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- Feb 15, 2013
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a mid mounted hub motor runs at much lower rpm than bldc .. thus lower decibel noise level.. but yes add sine wave and belt for even lower noise levels..
I like the torque of the 4t ,now i have a 14tooth in the front and a 25 rear so its arround 1.8 on 1. Maybe next year i will rebuild it then i would use a 5t with a 30s battery for even more torquej bjork said:Really nice :thumb:
If you are using it like a middrive, why not the 3T or 3T-?
The noice from a standart surron comes from the controller ,chain and high rpm-wining of the motor, i use sinus controller and low rpm hubmotor, first transmission is by 2 big 25 tooth sprockets with minor chainnoice, second is 14 to 25 with good lubed chain the noice is almost negligible.Tommm said:My friend, the noise comes from the square wave controller and the chain drive.
If you use chain drive from your hub, it will be louder and heavier than a belt drive sur ron.
j bjork said:I like the torque of the 4t ,now i have a 14tooth in the front and a 25 rear so its arround 1.8 on 1. Maybe next year i will rebuild it then i would use a 5t with a 30s battery for even more torquej bjork said:Really nice :thumb:
If you are using it like a middrive, why not the 3T or 3T-?
I don't have confirmed it myself, but that was what i understand reading here on esj bjork said:You sure have some nice, long tracks where you live
I have´nt heard that before, that the higher turn counts can take more abuse. So you mean a 300 amp rated 4T will heat up less at 450A than a 400 amp rated 3T at 600A?
Is that something you have confirmed yourself, or where is that info from?
You got it backwards there since the low turn motors don't need high voltage to go fast. They also create proportionally less torque per amp.As I understand it, as the lower turn counts can take more amps, they will give more performance if you go for higher voltage and the higher amps they can handle. Up to a point where the rpms get to high.
I get what you mean, wouldn't call it "ahead" though as that would mean that low turn motor is always better. kV is not a merit figure, it's only a constant to adjust and match with the rest of your system.Sure, but you can give the lower turn count motor more voltage too. Then it would still be ahead. But of course it needs more amps for the same torque output.
I want to try the 96120 sabvoton unlocked with a 30s 7p samsung 40T, so it wil be good for 250 battery-amps.j bjork said:I think you will get more starting torque if you keep your 4T and go 30s and more reduction. But you are limited in amp with your controller, so I am not sure.
I prefer to stay around 1000 rpm For the controller i will use the 96120 sabvoton unlocked can do 300batt and 500 phase@maximum, i go for 250batt and 400 phase thats enoughlarsb said:qs kv table for the 205 goes to 1200 rpm, thats still lower than 20 000 erpm and not a lot. I'd guess you can go to 30s 3t and 1700rpm and downgear it
what controller would you use though?
You could ask QS what they think about it. I can't see bearings getting issues or structural issues, maybe balancing.
larsb said:kV for full torque is 9,55*A/T so kV to match a 300A controller is 15; 4T motor (aaalmost 3T) and kV for 500A controller is 25; 3T with margin
j bjork said:larsb said:kV for full torque is 9,55*A/T so kV to match a 300A controller is 15; 4T motor (aaalmost 3T) and kV for 500A controller is 25; 3T with margin
Now it is getting interesting, can you explain the calculation a little more?
It says 106uh in the chart for 3Tlarsb said:Don't know about inductance risk. hasn't it got 32slots? and massive stator? based on their figures it would be 180uh for a three turn.
That's not small.