Minipro intermittently LIFE-THREATENING unsafe, veering right

[trevmar]

8 hours ago, FastForward said:

@trevmar

So you can replicate the issue and see what's happening. 

Could you please make a video of it?

OK. I am looking for a volunteer to get thrown off a miniPRO onto our concrete driveway. Please form a queue.

In other news, our new Airwheel S5 doesn't even pause when it comes to the same obstacle. I think the difference is that the miniPRO firmware is designed to protect the hardware at all costs. Not a good plan when this results in the riders getting hurt. The miniPROs should NEVER turn the balancing motors off without having fought to internal destruction to give the rider a chance to get off. If I am lying hurt on the road, I want my miniPRO to be lying dead beside me, not chirping happily to tell me it has protected itself from a fault condition...

[FastForward]

That was just a question, but you answered it so thank you anyway.

[Zephyrzone]

On 7/27/2019 at 3:22 AM, cleanoldman said:

Accomplished rider here. Many happy miles until March 2017. Same sudden turning behavior described here left me with a severely torn shoulder. Surgery was required. Recovery was over a year. Only after Segway read the 'black box' data, did they ship me a new one. This thread is the first I've found to acknowledge the problem in depth. I'm afraid someone is going to get killed. I truly love this machine but now my trust is gone.

Sorry to hear about this. Horrible. 

I had the same issue with mine and posted here a while back. Fortunately I was going only 2-3 mph when my first problem kicked in. Segway customer service was quite good for me and after some back and forth, they paid for me to return it and they fixed it. 

No explanation of exactly what the problem was and the black box data didn’t read out any issues. The unit was sent back with a new control board and worked fine after that. 

I ended up selling the unit because I too had lost trust in it and wasn’t comfortable. Not to mention that 10mph was too slow (yet also too fast should the issue arise again). 

I no longer wish to ride a device with 2 wheels in a horizontal orientation. If one goes out of sync, it could be death if the rider is thrown into traffic. I’m sticking to EUC. 

Again, I really feel for you. I’ve had many surgeries from years of extreme sports and being too hard on my body, and at 40 I’m now paying the price daily. I wish you all the best. 

[JonBMP]

Hi,

        I was riding my MiniPro (purchased July 10 from Frys) recently down a very small hill and all of a sudden it veered right throwing me off. I was able to catch myself (barely) but my feet dragged on the ground and my left shoe disintegrated (left ankle also twisted/sprained a little). I already bought and installed an aftermarket T bar as I am 6'2 and the knee bar did not make me feel comfortable riding at higher speed. This T bar attachment did not really help in this incident as others have noted.

I noticed the MP (before this incident) would get very 'squirrelly' going down any size hill and so I sort of knew I had to pick my 'line' going into a downhill slope. When this incident of veering right occurred I barely started downhill and it just veered off to the right. I don't recall if it was beeping or any signs of malfunction but my right knee was pretty scraped up so I rode it home (another .5 mile) over bumps and other downhill slopes. I made it home without further issues issues (thankfully). The steering bar felt 'loose' after the fall so I went about tightening up every bolt on the unit (I only had it for 2 weeks when this incident happened) and after tightening, the steering bar was as stiff/responsive as before.

I am going to contact Ninebot and see what they suggest but it will be awhile before I fully trust the MP again.

[FreeRide]

3 hours ago, JonBMP said:

Hi,

        I was riding my MiniPro (purchased July 10 from Frys) recently down a very small hill and all of a sudden it veered right throwing me off. I was able to catch myself (barely) but my feet dragged on the ground and my left shoe disintegrated (left ankle also twisted/sprained a little). I already bought and installed an aftermarket T bar as I am 6'2 and the knee bar did not make me feel comfortable riding at higher speed. This T bar attachment did not really help in this incident as others have noted.

I noticed the MP (before this incident) would get very 'squirrelly' going down any size hill and so I sort of knew I had to pick my 'line' going into a downhill slope. When this incident of veering right occurred I barely started downhill and it just veered off to the right. I don't recall if it was beeping or any signs of malfunction but my right knee was pretty scraped up so I rode it home (another .5 mile) over bumps and other downhill slopes. I made it home without further issues issues (thankfully). The steering bar felt 'loose' after the fall so I went about tightening up every bolt on the unit (I only had it for 2 weeks when this incident happened) and after tightening, the steering bar was as stiff/responsive as before.

I am going to contact Ninebot and see what they suggest but it will be awhile before I fully trust the MP again.

What is your weight?

[Boogieman]

My mini plus veered left, but i ASKED FOR IT.

I normally stress test new things when i am aware of that things can go wrong.

So in winter (maybe 3-4°C) i pushed my mini plus to max, as soon as tiltback wore off slightly i leaned fwd as much as i could.

I think i did that the times and it warned every time for speeding (slow down) but at the last attempt it quickly veered left (overload warning, i filmed my screen with a screen recorder app) (probably cutoff left wheel while right wheel kept running) and of i went on about 22km/h , forward and right my body went and i managed almost to run it out but the last steps was to much so i"fell" on the side, barely a black mark.

The mini plus gladly continued rolling left though and i guess wheel reengaged (as load (= me 95kg falling off) decreased as i fell off as it rolled right out towards the road and just stood there waiting like, "yo what happened, cant you balance dude" (but in a cute r2d2 voice :-p ).

Fell off in a similar way when i was trying you skid in gravel. Turn got a lot sharper than it should as one side lost grip and i guess it was not programmed for skidding so off i went, in the same direction this time. A few scratches on elbow was all as it was gravel.

But anyway, i didn't wear protection (but should have) since the speed was so low, but since i was prepared i wasn't cought off guard. Now i know the limits and can push it close to them (really hard to go past them in normal driving), but still thinking fw updates might have helped. Regardless, just like with any vehicle is good to be aware of the limits. Read data sheets about max declination, max weight, min temp if you don't feel like trying it out my way. But somehow one will get aware sooner or later unless it's just crusing (like they are actually made for) :-)

But seems like the mini pro had a different (real) problem, not related to the limits of the vehicle?

I mean downhill it can't really do much other than cutout if overloaded, even tiltback would not help. So the question is the metrics for the accident vs max metrics for the vehicle (declination angle of slope, weight of rider and so on)

 

Edited August 4, 2019 by Boogieman

[mrelwood]

Which firmware were you guys using at the times of the incidents?

[JonBMP]

11 hours ago, FreeRide said:

What is your weight?

I weigh 245 so, yes am over the weight limit but would that cause one wheel to lock out while the other keeps spinning? Firmware I have is latest - 1.4.0 installed when I bought it in July.

[FreeRide]

7 hours ago, JonBMP said:

I weigh 245 so, yes am over the weight limit but would that cause one wheel to lock out while the other keeps spinning? Firmware I have is latest - 1.4.0 installed when I bought it in July.

I can't say for sure, but it seems the MiniPro does have problems as the weight limit is reach or exceeded.  Hills seem to be one place where it's limitation appear first.  It's quite possible that the steering was not what caused it to veer, any issue between the wheels could cause it or a dip which then causes one to grab the handle bar such as you have installed.   If you want to travel safely I recommend a larger device with more powerful motor(s), make sure it has excessive power, do not operate at the limits.  At your weight I really would not trust the MiniPro.  Since you bought in July you likely have the 2018 version, which also has the reduced battery.  Do you have a the earlier model 320, or one of the newer ones?  In any case at your weight I would not think there is enough (or any) safety margin.  

[JonBMP]

50 minutes ago, FreeRide said:

I can't say for sure, but it seems the MiniPro does have problems as the weight limit is reach or exceeded.  Hills seem to be one place where it's limitation appear first.  It's quite possible that the steering was not what caused it to veer, any issue between the wheels could cause it or a dip which then causes one to grab the handle bar such as you have installed.   If you want to travel safely I recommend a larger device with more powerful motor(s), make sure it has excessive power, do not operate at the limits.  At your weight I really would not trust the MiniPro.  Since you bought in July you likely have the 2018 version, which also has the reduced battery.  Do you have a the earlier model 320, or one of the newer ones?  In any case at your weight I would not think there is enough (or any) safety margin.  

Thanks for the advice...from the model number on the MP....99997-00003, this appears to have dual 400 watt motors. Still the weight limit is the same (for 320 vs. 260 models )from what I can tell in documentation. Only difference in models - 260 being newer- is that battery is smaller in 260 model.

I was able to reproduce the jerking to right problem yesterday on my driveway and it feeds into theory that foot pad sensors affect which wheels lock at certain times along with possibility of flaw in calibration function in app.

1. I intentionally lifted MP up and pressed with right foot on right pad....MP started spinning at high speed the left wheel.

I put the unit back down rode it and seemingly no issue.

2. I then went to calibrate it using Ninebot calibration in app to make sure wheels wouldn't spin unexpectedly. I calibrated it on a slight uphill surface and upon completion of calibration, I then rode it again and the unit without even turning or touching steering bar would start jerking to right.

 

3. I then went to a more flat surface and calibrated again making device did not mean forward or back. after second calibration rode again and did not observe any jerking to right going up or down small hill.

[MetricUSA]

I guess I need to see this in person of this happening...ever since Segway put the stupid unneeded extension on knee control... People think they need to have thier legs constantly touching the arm....this is a false notion...not that is what is happening in the above circumstances... But if you do hit a bump or hole with one wheel, your leg will trigger a sudden turn! 

When I first started riding, when I got off, the one leg still on, would accidentally hit the control arm and the Segway would turn 180 ° with my foot 'trapped' in position (between wheel well and center hub)!!!! Talk about Pain! Don't ever do this!

I ride with feet touching wheel wells and never touching arm unless I am leaning into turn...

Edited August 4, 2019 by MetricUSA

[trevmar]

3 hours ago, JonBMP said:

Thanks for the advice...from the model number on the MP....99997-00003, this appears to have dual 400 watt motors. Still the weight limit is the same (for 320 vs. 260 models )from what I can tell in documentation. Only difference in models - 260 being newer- is that battery is smaller in 260 model.

No, the weight limit set by the designers for the bigger battery is only 85Kgm, and they explain why in their blog, which you can read with Google Translate from here:

http://bbs.ninebot.cn/forum.php?mod=viewthread&tid=4100&extra=page%3D1%26filter%3Dtypeid%26typeid%3D43 1/23

The 100Kgm is a number invented by the MARKETING folk stripping away the engineering safety factors, and then ruining the whole design by selling a smaller 234W-hour size battery than the design-team had intended. I weigh 90Kg, and twice the miniPRO has failed to support that weight, badly injuring me (firmware 1.1.7).

[JonBMP]

23 hours ago, trevmar said:

No, the weight limit set by the designers for the bigger battery is only 85Kgm, and they explain why in their blog, which you can read with Google Translate from here:

http://bbs.ninebot.cn/forum.php?mod=viewthread&tid=4100&extra=page%3D1%26filter%3Dtypeid%26typeid%3D43 1/23

The 100Kgm is a number invented by the MARKETING folk stripping away the engineering safety factors, and then ruining the whole design by selling a smaller 234W-hour size battery than the design-team had intended. I weigh 90Kg, and twice the miniPRO has failed to support that weight, badly injuring me (firmware 1.1.7).

Wow...not very reassuring reading this blog post link you sent...comparing the carrying load of a bag of rice up a hill seems to be geared toward one country's perspective on things and not very objective. Interestingly enough, conclusion of supporting a 15 degree slope is what the team decided on here

"

In the end, we put the experience in the first place and set the climbing ability at 15 degrees. Although the weight is increased and the cost is increased, we think it is worthwhile."

 

but hell, who knows for sure what this thing is safe to ride at unless the MP was objectively tested by UL in the U.S. or some other trusted agency for that matter.

 

So you are saying, the MP 320 is nowhere close to it's safe limits even if I ride it on flat/smooth roads?

 

On 8/3/2019 at 12:53 PM, FreeRide said:

What is your weight?

I weigh 245 so, yes am over the weight limit but would that cause one wheel to lock out while the other keeps spinning? Firmware I have is latest - 1.4.0 installed when I bought it in July.

[trevmar]

My wife weighs 70KG and has no problems at the same obstacles that caused the miniPRO to throw me (91Kg, 200Lbs).

[JonBMP]

2 hours ago, trevmar said:

My wife weighs 70KG and has no problems at the same obstacles that caused the miniPRO to throw me (91Kg, 200Lbs).

Ok..talked to Ninebot Support today....they had me do a factory 'reset' (balance MP upside down) and press/hold power button. Thought jerkiness was better initially after this reset but after 5 minutes riding on flat (slight downhill/uphill street) I started feeling it drift left and also jerk at times to left while riding at 6 mph. this thing is definitely tweaked after my fall so am hoping blackbox data sent to Ninebot today(in China of course) offers some clue as to what the hell is going on! U.S. Support was very pleasant to talk to and wanted to help but it felt like she/they were hamstrung on what to check as China/Ninebot is now where the engineering "core" team are located. 5 more days till my 30 day return is up at Fry's.....:(

[JonBMP]

On 8/6/2019 at 8:50 PM, JonBMP said:

Ok..talked to Ninebot Support today....they had me do a factory 'reset' (balance MP upside down) and press/hold power button. Thought jerkiness was better initially after this reset but after 5 minutes riding on flat (slight downhill/uphill street) I started feeling it drift left and also jerk at times to left while riding at 6 mph. this thing is definitely tweaked after my fall so am hoping blackbox data sent to Ninebot today(in China of course) offers some clue as to what the hell is going on! U.S. Support was very pleasant to talk to and wanted to help but it felt like she/they were hamstrung on what to check as China/Ninebot is now where the engineering "core" team are located. 5 more days till my 30 day return is up at Fry's.....:(

turned it back in to Fry's...from the look of shelves, I was not the only one! MP needs to be improved to handle more weight and tall(er) people...

[zzip]

Bummer!  After 500+ miles, well over half of it riding on sidewalks of various quality, with many bumps, I had the aforementioned sudden left hand turn at probably 7-8 mph.  Was able to walk away with only badly skinned knee.  Very lucky.

For last 6-8 months I have had to do the 'turn over and re-calibrate' because it would steer left.  Every time the re-calibrate fixed it.  As in other posts, I had noticed some minor abnormalities, almost unnoticeable.  Then bang, I'm on the ground.

I love this machine not sure how I'm going to replace it.  It was originally purchased to get around a large warehouse, with perfect concrete floors.  Then I started using it to walk the dog.    I don't have the time or patience to trouble shoot it.  

What are thoughts?  Based on the posts, it appears there is no consensus on what is at fault.  Are new ones trustworthy?  

(btw, 63, 185 lbs, still active and athletic)

 

[FreeRide]

4 hours ago, zzip said:

Bummer!  After 500+ miles, well over half of it riding on sidewalks of various quality, with many bumps, I had the aforementioned sudden left hand turn at probably 7-8 mph.  Was able to walk away with only badly skinned knee.  Very lucky....

 

Which exact model do you have?

[trevmar]

14 hours ago, zzip said:

Bummer!  After 500+ miles, well over half of it riding on sidewalks of various quality, with many bumps, I had the aforementioned sudden left hand turn at probably 7-8 mph.  Was able to walk away with only badly skinned knee.  Very lucky

Very similar experiences to mine except I dislocated a shoulder and an ankle (and skinned lots of knees) before relegating the miniPRO to tasks like "warehouse floors."

Although they have been discontinued and are hard to get, the Airwheel S5 is huge (75lbs) having a 1500W motor and a double-size battery, but is otherwise very similar to the miniPRO in design. Firmware is totally different, acting more like a traditional Segway than a miniPRO. Slow (17Kph max) and steady. It has 19" OD wheels with 100/100-12  4-ply motorcycle tires  and has no trouble on any of the obstacles at which the miniPRO decides to switch itself off. Have only had it for a month, so I cannot say there are no hidden 'gotchas'. But very happy at the moment. One thing though - use their app to upgrade to the latest factory firmware (3.1.1.4).

I have not tried it, but the slightly smaller (50lbs) Airwheel S3 is still being manufactured, and has all the benefits of the S5 except a slightly smaller battery (520Wh instead of 680Wh), smaller wheels, and therefore a smaller ground clearance and lower output power (1000W, 120Kg rated load). The outside diameter of the S3 wheels/tires is about 15"

Yes, they are much more expensive, but small when compared to an injury.  They are engineered and built very well indeed.

Edited August 12, 2019 by trevmar

[zzip]

Model is 99997-00003

which is the mini pro 320

[mrelwood]

Inmotion recently came out with it’s ”Minis”, E3 having pretty much identical specs to the MiniPro. Anyone tried yet?

 

[FreeRide]

2 hours ago, zzip said:

Model is 99997-00003

which is the mini pro 320

What was your battery level when the incident happened?

[Badguitar]

On 8/4/2019 at 1:48 AM, mrelwood said:

Which firmware were you guys using at the times of the incidents?

I think this is an excellent question.  I trust my MiniPro (M320) so much that reading this thread makes me re-think where I go.  I have 475 miles on my MiniPro and an running firmware 1.4.0.  I have never had any issue with my MiniPro.  Every time I connect via the app it asks if I want to upgrade and I say NO since I have never had the issue described on this topic.

It would be very interesting to know Mileage, Model and Firmware for the units that have seen this issue.  

[trevmar]

Well, I was running v1.1.7 when my ankle was wrecked and v1.1.9 when my shoulder was dislocated, as far as I can remember.

V1.3.1 (which is also the basis for Swallowbot) is even less forgiving and I similarly discarded 1.4.0 pretty quickly (along with Swallowbot).

The issue is that the MiniPRO does not give enough power to its motors to cope with fault conditions. To Segway/Ninebot, battery protection is more important than rider protection. It is the way the firmware is written, and Weagle95's last post here, the one announcing the release Swallowbot, identifies these weaknesses as being in all versions of Ninebot firmware, including Swallowbot. The miniPRO needs more batteries to safely carry a 'heavy' rider over obstacles.

You can see this, for example, in the video below. Both the Inmotion EUC and the new Gotway have approx the same motor power rating, yet one fails at rocks on the hill, and one does not. This is exactly the problem with the miniPRO. From day one I have been saying that the miniPRO will throw me (200lbs) every time I run over a 1" ledge at the base of our driveway, but not throw my 150lb wife at the same obstacle. The miniPRO shuts off momentarily and drops the rider. Then it beeps continuously to announce its hardware has protected itself from a fault condition.

However, the same heavy motor load is produced by rocky obstacles or a steep road (12 degrees) with a 'heavy' rider. Different EUC respond to these differently. The miniPRO really should not used by anybody over (approx) 170lbs. Which is roughly what its engineers designed it for (85Kg), not the 200lbs quoted by the marketing geeks (and which I weigh)... On a flat warehouse floor there is little risk of overload from 200lbs, however...

(for more info check out the post at https://forum.electricunicycle.org/topic/13495-the-swedish-hill-test-inmotion-v10f-and-gotway-nikola/?do=findComment&comment=230709

  .

 

[mrelwood]

 

2 hours ago, trevmar said:

You can see this, for example, in the video below. Both the Inmotion EUC and the new Gotway have approx the same motor power rating, yet one fails at rocks on the hill, and one does not. This is exactly the problem with the miniPRO.

I believe you are absolutely correct about the underlying issue of the MiniPro. But the video you linked to has got nothing to do with this issue.

It is a well known manufacturing/design fault of the V10F that it overheats way too easily, either because of insufficient cooling on the mainboard or overly conservative overheat limit in the firmware. All other wheels with the same sized battery are free of the issue. Going smaller, 840Wh 16S or even the V8 (480Wh?), while having a lot less power and speed, don’t overheat as easily.

And the Nikola battery at 1600Wh is a lot larger than the V10F at 960Wh.

It would be interesting to rig extra batteries to the MiniPro. Although the limits that kick in and cause the issue are probably measuring the actual motor current and not battery voltage fluctuations. So it might not even make a difference.