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dmethvin last won the day on April 15 2016

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About dmethvin

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  1. Ideally all the components in the system are sufficiently over-engineered so that they work properly in the most demanding situations, then you introduce a weak link like a fuse that is designed to fail before any of the components do when you're way outside normal operating range. However it must be difficult and/or expensive to design an EUC like that. It doesn't help that we emphasize maximum speed/range and constantly try to shave any margin of safety these wheels offer. Plus, when a tall 120kg person is riding it, all the testing by short 70kg Chinese riders mean nothing. The current state of the art seems to be a "shut off to protect the device" versus "keep balancing at all costs to protect the rider" trade-off. Wear a helmet.
  2. Since that fuse isn't active while riding it should be okay to do that. If it was in the power train during operation the only way I'd put in a fuse is by soldering it in. Too much shaking going on!
  3. My charge wires don't have reverse current protection or a fuse either. It's actually more common than you might think. Reverse current protection requires a diode, which introduces a 0.6-volt drop and that would ideally be accounted for in the charger. Usually the charge wires are thin enough that they'd act as a very crude fuse, but in my case they're wrapped with a bunch of other wires and it would be a mess to fix after that. Since the charger is usually 2 to 5 amps, you could easily put a 10 amp fuse on the charge lines and still offer reasonable protection. Of course if the fuse blew it would require disassembly of the EUC and might be hard to diagnose so maybe that's why they don't do it.
  4. Whenever I open up my wheel I am surprised how many things might go wrong. These wheels are shaking and jumping all the time, providing opportunity for wires to fray or connectors to work loose. Those motor wires take a very sharp turn at the point where they come out of the hub, and the spring around that wire tends to become deformed and not fully protect the wire. Be especially careful if you disassemble your wheel for example to fix the tire. Don't let any wires kink or get pinched!
  5. Has anyone seen reports of people being killed on an EUC? Those people aren't going to vote you know. I've had a couple of high-speed cutouts where I got some bad scrapes, and one where I hit a pothole and fell on my butt. Fortunately my butt provided enough cushion for that one.
  6. Don't worry about it! A few scratches don't hurt anything. By the time you've really beat it up you're ready for a new wheel.
  7. Yes, it is the debate on whether to get a "learner wheel" vs start with the Gotway Monster. If I was just getting started and didn't know whether I would be serious about EUCs, it might make a lot of sense if I could get a Ninebot C+ at a good price. The person who originally bought this is a good example of a person who would have wasted a lot more money by going with a more expensive wheel. They didn't ride it for 2 years and now they'll sell it at a loss.
  8. Just as a single data point on battery lifetime, I have had my Firewheel for 22 months and the battery seems to be in very good shape. I do tend to keep it at about 50-80% charge and use a Charge Doctor for a "full" charge close to the time I'm leaving. Only rarely do I top it off past the Charge Doctor cutoff. So if the EUC has been stored for a couple of years near half charge the batteries could be fine. They're usually too heavy to ship, so try before you buy and bargain for a good price.
  9. Wat? How did you quantify this?
  10. I think there are many wheels that do not have a diode on their charging ports, I'm pretty sure my Firewheel does not because I've shorted it before by accident. The charging wires are thin enough that they're basically a fuse if there is a sustained short circuit of a battery that size.
  11. I had one of the older boards that fried, but the replacement has lasted almost two years now. If it ever goes out I think I will get a new wheel, the case is pretty scratched up at this point. The battery is doing very well though!
  12. You could replace it if you just want to know it's a good fuse. Not sure what physical size the current fuses are but the MAXI should be close to the same size. Since all these fuses are technically going over the max voltage rating (32V) I wouldn't go with a smaller form factor.
  13. You can look up the curves for name-brand fuses to see how long it takes them to blow at which current levels. You can see one sample curve here for the Littelfuse MAXI series, which shows that even a 40A fuse can take a 100A load for about a second before blowing. If your EUC is drawing 100A for anything close to a second it is probably shorted. However, I would not trust that a cheap no-name 40A Chinese fuse would follow the same curve as a Littelfuse data sheet, even if it was the same size and color.
  14. I've used one of those small bike cable locks to secure my EUC to things when I was in a coffee shop and needed to go to the bathroom. I don't think I would ever leave it locked up at a bicycle stand for example, especially an outdoor one. It definitely must be tricky for the 18-inch and bigger wheels, you really can't carry those comfortably.