V12 Cutout tracking

[wheel-life]

1 hour ago, Richardo said:

Added two more events to the sheet this morning (Om moped, petranodon) and changed the speed column to include the actual speed when known

 

 

 

Another one.This was posted 12 min ago on om mopeds video:

 

[Mrd777]

OK, It obviously unsafe to ride our V12's, until we have an answer from @Inmotion Global we need a recall or a real answer. Im not risking it...

[.....]

  

Need I really say anything?

[Flying W]

22 minutes ago, ShanesPlanet said:

  

Need I really say anything?

Yes, I think we could use a splash of cold water on the face mixed with some humor 

[Bumblebees]

This is worse than the Abrams cutout from hard braking.  Rider weight and speed does not play much of an issue with these V12 cutouts.  Any bump in the road can cause the wheel to go out.  

I ride a V12 to work daily.  Speed is around 15kph.  I have only used the Inmotion app once to calibrate the wheel.  Never updated.   Changed the pedal angle and disabled assist mode using the touch screen on the wheel.  

Can a specific wheel setting on the app increase/reduce the chance of a cutout?

[.....]

4 hours ago, Flying W said:

Yes, I think we could use a splash of cold water on the face mixed with some humor 

Hmm... this is a tough one to make comedy from. I'll have to think about it. Easy enough to rant as my usual, but even Captain obvious would probably skip this one(but I won't).

Whats REALLY funny, is you could flip a coin to find out if its build quality or design related. At this point in the euc innovations, I think its simply wonderful to use coins for diagnositcs. I got a jar of pennies waiting and dey be da real onez...

At least its failure conditions are not commonly encountered. I mean geez, why would you expect to be able to travel at reasonable speed margins AND hit road imperfections? If you see a pebble, freaking walk it! The next version will have a better trolley handle, to help 'remedy' the issue. A screen will notify you of the prescense of rocks and/or cracks in the pavement.

Hasnt someone already figured out how to make an euc not do this? I would think there are some things you would kind of focus on first, THEN add the icing on after. Im just speaking out my a** tho, as Im an 18XL rider and my Sherman somehow works. Simply incredbible I know...

Edited January 1, 2022 by ShanesPlanet

[GoGeorgeGo]

[Tawpie]

Back when the prototypes were getting demo'd, someone posted a picture of how the MOSFETs are attached to the heatsink and motherboard. My inner manufacturing engineer twisted uncomfortably in its grave. The MOSFET-heatsink-solder joint assembly looks uber tricky. I'd have made tooling to ensure everything was lined up, attached the MOSFETs to their heatsink, mounted the heatsink and only after the heatsink was firmly attached to the control board would I have hand soldered the MOSFETs. This assembly would not be disassembled, it would become a unit forever. See, if you solder the MOSFETs to the control board before you attach them to the heatsink, the process of screwing them to the heatsink is going to apply stress to the solder joints and part leads because the part won't be perfectly aligned to the heatsink. These solder joints are subject to constant rapid thermal cycling, you do not want them to start off in a compression or tension state... the solder joints or the parts themselves can crack (cracked MOSFETs have been known to happen on the V11). Lead-free solder is already known to crack... it's a more brittle eutectic and much less reliable than leaded solder.

If you do wait to solder the MOSFETs until after they're attached to the heatsink, you're looking at a very challenging high temperature soldering operation in close quarters—it requires expert level soldering skills (special certification) to achieve a good joint without damaging the board. But waiting has the advantage of allowing the connection of the MOSFETs to the control board to be relatively stress free... custom fit if you will.

Obviously I have no idea if the problem is related to the MOSFETs or their connection to the heatsink, but when I saw the picture I wondered if this design could possibly scale—assembly was going to be very very tricky. It's not that you can't do this, you can. But it takes extra care, super trained solder techs, and a willingness to trash boards that were damaged in assembly.

InMotion will figure it out. It's not rocket surgery.

Edited January 1, 2022 by Tawpie
drat... extra word!

[spitfire1337]

6 hours ago, Bumblebees said:

This is worse than the Abrams cutout from hard braking.  Rider weight and speed does not play much of an issue with these V12 cutouts.  Any bump in the road can cause the wheel to go out.  

I ride a V12 to work daily.  Speed is around 15kph.  I have only used the Inmotion app once to calibrate the wheel.  Never updated.   Changed the pedal angle and disabled assist mode using the touch screen on the wheel.  

Can a specific wheel setting on the app increase/reduce the chance of a cutout?

I suggested to add a few details to the tracker in regard to this, and is something that I'm helping to track down from users that have had cutouts. Attempting to see if there is any correlation to a specific setting used.

[MegaObi]

Wow I saw the news up on Instagram was concerned. I been riding the v12 hard . I hit several bumps are high speeds never had an issue so far! Hope they sort this out.

[Gixxer]

7 hours ago, MegaObi said:

Wow I saw the news up on Instagram was concerned. I been riding the v12 hard . I hit several bumps are high speeds never had an issue so far! Hope they sort this out.

The issue is. You don't have a problem until you do. Hit lots of much larger bumps before this one. 

If you asked me on Wednesday about the wheel you would have gotten a glowing review about it's reliability and durability.

 

Now not so much.

[Brendan "nog3" Halliday]

I appreciate that people are having accidents on some units, but for context here in Australia we've had zero of these failures in our initial 30 unit order. 

 

I've read through the data already collected by this form and all of the comments I've read through online. From my experience this would suggest that the failures are perhaps related to a manufacturing batch/period that only affects a few suppliers orders.

 

Specifically relating to the form submissions (the first post claims there's 12 submissions, but the public results only show 7 submissions, 3 of which are for the 2 from Indonesia?)

 

Unknown Supplier (Indonesia):

2x Indonesia (Direct from inmotion, Om Moped video submitted twice)

Unknown Supplier (Probably Eevees)

1x Victoria BC

EWheels:

1x Tri-Cities Wa, USA 

2x Unspecified

 

In this case, I'd suggest to the authors of this form capture supplier and location (country) like @Gixxerrequested earlier on. The EUC community is understandably passionate when failures appear in new units, given it's our safety and health involved. But at the same time there's a significant overreaction in this community regarding anything that can be perceived as negative and it results in a rumor/chinese whisper mill of gigantic proportions.

 

I'm confident that Inmotion will get to the bottom of the failures however, given they are one of the only suppliers in the game currently to have blackbox style logging built into their units. It's reasonable to follow their warnings, but the sky isn't falling.

 

[Richardo]

1 hour ago, Brendan "nog3" Halliday said:

Specifically relating to the form submissions (the first post claims there's 12 submissions, but the public results only show 7 submissions, 3 of which are for the 2 from Indonesia?)

 

Looks like you're having some trouble understanding the spreadsheet, which contains three tables- form submissions, compiled data, and a sheet of graphs. They should appear as tabs at the bottom of the website, and the 'compiled data' tab has all the data we've been able to gather from various sources.

 

1 hour ago, Brendan "nog3" Halliday said:

In this case, I'd suggest to the authors of this form capture supplier and location (country) like @Gixxerrequested earlier on. The EUC community is understandably passionate when failures appear in new units, given it's our safety and health involved. But at the same time there's a significant overreaction in this community regarding anything that can be perceived as negative and it results in a rumor/chinese whisper mill of gigantic proportions.

 

It's a community effort! It'd be awesome if you'd reach out and gather more information, especially if you think of new angles 

[rolis]

I would love to check out the components of the wheel, but sadly mine hasnt arrived yet. Does anyone know which mosfets they used?

[EUC Phenomenon]

55 minutes ago, rolis said:

Does anyone know which mosfets they used?

I think it's the Infineon IPP023N10N5 100V MOSFET

[Chriull]

1 hour ago, Tel01 said:

I think it's the Infineon IPP023N10N5 100V MOSFET

Hopefully not - would be a bad choice for a 100.8V battery....

[fbhb]

29 minutes ago, Chriull said:

1 hour ago, Tel01 said:

I think it's the Infineon IPP023N10N5 100V MOSFET

Hopefully not - would be a bad choice for a 100.8V battery....

Ecodrift's teardown shows that exact spec of mosfet, which they were also quite concerned about at the time of inspection, shown in this image/text of theirs quoted below:

Maybe this has been the main/sole reason behind the cause of All the recent issues with V12 cutout dramas!?

"The marking of the field-effect transistors is clearly visible. This is the Infineon IPP023N10N5. These are the same transistors that are on the V11 and V10F. Everything would be fine, but the V12 voltage is higher. And the denomination of 100V looks very suspicious here. And will the field workers withstand a voltage of, say, 110V under heavy braking? We really hope that Inmotion has calculated all this."

Edited January 2, 2022 by fbhb

[Chriull]

26 minutes ago, fbhb said:

 And will the field workers withstand a voltage of, say, 110V under heavy braking? We really hope that Inmotion has calculated all this."

Breakdown voltage value is just a guarantee if one stays below - so depending on the specific mosfet it could already short curcuit at 100.01V ..

Definitely not a wanted design that could withstand reality.

If that's really the cause it's interesting that as rumoured only 10% broke down according to one reseller. So there seems to be some safety margin, at least for the one batch of mosfets that was used...

[Unventor]

@Chriull

How can braking generate a higher voltage than is used in the motor? 

If that were to happen then regeneration of brake energy could go over battery/cell charge rating. Or did I get my head around this wrongly? 

[Chriull]

1 minute ago, Unventor said:

@Chriull

How can braking generate a higher voltage than is used in the motor? 

The inverter is used as a step up converter to charge the batteries.

1 minute ago, Unventor said:

If that were to happen then regeneration of brake energy could go over battery/cell charge rating. Or did I get my head around this wrongly? 

Imho there should be enough spikes by swtching (pwm) so no special regen or other mode should be needed...

[spitfire1337]

On 12/29/2021 at 1:05 PM, Richardo said:

Hey all I figured it'd be worth tracking the v12 cutouts in one thread so we don't have to dig to ponder it. 

 

Here is a form to let us know if this happened to you

Here is a link to the tracking spreadsheet

 

If you want to be an editor and track down missing details or add new events, DM me and let me know, otherwise I'll add stuff I find here or things people post in this thread.

 

Entries so far:

1. Richardo's
2. Brandon Lott's
3. Conecones's
4. Revolvingrider's
5. Chester Copperpot's
6. Don M. Schiewer's
7. Kerberos's
8. Teeo's
9. Gixxer's
10. Om moped's
11. petranodon's
12. Winter's (see spreadsheet for story, winter hasn't written it up anywhere, but submitted the form)

 

 

Possible Cause

• 100v mosfets on a 100.8v battery wheel

I've gathered some of the info on riding mode and split mode and entered it, still missing a few responses I'm waiting on, could you update the form to ask for this?

[Wolverine]

Clearly the problem is in power MOSFETs. When choosing power MOSFETs to DC motor, we choose power MOSFETs that are rated for at least the power supply voltage and the maximum current the motor requires. But that is not all, there is more than that. When we design something, we leave a margin. In different fields of engineering, the margin can even be double. In the field of electronics, we must make sure that power MOSFETs drain-to-source voltage rating (VDS) is at least 20% higher than the supply voltage.

Inmotion V10, V10F and V11 system voltage is 84V and all these are using IPP023N10N5 100V power MOSFETs. As you see, the 20% margin has already been included. Now let’s talk about the V12. Inmotion V12 system voltage is 100.8V and it is using these same power MOSFETs which are in the V10, V10F and V11. Clearly a big mistake has been made in choosing the correct power MOSFETs. It's only a matter of time before poorly chosen power MOSFETs fail.

[Chriull]

Btw - a mosfet voltage discussion was already here a couple of days ago:

 

[mrelwood]

The mosfets’ voltage rating does sound like a plausible reason, but there are two aspects that make it hard for me to believe it as the root cause:

1) These failures are known to have happened in about a dozen units. Each of them has 12 mosfets, which would increase the odds for failure substantially. Yet they would’ve only failed in less than 0.1% of the units sold. An obvious issue like that should result in a much larger failure rate.

2) Inmotion has manufactured probably a hundred thousand mosfet driven BLDC motored vehicles. I’d like to lean towards thinking that they’d know how to design such a controller a bit better than any of the forum members, electronics engineers or not. I know that sometimes GW seems like they don’t have a single EE in their stables, but IM is not GW.

 We should be hearing from IM in a day or two. It’s a difficult wait, but I’d try to stay in my pants until they have something to report.

Edited January 2, 2022 by mrelwood

[Paul g]

3 hours ago, Wolverine said:

Clearly the problem is in power MOSFETs. When choosing power MOSFETs to DC motor, we choose power MOSFETs that are rated for at least the power supply voltage and the maximum current the motor requires. But that is not all, there is more than that. When we design something, we leave a margin. In different fields of engineering, the margin can even be double. In the field of electronics, we must make sure that power MOSFETs drain-to-source voltage rating (VDS) is at least 20% higher than the supply voltage.

Inmotion V10, V10F and V11 system voltage is 84V and all these are using IPP023N10N5 100V power MOSFETs. As you see, the 20% margin has already been included. Now let’s talk about the V12. Inmotion V12 system voltage is 100.8V and it is using these same power MOSFETs which are in the V10, V10F and V11. Clearly a big mistake has been made in choosing the correct power MOSFETs. It's only a matter of time before poorly chosen power MOSFETs fail.

Is it only I who thinks that a vehicle like the EUC, which depends so much on the electronics to ensure the safety of the rider, should have not only at least 50% margin in electronic components but also be redundant?? In aviation it is an absolute must for flight systems. Even in cars producers must provide double redundancy for brakes with a good margin for both (if someone knows the value in the industry please share here, it would be important as a guide). In an EUC the motor is not only the thing it keeps rider upright but also the only brake. You can die from a crash at 70km/h or 43mph, or even less speed than that, or you could suffer serious injuries. That is the reason I thought is a good idea to start the topic of a Standard of Quality for EUCs made by us, the riders, so we can hold the producers accountable for a certain level of quality, though it probably should be named a Code of Manufacturing after some thought. It also resonates with other trends about the same subject begun by other concerned users on the forum. The fact that in EU there is already a standard for EUCs it is a very good thing. But can it ensure the level of safety we need? More so tends to be prohibitive to new capabilities and level of performance that changes very fast with the fast pace technology.