I need help, as i dont have anywhere to ask, and no one to help me

Davidcroatia

100 W
Joined
Jun 23, 2020
Messages
180
Hello, this is my first ebike build and i dont have a clue what could be rhe problem, im adding throttle but almost nothing helps . https://imgur.com/a/4zvbfoy



https://youtu.be/lXGZ-mxtYY8

https://youtu.be/feRsy8ailhM
 
Davidcroatia said:
Its not so stripped , but its a little bit stripped, why it has stripped ? Thats why i need cassette adspter...

It probably didn’t get greased when it was originally installed. Maybe the thread was poorly machined on one side or the other.

That motor is only ever going to have a threaded freewheel on it. Cassette gears require a different side cover and a different axle.
 
Yes thats why im planning to buy leaf motor. Listen what is good sinusoidal brushless motor controller? Will this screen fit most of controllers? HRK 336.90 7%OFF | Electric bicycle accessories K-LCD8H color display ebike electrice bike LCD display
https://a.aliexpress.com/_d8zZaBU and is this a good controller ? HRK 148.98 23%OFF | DC 48V 1500W Electric Bicycle E-bike Scooter Brushless Motor Speed Controller A23 Dropshipping
https://a.aliexpress.com/_d8fAsfG
 
Davidcroatia said:
Yes thats why im planning to buy leaf motor. Listen what is good sinusoidal brushless motor controller? Will this screen fit most of controllers?
No, only KT controllers
Davidcroatia said:
and is this a good controller ?
Sure, seems like it would meet the requirements you've described so far; you get what you pay for of course.
 
There is no best, because every builder has his own requirements and priorities.

Just about any controller will do. The choice is up to you, according with the price that you want to pay and the features that you value the most. About the value for the money, just keep in mind that it is useless to pay for functions, size and power that you don’t need.
 
HRK 615.85 | Kelly KLS4812S,24V-48V,120A,SINUSOIDAL BRUSHLESS MOTOR CONTROLLER for in-wheel hub motor, powered by SIA
https://a.aliexpress.com/_ms5G583
 
120A is much more power than you want, if your goal is long range especially.

You need to buy the programming cable for this controller, to set it to the power that you want to feed.
 
MadRhino said:
120A is much more power than you want, if your goal is long range especially.

You need to buy the programming cable for this controller, to set it to the power that you want to feed.

Since the specs say 120A peak (for 20 seconds), 60 continuous motor (phase) current; that seems like it would roughly translate to 30A continuous battery current?
 
Davidcroatia said:
30a current is small right? For lik 1500 up to 2000 is 45amp? Normal current

Whether that's small or big, depends on your requirements, as MadRhino stated.
30A gives you just over 1500W continuous @ 52V. 60A peak gives you 3000W peak @ 52V.

Based on the simulator, you get the same speed, but have more torque for acceleration up to top speed, which looks to be about 40% quicker. At full speed, you're using around 1300W on flat ground.
https://www.ebikes.ca/tools/simulator.html?motor=Leaf%205T&cont=cust_30_60_0.03_V&hp=0&axis=kph&cont_b=cust_45_90_0.03_V&motor_b=Leaf%205T&hp_b=0&bopen=true&batt=B5220_GA&batt_b=B5220_GA

If you play with the simulator, you can determine what will work for your first, then you can ask a more targeted question about what controller would meet the requirements, instead of adding more details as you go along as folks attempt to help you. Things like budget should be part of your original question, not information added after people invest their time in responding (this type of guidance is included in the stickies, in order for you to get your answers efficiently).
 
I would like to know a lot of stuff, but english is not my native language so sometimes i struggle. I really appreciate all of the things that people do for me. My goal is to go up to 60km/h or maybe a tiny more on a 26 inch , but some stuff i barely understand. Like my goal is to have leaf motor kit 26 inch, but they dont sell sinewawe, and their rated otuput(not max) is i think 21 amp, so that is small. Im having trouble to understand how much max speed can some voltage give up to -example 48v can give on 26 inch 1500w max speed 50km/h , or 52v can give 60km h , then there are amps that give torque ? Also controllers arw confusing me with their rated amps, and peak and stuff. I read every day on this forum, thats why i want leaf, a lot of people say its their favourite, for me qs motor 1000w was the greatest hassle ever, also washers for qs motor doesnt sell anywhere and stuff
 
Speed and voltage relation is in motor winding. The motor KV (speed per volt) need to match the speed that you want for the voltage and tire size that you chose. Yet, keep in mind that faster does consume more. Faster acceleration, faster top speed, are the ennemies of long range.

About torque: watts are power, no matter the winding. A slower winding only has its efficiency zone at lower speed, making it more economical in acceleration for the time that you are not yet at efficient speed of a faster winding. But, since they both have the same weight of copper, they have the same torque potential. The only way to improve the torque of a motor (after it is fed watts close to saturation) is gearing it down. Gearing down a hub motor, is lacing it in a smaller wheel.
 
MadRhino said:
About torque: watts are power, no matter the winding. A slower winding only has its efficiency zone at lower speed, making it more economical in acceleration for the time that you are not yet at efficient speed of a faster winding. But, since they both have the same weight of copper, they have the same torque potential.

While it’s true in theory that different windings have the same maximum torque potential, there are a couple of caveats. 1) Most of us don’t drive our motors to saturation, or anywhere close to it, and 2) it gets expensive and inconvenient to use high current.

Watts are power, as you say, which means when the winding turns half as fast, you get twice the torque per amp. So the same 1500W controller does give you more torque, even though the motor’s theoretical maximum torque is unchanged.
 
Balmorhea said:
MadRhino said:
About torque: watts are power, no matter the winding. A slower winding only has its efficiency zone at lower speed, making it more economical in acceleration for the time that you are not yet at efficient speed of a faster winding. But, since they both have the same weight of copper, they have the same torque potential.

While it’s true in theory that different windings have the same maximum torque potential, there are a couple of caveats. 1) Most of us don’t drive our motors to saturation, or anywhere close to it, and 2) it gets expensive and inconvenient to use high current.

Watts are power, as you say, which means when the winding turns half as fast, you get twice the torque per amp. So the same 1500W controller does give you more torque, even though the motor’s theoretical maximum torque is unchanged.

Motor Kv is not a gearing. You should run your theory in the ebike simulator. Then you will see the loss of ´torque per Amp’ of a faster Kv, and for how long in acceleration the lower Kv has a (small) torque advantage.
 
MadRhino said:
Motor Kv is not a gearing. You should run your theory in the ebike simulator. Then you will see the loss of ´torque per Amp’ of a faster Kv, and for how long in acceleration the lower Kv has a (small) torque advantage.

Screenshot_20200904-211509.png

I dunno; it sure looks like wads more torque to me. I know which one of those two systems would be more fun to ride, and better at getting up a hill.

Screenshot_20200904-212427.png

It also looks like one of them is substantially more efficient, despite having the same basic motor architecture.
 
Balmorhea said:
MadRhino said:
Motor Kv is not a gearing. You should run your theory in the ebike simulator. Then you will see the loss of ´torque per Amp’ of a faster Kv, and for how long in acceleration the lower Kv has a (small) torque advantage.

Screenshot_20200904-211509.png

I dunno; it sure looks like wads more torque to me. I know which one of those two systems would be more fun to ride, and better at getting up a hill.

Screenshot_20200904-212427.png

It also looks like one of them is substantially more efficient, despite having the same basic motor architecture.


Looks more realistic to me:

BED7D906-D360-4A36-ACF3-2B36818AF9D4.jpeg
 
MadRhino said:
Balmorhea said:
MadRhino said:
Motor Kv is not a gearing. You should run your theory in the ebike simulator. Then you will see the loss of ´torque per Amp’ of a faster Kv, and for how long in acceleration the lower Kv has a (small) torque advantage.

Screenshot_20200904-211509.png

I dunno; it sure looks like wads more torque to me. I know which one of those two systems would be more fun to ride, and better at getting up a hill.

Screenshot_20200904-212427.png

It also looks like one of them is substantially more efficient, despite having the same basic motor architecture.


Looks more realistic to me:

BED7D906-D360-4A36-ACF3-2B36818AF9D4.jpeg

But which will be the cheaper, more widely available, and more legally inconspicuous controller and battery? All these factors can make a project more realistic.
 
Im sorry, im still confused about all. Yesterday one guy told some guy that if you have 48v 20ah 30amp bms- that will work on 1500w system. Good manager from upp told me it wont work, i mean it will but it will burn up i think, like controller draws lets say 40amp and bms is 30 what happens? Longterm ? Btw why is 48v 20ah 50amp bms , and why 52v 20ah 40amp bms?
 
Balmorhea said:
MadRhino said:
Looks more realistic to me:

BED7D906-D360-4A36-ACF3-2B36818AF9D4.jpeg

But which will be the cheaper, more widely available, and more legally inconspicuous controller and battery? All these factors can make a project more realistic.

What I meant, is that you are showing the simulation for a motor that is not available, in a winding that is more than double the speed, with a controller that is too small for it. That, is not realistic. Even with another similar motor, nobody would power a 26 lbs motor with a 20A controller.
 
MadRhino said:
What I meant, is that you are showing the simulation for a motor that is not available, in a winding that is more than double the speed, with a controller that is too small for it. That, is not realistic. Even with another similar motor, nobody would power a 26 lbs motor with a 20A controller.

It was a quick illustration of winding by itself multiplying output torque by more than 2X. I picked that motor because it’s one that has a large % variation of winding available in the simulator.

These results do raise the question: Why does a change in winding affect torque more in some cases than in others? Is it the controller multiplying phase current more for a low impedance motor? Torque per amp fed to the motor should vary in more or less direct proportion to the number of turns, given the same copper fill. So when that doesn’t happen, is it only the controller trading amps for volts, or is there something else at work?
 
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