houseofjob Posted November 11, 2017 Share Posted November 11, 2017 @LanghamP Looks like a variant of the almost 10-years old, gas-powered Australian Wheelman. Definitely not electric, you can see the gas tank in the middle compartment. Many Alibaba/AliExpress sellers tend to rip their product listings & descriptions off each other. Way better now is the electric DualtronMan that I own (electric is much quieter), one of the first electric-motored Wheelmans, made by a reputable, category-leading Korean e-kick scooter company called MiniMotors. DTM via MiniMotors DTM via KWK Smart Life / AliExpress My DualtronMan / Tami Wheeler YT Playlist My DualtronMan / Tami Wheeler Tricks YT Playlist Link to comment Share on other sites More sharing options...
US69 Posted November 11, 2017 Share Posted November 11, 2017 10 hours ago, Marty Backe said: Tell me about it. I guess I've learned the hard way about another scenario to be avoided with Gotway wheels. Never apply forward force on the wheel if it can't move. Sorry for your Mten failure...that sucks when the beloved wheel has to wait for a new board :-( But btw. Pushing a wheel when it is stuck somewhere might blow up ANY mosfet, no matter which brand. That should allways be avoided...gyro will go forward, amps get the highest peak as possible, but no way to go-> blow :-( Link to comment Share on other sites More sharing options...
meepmeepmayer Posted November 11, 2017 Share Posted November 11, 2017 That's what fuses should be for? Or do they not blow fast enough to protect the mosfet? Link to comment Share on other sites More sharing options...
US69 Posted November 11, 2017 Share Posted November 11, 2017 1 hour ago, meepmeepmayer said: That's what fuses should be for? Or do they not blow fast enough to protect the mosfet? Yes, sure, on a KS you have the board protection.... I just wanted to state that this behaviour leads to damage on all wheels, not only on Gotway. Link to comment Share on other sites More sharing options...
Slaughthammer Posted November 11, 2017 Share Posted November 11, 2017 1 hour ago, meepmeepmayer said: That's what fuses should be for? Or do they not blow fast enough to protect the mosfet? A transistor, combined with a fast acting melting fuse will reliably protect that fuse by burning faster ;-) Link to comment Share on other sites More sharing options...
Chriull Posted November 11, 2017 Share Posted November 11, 2017 2 hours ago, meepmeepmayer said: That's what fuses should be for? Or do they not blow fast enough to protect the mosfet? 37 minutes ago, Slaughthammer said: A transistor, combined with a fast acting melting fuse will reliably protect that fuse by burning faster ;-) Depends on the amperage of the fuse - could be a tricky design issue to find the right amperage/sensitivity between creating a new faceplant risk and just having the mosfets protecting the fuse... Imho a firmware side protection for this cases would be the best solution - there are already some current/power limits implemented. Calculating the thermal power dissipation abilities in the firmware is not a big deal... Maybe some additional temperature sensors would be helpfull (ambient, compartment and heatsink temperature). Link to comment Share on other sites More sharing options...
meepmeepmayer Posted November 11, 2017 Share Posted November 11, 2017 Is there a (resonable) purely electrical (non-firmware, only in hardware) possibility of preventing mosfets blowing with locked wheels? Link to comment Share on other sites More sharing options...
Chriull Posted November 11, 2017 Share Posted November 11, 2017 15 minutes ago, meepmeepmayer said: Is there a (resonable) purely electrical (non-firmware, only in hardware) possibility of preventing mosfets blowing with locked wheels? Yes, a fuse at the battery side or 2-3 at the motor side. At the battery side it would be easier (less amperage) and by this less voltage sag/implications while normal operation. One just should do some measurements before to get the right ratings, or one risks the beformentionent new faceplant cause or a useless fuse.. Edit: also an electric fuse which resets automaticly after some time could be a nice solution... Link to comment Share on other sites More sharing options...
Marty Backe Posted November 11, 2017 Share Posted November 11, 2017 4 hours ago, KingSong69 said: Sorry for your Mten failure...that sucks when the beloved wheel has to wait for a new board :-( But btw. Pushing a wheel when it is stuck somewhere might blow up ANY mosfet, no matter which brand. That should allways be avoided...gyro will go forward, amps get the highest peak as possible, but no way to go-> blow :-( What's frustrating is that I didn't even know that I was in this situation. It was literally ~1 second. In the future I'll avoid all possibilities of riding where the wheel might briefly get wedged into something. Link to comment Share on other sites More sharing options...
Treponema Posted November 11, 2017 Share Posted November 11, 2017 On 10/11/2017 at 12:47 AM, guyr said: I'd rather not die. But the Tesla is newer, so much more powerful, and cheaper. I'm about to buy my first EUC . I'm debating this too. Higher spec's on the tesla, vs reliabilty of the kingsong. However i've found them both for the same price. Link to comment Share on other sites More sharing options...
Marty Backe Posted November 11, 2017 Share Posted November 11, 2017 5 hours ago, Treponema said: I'm about to buy my first EUC . I'm debating this too. Higher spec's on the tesla, vs reliabilty of the kingsong. However i've found them both for the same price. As far as we know, nobody has died from an EUC accident. Can't say the same thing about bicycles or skateboards. Link to comment Share on other sites More sharing options...
esaj Posted November 12, 2017 Share Posted November 12, 2017 On 11/11/2017 at 2:06 AM, Hunka Hunka Burning Love said: Aw man that sucks. Hopefully they can express a new control board out to you quickly. Too bad they can't use like a resettable fuse like on a GFCI outlet so at least when it blows you just press a button to get it working again while it protects the control board. Ground fault current interruptor is not a fuse, it measures the outgoing and returning current, and if there's too big of a difference (like 10-30mA), it interrupts the circuit, because current is "leaking" to ground/earth somewhere (usually something has shorted to ground/earth). The current limit is small, because the short might be caused by a person, and 10-30mA is low enough not to kill (usually). But it won't work as a fuse, ie. it won't cut the circuit based on the total amount of current, but small amount of "missing" current. Someone might wonder why they won't cut even at lower missing current, but many house appliances "leak" a small bit of current to earth, and some devices do this by design via a resistor going to ground/earth (I must admit that I don't know why though). That said, there ARE resettable fuses (called "automatic fuses" here, automaattisulake in Finnish, GFCI's are "vikavirtasuoja" in Finnish), but they usually don't have very large current carrying capabitilities, at least the ones I've seen have usually been made for 110/230V (RMS) mains, something like 10 or 16A, and they're fairly large as they're meant to be installed in a mains cabinet DIN-rail: There might be physically smaller-sized, higher current limit versions of automatic fuses too, but a wheel can draw very high transient current for short while during take off or acceleration (tens or even a hundred amperes for high power models?), and they might cut the power when it wasn't really supposed to KS uses 30A or 40A blade-fuses on the board where the battery wires come in (separate per battery pack for the KS16S, so 80A total basically), although I guess most of the transient peak current is delivered by the capacitors on the board and not drawn (as much) from the batteries themselves. At one point I was considering PTC-fuses (Positive Temperature Coefficient, the kind of polymer-fuse that cuts the power once it overheats from too high current and then resets after it cools down) for something I was planning to stick to my wheel, but SMD-versions of those have usually a voltage limit of up to 60V, above which they might not work (ie. they might not cut the power when they're supposed to), some THTs go up to 72V. Link to comment Share on other sites More sharing options...
Chriull Posted November 12, 2017 Share Posted November 12, 2017 On 11.11.2017 at 11:47 AM, KingSong69 said: ...But btw. Pushing a wheel when it is stuck somewhere might blow up ANY mosfet, no matter which brand. That should allways be avoided...gyro will go forward, amps get the highest peak as possible, but no way to go-> blow :-( On 11.11.2017 at 3:27 PM, meepmeepmayer said: Is there a (resonable) purely electrical (non-firmware, only in hardware) possibility of preventing mosfets blowing with locked wheels? Imho after looking into this a bit more i would reject this, especially in regard to "reasonable"... 22 hours ago, Marty Backe said: What's frustrating is that I didn't even know that I was in this situation. It was literally ~1 second. In the future I'll avoid all possibilities of riding where the wheel might briefly get wedged into something. I just made two graphs with the maximum power/current over speed abilities of an EUC (should be around the data for an MSuper v3s+, no switching losses regarded for the mosfet). Once with the quite some time ago by gotway representative stated 120A motor current limiting by firmware: If now for this wheel if it is stuck and the ~120A current limiting is working and the mosfet blows up in this situation after ~1 sec, there is not much to do but hope for better firmware itendifying this "stuck wheel" state to protect the motor. This maximum current by limiting can be reached up until a bit over 30 km/h in the max load situations - the only difference why the mosfets survive at higher speeds could be the head wind and then the next weak link in danger are unsufficient wires/connectors? Current measuring (for example at the two shunt resistors in the motor current path) and by this cutting the battery supply after some delay ("electric fuse") would by this endanger one to get a "high speed" cutout going up a steep hill! A "simple" fuse at the battery side won't help too much either, as maximum current at the battery side at about stand still is "just" a bit above 30 Amps and raises to a maximum of ~80+ Amps at ~30 km/h. So the fuse has to withstand ~80+ Amps not helping anything for the stuck wheel state. For the case this current limiting is not really working perfectly (for low speeds) this would lead to about the following situation: So here some 100A (?medium?) fuse could maybe help?! Still leaving some additional risk to cause some higher speed faceplants. And 100A fuses are not really small and nice ... This graphs are just extrapolated from some data given from @zlymex and they are just good to get some ideas about the dimensions - i would not dare to base any fuse design on this. This would need extensive measurements to get real reliable data and the most work should be in the following analysis, so no "operating point"/state of the wheel is missed. One has the differents battery states (capacity, voltage, internal resistance), changing coil resistance of the wheel by temperature, ... The exact controll protocoll of the 6 (12) Mosfets in the H-Bridge should be analyzed (for example how free-wheeling is achieved - active or "just" via the body diodes. ?maybe the "algorithm/design" is just prone to bridge shut throughs in the stuck state?).. The case of braking with the wheel also should not be inflicted by the "fuse"...Which kinds of limiting is already implemented in firmware should be analyzed: In some past firmware updates for the KS16 B/C an increased power limit for low speeds was announced to cure the "cut-off at drive-off" Would be interesting if modern KS (or other brands) survive this stuck state - I felt the urge to try it with my KS16S but resisted - one does not have to know everything Link to comment Share on other sites More sharing options...
dmethvin Posted November 13, 2017 Share Posted November 13, 2017 On 11/12/2017 at 9:23 AM, Chriull said: So here some 100A (?medium?) fuse could maybe help?! A typical melting-link fuse rated 100A will tolerate probably 200A for 0.25 second and by then you've fried something. I think this problem would need to be solved in firmware. Detect that the wheel isn't spinning but there's a lot of current being applied, and shut off after half a second or so? Link to comment Share on other sites More sharing options...
Stanor Posted November 13, 2017 Share Posted November 13, 2017 @Marty Backe Not even afraid ! I go there every day, with my feet on my wheel! Link to comment Share on other sites More sharing options...
Marty Backe Posted November 13, 2017 Share Posted November 13, 2017 32 minutes ago, Stanor said: @Marty Backe Not even afraid ! I go there every day, with my feet on my wheel! Looks almost identical to what I went through that day. Don't say that you weren't warned Link to comment Share on other sites More sharing options...
Stanor Posted November 13, 2017 Share Posted November 13, 2017 @Marty Backe I noticed one thing: the difference between an American setting, and a French setting ... Link to comment Share on other sites More sharing options...
Marty Backe Posted November 13, 2017 Share Posted November 13, 2017 18 minutes ago, Stanor said: @Marty Backe I noticed one thing: the difference between an American setting, and a French setting ... I hate to disappoint you but the picture I used came from Google Image Search. It's not the actual turnstile that I got stuck it. So the "USA" model may actually have been in France Link to comment Share on other sites More sharing options...
Stanor Posted November 13, 2017 Share Posted November 13, 2017 Link to comment Share on other sites More sharing options...
Cannings Posted November 15, 2017 Share Posted November 15, 2017 Thanks for this thread, gave me some good advice on my first euc, gone for the Tesla Link to comment Share on other sites More sharing options...
Meng Yang Posted November 15, 2017 Share Posted November 15, 2017 2 hours ago, Cannings said: Thanks for this thread, gave me some good advice on my first euc, gone for the Tesla Tesla's an awesome wheel! Today, I was following a few cyclists around at 40+ kph ... fun! Link to comment Share on other sites More sharing options...
guyr Posted November 16, 2017 Author Share Posted November 16, 2017 Thank you for the very helpful replies! I've gone for the Tesla as well Link to comment Share on other sites More sharing options...
Zenko Posted November 16, 2017 Share Posted November 16, 2017 5 hours ago, guyr said: Thank you for the very helpful replies! I've gone for the Tesla as well I hope you don't die buddy ! As much as I like @Marty Backe intervention, I must say that GW has a huge record for cut-off... Dude you have even been caught on camera, remember the oscillation cut-out ? Well, I saw that. Even today, Tesla get some cut-out videos, from unknown reasons, design failures, and you can't say yet this wheel is reliable. No one is dead yet from EUC, but we're getting in the speed when it's getting easier to die from a simple fall. I've seen a case of huge hospitalization because of a fall. You might not worry to much about design failures for previous GW models, but still have to worry about quality failure, that's why every cautious GW rider has to open it up and check if everything is alright. Now with Tesla, you need to worry about quality failures AND design failures, since this new model gets to new land (big W motor, motherboard confinement with vent...). Be a cautious DIY like @Marty Backe and you will probably not have troubles doing the right checks, but if you're not into getting you hands dirty, i would highly advise to go for a KS brand for now. I respect Tesla buyers as they stay aware of this, I even own a GW ACM16, but facts for now make GW less reliable than recent KS models, that's a fact, even if pilot's behavior make it 95% of falls & accidents. I just don't want to be in the 5% lot. Good ride ! Link to comment Share on other sites More sharing options...
Zenko Posted November 16, 2017 Share Posted November 16, 2017 1 minute ago, Zenko said: I respect Tesla buyers as they stay aware of this, I even own a GW ACM16, but facts for now make GW less reliable than recent KS models, that's a fact, even if pilot's behavior make it 95% of falls & accidents. I just don't want to be in the 5% lot. And i said that with my GW, wow. Well it was the only wheel i could get at that time :'( Plz don't bash ! Link to comment Share on other sites More sharing options...
xebeche Posted November 16, 2017 Share Posted November 16, 2017 1 hour ago, Zenko said: I hope you don't die buddy ! As much as I like @Marty Backe intervention, I must say that GW has a huge record for cut-off... Dude you have even been caught on camera, remember the oscillation cut-out ? Well, I saw that. Even today, Tesla get some cut-out videos, from unknown reasons, design failures, and you can't say yet this wheel is reliable. No one is dead yet from EUC, but we're getting in the speed when it's getting easier to die from a simple fall. I've seen a case of huge hospitalization because of a fall. You might not worry to much about design failures for previous GW models, but still have to worry about quality failure, that's why every cautious GW rider has to open it up and check if everything is alright. Now with Tesla, you need to worry about quality failures AND design failures, since this new model gets to new land (big W motor, motherboard confinement with vent...). Be a cautious DIY like @Marty Backe and you will probably not have troubles doing the right checks, but if you're not into getting you hands dirty, i would highly advise to go for a KS brand for now. I respect Tesla buyers as they stay aware of this, I even own a GW ACM16, but facts for now make GW less reliable than recent KS models, that's a fact, even if pilot's behavior make it 95% of falls & accidents. I just don't want to be in the 5% lot. Good ride ! Ouch! What the heck even happened there? Was it cut out or gyro went nuts after the wheel hit that bump? Look at the pedals after he hit the bump, but the wheel seems to have kept running? Nasty, nasty fall Link to comment Share on other sites More sharing options...
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