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Seba

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Seba last won the day on January 31

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About Seba

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    https://najednymkole.pl

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  • Location
    near Gdansk, Poland

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  1. This is intentional. Pause button is mainly intended to show on the map that you took a break. It will still record your mileage, wheel data and track. In addition, when you are "paused", if you turn off the wheel without disconnecting, you won't get connection lost beeps. If you want to stop tour recording, just finish it. Soon I'll implement tour segments, currently it's not working (regardless of setting, new tour is started).
  2. It's common to protect aluminium sheets and heatsinks with plastic foil. So it could be a small strip of such foil that unnoticed left bounded to the heatsink plate. To be honest, I don't know and I don't believe it's the case. And I admit that I may be wrong, but I don't think it's a residue of protective foil from silicone thermal sheet. I've been using this kind of thermal insulation for years and never received from the supplier with any kind of foil or paper. Of course there are thermal sheets that are protected with foil. But this usually applies to gel or rubbery, elastic (usually white, blue or rose) sheets that is somewhat adhesive by itself and need to be protected from dust etc.
  3. In general it's a bad design practice to keep heatsink at any electrical potential. It's also common that low-side MOSFET drains are not connected together and directly to the negative battery terminal, but there are separate shunt resistors to measure phase current. Also I wouldn't blame silicone insulating sheets as they're very goot thermal conductors. Not as good as thermal silicone paste, but difference is not important here.
  4. You can't use paste in this case, because metal tab of each MOSFET is electrically connected with center pin (so called "drain"). You can also notice a plastic insulation sleeves used to insulate thermal tab from the screw (that is electrically connected to the radiator). This type of insulation thermal sheets is not adhesive and there is no additional paper or foil.
  5. You're right. It also seems that there is no temperature probe near the radiator or MOSFETs. This is a major design flaw, as PCB temperature where temp probe is apparently located in Nikola, being additionally cooled by the fan located on wrong side, doesn't reflect MOSFET tab or package temperature. This is why @Marty Backe got misleading, very low temperature readings. For example, in KS-18L/XL there is a temperature probe located close to the heatsink and MOSFET that is farthest from the cooling fan. This is why L/XL may be perceived as a "hot running wheel". Nikola wasn't "cold running wheel", it was just a "very hot running wheel with low temp readings". From what I see, PCB design may cause MOSFET source (S) leg to overheat, as there is highest thermal resistance due to small copper pad directly under the MOSFET leg. I don't see the other side, but i assume it's similar so drain (D) legs are also connected using small pad located on an edge of larger copper plane. Another design flaw is to use two TO-220 MOSFET instead of one TO-247. Doubled small package design is prone to many failures. MOSFET leg fracture during bending or PCB assembly will increase leg resistance. Improper soldering or improper PCB design may cause current imbalance, so it wont be divided 50/50 between both transistors. And if one MOSFET will fail, but won't short, second MOSFET failure is a matter of short time, as it takes over full current instead of part of it. As we can see in the photo, it was the case. Failed both MOSFETs on one side of a motor phase half-bridge circuit. Double MOSFET design may work well only if is properly oversided, so each single MOSFET is able to carry maximum current expected to flow in the motor phase circuit. But as failing MOSFET will likely create a short circuit, secondary MOSFET won't be beneficial.
  6. The problem is that whatever predefined/well-known BLE service you'll use, you will be able to provide very narrow set of wheel data. For example you can transmit speed using services like CSCS or FMS. You can also send battery level using BAS. But what about power? Current? Voltage? These are definitely one of most important wheel parameters. Main limitation is that all of these services are very specialized in their application. This is why it's much better and easier to use smartwatch and create companion app for it. It's already implemented in WheelLog that can be used with Pebble and Gear Sx watches.
  7. You have to make your tour visible Gotway in contrast to other wheels doesn't report real battery current. Instead they report motor phase current, which only a rough and arbitrary value representing motor load. Spikes above 100 A are not uncommon
  8. In new WheelLog version there is an option to decide if you want to reset wheel data on manual reconnect. Also I removed a bug that causes wheel counters to reset on entering settings pane.
  9. The problem is that internal cavity width is insufficient to fit wider tire. It barely fits original one.
  10. There is not enough clearance between tire and the shell. No chance to fit 18x3 tire in L/XL.
  11. Seems your wheel is in bootloader mode. I think that KS service app may help and you won't have to send your wheel to repair.
  12. It's already implemented in the app, but it still needs implementing on the server (euc.world) part. I'm not sure if I'll finish it before my 800 km trip from north to south of Poland (22-28.06.2019).
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