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Olav

Blown mosfet?

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Hi guys

 

Went out riding today, and approx. half way through my Tesla threw me off. I think its a blown mosfet, but I'm not 100% sure.
'Luckily' I had my GoPro with me, and filmed at the time, so you can judge for yourselves.

Had to get a taxi home (48GBP/62USD)...

 

The wheel didn't turn freely, but after taking it to work and disconnecting the motor from the board, it does. So I'm assuming board failure. You guys agree?

 

Hopefully Speedyfeet has a board in stock, and I'll order a new one (doubt the seller, who I bought the wheel from, here in Norway has one, but I'll ask anyway).

This thread helped me, so thanks to @Nate Bryan and those who replied to it: 

 

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2 minutes ago, Olav said:

The wheel didn't turn freely, but after taking it to work and disconnecting the motor from the board, it does. So I'm assuming board failure. You guys agree?

Yes - typical symptoms of blown mosfet(s).

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@Olav you idiot! Don't you know it's always less embarrassing to have your wheel fail where others can't witness it.  ;)

But seriously, bad luck.  Why did you go down? that looked slow enough to run off, even for an out of shape old man like me.

What was that noise a few meters before the fail? was it the sound of the ice cracking or did you lose grip and the wheel spun up to speed?

It's weird that a MOSfet would fail when you were putting it under zero strain.  Even the lowest generic wouldn't stress out on that trail.

Tesla's haven't been out for 2 years so you are under warranty, why not chase your supplier FIRST rather than pay Speedyfeet for a new board?

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4 minutes ago, Smoother said:

@Olav you idiot! Don't you know it's always less embarrassing to have your wheel fail where others can't witness it.  ;)

But seriously, bad luck.  Why did you go down? that looked slow enough to run off, even for an out of shape old man like me.

What was that noise a few meters before the fail? was it the sound of the ice cracking or did you lose grip and the wheel spun up to speed?

It's weird that a MOSfet would fail when you were putting it under zero strain.  Even the lowest generic wouldn't stress out on that trail.

Tesla's haven't been out for 2 years so you are under warranty, why not chase your supplier FIRST rather than pay Speedyfeet for a new board?

I think my wheel is evil, and all it wants to do is to make me look bad :P

 

Wasn't very fast no, but I suppose it surprised me, and down I went. If it had been on one of the steep hills I rode 10-20 min before, I would probably be running of it.

 

The noise was ice yes. And I went down on a soft patch, as can be seen when turning back to the wheel after getting up.

 

The wheel is 4 months old, bought it in october. The company I bought it from isn't known for its good customer service, and I just want to get out riding again, so I'm just getting a new board. Warranty will probably take some time, so I'm not bothered to deal with that now. Could also be said I rode it in weather its not supposed to be ridden in (bo*****s, I know), so its ridden in a way its not meant to. Being 16+ stone doesn't help :cry2:

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22 minutes ago, Olav said:

I think my wheel is evil, and all it wants to do is to make me look bad :P

The wheel is 4 months old, bought it in october. The company I bought it from isn't known for its good customer service, and I just want to get out riding again, so I'm just getting a new board. Warranty will probably take some time, so I'm not bothered to deal with that now. Could also be said I rode it in weather its not supposed to be ridden in (bo*****s, I know), so its ridden in a way its not meant to. Being 16+ stone doesn't help :cry2:

All our wheels are trying to kill us.  Yours is just more eager than others.

Ok, I understand about the customer service, BUT.... why not open a warranty claim anyway, as well as buying a quickie replacement board.  That way, 1.) you give Mr. bad service the chance to either confirm or deny his reputation, and 2. in a few months you may have a free spare board for when your wheel tries to kill you again.

As for being 16 stone (224lb). Well I'll just assume it is all muscle :rolleyes: cough cough.  BTW is it common to measure weight in stone in Norway, or have you lived in England as some sort of punitive arrangement?  For you new worlders, a stone is equal to 14 lbs.  Why? I don't know; some ancient crap I imagine.  It's not as if keeping metric and imperial straight in our heads, isn't enough :facepalm:

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14 minutes ago, Smoother said:

All our wheels are trying to kill us.  Yours is just more eager than others.

Ok, I understand about the customer service, BUT.... why not open a warranty claim anyway, as well as buying a quickie replacement board.  That way, 1.) you give Mr. bad service the chance to either confirm or deny his reputation, and 2. in a few months you may have a free spare board for when your wheel tries to kill you again.

As for being 16 stone (224lb). Well I'll just assume it is all muscle :rolleyes: cough cough.  BTW is it common to measure weight in stone in Norway, or have you lived in England as some sort of punitive arrangement?  For you new worlders, a stone is equal to 14 lbs.  Why? I don't know; some ancient crap I imagine.  It's not as if keeping metric and imperial straight in our heads, isn't enough :facepalm:

I try to use a system the receiver will understand naturally, so for you its stone, for someone in europe its kg, and for someone in the US its lbs :blink:
I use kg myself, as does most/all norwegians, and I've never lived in the UK (just visited a few times).

 

Some of it is muscle :P
I'm a bit lazy (its one of the reasons why I'm 16+ stone / 101+ kg / 224+ lbs / 508023+ carat :cry2:) and just want to get out on the wheel again, so I'll get a new board first. Then possible go for a claim.

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   That has to be the least remarkable mosfet failure I have seen. It has to be the women. I won’t jump a 2.54 cm curb in front of a woman. :facepalm: 

 Sorry, I didn’t know how to conver inches to stones. :rolleyes:

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13 hours ago, Smoother said:

@Olav you idiot! Don't you know it's always less embarrassing to have your wheel fail where others can't witness it.  ;)

But seriously, bad luck.  Why did you go down? that looked slow enough to run off, even for an out of shape old man like me.

What was that noise a few meters before the fail? was it the sound of the ice cracking or did you lose grip and the wheel spun up to speed?

It's weird that a MOSfet would fail when you were putting it under zero strain.  Even the lowest generic wouldn't stress out on that trail.

Tesla's haven't been out for 2 years so you are under warranty, why not chase your supplier FIRST rather than pay Speedyfeet for a new board?

When a wheel shuts off you faceplant. You can only runoff the wheel when the pedals are still operating and you have something to push off against. I don't care how fit you are.

Or maybe you just like giving @Olav a hard time ;)

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Really bad luck. We all hope a random failure like this never happens when we are riding fast. Fortunately you weren't, so good that you didn't get injured.

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2 hours ago, Marty Backe said:

When a wheel shuts off you faceplant. You can only runoff the wheel when the pedals are still operating and you have something to push off against. I don't care how fit you are.

Or maybe you just like giving @Olav a hard time ;)

I did not know that.  Next time I have a low speed cut off I'll be cursing your name all the way to the ground for giving ME something else to worry about..  Damn you BAAAACCCKKKKKEEEEE thump

Edited by Smoother
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11 hours ago, Marty Backe said:

Or maybe you just like giving @Olav a hard time ;)

I think this might be it :o                    :P

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18 minutes ago, Olav said:

I think this might be it :o                    :P

What! :( I don't even know the guy.  And besides, He's bigger than me.:rolleyes:

Edited by Smoother
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12 hours ago, Marty Backe said:

Really bad luck. We all hope a random failure like this never happens when we are riding fast. Fortunately you weren't, so good that you didn't get injured.

Thinking back I do find it a bit strange that it happened at that time, as I had ridden up and down quite steep hills 10 minutes before without any issues. Do you guys think that riding those hills that long before could have had anything to do with it?

What I'm also thinking is it could be an overlean, due to hitting that soft patch, and the wheel trying to catch up but blowing a mosfet doing it. 

 

Regarding new board, the seller I bought the wheel from got back to me telling me that they will have their technician take a look, and then get back to me.

Ian has also said that they have. So hopefully I'll be riding again soon, depending upon how fast I can get a board. I'll probably get it from the norwegian seller if they have it (as I don't have to deal with customs and VAT as I will if I buy it from Ian), but if no reply by midday tomorrow, or so, I'll order from Ian. 

 

Sidenote: While riding those hills I obviously thought of @Marty Backe and his mountain stress tests :P

2 minutes ago, Smoother said:

What! :( I don't even know the guy.  And besides, He's bigger than me.:rolleyes:

Well, maybe not bigger, as in taller, but probably wider :o :P

Edited by Olav
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2 minutes ago, Olav said:

Well, maybe not bigger, but probably wider :o :P

Do you think the added wind resistance caused your MOSfat fet to blow?:D

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Just now, Smoother said:

Do you think the added wind resistance caused your MOSfat fet to blow?:D

Well... :efefb6a84e:  :P

Have ridden it in quite high headwinds (like 10+ m/s / 22+ mph), and had to crouch to stay on the wheel :blink:

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Look. In all seriousness, you should not have blown a MOSfet on that path, on that day, at that speed, in those conditions.  Should never have happened.  But it did. Many thousands of miles under our collective wheels, of all brands, often under much more stress than this, prove this is not normal behavior of a healthy, well installed MOSfet. Conclusion, your board had a defect that was a ticking time bomb, possibly heat from climbing the hill set it off.  BUT it shouldn't have.  You did nothing wrong. The good news is your replacement board, statistically, should not have this problem. Two bad MOSfets to the same rider?  inconceivable!.

Like this conversation I had recently when hitch hiking:

Me: "Thanks for picking me up. But how do you know I'm not a serial Killer?"

Driver:" Two serial killers in the same car? Inconceivable!"

Me:" Gulp!, Right here will do"

 

Edited by Smoother
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20 minutes ago, Smoother said:

your replacement board, statistically, should not have this problem. Two bad MOSfets to the same rider?  inconceivable!.

Sorry.  Forgot to add.  Your next board will probably have a faulty gyro. :facepalm:

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Hmm, cold weather, may be its the battery/ BMS problem since you said after a reset it works ?

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37 minutes ago, yuweng said:

Hmm, cold weather, may be its the battery/ BMS problem since you said after a reset it works ?

Welcome @yuweng.  Let us know what you ride and what type of riding yo do,  Not here.  People seem to put them in the rules and regulations thread.

Now as for your statement.  I don't think @Olav said "after a reset it works". 

On 2/10/2019 at 5:09 PM, Olav said:

The wheel didn't turn freely, but after taking it to work and disconnecting the motor from the board, it does. So I'm assuming board failure

But don't worry, things are often misunderstood here.  Keep contributing.

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13 hours ago, Smoother said:

 

Welcome @yuweng.  Let us know what you ride and what type of riding yo do,  Not here.  People seem to put them in the rules and regulations thread.

Now as for your statement.  I don't think @Olav said "after a reset it works". 

But don't worry, things are often misunderstood here.  Keep contributing.

Thanks @Smoother i think i got confuse when OP mention wheel & motor, now that i re-read, it does seems like blown mosfets, my bad :P

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1 hour ago, yuweng said:

Thanks @Smoother i think i got confuse when OP mention wheel & motor, now that i re-read, it does seems like blown mosfets, my bad :P

Hey, No problem.  If everyone understood what everyone else was trying  to say, this forum would be 3 pages long, tops ;)

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Ok, new board is ordered, hopefully Ian will have it here on Friday (fingers crossed), but could be Monday :cry2:

We'll see :thumbup:

On ‎2‎/‎11‎/‎2019 at 8:46 PM, Smoother said:

Sorry.  Forgot to add.  Your next board will probably have a faulty gyro. :facepalm:

Don't say that... :cry2:

Luckily I have an Bell Super 3R on the way, so hopefully my teeth and jaw will be safer when I start riding again B)

Hmmm.... did anyone mention kneepads? :efefb6a84e: (Goes away to look for some)

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If blown mosfets are caused by stress, I wonder if idling your wheel is then highly recommended. Blowing a mosfet while idling is far safer than while riding especially if you're crouched expecting that wheel to blow on you.

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7 hours ago, LanghamP said:

If blown mosfets are caused by stress, I wonder if idling your wheel is then highly recommended. Blowing a mosfet while idling is far safer than while riding especially if you're crouched expecting that wheel to blow on you.

I believe over the years there have been several reports of idling induced Mosfet failure.  I won't do it.  No point.  If I want to be stationary for a while I just put a foot down. I try to stress my MOSfets out as little as possible, they are the main things keeping my face out of the asphalt, them, and everything else on the "infernal machine"

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