US69 Posted July 18, 2016 Share Posted July 18, 2016 1 minute ago, OliverH said: Tire is on max pressure. My wife didn't have my weight, she has the same problem. Comparison: Take a Firewheel F779 and it goes like a charme. The case is between your legs and you can ride it that it don't touch your legs. No nervous driving. Ok...was just a tip...like i said, as you are experienced i did not expect it to be the "to less air" prob.... But all that you mention....i can do with the KS16..i find it to be excellent smooth with the right pressure....In the Moment my number one wheel! And i can compare it to KS14 and KS18 which i own, and Gotway MCM2s, MCM3, MCM4HS, which i rode.... Hmmh, seams everyone prefers another ride style..... Btw: Have you ever tried another KS16 to rule out that it is a specific wheel Problem? Link to comment Share on other sites More sharing options...
US69 Posted July 18, 2016 Share Posted July 18, 2016 52 minutes ago, Reivax said: What I resent is when he says no pedal broke, when they break it is smooth, users break pedals because they don't know how to use a wheel, and there is no pedal issue while KS came up with two new designs. Btw... This "when they brake, they brake smooth"....was a Statement from Jason...not 1Radwerkstatt. Otherwise i agree totally to your Statement! :-) Link to comment Share on other sites More sharing options...
Reivax Posted July 18, 2016 Author Share Posted July 18, 2016 59 minutes ago, KingSong69 said: Btw... This "when they brake, they brake smooth"....was a Statement from Jason...not 1Radwerkstatt. OMG... You are right... I feel silly now. Okay, I do apologize for this mistake. Link to comment Share on other sites More sharing options...
HEC Posted July 18, 2016 Share Posted July 18, 2016 5 hours ago, HunkaHunkaBurningLove said: It appears that most EUC boards are always using either 6 or 12 MOSTFETs. If the answer is that obvious to use IGBT instead or higher rated MOSEFTs, why haven't the controller board designers done so with new versions? A multimillion dollar company like Ninebot with huge backing from Xiaomi should have a few knowledgeable electrical engineers on hand. Wouldn't you think that they could have come up with some smarter solutions? I'd love to see a burn out proof controller, but maybe there's some reason they are sticking to this 6 or 12 design. Do you think you could modify a controller to work with IGBT's or higher rated MOSFETs or would it take an entirely re-engineered board to do so? There was another thread here in forums discussing both 6 vs 12 MOSFETs as well as why it would not be beneficial / possible to use IGBTs in current range of EUCs with great explanation from @esaj and several other knowledgeable forum members (can't find it right now) so that worth reading. Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted July 18, 2016 Share Posted July 18, 2016 Yes I remember that discussion, but I was wondering whether 1Radwerkstatt might know something else that could help point EUC makers in a better direction with their controller design. Maybe the manufacturers just haven't put much money into a redesign as the current design seems to be working for the most part? I just don't know. Maybe they are all copies and variations of Solowheel's controller? If someone is claiming there is a better way to go about something I'm very curious to find out about it. Link to comment Share on other sites More sharing options...
esaj Posted July 18, 2016 Share Posted July 18, 2016 38 minutes ago, HEC said: There was another thread here in forums discussing bot 6 vs 12 MOSFETs as well as why it would not be beneficial / possible to use IGBTs in current range of EUCs with great explanation from @esaj and several other knowledgeable forum members (can't find it right now) so that worth reading. You're probably confusing me with @Chriull, I know next to nothing about IGBTs, just basic electronics If working perfectly in tandem, 12 mosfets should help with lower current / heat per fet, but like @1RadWerkstatt pointed out, differences between the two mosfets in each pair could lead to more trouble than solve (gate charges, threshold voltages etc?), if another one of them doesn't fully turn on, turns on slower or such, causing the other one to bear the brunt of the load. Some of the electronic load designs (meant for measuring power / current output, heating and such) I've seen used separate shunt resistors / op-amps for each mosfet, so even though they are sharing the load, each mosfet was controlled separately to keep the current per fet more even. But that's a bit different than the wheel motors... 33 minutes ago, HunkaHunkaBurningLove said: Yes I remember that discussion, but I was wondering whether 1Radwerkstatt might know something else that could help point EUC makers in a better direction with their controller design. Maybe the manufacturers just haven't put much money into a redesign as the current design seems to be working for the most part? I just don't know. Maybe they are all copies and variations of Solowheel's controller? If someone is claiming there is a better way to go about something I'm very curious to find out about it. From what I've seen and understood, 1RadWerkstatt / Chris are very good with electronics and electronics design. If I say one thing and they say the opposite (at least when it comes to electronics), it's 99.999% certain that I'm wrong and they're/he is right Link to comment Share on other sites More sharing options...
Chriull Posted July 18, 2016 Share Posted July 18, 2016 12 hours ago, 1RadWerkstatt said: ... But i can say (this is real) 12 Mosfet´s is electrical trash!(you can make this on hobby table when you have not the right parts on hand) You can stack stones for a wall but not MosFet´s for HighPower. When a car need´s more Engine Power you can put a Engine on top to the other Engine and can not see to the Street in fact the right way is one larger Engine with more Power. When you double MosFet´s on one side is split current but Energy is fast and very exact one MosFet switch faster on later one is internal a little bit different and more stress to the gate driver...many electrical things...other side you double the failure in MosFet self....wrong way is stacking... You can buy one MosFet with can handle hundreds of Ampere or a module with 6 matching MosFet´s in one case...this and only this is the right way... Quote ...one industrial case (IGBT) with correct internal mounting and.....work 32 minutes ago, esaj said: You're probably confusing me with @Chriull, I know next to nothing about IGBTs, just basic electronics If working perfectly in tandem, 12 mosfets should help with lower current / heat per fet, but like @1RadWerkstatt pointed out, differences between the two mosfets in each pair could lead to more trouble than solve (gate charges, threshold voltages etc?), if another one of them doesn't fully turn on, turns on slower or such, causing the other one to bear the brunt of the load. Some of the electronic load designs (meant for measuring power / current output, heating and such) I've seen used separate shunt resistors / op-amps for each mosfet, so even though they are sharing the load, each mosfet was controlled separately to keep the current per fet more even. But that's a bit different than the wheel motors... My practical knowledge of IGBTs is also not existand - i just took datasheets, application papers and some big reseller listings to get an range of operation specifications. From this i could not see any advantage for IGBTs over MOSFETs for EUCs. My main points from that post: Mainly the lowest Vce saturation voltages are ~1V for IGBTs and the Rds on for MOSFETs is ~7mOhm. Turn off time is (normaly) slower for IGBTs - so the power dissipation for IGBTs is higher than for MOSFETs as they are used in EUCs (~67V, up to 40A, normaly aroung 5-15A) - for Tesla i.e. it's a totaly different story. I totally agree with @1RadWerkstattthat it is nonsense to parallel Mosfets while screwing up the heatsinks. The currently used Mosfets can handle the burden of an EUC without any problems - and the power dissipation is nowhere near to unsolvable for EUCs. Just points like this make them overload: Quote Problem in all Wheels is mounting a MosFet correct...first: stupid 1mm thick heat conductive rubber (stupid stuff) second: mounting in the corner from the heat sink third: mechnical stress...screw mosfet with soft rubber on heat sink.....all not OK.... And as @esajmentioned paralleling power switching mosfets is not a trivial task. I just scanned briefly some application notes from some of the big mosfet manufacturers. It can be implemented safely and without expensive additional "circuitry" - but it needs quite some thought before from the designer. And all of this just because they messed up the heatsink design - imho it would be much better to repair the first bad design choice then just ignore this and introduce a new complexity. Imho paralleling the mosfets makes sense like with the overcurrent protection for BMS, where most of the times three of them are in parallel - so the whole dissipated power is on third. There are no real heatsinks possible, so thats about the only easy solution. And there are no switching happening - the mosfets are just on 99,99999% of the time... Quote From what I've seen and understood, 1RadWerkstatt / Chris are very good with electronics and electronics design. If I say one thing and they say the opposite (at least when it comes to electronics), it's 99.999% certain that I'm wrong and they're/he is right +1. Quote And many other things.....but EUC´s absolute great stuff!! Exactly! Link to comment Share on other sites More sharing options...
OliverH Posted July 18, 2016 Share Posted July 18, 2016 9 hours ago, KingSong69 said: Ok...was just a tip...like i said, as you are experienced i did not expect it to be the "to less air" prob.... But all that you mention....i can do with the KS16..i find it to be excellent smooth with the right pressure....In the Moment my number one wheel! And i can compare it to KS14 and KS18 which i own, and Gotway MCM2s, MCM3, MCM4HS, which i rode.... Hmmh, seams everyone prefers another ride style..... Btw: Have you ever tried another KS16 to rule out that it is a specific wheel Problem? I need to cross check. I know 3 guys owning a KS16 - in both battery versions. Link to comment Share on other sites More sharing options...
EricGhost Posted July 18, 2016 Share Posted July 18, 2016 12 hours ago, OliverH said: Tire is on max pressure. My wife didn't have my weight, she has the same problem. Comparison: Take a Firewheel F779 and it goes like a charme. The case is between your legs and you can ride it that it don't touch your legs. No nervous driving. Well in true I'm 1.9 mt for 88 kg, ks16 tyre is pumped up to 3.75 bar (better say something in between 3.5-4.0 bar , as bike pumps sensor are rough) . While I drive I need to have a tight control with my legs on the wheel 'cause there is a tendency to oscillate ( wobble??) around the Vertical axis (Zaxis) when meeting small holes,steps or other irregularites on the road, the most difficult control is on the park track with gravel, but I thought it was normal plus my inexperience. Link to comment Share on other sites More sharing options...
US69 Posted July 18, 2016 Share Posted July 18, 2016 2 hours ago, EricGhost said: Well in true I'm 1.9 mt for 88 kg, ks16 tyre is pumped up to 3.75 bar (better say something in between 3.5-4.0 bar , as bike pumps sensor are rough) . While I drive I need to have a tight control with my legs on the wheel 'cause there is a tendency to oscillate ( wobble??) around the Vertical axis (Zaxis) when meeting small holes,steps or other irregularites on the road, the most difficult control is on the park track with gravel, but I thought it was normal plus my inexperience. perhaps you should try other wheels in this specific situation? i can say from myself that in the first 2'months you are a learner! ok, Oliver did not seam to like the wheel behaviour.... But in general the most do and i for myself could say its one of the smoothest rides i take ever.... in the moment i even regret to purchased a KS 18...as i like the Ks 16 much more...but i wanted more power, which i have now, and is not the solution to all my EUC dreams.... try some other wheel...wobble as a beginner is absolut normal..... Link to comment Share on other sites More sharing options...
DS Posted July 19, 2016 Share Posted July 19, 2016 22 hours ago, EricGhost said: While I drive I need to have a tight control with my legs on the wheel 'cause there is a tendency to oscillate ( wobble??) around the Vertical axis (Zaxis) I found that when I overpump the tire (make it hard as a stone) the wheel becomes very sensitive and kind of unstable. The first let's say 20 km feels oddly but after that, I'm getting used. IMO, this behaviour is normal since the friction between the tire and the surface lessens. Every rider has to find his comfort level of tire's air pressure. Link to comment Share on other sites More sharing options...
DS Posted July 19, 2016 Share Posted July 19, 2016 On 7/18/2016 at 11:04 AM, KingSong69 said: And i can compare it to KS14 and KS18 which i own Now I know where to look KS for rent if I visit west part of Germany Link to comment Share on other sites More sharing options...
US69 Posted July 19, 2016 Share Posted July 19, 2016 59 minutes ago, DS said: Now I know where to look KS for rent if I visit west part of Germany haha! you are welcome! Link to comment Share on other sites More sharing options...
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