(New) Gotway " Extreme Bull " Commander leaked datasheet

[That Guy]

Thank you for the clarification, @RagingGrandpa. 

[mrelwood]

21 minutes ago, That Guy said:

whether temperatures of say, 75 degrees C (167F) are "too high" for any electronic board

The thing with EUCs is that the mosfets can quickly heat up to over 100•C, but it can take a good several minutes for the rest of the board and the temperature sensor to catch up, depending completely on the sensor location.

So the term “cool running wheel” doesn’t mean that the mosfets themselves would be significantly cooler, but that the temperature sensor is located further away from the mosfets. That’s why different wheels have very different temperature limits for the overheat warning.

[mrelwood]

10 minutes ago, RagingGrandpa said:

you should expect that the air-cooled controller will rise in temperature nearly identically to the outdoor temperature

That can’t be right. Whether the ambient temperature is 70•F or 80•F doesn’t make much difference if the mosfets themselves are cooking at 300•F. The difference in the cooling capability is 4%. For a 175•F sensor itself it’s 10%.

[That Guy]

Ok, and why then the temperature alarms are set for 80C (and the tilt-backs, etc.) if the electronics can sustain much hotter? Is it to protect any "weak link/s" or it is just an overall "watchdog type" protection from an internal failure that generates extreme heat?

[RagingGrandpa]

26 minutes ago, RagingGrandpa said:

You should expect that the air-cooled controller will rise in temperature nearly identically to the outdoor temperature

 

9 minutes ago, mrelwood said:

That can’t be right.

Hehe ok, let's see if we can come together

First, I'm considering steady-state 'equilibrium' temperature...
During a constant electrical output power...
At a constant airflow rate (riding speed)...
measured anywhere you please (on the board or heatsink).

Then, for example, my FETs have a (time-average) of 50W thermal dissipation.
This dissipation does not change with ambient temperature.

The heat transfer rate (Joules/sec, or Watts, another unit of power) from the heatsink (and FETS, and board) once in equilibrium is:
K * (Tdevice - Tambient) = 50W
Where K is a constant with a value resulting from the mechanical design and airflow rate.

So, Tdevice rises as Tambient rises, 1:1.

Feedback appreciated

 

10 minutes ago, That Guy said:

why then the temperature alarms are set for 80C (and the tilt-backs, etc.) if the electronics can sustain much hotter?

To protect any "weak links" as you said.

We cannot measure the temperature everywhere on the board, and if any one component fails, performance suffers.

[mrelwood]

7 hours ago, RagingGrandpa said:

Hehe ok, let's see if we can come together

First, I'm considering steady-state 'equilibrium' temperature...
During a constant electrical output power...
At a constant airflow rate (riding speed)...
measured anywhere you please (on the board or heatsink).

Then, for example, my FETs have a (time-average) of 50W thermal dissipation.
This dissipation does not change with ambient temperature.

The heat transfer rate (Joules/sec, or Watts, another unit of power) from the heatsink (and FETS, and board) once in equilibrium is:
K * (Tdevice - Tambient) = 50W
Where K is a constant with a value resulting from the mechanical design and airflow rate.

So, Tdevice rises as Tambient rises, 1:1.

Feedback appreciated

Oh boy, there were too many terms I’d have to check or use a translator for, that I just can’t make myself to bother right now.

You could well be right, it just didn’t sound right to me. Maybe I’ll get back to you on this at a later time. 

[Paradox]

Marty posted this on youtube.

 

[AtlasP]

Gotway: Dremel Not Included (tm).

[Paradox]

I don't know if these links were posted already.  Sorry if They have been posted already.

 

[DavidB]

The Begode mod did not work according to Marty's last two vids. He even made his own mod to let more air in the front but that only resulted in a 2 degree Celsius drop in temperature

With many westerners being 50% heavier than the fit young Chinese guys they have for test riders at Begode the wheel works 50% harder than they thought.

And while the UK guys have no issues, both Afeez and Kevin are smallish and the UK is cold this time of year.

I guess Jack was right. It is not a finished wheel. Hopefully they can sort it out. People seem to love the ride.

 I think that whistle would bother me, tho'.  I wonder if it is the aero of the handles. 

Edited November 10, 2021 by DavidB
Grammar

[Paradox]

25 minutes ago, DavidB said:

The Begode mod did not work according to Marty's last two vids. He even made his own mod to let more air in the front but that only resulted in a 2 degree Celsius drop in temperature

Here is @Marty Backe's video:

 

https://www.youtube.com/watch?v=ccNIygupJrU

 

Edited November 10, 2021 by Paradox
spelling

[Planemo]

I've not really been following the Commander info, but are people happy that it is indeed 'hot' as opposed to 'normal'? I mean, it all depends where the probe gets put to some degree (no pun). I know the Sherman and MSX run around 39~44deg usually (unless ambient is really hot) but the probe could be on the opposite side of the board to the commander for all I know.

[RagingGrandpa]

1 hour ago, Planemo said:

it is indeed 'hot' as opposed to 'normal'?

It's hot.

The cooling design is fundamentally "less convection" that similar-power EUC's.
The only way for the heatsink to receive convection is via the tiny perforations near the headlamp.
Compare it to Sherman (large oval inlet behind headlamp), Nikola & MSuper (heatsink directly exposed to side of wheel cavity), 16X & V11 & V12 (heatsink exposed to top of wheel cavity.

At least there are many practical ways for the end-user to increase airflow, without special tools. If you're using the commander in a way that overheats it, mod it. (The same as the MonPro riders must do.)

I think Commander HT riders in non-mountainous non-desert locations will be fine without mods...

[Planemo]

Fair enough. It was only because Marty went to the extent of creating a huge gap under the headlight and it making virtually zero difference that made me suggest whether it was indeed actually 'hot'.

I appreciate though that the headlight test wouldn't be conclusive unless it was mated with a similar exit airflow somewhere.

 

[That Guy]

My understanding is that Commander has a fundamental design flaw. It doesn't look like it will be easy to fix without a major redesign, which means the next batch may be a completely new machine?

[Rawnei]

9 hours ago, That Guy said:

My understanding is that Commander has a fundamental design flaw.

Would you care to elaborate what you mean so we don't have to guess?

[That Guy]

27 minutes ago, Rawnei said:

Would you care to elaborate what you mean so we don't have to guess?

Of course. I think the engineers who designed the Extreme Bull Commander didn’t provide for cooling. It is not just inadequate or weak or unreliable - it is just non-existent. It was obvious for people who had the first look inside. It was confirmed in the first trials. The wheel is running hot and it is simply because the engineers sadly didn’t have a clue it was needed. And does bother me when a new company tries to build something (not really new or innovative any more) with a fundamental lack of understanding.

They will need to lift the top part by up to an inch and let more air flow under the electronics compartment to rectify the problem. And then it will be a different wheel all together.

Just my understanding.

[Bizra6ot]

They just need to implement the Extrembull K4 liquid cooled mod and it should be fine

[Paul A]

EB creates a cavity with a slot that a sealed ice block slides into next to the heat sink....

Would have thought engineers should be competent enough to have considered cooling electronics.

Bit difficult to have confidence in the quality, safety, reliability etc.

 

[div]

2 hours ago, That Guy said:

And does bother me when a new company tries to build something (not really new or innovative any more) with a fundamental lack of understanding.

It is indeed worrisome to know the other components are conceived by people who lack understanding of basic physics. Making errors who are completely avoidable is a very Begode thing though, I doubt there is a separate team for EB.

IMO possible fixes:

- much larger vents (like the Sherman) and properly places fans (could even be large flat graphic card style)

- make the heat sink get cooled by the wheel well, might be possible with some retooling.

[supercurio]

3 hours ago, That Guy said:

Of course. I think the engineers who designed the Extreme Bull Commander didn’t provide for cooling. It is not just inadequate or weak or unreliable - it is just non-existent. It was obvious for people who had the first look inside. It was confirmed in the first trials. The wheel is running hot and it is simply because the engineers sadly didn’t have a clue it was needed. And does bother me when a new company tries to build something (not really new or innovative any more) with a fundamental lack of understanding.

They will need to lift the top part by up to an inch and let more air flow under the electronics compartment to rectify the problem. And then it will be a different wheel all together.

Just my understanding.

Agree with your assessment.

Everything indicates that the OEM:

• Didn't take cooling in consideration in the initial design: there's no way it'll work.
• Didn't test, iterate, fix, repeat
• Still increased the power rating compared to previous wheels significantly

Instead, they simply started production with complete disregard of what would happen to these wheels and the people riding them: which is as we already know early board failures. Some of them are bound to result in harmful crashes and hospitalisation.

I mean... 
Just don't buy it I guess? Everyone.

[Paul A]

Beginning to suspect maybe there are no engineers at Begode.

Reading through the various posts and threads, the volume of observations pointing out deficiencies, some that seem so basic and obvious....perhaps the engineers/competent personnel left with the formation of Veteran.

 

[supercurio]

18 minutes ago, Paul A said:

Beginning to suspect maybe there are no engineers at Begode.

Reading through the various posts and threads, the volume of observations pointing out deficiencies, some that seem so basic and obvious....perhaps the engineers/competent personnel left with the formation of Veteran.

While it is pure speculation, from the direction and evolution we can observe on both manufacturer it seems plausible, when comparing what Leaperkim came up with the Abrams and Begode with the Extreme Bull.
The Hero might be an outlier disproving this theory tho.

[Paul A]

Yes, just speculation.

Just disturbing that eWheels replacement and safety improvements seem to be quite significant....and that others around the world are going to be left exposed.

 

[div]

4 hours ago, supercurio said:

While it is pure speculation, from the direction and evolution we can observe on both manufacturer it seems plausible

Could also be bad enterprise culture. When an ignorant or careless boss micromanage without listening to employes observations, one end up with such. When the working employee aren’t invited to voice their concerns.. I express myself badly but you get the gist.. 

Gotway have lost several employes to other brands over the years. 

Edited November 11, 2021 by div