Did 5 Sherman’s really die at overheat hill? Yikes!

[GothamMike]

I typically avoid puddles, and will now avoid mud. I know the mud was hidden under a layer of dirt and gravel. If you feel you are in mud, stop immediately!

[supercurio]

1 hour ago, GothamMike said:

I typically avoid puddles, and will now avoid mud. I know the mud was hidden under a layer of dirt and gravel. If you feel you are in mud, stop immediately!

I'm imagining a rider from the UK reading this; uh-ho 

[RagingGrandpa]

yum

[Whitebeard]

On 10/25/2021 at 6:43 AM, GothamMike said:

V1 or V2?

I was one of them. Mine was V2, didn’t matter. Something blew. Smelled like burned electronics. My board looked fine, but I haven’t checked the bottom of my board, not battery fuse. Visual inspection of both could not tell of any damage. The other one that died was a brand new V2 Sherman. The 3rd one that died was V1 Sherman with a completely burned up board. The last Sherman owner Knew better and never turned his wheel back up until he went home and cleaned his wheel. His Sherman was fine. 

[Whitebeard]

On 10/25/2021 at 1:20 PM, Mrd777 said:

There was a simple modification to change the fuse connected to the battery from 50amps to 30. Ewheels sent out fuses to those who requested them.  I’m curious how many made this change and if it would have made a difference?

My fuse was 30amps and mine died as well. Visual inspection of the fuse looked fine, but I smelled burned electronics. Will need to perform a surgery to really see where that smell came from. Hopefully this weekend. 

[Whitebeard]

On 10/25/2021 at 2:41 PM, Mrd777 said:

It would be great to find out the grade, temp, speed and distance on that hill that wiped out the Sherm’s. Maybe someone can share their data. 

It started to turn from drizzle to rain on dirt road, and  my thought was to get out of the single lane dirt road right next to the cliff. I saw my knobby picked up a ton of mud but it did not cross my mind that my internal component would burn since the weather was about high 60 degree Fahrenheit at the time. 

[Whitebeard]

On 10/28/2021 at 9:33 PM, Whitebeard said:

My fuse was 30amps and mine died as well. Visual inspection of the fuse looked fine, but I smelled burned electronics. Will need to perform a surgery to really see where that smell came from. Hopefully this weekend. 

Just an update since I revived my wheel (V2 Sherman) last weekend. Confirmed MOSFET burned out. My board looked fine from top down, but when I flipped it, it was obvious all MOSFET were burned. The other rider V1 Sherman's board, heatsink fan, and a few cables were all burned pretty badly. 

[Arbolest]

1 hour ago, Whitebeard said:

Just an update since I revived my wheel (V2 Sherman) last weekend. Confirmed MOSFET burned out. My board looked fine from top down, but when I flipped it, it was obvious all MOSFET were burned. The other rider V1 Sherman's board, heatsink fan, and a few cables were all burned pretty badly. 

Glad you got it up and running again!

[mhpr262]

From what I have read the motor of the Sherman is wound for speed and high rpms. Forcing such a motor to put out high torque at low rpms (like when laboring through mud or slowly climbing a hill) means making it operate far outside its optimal efficiency range. That will make it pull huge amounts of current and generate lots of heat, in the control electronics as well as the motor itself. I have been doing high powered R/C sports for decades, and matching the correct motor (with the correct windings) to a certain car and purpose is super important. Get it wrong and you will end up with a smoking car.