Jump to content

Gotway oscillation issue on V8?


mezzanine

Recommended Posts

@CaptainKBLS You might be right about the V8 having too high a reputation.  I noticed there are a lot more V8 users on the french forum and I may do some digging there to see if I can learn whether others have experienced something similar. 

@WARPed1701D Good point about wheellog.  I have it on my phone, but don't have data and haven't looked into logging my rides.  I will now, though. 

Link to comment
Share on other sites

On 10/29/2017 at 10:04 AM, Meng Yang said:

Nope, he didn't. He's not a power user. Its his usual kind of gradual acceleration that's been done for months w/o issue. He's a careful noob.

I am also curious how this exactly happened (I assume you didn't try to reproduce the behavior?). If I turn on the wheel, it first levels the body horizontally, which can take close to a second, it's actually quite smooth and nice to watch :). I could imagine that driving off during this process may be problematic. After that, I'd be surprised about a problem, also because I never observed any of this. Though in a way I am also a careful noob as I always remain sensitive as to whether the wheel is in the self-balancing state before to "hop on". Yet I never specifically wait for the wheel to stabilize for more than a second. Yet I am curious enough that I will try to start driving the wheel while still in the leveling process the next time I have the opportunity.

Edited by Mono
Link to comment
Share on other sites

3 hours ago, Mono said:

 leveling process

I've never really paid much attention to this leveling process, but now that you've mentioned it, this is what I see: Most of the time, I'll hold the V8 upright before powering on, thus there little movement of the wheel. Don't think I ever saw the footrests move. But if I held is slanted and power ON, the wheel body moves back to vertical. For me, I do wait for everything to be vertical before moving off. Don't think I ever moved off before it being vertical. Maybe my friend did, but don't think that's the issue. Its not about cutting into the "leveling process". Its something else. Sometimes when I power ON the V8, even waiting a few seconds, either the footrests are not angled properly, or when you ride it, the angle and the dips in the footrests just isn't right. If I were to continue, it'll either feel terribly off, or I'll risk falling off coz its just not balanced. My friend was likely thrown off by this. What I normally do (if I felt weird), is to stop, re-power ON and see if system is re-booted properly again (sometimes that's all I need to do); or if re-powering ON doesn't work, I'll just re calibrate - which always work - before going on my ride.

  • Upvote 1
Link to comment
Share on other sites

My ACM does the exact same. Starts balancing as soon as it is level enough (luckily it won't balance if held too tilted, good so it won't try to run away), and then it slowly fine-tunes a few degrees to actually level. Indeed neat to look at.

Wouldn't be surprised if all EUCs use the same cheapo China chipset (or whatever the part is) with that behavior. Or maybe there are good reasons for it?

  • Like 1
Link to comment
Share on other sites

On 10/31/2017 at 5:47 PM, meepmeepmayer said:

My ACM does the exact same. Starts balancing as soon as it is level enough (luckily it won't balance if held too tilted, good so it won't try to run away), and then it slowly fine-tunes a few degrees to actually level. Indeed neat to look at.

Wouldn't be surprised if all EUCs use the same cheapo China chipset (or whatever the part is) with that behavior. Or maybe there are good reasons for it?

The ninebot does that much quicker than the ACM.  I noticed that in one of @Marty Backe's videos a few months ago.  It does look better with the slower rise to level.  More deliberate and precise.  The ninebot just kind of moves too fast to level out, and then the level is not good sometimes.

Edited by steve454
  • Upvote 1
Link to comment
Share on other sites

53 minutes ago, meepmeepmayer said:

My ACM does the exact same. Starts balancing as soon as it is level enough (luckily it won't balance if held too tilted, good so it won't try to run away), and then it slowly fine-tunes a few degrees to actually level. Indeed neat to look at.

Wouldn't be surprised if all EUCs use the same cheapo China chipset (or whatever the part is) with that behavior. Or maybe there are good reasons for it?

 

13 minutes ago, steve454 said:

The ninebot does that much quicker than the ACM.  I noticed that in one of @Marty Backe's videos a few months ago.  It does look better with the slower rise to level.  More deliberate and precise.

Imho the ks16b/c had this same behavior slow level adjustments from time to time which i never really expierienced with the ninebot one e + or with the ks16s (until now - have not driven it extensively). I‘d strongly assume this to be an fimware issue.

Maybe this also relates to the dimensioning/„health“ state of the main capacitor - once one leg of this capacitor at my ks16b was broken it behaved extremely strange in regard to leveling

Edited by Chriull
  • Upvote 3
Link to comment
Share on other sites

23 minutes ago, Chriull said:

dimensioning/„health“ state of the main capacitor - once one leg of this capacitor at my ks16b was broken it behaved extremely strange in regard to leveling

With a broken capacitor leg i would guess it behave extremly stange in all regards, or?

Without capacitor faceplanting is very near...pedals get weak, but thats only the visible aspect. The next middle or fast amperage draw, will send you to the bottom, as  batterys alone can not deliver fast enough...

 

The leveling i would not think its an firmware issue, i would guess that in some ways the wheel has to „adjust“ to the horzontal level, as we can not start riding with a 30degree leveled pedel.

Some wheels are doing it slowly...on the newer „S“ series firmware, when i power on the wheel when not leveled horizontal, it will first do nothing, and then when i (by myself moving) go more near to horizontal with the wheel, it kind of slams/clicked in on the correct level in a nanosecond  and from this moment on is 100% there...

hard to explain with my broken english :-(

  • Like 2
Link to comment
Share on other sites

18 minutes ago, KingSong69 said:

With a broken capacitor leg i would guess it behave extremly stange in all regards, or?

Without capacitor faceplanting is very near...pedals get weak, but thats only the visible aspect. The next middle or fast amperage draw, will send you to the bottom, as  batterys alone can not deliver fast enough...

Middle amperage draws were handled quite ok but just a bit „strange“ - exactly with this retarded leveling (and „weak“ feeling). The fast amperage draw with my broken capacitor leg ks16b brought my brother to the ground because the fuse melted.

Quote

The leveling i would not think its an firmware issue, i would guess that in some ways the wheel has to „adjust“ to the horzontal level, as we can not start riding with a 30degree leveled pedel.

Some wheels are doing it slowly...on the newer „S“ series firmware, when i power on the wheel when not leveled horizontal, it will first do nothing, and then when i (by myself moving) go more near to horizontal with the wheel, it kind of slams/clicked in on the correct level in a nanosecond  and from this moment on is 100% there...

That´s about my memory of the ninebot e+ behaviour. By the quite different powers it‘s imho a firmware or capacitor issue.

But ofcourse could also be also be some gyro malfunction or whatever issue - quite impossible to determine without proper data.

Edited by Chriull
  • Upvote 1
Link to comment
Share on other sites

To be fair, pretty sure the fine-levelling is a deliberate behavior of the "chip" (it's 100% the same every time for my wheel). Either to cover for a weakness/limitation that might otherwise be exposed, or just because it's better than not doing it for some technical reason.

Link to comment
Share on other sites

No idea how many km on my V8 now (as i can't be bothered to get of the couch and go turn it on), but so far the only crashes have been my fault :)

Some pretty impressive leaning back on the vid clip at about 0:50. Don't know that i would have the bottle to do that.

Link to comment
Share on other sites

  • 9 months later...

V8 did a "Gotway oscillation issue" on me today and I crashed.

I have 3 wheels:
- Ninebot One E+: 3000km (1864miles) - zero problems
- Inmotion V8: 3700km (2299miles) - one crash because of Gotway oscillation issue at 3700km
- Gotway MSuper V3s+: 3700km (2299miles) - zero problems

I don't remember exactly, but I think I was riding at near full speed and heard the nuclear warning sound when problem happened.  Engine did not cut off, I just couldn't handle the oscillation.
Temperature is fine today, it's warm (24C (75.2F), maybe little more).  Road nearly clear, only small bumps, but really small, really... it's nothing for this wheel, it handled much more and did it hundreds and hundreds of times...  Battery - more than 50%.

I am very happy with what my body did.  One or two years ago I trained on how to properly "crash" for a day or two.  I did somersaults over the shoulder, protecting the head.  I did it, I don't' know, maybe 100 times.  Today - during the accident - my body did exactly the same, wow :).

  • Like 2
Link to comment
Share on other sites

@vla oh good for you that you were prepared.

Sorry that you experienced it. V8 starts wobbling due to lack of power in certain situations and as I understand there is some failsafe behavior which prevents it to end this state in reasonable time, as you're not the first one to report that you tried to maintain it for some seconds.

  • Like 1
Link to comment
Share on other sites

If strong vibrations like train tracks are causing an issue, make sure the boards are all secured very well, add extra standoffs if they can flex at all. Also check for loose connections, but this is hard to do as it might take some force to activate it. Check if the pcbs have any hairlines cracks; also very hard to spot. It's probably software, but these issues have been already been solved in software algorithms so i wouldn't rule out hardware. 

Link to comment
Share on other sites

  • 2 years later...

Just had the same issue, went over a speed bump, started doing the oscillation  threw me off. Broke my collar bone, currently in the hospital, typing this with my left hand at the moment... second time the oscillation happened,  any solutions?

  • Like 2
Link to comment
Share on other sites

48 minutes ago, Enforcerke said:

Just had the same issue, went over a speed bump, started doing the oscillation  threw me off. Broke my collar bone, currently in the hospital, typing this with my left hand at the moment... second time the oscillation happened,  any solutions?

Ouch, hope you get well soon. What speed did you hit the bump? Any eta on recovery time?

Link to comment
Share on other sites

1 hour ago, meepmeepmayer said:

I'm afraid the only solution is: get a stronger wheel. The V8 seems to be too borderline weak (for you at least... what's your weight?).

Hope your bones heal fast.

My last overlean incident was on my v8. Was buzzing down a sidewalk at like 12 mph, hit tiltabck and beeps a couple times at bumps and drops along the route (that sidewalk is garbage). Came to an area with just a little drop, maybe 2 inches tops. The little guy dropped me with little to no warning. It was shortly after i had recieved my v11 so i was being to aggressive with it. Im only 185-190ish . Of course it was the one time i didnt put knee pads on so i got a nice little cut. Thankfully i had wrist guards on and was able to absorb most of the impact without further damage. No worse than diving for a ground ball or diving for a loose ball😋

  • Like 1
Link to comment
Share on other sites

On 5/16/2021 at 9:29 PM, ShanesPlanet said:

Ouch, hope you get well soon. What speed did you hit the bump? Any eta on recovery time?

Thanks had surgery yesterday, went over the bump at around 27 ish km/h... recovery a couple of weeks

  • Like 1
Link to comment
Share on other sites

On 5/16/2021 at 11:10 PM, meepmeepmayer said:

I'm afraid the only solution is: get a stronger wheel. The V8 seems to be too borderline weak (for you at least... what's your weight?).

Hope your bones heal fast.

Hmmm thought so... i only weigh 70kg. I almost always drive it at almost top speed (26-29ish km/h)

Thanks hope i can ride again soon

Link to comment
Share on other sites

  • 2 weeks later...

The issue is that the V8's 800W (60V), even when over driven at 84V can draw more power power than the 40 cells 10A batteries can handle. So even on a V8 that I recently go that has 30Km on the clock if you hit it hard or do something that requires a massive power draw the pack is not going to be able to meet the power demmand, so it may temporarily dip forwards.

More importantly if you slam you breaks hard on it, the unicycle will simply fail and you will land on your ass and your wheel will carry on forward. My friend has had to compensate two people that he injured when the V8 left him on the floor and it rolled and hit someone. When I first go a V8 I did the same thing twice and landed on my ass... didn't injure anyone.

Not tried the stressing a V8F, but I don't see it being any bettery with the Sanyo GA batteries....

The only way you can fix this is doing what Inmotion do for the V5, is to stick 20A cells in it. I built a pack with VTC6 and ended up putting in in a V5F, instead of a V8 and it flies. reality is that the we an 80 cell small/light unicycle from Inmotion - a 800W overdrivve motor with a 1000Whr. the V11 and V12 are a turn off for beginners here in HK and lack the breaking power for riding on the pavements.

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...