February 25th, 2008
Open Letter to Vectrix Corp.
also to be posted on
http://visforvoltage.org/I would like to alert Vectrix of a potentially serious safety issue with their Vectrix Maxi Scooter.
I have had two consecutive Vectrix Maxi’s fail completely during normal riding.
The failures happened spontaneously without any warning of impending trouble, and caused an immediate loss of function of all electrical systems.The indicators, front and rear light and brake light were affected along with everything else, making it impossible to signal the need to get off the road to other traffic.
It happened at about 1400km total mileage with my first Vectrix, and at 1004km with the replacement Vectrix.
I am aware of the same issue with at least one other Vectrix in Tasmania.I am disappointed to learn that almost six weeks after the initial incident, and almost three weeks after the replacement of my defective vehicle with a new one, the cause of the failure has neither been investigated, nor remedied.
I request that Vectrix makes it a top priority to investigate these failures and considers appropriate actions to avoid harm to Vectrix riders.
I will not feel safe to get back on a Vectrix until the cause of these recurrent failures has been established and remedied.
If this cannot be achieved within a reasonable time-frame, I will have no choice but to take steps to cut my losses and recover the purchase price.Please be aware that I might submit replies by Vectrix to peer review on the “V is for Voltage” forums, in order to determine if a suggested cause for the failure - and any suggested remedy - is plausible enough to warrant taking the risk for a third time.
I would however prefer it – and highly recommend it to Vectrix Corp. - if Vectrix could contribute directly to the discussions on the “V is for Voltage” forums.
Not addressing the varions problems reported by several Vectrix riders in the “V' forums is likely causing detrimental effects on present and future sales for Vectrix Scooters.
It is very unlikely that a prospective Vectrix buyer will not come across the “V is for Voltage” forums whilst researching the Vectrix. The forums come up in first place on Google searches for the majority of likely search strings.Vectrix Corp. has responsibilities towards both riders and shareholders, and might in my opinion be neglecting both by not publicly responding to the concerns expressed in the forums.
Despite the above mentioned concerns I believe the Vectrix Maxi is currently the best electric production scooter in the world.
Problems with early production new technologies are inevitable.
One can expect some initial problems, but the problems need to be taken seriously and be acted upon immediately.The public needs to be kept informed of the progress, lest the public gets the impression that there is no progress.
Yours sincerely,
This was sent on February 25th, 2008 to the Australian Vectrix dealer, three high ranking persons within Vectrix USA, and the secretary for Vectrix UK.
Details made available to the moderators in a PM.
Mr. Mik
See below - it somehow got doubled up.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I just received an email with this text:
I have considered thoroughly, and long, and repeatedly before writing the Open Letter.
The above email is so full of errors and wrong accusations, I do not know where to start.
Neither do I see the immediate need to start on it.
There was no tampering, no third party anything.
Equating a sudden loss of all power at 60km/h (on two new Vectrix scooters) with a stall during take-off characterizes the caliber of the other false comments in the email.
I can back up every single word I posted, and if necessary I can start to post the multiple unanswered emails I wrote. I just do not think that would be in anyones interest at this stage.
At this stage I would like to invite the dear reader to review my multiple postings, and then comment on this question (or comment anyway on whatever you feel is appropriate):
What part of the test rides on my two Vectrix scooters was outside of the advertised specifications?
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Here is what the ACCC has to say in this respect:
"If it appears to the minister that certain goods create an imminent risk of death, serious illness or severe injury, an emergency order can immediately be made, without a conference, for a ban or a product recall, disclosure of defect and disposal, repair, replacement or refund of price."
http://www.accc.gov.au/content/index.phtml/itemId/788555/fromItemId/788579
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
"...It is apparent that you have been using your Vectrix beyond the scope of normal use, as evident by the many trials you have posted on the internet. I am also concerned of the tampering evident on your first vehicle, including third party lubricant added inside the throttle housing and other signs of dismantling which were not evident at the time I agreed to exchange your first vehicle..."
So far it sounds like you have been diplomatic and fairly reasonable. I have two questions. (I don't own an E-Scoot, but I am interested in their developement and their integration into society for those individuals for whom they may be useful).
Is he implying that you added unauthorised lubricant (to what I can only assume was a "sticky" throttle, why else to add lubricant?) that may have caused an electrical short?
It also seems to be a vague statement about you using your vectrix beyond "normal use". He doesn't state what he feels normal use is, but accuses you of somehow being "too hard" on your Vectrix (and assumeably, your severe use exceeded the Vectrix's capabilities, and led to a failure that "gentle use" would not have).
Briefly, could you describe you weekly user profile?
While it is unfortunate, Mr. Mik that you are experiencing these difficulties, I would like to add some positive input. I love my bike it brings me nothing but joys and thrills.
I'm 18 and I ride pretty dang fast, and its cold here. I notice that the battery provides slightly less power, for hard acceleration at about 45 degrees F and below. I've riden well below freezing with no problems. I ride in the mountains, city, and highway. How ever I acknowledge that my bike does significantly less 'work' than yours because of the payload.
My brief problem was due to assembly error and quickly fixed. No other problems to report, even my partly charged battery issue cleared up after firm ware update.
I hope you and Vectrix can work things out in a symbiotic manner. Best of luck to both of you!
I received an email today from a newly appointed technical representative for Vectrix in Australia.
It shows some serious commitment to start working out the problems.
Rather than posting the entire email here, I post my reply to it:
(Names changed: TR= Technical representative; SM= salesman; Mr. Mik=myself)
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Thumbs up to your TR so far: good luck Mik! :D
Time for an update, for as of today I have had more days with a non-roadworthy Vectrix than with a road-worthy one.....
That applies to each individual Vectrix as well as to the overall total so far.
.
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I have exchanged several more emails with the new Vectrix technician (TR) and also spoke with him on the phone a few days ago.
TR requested that I keep our communications confidential for now until the cause of the problems has been determined. Fair enough.
He has come up with a hypothesis regarding the failures of my two scooters, but it's too complex for me to fully assess it's validity.
I believe that it will also be too complex for TR to assess the validity of the hypothesis without full cooperation by Vectrix Corp.
As far as I know he has asked Vectrix for advice, but I have no way of knowing if Vectrix Corp. are doing anything about the problem, if they are giving sensible answers to TR's questions, or if they are even answering at all.
I have not received any reply from Vectrix Corp. to the Open Letter so far (except from SM and TR as outlined above in this forum).
Mr. Mik
ps: I emailed the text of this post to "TR".
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Why don't you just ask for your money back and wait till a dependable, reliable scoot of this size is available. I'm sure somebody will be coming forward with that eventually. I mean for the money these scoots cost you could have probably purchased a great EV conversion done by professionals on an existing auto that you like!
Just my thoughts...
Gushar
Gus
I must admit, some of the responses of the first e-mail were rather contrived. Except for reduced range due to steady high speed use, Rural use should be easier in the scooter than stop and go city use.
However, I must agree with the e-mail that the safety issue of sudden loss of power on a motorcycle on the highway cannot be compared to sudden loss of power, and subsequent stall, of an aircraft on takeoff.
I can't make up my mind if you are kidding or if you read "SM"'s email a bit too quick.
He requested that I change the fault description to:
But in fact, both failures happened at a steady speed of about 60km/h on a mild uphill road.
No aircraft has been involved (so far).
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
yep, I was skimming the e-mail, saw "stall" and "take-off". and thought "airplane".
I'm not familiar with the term with regard to motorcycles.
As Gilda Radnor in the old "Saturday Night Live" news skits used to say: "Neever Mind!"
Uhhhh, isn't this an electric bike?
Usually when people talk about a bike stalling at take off they are referring to a motorcycle with gears and a clutch, and the reason that it stalls is generally attributed to operator error (IE they popped the clutch too soon).
You would have been soooo right until the glorious appearance of the Z-20!!!
It has taken stalling to a whole new (electric!) level!
As DonChristobal wrote:
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Well, my Vectrix Nr. 2 has been fixed by "TR" (= Technical representative) and is running again since March 19th, 2008.
"TR" has been very good in trying to work out what the problem is that is causing the failures.
As I expected, it was the main fuse = motor controller fuse that blew, again.
The question is WHY DOES IT CONTINUE TO HAPPEN?
.
After fixing my Vectrix' fuse we drove to Brisbane and TR fixed the same fuse in another Vectrix, with less than 1000km on the odometer.
Thats four blown main fuses that I know of with certainty.
.
Because the fuses all failed unannounced and cut all power instantaneously it's kind of important to work out why, before one fails at 100km/h on the middle lane on the highway.
I would like "Peer Review" from the knowledgeable VisforVoltage members to help me decide if the explanation - and proposed cure - is good enough to risk a potential third failure in traffic.
.
.
.
Here are the core components of the hypothesis proposed by TR:(as I understand them)
A) The fuse burns incrementally until it suddenly burns completely under no particular load.
.
B) The partial burning of the fuse is caused by "Rotor Slip" in combination with low battery levels. This is supposedly causing current surges which are worst when a low battery is required to supply high amps, as in riding uphill at full throttle when the battery is almost empty.
It could also be worse when the battery is hot due to high ambient temperature and/or prolonged high speed or uphill driving.
.
C) The problem (recurrent small, additive damages to the fuse) can be prevented by avoiding driving in hilly country with less than 4-5/17 left on the battery display.
.
.
.
Here are some pictures of the dead fuse:
The scale is metric.
Littelfuse
POWR-GUARD
SEMICONDUCTOR FUSE
L25S 125
250VAC
250VDC
RoHS SA SU
I. A. 200KA
POWR-GUARD Products
Des Plaines, IL
1800-227-0020
Assembled in Mexico
..
.
Here are some links to pages about the fuse:
http://www.ortodoxism.ro/datasheets/littelfuse/L60S8.pdf
http://littelfuse.com/data/en/Data_Sheets/semi.pdf
The old fuse out of my Vectrix looks slightly different to the fuses in the pdf files above. And the replacement fuse I'm riding around on looks just like the blown one....
.
Here is a picture of the replacement fuse mounted in my Vectrix:
.
Apparently Vectrix Corp had not answered TR's questions regarding the above hypothesis, but instead said there had been a faulty batch of fuses. But that info is now weeks old and might be outdated.
.
.
My main problems in assessing the validity of this hypothesis are these:
Re A): I cannot find info on how these particular fuses blow - is it all-or-nothing or a-bit-at-a-time? And why would the last bit of the fuse blow at 60km/h slightly uphill with a 3/4 full battery?
Re B): It appears to me that Rotor Slip might indeed cause a current surge in a DC motor controlled by a VFD (Variable Frequency Drive), but I am out of my current depth here.
What I definitely don't understand is why a hot battery (with higher internal resistance) would make it worse; I figure if it has higher resistance, it will deliver less amps, and would be less likely to blow the fuse.
Thanks for your help!
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
few comments:
I've never heard of a normal fuse burning out "a bit at a time"- the fusible metal reached it's melting point and rapidly breaks the circuit, or it doesn't. A "semiconductor fuse" is even faster acting. I'd be suspect of the technical competence of anyone who stated a fuse could burn out a bit at a time.
Is this fuse for the battery pack circuit? Motor phase circuits?
The current should be dictated only by motor speed (lower = higher current) Motor torque (higher = higher current) and the controllers current limiter setting. I'm not sure how the battery pack state of charge could anything to do with it.
Can you explain what "rotor slip" is? Does the Vectrix have some kind of torque converter?
The fuse seems to be connected to the "plus" cable of the battery. See photo of circuit board above.
Regarding rotor slip: I spent a few hours researching it and have a basic understanding of it now, but am not ready to explain it clearly.
Here is a good starting link:
http://en.wikipedia.org/wiki/Induction_motor
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I'm a bit surprised they don't use a relay. Then you could just press 'reset'.
It is a mayor job to replace that fuse, and it is potentially lethal due to the electricity involved. It takes 1 to 2 hours for a trained technician. It also involves lifting about 45kg of battery out of the frame.
To re-connect the batteries after replacing the fuse a special cable is needed that connects the two batteries together for about 1/2 a minute before connecting them permanently.
The blue connector in the below picture must be disconnected to avoid electrocution. This blue connector is also the one that needs to be "bridged" for 1/2 a minute before reconnecting it.
A push-to-reset type of fuse would create an immediate and full connection, instead.
It would likely fry something, but I do not know what exactly.
But I'm still out of my depth, paddling and catching a breath here and there...
Luckily I am good at diving!
From the location of the fuse I would say that it was expected to rarely need replacement.
In regards to the "Rotor slip" phenomenon:
"The fuse could be blowing because of excessive rotor slip, this is when the rotor speed falls behind the coil frequency of the windings and causes a stalling effect even though the motor is turning. The result is very rapid increase in current draw and pop goes the fuse."
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Here is more detail about the fuse:
Follow the Link for more information: http://www.littlefuse.com/part/L25S125.html
Does anyone know if this type of fuse can blow "incrementally", or get slowly damaged by operating conditions until they suddenly fail?
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I don't know much *cough* about semiconductor fuses, but I'm inclined to say, "No."
A metal fuse could, however, potentially burn out slowly. If it's the "right" size, it can get a little melted every time you accelerate, and eventually get to the point to where it just gets hot, increases its resistance (in turn getting even hotter), and suddenly blow. I did this with my skateboard fuse once. Not very often that happens, AFAIK.
The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai
I found an interesting website containing something about the use of fuses for solid state controls.
If the writer is right, then maybe the fuse in the Vectrix is not going to do the job of protecting the controller, anyway!
I could so far not find any specs or testing that verify that the fuse (Littelfuse L25S 125) meets the 2ms requirement for protection of solid state controllers that the writer claims is necessary.
Here is the link and a bit of the text:
What sort of fuses (or other protection) do the other commercial and DIY E-bikes have between batteries and controller?
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Hello,
nice pics,
About the slip effect, the Vectrix motor is not an induction motor. It seems to be a brushless permanent magnet motor : Vectrix motor
Jean-François
That is a new approach, placing the motor in the swing arm. Also if I under slip correctly it can not happen in this type of a motor so the tech seems to be blowing smoke. (I might be wrong?)
Grandpa Chas S.
Chas - is that a pic of the Vectrix swing arm? That's a nice setup - now all they need to do is replace the single-stage planetary gearbox with the DaVinci (is that right) set up. It strikes me this is the "best of both worlds" (world 1 being hub motor for minimum transmission loss/minimum noise and world 2 being non-hub-motor so that one can have more flexibility with gearing).
Mik - sorry I don't have much to add to the peer review.
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
Thank you all for your input so far!
I could not find any info on it in writing either, so I called Littelfuse today and spoke with an engineer.
He confirmed that the L25S 125 type of fuse can indeed receive small incremental damages from "transient currents" or "inverse pulses".
"It could be that transient pulses open the fuse after having been applied a number of times".
.
Regarding what the fuse does: According to TR it protects the IGBT on the VFD card; and also guards against runaway current in the event of excessive loading on the VFD systems.
.
So far then, this part A) of the hypothesis holds.....
.
.
So, on to part B), the rotor slip/eddy current/stalling effect part of the hypothesis:
I initially also thought the explanation might be incorrect, so I asked "TR":
I cannot recall the exact answer, but as a synopsis of various conversations I can put this together:
The only really new part of the Vectrix technology is the motor.
Everything else is made of proven, standard electronic components (of high quality).
Although the motor is a DC motor, it is controlled by a VFD (Variable Frequency Drive) and therefore shows some of the characteristics of AC motors (like rotor slip).
Eddy currents in the rotor housing could change the coil inductances and thus change the coil resistances affecting the current draw.
That might cause the incremental damage confirmed to be possible by the Littelfuse engineer.
Does this make sense?
Thanks again,
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Strange.
i found articles about the electronic board and motor :
board pic ; Texas instrument chip ; chip doc
In the second one, they talk about "tuning the motor's phase angle advance". This can cause big unexpected current if done incorrectly and can be compared to "slip".
In this article, is mentioned the TI TMS320F241 which has apparently been discontinued.
The previous reference LF2401aseems to be the actual version.
What is yours ?
If you had a higher resolution pic of the board, you could read the references of the components and googling it could give more infos.
BUT according to the way of Vectrix Corp answered you, i don't think they will appreciate this kind of reverse engineering...
Jean-François
Thank you, great finds!
Does anyone know if this sort of post could be seen as reverse engineering?
I would actually see it as a very forward way of collaborative troubleshooting.
Of course it's a worry if Vectrix Corp has the SH*** with me, particularly when looking at the complexity of some of the electronics needed to run the scooter.
It would be a very interesting project to keep it going without a warranty...
I think this deserves a new forum: What is reverse engineering?
http://visforvoltage.org/forum/3231-what-reverse-engineering
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
"SLIP --if an armature whose conductors form closed circuits be placed in a rotating field, it will develop dortorque because of the induced currents acting in conjuntion with the rotating field" the armature can attain the speed of thr rotating magnetic field, for if it did the cutting of conductorsby flux would cease and there would be no rotor current toruqe " "the differencebetween the speed of the rotating field and that of the rotor is called the revolutions slip" quote from Dawes Electrical Engineering V II copy 1947 a bldc motor is but an ac motor with the bias line moved to mid voltage and rotatied my artificial meens
thank GOD I wake up above ground !!!!
After some deliberations at http://visforvoltage.org/forum/3231-what-reverse-engineering#new
(and another day without an answer from Vectrix Corp) I decided it is necessary to supply some more information in order to come to reasonably reliable conclusions here.
So here is the portion of the board in question, hope it helps:
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
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