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About andress

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    Prague, Czech Republic

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  1. Ninebot One Z : Z6-Z8-Z10

    Actually the voltage sag that is more pronounced with bad batteries would cause higher currents running through the wires while using the same wattage and since it is current and not voltage heating the wires up it could actually in theory worsen the situation with overheating wires.
  2. So do I understand correctly, these connected two in series would be perfect fit for the higher voltage gotways and inmotions? 36v / 3,6v = 10 cells so two LiGos means 20 cells in series - same as the batteries in those wheels right?
  3. Barcelona, in Spanish

    Hola! Soy de la Republica Checa I voy a visitar Espana 8-22.7. And thats about as far as my Spanish goes. I just waned to ask whether you have any gathering planned for the period I will be in Spain. Most of the time I will be in Barcelona. Also is there someone or somewhere that I could cheaply rent EUC from? I cannot take mine as I am flying
  4. Successful axle change - KS14C

    There is some play (fraction of a millimeter) until you press it down firmly. So either it is not moving anymore because of friction or it is finally in the right spot IDK. Nothing worse than going down a curb on this motor. On the older one I have done half meter drops but since that one broke I calmed down a lot As you can see I already did change all of them once...
  5. Successful axle change - KS14C

    I tried to use the shims but found them pretty useless. Even when using them the cover realigned the axle during tightening of the screws- I assume this by the sounds it made.The covers are not aligned by the screws but by the rim that goes around the circumference of the cover. It only goes in the right positions when pressed to the outer hub so that's why it seems that it is the screws that align it but they are there really just to keep it all pressed together. So the bigger screw holes allow only for a angle shift which should not affect the axle at all. I tried to take a little video of what I mean but I'm not sure that you can see it. Basically I try to demonstrate that the cover stays in one position even without any screws at all. https://goo.gl/photos/RYUDr45ZcEiQ7RCK8
  6. Successful axle change - KS14C

    So I disassembled the motor again and there were some marks on the magnets as if from rubbing by the stator so I guess that's the cause for the once-per-revolution wobble. I tried to put on the original motor covers. Those I had marked the exact positions they were in before ever taking them off. It didn't help. It was actually slightly worse because of worse bearing that were on these covers. So I flipped the stator in the other direction against the outer rotor and that helped! Even with the new covers the once-per-revolution wobble is gone! Even though the wobble mentioned above is gone you are probably right. It still rides different in each direction. In backwards direction it actually feels better than the original (as far as I remember, no other KS14C around to verify). In forward direction there are some oscillations when there is a bump. I will leave as it is for now. It works and I'm kinda tired off messing with the motor and not riding the unicycle. But if I manage to get the same sensors that were there before (unlikely cannot find them anywhere) I will change them BTW Does anyone know whats the normal maximum free spin speed for the newer board and motor version of KS14C with full battery? Good that is works for you but as I said I have entirely different way the pedals holder attaches to the axle... It is much simpler way and if it isn't the actual cause of the axle breaks it seems to be better way as I had never had a problem with it getting loose. Thanks again for everyone's suggestions on the cause! As it is right now I call it great success and you can expect another project with the older motor during the summer.
  7. Darnit, my first faceplant and ground hit.

    I also go 19mph (30km/h) regularly. Few times I also went as fast as 22 mph but that was on flat smooth road. No cut outs so far. I once fell at around 18 mph because I hit a bump (root growing under concrete) and it threw me in air - no cut out and zero chance of running that out. KS14C both older and newer version of motor and board
  8. KS fidget spinner!

    So since it seems that fidget spinners are the cool thing now I wanted to show you the KingSong Fidget Spinner Ultra Mark II
  9. Successful axle change - KS14C

    I tested all of them after installing using arduino. They all work. Shorts are close to impossible the sensors are glued in the socket and the legs are soldered to the mini pcb which is also glued to the motor. I bought them here in Czech republic in reputable electronics part shop. I really don't think they are the problem. There is tens of times that the hall sensors change their output per revolution but the wobble happens only once per revolution.
  10. Successful axle change - KS14C

    That's what I thought might happen so I did change all of them.
  11. Successful axle change - KS14C

    It is once per revolution I just verified before seeing your message I did not try that, but I will. It seems like the most likely cause so far. Also I just remembered didn't @electric_vehicle_lover say that hall effect sensors are only used in slow speeds? Because this happens at every speed...
  12. Successful axle change - KS14C

    It was Freeman A4H and the specs of the sensors are so similar that I doubt that that is the problem. but I will try to find and buy the same type if no one has better suggestion. It will probably take a lot of time as they will have to be purchased probably from china. I will check even though the connection felt solid. I should have time to that over the weekend.
  13. Successful axle change - KS14C

    I hope not. On the other unicycle I used these as well because I didn't know what types were used there and it works well without any negative effects.
  14. Successful axle change - KS14C

    I'm not sure this is what you mean, but KS uses different way to mount the pedals than most manufacturers. Have a look here. You just clamp the axle and tighten it using the two screws on top.
  15. So we all know KS14C has a bit of a trouble with the axle cracking. The first time it happened to me I went trough half a year long warranty process and apart from the time it cost me 290 USD as apart from the motor itself I needed new board (old one is not compatible with the new motors) and I also wanted new shell and I had to pay the shipping and taxes. I thought that with new type of motor they would have solved the issue but no... after 1400 km according to the app my axle broke again! This is how it looks from outside when your axle breaks: detail after removing the pedals: This time I was so careful! I didn't jump the curbs I had barely any falls... but maybe it was caused by not using the spacers that come between the pedal holders and motor. I didn't use them because the ones from the old motor were not compatible with the new one and I didn't receive new one with the new motor. Tina said to proceed without them but I think that was the reason why the axle broke so soon because maybe I put them a bit further apart or something like that. Anyway I didn't want to pay another hefty sum for a new motor to have it broken in few months again and I actually had a new 500W KS motor on hand since they sent it to me by mistake at first instead of the 800W one. First I tried whether it will work with my board meant for 800W motor. No surprise, it doesn't . But the axle is the same so I decided to gut the never used motor to get mine going again. So I took both motors apart. And this is how i looks: The way the wire are connected to the windings Detail of the axle: Detail of the hall effect sensor: To remove the axle you need access to a hydraulic press. I tried to hammer the axle out but had no success, I only damaged the axle even more. I study a technical university so I just went to the building of mechanical engineering and after few minutes I had time setup when I could come to use the press. In the end the people there just did it for me because of safety concerns. The press ( very old made in now nonexistent country of Czechoslovakia :D) Video of the actual removal: https://goo.gl/photos/nJ5HVcn3ogqr8ECB6 Detached axle: To remove the axle I had to remove the cabling first and of course the cabling got damaged while being pulled trough the axle. The original phase wires were 1,22mm2 with plastic insulation the hall sensor wire were 0,22mm2 also with plastic insulation. The replacement cables I used were 1,5mm2 and 0,25mm2 with silicon insulation. So potentially higher quality but they were also thicker so now sheath to put them all together could fit in the axle so i kept them separate. Also as you can see they didn't have the right colors which caused me some trouble later on when connecting to the control board. I had them labeled but the tags fell while I was pulling the cables through the motor cover So when finishing up there was a lot of experimenting with the right order. I knew which wires were for hall sensors and which for phases from thickness and I knew which wires were the power for the hall sensors because these were the only ones with the correct color. But I still had two groups of 3 wires each. That gives me 36 combinations. Anyone who ever connected the wires wrong knows how crazy the unicycle acts if you do that :/ Luckily it only took me 8 tries! Those were some horrible couple minutes! To pull the cables through the axle I used the same method as @Rehab1 - solder them all together and use single wire to pull the trough. Thanks for inspiration! Unfortunately some of the hall sensors got damaged during the axle removal so I had to change them too. The original sensors were MT4451-A (TO-92 package) as @esaj helped me discover from the markings. I could not get these in Czechia so I used TLE4935L instead as I have already used them once on different unicycle and they worked. Damaged hall effect sensor: And here is finally the finished motor with new wiring and hall sensors: After putting everything together the unicycle works! But there are some problems. It does wobble. When I ride it swings back and forth a little. It it pronounced way more while riding forwards then by riding the unicycle the wrong way with the brake light forward. Anyone has any ideas what could cause this? Here is a video of this https://goo.gl/photos/WfKaDb1iGzgadY1p6 Also the free spin maximum speed is different in each direction it is 40,6 km/h in forward (more wobbly direction) and 38,5 km/h in backwards (more stable direction). So IDK is this some mechanical problem ? the bearing perhaps? I used the motor covers from the 500W as the bearings spin much better. Could this be the cause? They seemed the same otherwise and they fit with no problem. Problem with the board maybe? During the experimenting with the right wire order combinations some nasty thing were most likely happening to the board..:/ I will see how it progresses but please if someone knows what it could be let me know I would hate going trough all this trouble to have the unicycle break down again soon after. So in total this cost me about 20 USD. 10 USD for the beers I bought the people who helped me with the press and 10 USD for the wires and hall sensors. It would cost more if I had to have the axle machined. PS. There will be part two with the older motor from the first time my axle broke and new machined axle for that