you could get lethal shocks from the electronics), as well as make other parts of the circuitry more complex / damage prone (for example the microcontrollers running the wheels use 3.3V, that's quite a drop from up to 84V). But I don't really know, I'm just an amateur when it comes to this stuff.

I've been thinking why Uniwheel (the UK designed electric unicycle), which was announced late 2015, still hasn't debuted. My guess would be that they've run into unexpected problems making the wheel reliable enough, even though it seems they have very talented people working on it.

 

Quote

I fear taking my KS14C to any remote areas because a deeply embedded fuse might blow because I overload the wheel a little. If they are going to use fuses, at least use re-settable ones that can be accessed without any tools.

I don't think resettable (assuming you meant temperature-based self-resetting PTC/polymer) fuses aren't available in large enough voltage/current ratings for this use. I don't know how high currents you can use with the kind that you find in modern house electric systems, but there the currents are much lower due to high voltage... for example, this house has 230V RMS system with 3 phases, each behind a separate 35A "regular" mains fuse, despite the (relatively) low current, it can provide up to 3 * 35A * 230V  = about 24kW of power. The largest resettable 230V -mains fuses go up to 16A, I think, but in industrial usage there might be much larger ones available too (but they might be physically too large to use in a wheel?).

So, the fuse -solution is a bit of double-edged sword, on the other hand, should it burn, you "only" need to open up the wheel and replace it (after, possibly, eating some dirt and maybe breaking a few bones... ), instead of replacing the entire mainboard. On the other hand, if the fuse isn't rated high enough/burns too easily, you might end up eating dirt when it really wasn't necessary. 

I'm just drunk and blabbering, nevermind me... 

[Rehab1]

1 hour ago, KingSong69 said:

@Rehab1 Btw.: why you want to see the motor and screw the wheel completly open?

I thought you only want to visit the board?

It has become my little Mount Everest... complete the task at hand. My secondary reason: If I ever had to change the tire I would like to learn how to access the area without using a crowbar. 

8 minutes ago, Hunka Hunka Burning Love said:

Heeey I'm just multitasking my thoughts, and they spill out quite easily.    

Someone else comes to mind

 

[Marty Backe]

2 minutes ago, KingSong69 said:

@Marty Backe

i forgot to say that i would like better solution, also :-) No fuse, or a "setback" fuse, or unlimited power boards....

Or Gotway wheels with qualitycontrol and testing(ironic) :-)

@all

to hijack this thread completly:

first v3s+ with original GW black sidepanels has been sighted :-) :

https://www.facebook.com/linnea.lin.14/posts/1918410931769522

 

Nice segue. I had seen that earlier and was wondering what was special about the picture. Didn't realize that it was a V3s+

[meepmeepmayer]

You do realize this is all an elaborate piece of performance art/lame trolling? Come Monday (what the hell, Tuesday) I'm going to say Ian has allowed me to open the wheel, but unfortunately I have to go on a 2 week trip just before I can do that. I already wrote the "you won't believe what I found" thread for after the "trip", but it's complicated and my camera broke and I'm being irritatingly ambiguous in describing the issue and so on... this can go on for a long time, "do your wheels also have this <made up engineering quirk>" -  I have a lot of ideas

Offtopic: a fuse is not a solution if it decides for the wheel's health instead of the rider's health. Literally no other means of motorized transport would even do such a thing. Stuff should simply be monitored and warn you when it gets into dangerous territory instead of letting you go on. How hard can it be to monitor a current, have a bigger wire that can be overloaded for at least a few seconds, time enough for beeping and tiltback until you stop?

[Rehab1]

@Linnea Lin Gotway It appears you are currently signed on to the forum. Please either comment on this topic or share our deep concerns with Gotway management. Thank you

Question: Why does a representative  from Gotway refuse to engage in forum topics concerning the health and safety of consumers that use their products?

Update: @Linnea Lin Gotway has signed off without comment!

[esaj]

16 minutes ago, meepmeepmayer said:

You do realize this is all an elaborate piece of performance art/lame trolling? Come Monday (what the hell, Tuesday) I'm going to say Ian has allowed me to open the wheel, but unfortunately I have to go on a 2 week trip just before I can do that. I already wrote the "you won't believe what I found" thread for after the "trip", but it's complicated and my camera broke and I'm being irritatingly ambiguous in describing the issue and so on... this can go on for a long time, "do your wheels also have this <made up engineering quirk>" -  I have a lot of ideas

You mean your flux capacitor is out of whack too? I tried to replace mine with a fresh one of the replicator, but after cutting the shell open with a lightsaber, my sonic screwdriver just quit on me...

 

16 minutes ago, meepmeepmayer said:

Offtopic: a fuse is not a solution if it decides for the wheel's health instead of the rider's health. Literally no other means of motorized transport would even do such a thing.

Preferably, if it's really a matter between faceplanting and having a fried mainboard, or "just" faceplanting, I pick the latter.  But yeah, it could blow for no real reason too. Also, comparing unicycles to other types of transports (like cars or motorcycles) is a bit hard due to the requirement of self-balancing. You can still stop a car or motorcycle relatively safely if the engine turns off or catches fire

 

16 minutes ago, meepmeepmayer said:

Stuff should simply be monitored and warn you when it gets into dangerous territory instead of letting you go on. How hard can it be to monitor a current, have a bigger wire that can be overloaded for at least a few seconds, time enough for beeping and tiltback until you stop?

Not that long ago, people were rejoicing because apparently newer KS firmware allows them to ride at faster speeds with more depleted batteries. Waiting for the wave of reports of people faceplanting with low batteries, as a result of too much speed at too low voltage and the battery quitting on them... Well, hopefully not   But if really forced to choose between higher risk and lower top speed/lower range, which way would you lean?   "Here's our new wheel, it will never fail, but it can go max 10km/h for about 5 kilometers..."      But realistically, probably a lot more can be still done to improve the safety of current wheels...

[Linnea Veteran]

Hi @meepmeepmayer,  your wheel should burnt the mosfets, not the problem of cables. Since the end of November, 2016, we changed the cable connectors. There are only some Msuper V3 1600wh models has such problems. ACM 1300wh/1600wh and Monster were began to make after we changed the new connectors. I enclosed the pictures of both connectors. We use cold pressing technology to avoid the cables slip off again when the high tempreture melted the tin solders. Your wheel should be burn the mosfets as you keep climbing the moutains, the high temperature make the mosfets burn. Please check it with your seller to change the mainboard. 

[meepmeepmayer]

Ok, thank you! My wheel is from December 2016, so it should have the new connectors then.

We will see what really happened once I can open the wheel.

[Marty Backe]

56 minutes ago, Linnea Lin Gotway said:

Hi @meepmeepmayer,  your wheel should burnt the mosfets, not the problem of cables. Since the end of November, 2016, we changed the cable connectors. There are only some Msuper V3 1600wh models has such problems. ACM 1300wh/1600wh and Monster were began to make after we changed the new connectors. I enclosed the pictures of both connectors. We use cold pressing technology to avoid the cables slip off again when the high tempreture melted the tin solders. Your wheel should be burn the mosfets as you keep climbing the moutains, the high temperature make the mosfets burn. Please check it with your seller to change the mainboard. 

Well @Rehab1 (and everyone else), this should make you feel good about your ACM. Unless I'm not reading this properly, all 84v ACM's and Monster's have the new connectors.

Assuming @meepmeepmayer's failure is from the mosfets I've learned an important lesson. Don't ride 20 degree slopes for extended periods. Fortunately all of my steep hill climbing is only for short spurts (< minute)

[Xima Lhotz]

6 hours ago, Marty Backe said:

 Don't ride 20 degree slopes for extended periods. 

My thinking in this (or any situation where you ride a wheel) is that you should never have to think about the wheel. 

The wheel should tell the rider if there is a problem with the way you are riding.

For a hill situation it's so simple (in my head) :-) 

If heat or current is over a limit then reduce power + tilt back+beep forcing a stop. (I'm good time, not just before failure)

This is the only solution for (almost) every situation where a possible danger is exposed to the wheel due to rider.

With this in mind I can't believe than any failure would happen (if done right ofcourse)

Only thing left is steep downhill slopes bit i think a "auto break" function combine with nine bots " shaking" alert could be implemented to solve this problem.

This is how I would like all wheels to be safety wise.

[Xima Lhotz]

9 hours ago, Linnea Lin Gotway said:

Your wheel should be burn the mosfets as you keep climbing the moutains, the high temperature make the mosfets burn

I guess this might be "Your wheel could burn mosfets".

But even so, if the temperature is to high then: tilt back forcing a stop (before critical temp)

If not done this way it puts every hill and safety decision in the riders mind, not knowing "Is this the hill where the wheel might fail?" It might not even be the same hills, it might be a really warm day outside so the hill where you normally go is now too steep.

Well, I think Gotway are doing great wheels (I've looked at an acm for a while now) but in general with all wheels, safety should always be in the hands of the wheel and not the rider, I think.

 

[esaj]

3 hours ago, Xima Lhotz said:

My thinking in this (or any situation where you ride a wheel) is that you should never have to think about the wheel. 

The wheel should tell the rider if there is a problem with the way you are riding.

For a hill situation it's so simple (in my head) :-) 

If heat or current is over a limit then reduce power + tilt back+beep forcing a stop. (I'm good time, not just before failure)

This is the only solution for (almost) every situation where a possible danger is exposed to the wheel due to rider.

With this in mind I can't believe than any failure would happen (if done right ofcourse)

Only thing left is steep downhill slopes bit i think a "auto break" function combine with nine bots " shaking" alert could be implemented to solve this problem.

This is how I would like all wheels to be safety wise.

 

2 hours ago, Xima Lhotz said:

I guess this might be "Your wheel could burn mosfets".

But even so, if the temperature is to high then: tilt back forcing a stop (before critical temp)

If not done this way it puts every hill and safety decision in the riders mind, not knowing "Is this the hill where the wheel might fail?" It might not even be the same hills, it might be a really warm day outside so the hill where you normally go is now too steep.

Well, I think Gotway are doing great wheels (I've looked at an acm for a while now) but in general with all wheels, safety should always be in the hands of the wheel and not the rider, I think.

 

My suspicion is that the temperature sensor is either inside the gyro- or the microcontroller-chip, which is too far away to sense faster temperature rise in the mosfets/heatsink to warn you in time. Basically it's more like sensing the air temperature inside the mainboard enclosure, and that will take a lot of time to go up compared to how fast the mosfets heat up...  A separate sensor in direct contact with the heatsink would probably work better.

[Rehab1]

11 hours ago, Marty Backe said:

Well @Rehab1 (and everyone else), this should make you feel good about your ACM. Unless I'm not reading this properly, all 84v ACM's and Monster's have the new connectors

It does heighten my confidence but why can't this important information and other pressing safety updates be formally posted on Gotway's website so owners have immediate access?

My 2 cents ( slight blowing of steam): 

We, as a revered EUC group, should not have to beg and plead for answers to our concerning questions? Owners of Gotway models, (or any other brand) have literally become non-paid surrogate representatives of these company's where forum members are forced to perform both R&D and product fault analysis on their wheels without having access to detailed specs or product information about critical updates that have been implemented at the factory! 

Question: Were any EUC members notified of the Gotway improved connector modifications prior to last night? Not that I am aware of! What prompted Gotway to initiate the modification? Hopefully it was Gotway representatives watching our forum and listening to member's concerns!

We simply deserve more! A weekly or even monthly exchange of information is not that much to ask from company reps! If a critical modification is implemented at the factory please tell us!! Provide information on where to the purchase the improved parts ( in this case electrical connectors) and how to perform the modification including disassembly of the wheel.

This is simple customer service 101 that would go along way to enhance Gotway consumer confidence and reduce presentiment. An added benefit would be increased sales which would be advantageous for both parties!

[US69]

i am still not convinced that this was a "pure" mosfets failure...

To all who are a bit in electrical connections: a "cold press"- crimped connector is able to give a much higher resistance to the connection...what in result means, that even more heat is produced there. 

but we will have to wait till the wheel is open :-)

 

Also: Linnea stating that this failure "only" happens to "some" 84 Volt Msuper, THIS has been the mosfets...is pure sarcasm...and questionable at least!

We have undeniable proof here in the original thread that some 67volt Msupers also failed..melted connectors/shorts etc etc...

On the french forum, there are also documented ACM and Monster failures (which btw. was commented by GW France " only first batch of monsters :-) )....

Then i think: Even IF it was not the connection anymore....is it any better, that then instead the Mosfet blows when much torque is needed for a certain time? As far as i now the Acm was not used out of its "flight envelope"....

 

but maybe it makes me just sick of hearing of one fault after the other....connection, mosfets, pedals.....yeah, pedals?!, any Gotway statement here? It really, really is time for the competition to give us some alternatives!

[Marty Backe]

2 hours ago, esaj said:

 

My suspicion is that the temperature sensor is either inside the gyro- or the microcontroller-chip, which is too far away to sense faster temperature rise in the mosfets/heatsink to warn you in time. Basically it's more like sensing the air temperature inside the mainboard enclosure, and that will take a lot of time to go up compared to how fast the mosfets heat up...  A separate sensor in direct contact with the heatsink would probably work better.

I agree, this makes sense to me because I thought that's the reason the wheels stop if the temperature exceeds 79c (for Gotway's), to protect the mosfets.

When I'm being aggressive with the wheel (going up steep/rough hills) I'm monitoring the temperature. Now I know that if I see the temperature start to steadily rise, pull over and give the wheel a few minute rest.

[Marty Backe]

1 hour ago, Rehab1 said:

It does heighten my confidence but why can't this important information and other pressing safety updates be formally posted on Gotway's website so owners have immediate access?

My 2 cents ( slight blowing of steam): 

We, as a revered EUC group, should not have to beg and plead for answers to our concerning questions? Owners of Gotway models, (or any other brand) have literally become non-paid surrogate representatives of these company's where forum members perform both R&D and product fault analysis on their products without having access to detailed specs or information about critical updates that have been implemented at the factory! 

Question: Were any EUC members notified of the Gotway improved connector modifications prior to last night? Not that I am aware of! What prompted Gotway to initiate the modification? Hopefully it was Gotway representatives watching our forum and listening to member's concerns!

We simply deserve more! A weekly or even monthly exchange of information is not that much to ask from company reps! If a critical modification is implemented at the factory please tell us!! Provide information on where to the purchase the improved parts ( in this case electrical connectors) and how to perform the modification including disassembly of the wheel.

This is simple customer service 101 that would go along way to enhance Gotway consumer confidence and reduce presentiment. An added benefit would be increased sales which would be advantageous for both parties!

Well said, and I agree. Then again this is nothing new with the Chinese wheels and I don't expect anything to really change until they have a western branch office established. I have my doubts whether that will ever happen. Yet we are still early in the game - how long has Gotway been producing wheels. If they continue to be successful you have to believe they will mature and maybe 5 years from now the communications will look substantially different. Let us hope.

In the mean time I'm feeling really good about my ACM and Monster. Yeah.

[Marty Backe]

13 minutes ago, KingSong69 said:

<snip>

Also: Linnea stating that this failure "only" happens to a "some" 84 Volt Msuper, THIS has been the mosfets...is pure sarcasm...and questionable at least!

We have undeniable proof here in the original thread that some 67volt Msupers also failed..melted connectors/shorts etc etc...

<snip>

The way I read this was, the 84 volt wheels were being addressed by the comment, and there are some MSuper V3s/s+ wheels that have the old style. I assume all the 67v wheels have the potential problem.

[houseofjob]

1 minute ago, Marty Backe said:

The way I read this was, the 84 volt wheels were being addressed by the comment, and there are some MSuper V3s/s+ wheels that have the old style. I assume all the 67v wheels have the potential problem.

The way I read this was, believe nothing, open up your Gotway and check against the pictures!