[1860Wh MSX Warning - Oscillation!] Gotway Repeats The MSuper V3s+ Debacle of 2017

[Marty Backe]

[Split from this thread about the 1860Wh 100V MSX.]

Gotway Repeats The MSuper V3s+ Debacle of 2017

So while I was visiting the San Diego riders this past weekend, I got to ride @ZenRyder's and @Nick McCutcheon's new 1860wh MSX's from Jason.

First I rode Mark's MSX which he had already customized by putting a massive street/knobby tire on it. This was Mark's first Gotway. I asked if I could ride to see how the new tire felt. Something was strange but I couldn't put my finger on it. I was in the parking lot and therefore didn't ride it very fast. I concluded that it felt like maybe the axle nuts were not tight. Being Gotway, I know this has happened before. But then the discussion moved on to other topics.

As we started our ride, hosted by @Flyboy10, we were riding through downtown San Diego when I was watching Nick on his 1-week old MSX. This was his first "real" ride on the wheel. Nick is quite the rider (he won a V10 at the LA EUC Games for his performance in the Gran Prix) but still doesn't have extensive experience riding lots of different wheels, including the MSX. His MSX was wobbling back and forth (not side-to-side). I thought he was making it happen (which he kind of was), but you shouldn't be able to do this on a Gotway even if you try. 

I asked him what was going on but he didn't have a good explanation other than it didn't seem to be behaving properly. So I asked to ride it. Whoa! This was horrible. As I rode down the street fairly fast the wheel was in a constant state of back and forth oscillation. The pedals were in hard mode. We weren't in Kansas anymore 

I then thought back to Mark's experience. A bit later I tried his wheel again, this time at speed. It was riding identical to Nick's - horribly. And it felt very unsafe, because if you hit any bumps the oscillation would be amplified. Later in the ride Nick almost lost it, and to me, he looked like he aged 5-years  He said he wasn't going to ride it again until this was resolved.

As soon as I got home I wrote Jason to tell him that his batch of special MSX's were unsafe. Somehow Gotway installed bad firmware, which I'm still kind of flabbergasted at. I mean, any experienced rider would detect something was seriously wrong within 10-seconds of riding the wheel. This wasn't an edge case like the 2017 MSuper V3+ firmware issue.

You can imagine that this made Jason a happy fellow  , to know that Gotway shipped him a container of MSX's which will need new control boards.

Jason confirmed that one other owner complained and the problem was fixed by replacing the control board. But since Jason had only received one complaint, he assumed, rightly so, that it was a one-off problem of some sorts. But with my report from San Diego, the nail in the coffin was set.

Gotway has confirmed the issue which apparently is evidenced by the new rear ring light not functioning. You know, that new thick ring LED that surrounds the 5 LED battery indicator. So it appears that someone at Gotway who shouldn't be allowed near the firmware installed the wrong firmware on these wheels. There are probably other riders like Mark who have never ridden a Gotway before, who don't realize that their new MSX is faulty and actually dangerous.

Of course @Jason McNeil is on top of it and will make everything right. Once again I feel sorry for what Jason gets put through by these Chinese companies (it's not just Gotway). I don't know if this version of the MSX is being shipping elsewhere besides EWheels, but if so, people need to beware.

And for your enjoyment, here is a video I shot that shows the problem (and where Gotway observed the lack of the ring light)

And this video of Mark on his new baby, demonstrates how dangerous this wheel is with this bad firmware. If you have one of these wheels I strongly advise you not to ride it until fixed by EWheels.

 

Edited November 27, 2019 by meepmeepmayer

[atdlzpae]

1 hour ago, Marty Backe said:

Gotway has confirmed the issue which apparently is evidenced by the new rear ring light not functioning. You know, that new thick ring LED that surrounds the 5 LED battery indicator. So it appears that someone at Gotway who shouldn't be allowed near the firmware installed the wrong firmware on these wheels. There are probably other riders like Mark who have never ridden a Gotway before, who don't realize that their new MSX is faulty and actually dangerous.

A prime example for a firmware update feature. For KingSong or InMotion this would be a non-event.

@Marty Backe @Jason McNeil I have extensive experience with STM32's. For the last 3 years I've been working on them daily, on a project that uses GPRS  to load new firmware.
I could write a bootloader via Bluetooth for Gotway if they are interested. Will you please pass the message? Gotway is AFAIK the only major wheel without this feature.

[Planemo]

2 hours ago, Marty Backe said:

I don't know if this version of the MSX is being shipping elsewhere besides EWheels, but if so, people need to beware.

I don't know whether to laugh or cry. I have an incoming 1860Wh MSX as I type, expected in 1 to 2 weeks. Ordered from Intelligent Walking Store.

To say I am gutted with this news is an understatement, but I really appreciate you giving us the heads up on this Marty, before someone seriously hurts themselves.

I will be keeping all fingers and toes crossed, and will update once I have confirmed if I am one of the unlucky ones or not.

[ZenRyder]

You can see the forward/backward oscillation when I'm going down the first hill. It's tilting back and forth. I just put it down to inexperience on my part, but in hindsight and with @Marty Backe 's testing confirm that it's the wheel.

The GPS stops before the crash, but I was probably going 22-25 mph. I have the EUC World logs if it matters. 

The second problem that Nick and I both had is death wobbles at speed. I had already been up to 29 mph on this new MSX, but it was on a long straight paved bike trail and luckily no hard deceleration was required. But on the hill by my house, which is also very steep I had to stop because of the stop sign at the bottom with likely traffic. So it wasn't an option to accelerate out of it. 

Who knew an MSX could fly using those little pedals? 

Anyway, the fender popped off, but I was able to snap it back on, no problem. The only serious damage was to my pride. 

I am disappointed that this firmware screw-up happened. But overall, I still like the MSX and want to get it fixed ASAP. I'll let you know how it goes. Let me know if you have any questions. 

[mike_bike_kite]

18 minutes ago, ZenRyder said:

The second problem that Nick and I both had is death wobbles at speed. I had already been up to 29 mph on this new MSX, but it was on a long straight paved bike trail and luckily no hard deceleration was required. But on the hill by my house, which is also very steep I had to stop because of the stop sign at the bottom with likely traffic. So it wasn't an option to accelerate out of it. 

I believe the idea of accelerating out of "wobbles" comes from motorcycles where the idea is to take the weight of the front wheel. If you only have just one wheel, then wouldn't accelerating just mean you crash faster? I'm just a beginner so forgive me if it's a stupid question.

[ZenRyder]

1 minute ago, mike_bike_kite said:

I believe the idea of accelerating out of "wobbles" comes from motorcycles where the idea is to take the weight of the front wheel. If you only have just one wheel, then wouldn't accelerating just mean you crash faster? I'm just a beginner so forgive me if it's a stupid question.

I thought the idea came from stopping the input (deceleration) which caused the problem. By acceleration I meant no longer leaning hard back to decelerate. So I didn't accelerate but I did attempt to ease off the hard deceleration. Never even had a hint of a single wobble prior to this. Only seems to happen at higher speeds. @Nick McCutcheon, who is much more experienced than me, also experienced the wobbles at higher speeds. 

[meepmeepmayer]

Split for visibility.

Are any MSXes affected? Only 100V?

Is the back light not working a sure sign the MSX is bad? If the light works, does that mean you're good?

[mrelwood]

1 hour ago, ZenRyder said:

I thought the idea came from stopping the input (deceleration) which caused the problem. By acceleration I meant no longer leaning hard back to decelerate. So I didn't accelerate but I did attempt to ease off the hard deceleration. Never even had a hint of a single wobble prior to this. Only seems to happen at higher speeds. @Nick McCutcheon, who is much more experienced than me, also experienced the wobbles at higher speeds. 

The #1 way to kill a sideways wobble seems to be to carve. When standing symmetrically (braking or not), the wobble has a good platform to keep going, since both sideways movements are met with an equal backbounce. When carving, the stance is no longer symmetrical, so left and right wobbles are met with differing forces. This kills the resonance pretty effectively.

The firmware issue is of course very effective in creating and sustaining a sideways wobble, so even carving might not be enough to save the situation at 20+ mph.

I’m so disappointed at the firmware issue. I hope no-one has or will get badly hurt. I’m sure GW will be on it pretty quickly like they were on the Nikola gluegate, but as Marty wrote, new riders don’t necessarily recognize an issue like this.

Edited November 27, 2019 by mrelwood

[xorbe]

Marty, the second video in your post, image stabilization is trying to stabilize the wobble out of the video I suspect, hah.

2 hours ago, mike_bike_kite said:

I believe the idea of accelerating out of "wobbles" comes from motorcycles where the idea is to take the weight of the front wheel. If you only have just one wheel, then wouldn't accelerating just mean you crash faster? I'm just a beginner so forgive me if it's a stupid question.

"When in doubt throttle out," yeah throttle takes pressure off the front tire, which reduces its influence on the bike if wobbles are in progress. If you lift (wheelie) the front tire, just straighten and set back down problem solved but hard to do when the throttle hand is getting whipped all over the place and the bike isn't lined up.  Braking applies larger force to the front and amplifies the problem.  Same effect with cars -- people making an aggressive curve at speed and let off the gas, the weight transfer to the front causes the front to have more control resulting in "snap oversteer" and they go spinning, because they didn't let off the steering while letting off the gas.  I don't think any of this applies to EUCs as there's only one tire.  It does make sense that carving could cure euc fishtail / death wobble.  This is similar to a car with worn out loose steering components -- wobbles when driving straight, but making a curve pins all the forces to one side and becomes steady.

I posted a psa on r/ElectricUnicycle to this thread but I can't pin it.

Edited November 27, 2019 by xorbe

[FlyboyEUC]

 

1 hour ago, meepmeepmayer said:

Are any MSXes affected? Only 100V?

My 1230wh 100v MSX does not have this issue. Just to clarify that it is only the new 1860wh from ewheels. Not sure if @Marty Backe rode mine in the parking lot but @Nick McCutcheon definitely did and said that it was fine.

Edited November 27, 2019 by Flyboy10

[FlyboyEUC]

I also got a lot of footage of @Nick McCutcheon 's wheel oscillating in action. I'll post the clips here when I get to it.

 

Edit:  YouTube video

Edited November 28, 2019 by Flyboy10

[Jason McNeil]

6 hours ago, Marty Backe said:

So while I was visiting the San Diego riders this past weekend, I got to ride @ZenRyder's and @Nick McCutcheon's new 1860wh MSX's from Jason.

Latest development on this: GW just advised, that they believe that this instability is a consequence of the internal piezoelectric speaker being in too close proximity to the gyro sensor, at least one Wheel has been tested, it looks promising. Waiting for feedback from a couple other Customers from this batch. If this is the case, the fix is a fairly simple speaker further out from the controller.  

[meepmeepmayer]

4 minutes ago, Jason McNeil said:

GW just advised, that they believe that this instability is a consequence of the internal piezoelectric speaker being in too close proximity to the gyro sensor

Electromagnetism, how does it work? The electrical engineers at Kingsong (18L) and now Gotway, too, apparently don't know

Is the speaker placement or model different on the 1860Wh MSXes? What changed?

[ZenRyder]

3 minutes ago, Jason McNeil said:

Latest development on this: GW just advised, that they believe that this instability is a consequence of the internal piezoelectric speaker being in too close proximity to the gyro sensor, at least one Wheel has been tested, it looks promising. Waiting for feedback from a couple other Customers from this batch. If this is the case, the fix is a fairly simple speaker further out from the controller.  

Interesting, I noticed that they moved the speaker up right next to the fan. Here is a picture of the location in the case:

You're saying that it will be easy to relocate, but there isn't any other room on this side of the case due to the extra battery pack. That's why they had to move it in the first place. 

There is a lot more room on the other side. 

[meepmeepmayer]

@Jason McNeil Great work following this up so quickly, by the way

[meepmeepmayer]

So this is only because they had to move the speaker for the 1860Wh mod to fit? That means other MSXes are good Phew...

[xorbe]

8 minutes ago, meepmeepmayer said:

Electromagnetism, how does it work

But piezo doesn't have a magnet or a magnetic field.  What about the rear tail light?

Edited November 27, 2019 by xorbe

[ZenRyder]

4 minutes ago, ZenRyder said:

You're saying that it will be easy to relocate, but there isn't any other room on this side of the case due to the extra battery pack. That's why they had to move it in the first place. 

There is a lot more room on the other side. 

I realized how ambiguous this sounds. I have over used the word "other" to make my statement incoherent. 

To clarfy:

There is no more room to the left of the control board because the extra battery pack now fills that spot. 

There is still some room on the opposite side of the wheel. 

[meepmeepmayer]

11 minutes ago, xorbe said:

But piezo doesn't have a magnet or a magnetic field.  What about the rear tail light?

I meant mostly that if the sensor is so susceptible to interference, maybe some electromagnetic shielding (aka a metal casing) wouldn't be the worst idea. Right now, it looks like you could build a "zapper" that makes every wheel oscillate!

As far as what causes this, I have to trust what Gotway and Jason say. Good idea with the rear light, though. Maybe it is the culprit, after all it doesn't work in those cases and it seems more likely the rear light interferes with the sensor than the beeper interfering with both the sensor and rear light. On the other hand, the beeper was moved, the rear light was not. And since it has power cables going to it, I think it will do electromagnetism Maybe it's the combination of beeper and light, too

Edited November 27, 2019 by meepmeepmayer

[Jason McNeil]

Here's the primary evidence for the speaker-stability interaction behaviour. It's possible this is a red-herring, but GW Engineers believe that there is a direct correlation. If this is true, at least it's an easy diagnostic method. Note: that's not me in the video... 

 

Edited November 27, 2019 by Jason McNeil

[xorbe]

Yeah as an EE, I wouldn't jump to a conclusion on that without digging in.  Just have to wait.

Edited November 27, 2019 by xorbe

[Marty Backe]

1 hour ago, Jason McNeil said:

Latest development on this: GW just advised, that they believe that this instability is a consequence of the internal piezoelectric speaker being in too close proximity to the gyro sensor, at least one Wheel has been tested, it looks promising. Waiting for feedback from a couple other Customers from this batch. If this is the case, the fix is a fairly simple speaker further out from the controller.  

Fascinating. Can't wait to hear what the final resolution is.

As others have said, what about the rear ring LED not working? Maybe that's just another unrelated problem?

And, nobody with experience at Gotway actually rode one of these wheels? I find that hard to believe.

[Marty Backe]

5 hours ago, ZenRyder said:

You can see the forward/backward oscillation when I'm going down the first hill. It's tilting back and forth. I just put it down to inexperience on my part, but in hindsight and with @Marty Backe 's testing confirm that it's the wheel.

The GPS stops before the crash, but I was probably going 22-25 mph. I have the EUC World logs if it matters. 

The second problem that Nick and I both had is death wobbles at speed. I had already been up to 29 mph on this new MSX, but it was on a long straight paved bike trail and luckily no hard deceleration was required. But on the hill by my house, which is also very steep I had to stop because of the stop sign at the bottom with likely traffic. So it wasn't an option to accelerate out of it. 

Who knew an MSX could fly using those little pedals? 

Anyway, the fender popped off, but I was able to snap it back on, no problem. The only serious damage was to my pride. 

I am disappointed that this firmware screw-up happened. But overall, I still like the MSX and want to get it fixed ASAP. I'll let you know how it goes. Let me know if you have any questions. 

Yeah, I love watching your MSX do multiple rotations in slo-mo. Sorry 

There were just shy of 3 complete 360-degree rotations of the wheel in the air. Amazing it wasn't damaged more (usually the pedals hit and they get twisted).

Edited November 27, 2019 by Marty Backe

[Marty Backe]

5 hours ago, Planemo said:

I don't know whether to laugh or cry. I have an incoming 1860Wh MSX as I type, expected in 1 to 2 weeks. Ordered from Intelligent Walking Store.

To say I am gutted with this news is an understatement, but I really appreciate you giving us the heads up on this Marty, before someone seriously hurts themselves.

I will be keeping all fingers and toes crossed, and will update once I have confirmed if I am one of the unlucky ones or not.

Do you have experience riding Gotway wheels? Just know that your wheel should ride smooth with zero back and forth oscillation. When riding straight it really should feel like your Z10.

[Marty Backe]

6 hours ago, atdlzpae said:

A prime example for a firmware update feature. For KingSong or InMotion this would be a non-event.

@Marty Backe @Jason McNeil I have extensive experience with STM32's. For the last 3 years I've been working on them daily, on a project that uses GPRS  to load new firmware.
I could write a bootloader via Bluetooth for Gotway if they are interested. Will you please pass the message? Gotway is AFAIK the only major wheel without this feature.

All indications point to Gotway having zero configuration management in place. This is why when you get replacement parts, particularly control boards, there's no guarantee that they will fit or work. They have essentially admitted that implementing firmware updates is beyond their capability because they have no insight into which wheels have which versions of various components.

So it's not a technological problem (developing hardware/firmware that allows for upgrades), but a process problem.

This BTW probably explains why Gotway is so prolific in creating new wheels and new versions of wheels. Configuration Management takes time and slows everything down due to the necessity of documenting everything you are doing. I have images in my head of the Gotway factory where people are excitedly taking components off the shelf and experimenting with new design iterations, guys hacking the firmware, etc. In other words, a madhouse. But this explains the steady stream of wheel interactions always arriving at our front door