My Sherman Trials, Tribulations, and Triumphs

[Mark Wilson]

On 7/16/2020 at 10:53 AM, Marty Backe said:

Failure Resolution?

A new control board is on its way to me. What did Veteran change?

• Apparently no hardware changes
• Firmware modified: "Now the current will be lessen once temperature goes up, it will stop you to ride on high temperature. After it cool down, it become normal again"
• They did some "climbing tests" with a 80kg rider (a real Chinese heavy weight apparently) and "it is fine"

Hmmm

So clearly the Sherman will never zoom up Overheat Hill like Jason had hoped and it will instead overheat like many previous wheels (I think the V10F being the last one).

 

3 minutes ago, Ben Kim said:

The engine would throw a light and go limp if something went awry which would still enable you to stop and operate the vehicle in a limited state; something a self balancing PEV doesn’t have the luxury of doing. 

You can’t make an EUC go into limp mode on failure because it’s simply the way these things are designed. When you have an EUC with no limits it is up to the user to determine what those limits are and ride accordingly. For everyone else, there’s Kingsong and Inmotion. 

You can make a limp mode on an EUC and it sounds like Veteran will do this.

[Bvoland]

15 minutes ago, Planemo said:

I don't think anyone is under any illusion that the majority of wheels are made by small backstreet companies. Hence the issues. I'm certainly not surprised at the hardware issues, doesn't mean I am happy with it, or indeed that I will expect it will get sorted anytime soon. It is what it is.

Never going to happen. The Chinese found money in wheels many years ago when virtually zero people were buying them. The market has only got bigger since, and will continue to do so. That's not to say some won't fold (Boosted for example) but there will be many more waiting in the sidelines.

In these unprecedented times it is especially impressive that a group of engineers leave Gotway to go out and start a new business. It appears that on their first wheel they have done an incredible job of making a solid all around wheel based on feedback from people that I respect in the EUC community. Some of them said it is the best wheel they have ever ridden. I came to this Veteran thread to decide whether to buy the wheel or the New Monster Pro and after watching Marty's review as well as all the others I think I am comfortable. I am sure that Marty is still comfortable with is decision to put a deposit on the Veteran.

[Patton250]

11 minutes ago, Ben Kim said:

The engine would throw a light and go limp if something went awry which would still enable you to stop and operate the vehicle in a limited state; something a self balancing PEV doesn’t have the luxury of doing. 

You can’t make an EUC go into limp mode on failure because it’s simply the way these things are designed. When you have an EUC with no limits it is up to the user to determine what those limits are and ride accordingly. For everyone else, there’s Kingsong and Inmotion. 

Lol you went there. 

[Patton250]

2 minutes ago, Bvoland said:

In these unprecedented times it is especially impressive that a group of engineers leave Gotway to go out and start a new business. It appears that on their first wheel they have done an incredible job of making a solid all around wheel based on feedback from people that I respect in the EUC community. Some of them said it is the best wheel they have ever ridden. I came to this Veteran thread to decide whether to buy the wheel or the New Monster Pro and after watching Marty's review as well as all the others I think I am comfortable. I am sure that Marty is still comfortable with is decision to put a deposit on the Veteran.

I completely agree. Well put

[Marty Backe]

38 minutes ago, Bvoland said:

In these unprecedented times it is especially impressive that a group of engineers leave Gotway to go out and start a new business. It appears that on their first wheel they have done an incredible job of making a solid all around wheel based on feedback from people that I respect in the EUC community. Some of them said it is the best wheel they have ever ridden. I came to this Veteran thread to decide whether to buy the wheel or the New Monster Pro and after watching Marty's review as well as all the others I think I am comfortable. I am sure that Marty is still comfortable with is decision to put a deposit on the Veteran.

Absolutely. I'm still first in line to get a Sherman. Absolutely fantastic wheel, in broad strokes. I've learned that it won't be the best for hilly off-road riding (which I suspected from the beginning) but it's great for cruising and more mellow off-road adventures.

[Bvoland]

2 minutes ago, Marty Backe said:

Absolutely. I'm still first in line to get a Sherman. Absolutely fantastic wheel, in broad strokes. I've learned that it won't be the best for hilly off-road riding (which I suspected from the beginning) but it's great for cruising and more mellow off-road adventures.

That is awesome! Exactly what I wanted was a great cruising wheel. I have the Nikola Plus if I choose to go off road riding but it will probably be nothing like over heat hill. When this pandemic ends would love to come out you way and do a group ride or participate in EUC games. Keep up the great work.

[Ben Kim]

1 hour ago, Mark Wilson said:

 

You can make a limp mode on an EUC and it sounds like Veteran will do this.

Limp mode when something fails is it dropping you on your face.  Don't kid yourself if you think otherwise.  

22 minutes ago, Marty Backe said:

Absolutely. I'm still first in line to get a Sherman. Absolutely fantastic wheel, in broad strokes. I've learned that it won't be the best for hilly off-road riding (which I suspected from the beginning) but it's great for cruising and more mellow off-road adventures.

I thought you were planning on buying the Sherman demo from Jason? 

[AtlasP]

@Marty Backe, have you measured the actual/literal outer diameter of the Sherman tire like you have with many other wheels? (IIRC in the past you said the 16X & Nikola are both ~17.25", the KS-18XL is ~18.5", the MSX is ~19.5", the Monster is all-but/just-shy-of 23", etc.)

Edited July 17, 2020 by AtlasP

[Planemo]

2 hours ago, Marty Backe said:

Absolutely. I'm still first in line to get a Sherman. Absolutely fantastic wheel, in broad strokes. I've learned that it won't be the best for hilly off-road riding (which I suspected from the beginning) but it's great for cruising and more mellow off-road adventures.

Totally agree. The Sherman will sell by the bucketload, just as the MSX did before it.

[Mark Wilson]

1 hour ago, AtlasP said:

@Marty Backe, have you measured the actual/literal outer diameter of the Sherman tire like you have with many other wheels? (IIRC in the past you said the 16X & Nikola are both ~17.25", the KS-18XL is ~18.5", the MSX is ~19.5", the Monster is all-but/just-shy-of 23", etc.)

Someone, I forget who (maybe kuji?), said the Sherman tire was somewhere around 1/4 or 1/2 an inch larger than the MSX or MSP. I remember whoever it was saying the difference was mostly in the knobs of the Veteran tire.

[AtlasP]

12 minutes ago, Mark Wilson said:

Someone, I forget who (maybe kuji?), said the Sherman tire was somewhere around 1/4 or 1/2 an inch larger than the MSX or MSP. I remember whoever it was saying the difference was mostly in the knobs of the Veteran tire.

 

 

Yeah, I've heard similar, but I like the idea of seeing/comparing the measurements all taken by the same person (in this case Marty) as it cuts down on potential variability in measurement methodology. And Marty is one of the few people who has access to a wide number of wheels and has already provided a bunch of measurements in the past.

I've really found his measurements useful to get a sense of scale. If one just went by the official specs (either by the tire MF or the EUC MF) it could lead one to very different perceptions, whereas Marty's previously-provided outer-dimension measurements did a better job quantifying their relative sizes.

Edited July 17, 2020 by AtlasP

[Marty Backe]

2 hours ago, Ben Kim said:

Limp mode when something fails is it dropping you on your face.  Don't kid yourself if you think otherwise.  

I thought you were planning on buying the Sherman demo from Jason? 

This thing has been through hell   I'm going for a new shiny one 

[Marty Backe]

1 hour ago, AtlasP said:

@Marty Backe, have you measured the actual/literal outer diameter of the Sherman tire like you have with many other wheels? (IIRC in the past you said the 16X & Nikola are both ~17.25", the KS-18XL is ~18.5", the MSX is ~19.5", the Monster is all-but/just-shy-of 23", etc.)

Yes, I have measured them, specifically comparing the Veteran to the MSX/MSP tire. It's 1/4-inch larger in diameter. Same width. I think the 1/4" only come from the much thicker tread.

The tire feels wider because of the tread, which effectively sticks out wider on the sides.

So yeah, if you consider the Veteran a "20-inch wheel", then that's what the MSX/MSP is also.

[Marty Backe]

23 minutes ago, Mark Wilson said:

Someone, I forget who (maybe kuji?), said the Sherman tire was somewhere around 1/4 or 1/2 an inch larger than the MSX or MSP. I remember whoever it was saying the difference was mostly in the knobs of the Veteran tire.

That was probably me 

[Alj]

7 hours ago, erk1024 said:

I guess it's just time for Veteran to make their lower speed High Torque Wheel. Gotway MSX --> MSP.  Veteran Sherman --> ??? 

that is not related to the subject really. I mean if the torque of Veteran Sherman was not enough for you  then yes, sure. But we talking about that random wheel usage should not cause magic smokes.

[Violinfun]

On 7/16/2020 at 11:53 AM, Marty Backe said:

Failure Resolution?

A new control board is on its way to me. What did Veteran change?

• Apparently no hardware changes
• Firmware modified: "Now the current will be lessen once temperature goes up, it will stop you to ride on high temperature. After it cool down, it become normal again"
• They did some "climbing tests" with a 80kg rider (a real Chinese heavy weight apparently) and "it is fine"

Hmmm

So clearly the Sherman will never zoom up Overheat Hill like Jason had hoped and it will instead overheat like many previous wheels (I think the V10F being the last one).

Are you planning on repeating the Overheat test to see if the changes save the hardware?

On 7/16/2020 at 11:53 AM, Marty Backe said:

Failure Resolution?

A new control board is on its way to me. What did Veteran change?

• Apparently no hardware changes
• Firmware modified: "Now the current will be lessen once temperature goes up, it will stop you to ride on high temperature. After it cool down, it become normal again"
• They did some "climbing tests" with a 80kg rider (a real Chinese heavy weight apparently) and "it is fine"

Hmmm

So clearly the Sherman will never zoom up Overheat Hill like Jason had hoped and it will instead overheat like many previous wheels (I think the V10F being the last one).

Are you planning on repeating the Overheat test to see if the changes save the hardware?

[Marty Backe]

27 minutes ago, Violinfun said:

Are you planning on repeating the Overheat test to see if the changes save the hardware?

Are you planning on repeating the Overheat test to see if the changes save the hardware?

Perhaps. I will try some precursor hills first and if I notice a difference in behavior I may try again with coordination with Jason.

[Jon Stern]

6 hours ago, Ben Kim said:

Limp mode when something fails is it dropping you on your face.  Don't kid yourself if you think otherwise.  

If the “limp mode” were to kick in a couple of hundred milliseconds before the controller board was about to pop (the permanent limp mode), then yes you’d be on your face, but you were going to be anyway, only with a dead wheel instead of a still working one.

If the “limp mode” cuts in too early, face planting you for no reason then, yes. That’s a fail.

But why the defeatism? I don’t think you are a motor drive circuit engineer, so why do you assume the first scenario is not achievable?

There no magic in the controller board blowing. It’s deterministic and could be anticipated by monitoring the right parameters, and with thorough lab engineering metrology work to calibrate the system.

Yes, it would add some cost for possibly per-MOSFET temperature sensors and current sensors, but that would be a small adder on the total cost of a wheel.

[erk1024]

7 hours ago, Alj said:

that is not related to the subject really. I mean if the torque of Veteran Sherman was not enough for you  then yes, sure. But we talking about that random wheel usage should not cause magic smokes.

Ah, Yes. My apologies from straying from the subject!

And this IS an important topic to discus. We haven't discussed anything like this before. Well, except for that one time when Marty's Nikola blew up on overheat hill because the mosfets burned up. Or when those two MSX's blew up. Or when the 18XL didn't make it up ... 

But getting back to the Nikola for a moment. This is what happened:

1. The 84v Nikola mosfets let out the magic smoke up overheat hill.
2. Marty disassembled it and discovered that there was hot glue being used to hold on the heatsink material during manufacture, and that probably caused the failure.
3. Marty and Jason at eWheels worked with Gotway on a solution, and Gotway issued new control boards with awesome TO-247 mosfets, and no glue. Jason sent them to customers with the old control boards.
4. Then Marty took up his Nikola to overheat hill, made it with ease, and climbed it fairly fast as well!

So by the community engaging with the dealer and the manufacturer, the problem was solved and now everybody has Nikola's that can make it up overheat hill. Problem solved! That's so cool! Thanks @Marty Backe and Jason!

I think something like that will happen in this case. Veteran will make a fix so if the wheel starts to overheat, it will go into tiltback mode. The worst that should happen is that the rider will have to get off and let the beast cool down a bit before continuing. I think the Veteran is an awesome wheel, and we'll all have a lot of fun with it.

Taking the long view, this problem will likely get resolved, and then we can look to the future. What if we actually want a Veteran that is more of a hill climber? Then maybe they can change the motor to favor torque instead of speed, and we could have a whole new Veteran to ride! 

... oops. I did it again! Went off topic! My bad! 

 

Edited July 18, 2020 by erk1024

[MrRobot]

@Marty Backe

Anyway I can ask for a favor? 😅 I see Kuji Rolls is only somewhat active on this forum. Would you have a way to contact him to see what his impressions are on which tire he prefers for strictly city riding?

Would love to hear his opinion since he's ridden with both and see if he thinks the street tire still gives the roll cage enough clearance and has enough sidewall support. 

Need to know before ewheels asks which I want! 😀

[Marty Backe]

8 hours ago, MrRobot said:

@Marty Backe

Anyway I can ask for a favor? 😅 I see Kuji Rolls is only somewhat active on this forum. Would you have a way to contact him to see what his impressions are on which tire he prefers for strictly city riding?

Would love to hear his opinion since he's ridden with both and see if he thinks the street tire still gives the roll cage enough clearance and has enough sidewall support. 

Need to know before ewheels asks which I want! 😀

Have you tried asking him via a question on his YouTube video(s)? Or PM him here (he last visited on Monday).

[Boogieman]

22 hours ago, Marty Backe said:

From memory, maybe 1 or 2 of the 12 MOSFET didn't have their legs burned off. So you're observation about the capacitor is wrong 

Ok, in Your video I just heard you saying "all the leads look blown" and I tried to make out if it was both banks or just one bank. It was really hard to see with all the black soot (contrast suffers) but one bank looked healthier than the other for sure. I double checked and made a screen shot now and its still really hard to tell, so nice to have a confirmation on what actually did disintegrate :-)

So maybe capacitors are not per bank, doesn't mean a short at the capacitor solder vs cooler couldnt be the reason for the devastation though, or?

Would really like to have a circuit diagram of the board, are they using a proper driver? I have limites knowledge on M fest, but at least made a few circut boards of my own like an alarm and it should be fairly easy for some electric engineer to find the root cause. Seems like there are a few holes to step in when it comes to design like  below (even though for a power supply) www.power-and-beyond.com/mosfet-driver-a-common-cause-of-failure-a-883520/

 

Edited July 18, 2020 by Boogieman

[meepmeepmayer]

Offtopic stuff split off to

[Marty Backe]

 

[MrRobot]

4 hours ago, Marty Backe said:

Have you tried asking him via a question on his YouTube video(s)? Or PM him here (he last visited on Monday).

I did, sent him a message last night. I guess I have more time now since the ewheels orders got pushed back.