KT LCD Settings

General Discussion about electric bicycles.
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deeph46   1 mW

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KT LCD Settings

Post by deeph46 » Jan 05 2020 11:09pm

Hi,

I'm setting up a KT controller and LCD8H with a geared 60V 1000W motor. And little bit problem with motor's magnets count.
For P1 setting,
The P1 settings are a motor characteristic parameter where: P1 = Motor Gear Reduction Ratio × Number of Rotor Magnets Rounding to a full number is necessary. The P1 setting ranges between 1 and 255.
I have told the motor has 8 magnets and reduction gear ratio is 1:23. So is it just 23 X 8 magnets equals 184 and input in P1 setting value is 184?

But I'm not sure if the motor only have 8 magnets. Actually, which magnets that I should count? Magnets on the body? I saw somewhere in the motor have 2 places of magnets but I'm forget where I saw this.

deeph

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Re: KT LCD Settings

Post by amberwolf » Jan 05 2020 11:25pm

which motor?

some have sepaate speed sensor wire so if the controller also has separate speed sensor wire then you use the speed sensor's number of poles rather than the motor's, and no gearing/etc is involved.

for instance the bafang g310 uses a six pole speed senosr separate from the motor

deeph46   1 mW

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Re: KT LCD Settings

Post by deeph46 » Jan 06 2020 12:10am

This motor, it’s Yalu mid drive motor. And only have those cables.
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Re: KT LCD Settings

Post by amberwolf » Jan 06 2020 1:08am

ah. then you're stuck with multiplying the poles by the gear ratio to get the number. if that info isn't in the yalu thread, then the manufacturer is the only other place i know of to find it, unless somewhere else on the web happens to have an info page on them.


however.....since that is a middrive, using any speed sensing from it for the speed sensor input on the controller is kinda silly, since it will only tell you the motor speed, not the bike speed.

you would have to put a speed sensor on the wheel to measure bike speed.

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Re: KT LCD Settings

Post by deeph46 » Jan 06 2020 1:45am

They gave the info in the web, that the ratio is 1:23. Just curious they told me only 8 magnets. So do you think it has speed sensor? But the KT controller that I bought dont have speed sensor connection. I might open up the case then.

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Re: KT LCD Settings

Post by E-HP » Jan 06 2020 10:23am

deeph46 wrote:
Jan 06 2020 1:45am
They gave the info in the web, that the ratio is 1:23. Just curious they told me only 8 magnets. So do you think it has speed sensor?
If the hall sensor cable on the motor only has 5 wires, then no. Plus, it's unlikely that a mid-drive motor would have a speed sensor, since the bikes speed will depend on the gearing of the drive train, beyond the motor.

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Re: KT LCD Settings

Post by docw009 » Jan 06 2020 10:32am

You have to have an external speed sensor on the wheel with a mid drive. Set P2 = 1 on the lCD and the controller will use the external speed sensor input. Then the value of P1 will not be used and it can be anything.

When users don't have an external speed sensor, then the controller will try to calculate speed knowing the P1 value. On a geared motor with clutch, the controllers lose the speed info on coasting because the motor no longer turns. Not a big deal, but t does affect the odometer reasing.

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Re: KT LCD Settings

Post by AHicks » Jan 06 2020 10:40am

My experience (so I could be wrong) has been that the magnet count and gear ratio info are only for generating the correct speed. In the case of the mid drive (or gear driven hub), you just don't care about the speed it's calculating as you're going to need to use an external speed sensor anyway!

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Re: KT LCD Settings

Post by amberwolf » Jan 06 2020 12:12pm

deeph46 wrote:
Jan 06 2020 1:45am
They gave the info in the web, that the ratio is 1:23. Just curious they told me only 8 magnets. So do you think it has speed sensor?
irrelevant if it has a speed sensor or not, it's a middrive, you can't sense the bike speed from it.

you must use a separate speed sensor on the wheel itself for that.



the only thing you can tell with any wires coming from the motor is the motor speed.

if motor speed is what you want to display, then using the wires from teh motor will work fine, and you use the numbers the motor manufacturer provided.


if not, then they won't.

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Re: KT LCD Settings

Post by deeph46 » Jan 07 2020 9:13pm

I’m looking for wheel speed, so you guys said I have to run speed sensor. But does anyone know how to add the speed sensor to KT controller? The controller itself don’t have speed sensor cable input.

I also checked the magnets in it, it has 8 magnets inside.

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Re: KT LCD Settings

Post by amberwolf » Jan 07 2020 10:13pm

there should be a place to add the sensor, though you may have to add wires to the pcb inside to do it.

look up the opensource firwmware threads for the kt kunteng kun teng controllers, by casainho, stancecoke, marcos, etc., as they link to and ahve various wiring info in them for various versions, and should show where to put the sensor.

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Re: KT LCD Settings

Post by deeph46 » Jan 09 2020 9:22pm

ended up take a bike speedo meter so it runs independently.

Btw, I tried to run the Yalu motor with KT controller. I managed to run it by change the Hall and Phase combination. But when run it runs slow, about 120 - 135 watts. It looks like there is current limiter or speed limiter. When I tried to run with stock controller it runs smooth and full power. Does anyone know how or idea why the motor run slow when using KT controller?

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Re: KT LCD Settings

Post by E-HP » Jan 09 2020 11:01pm

deeph46 wrote:
Jan 09 2020 9:22pm
ended up take a bike speedo meter so it runs independently.

Btw, I tried to run the Yalu motor with KT controller. I managed to run it by change the Hall and Phase combination. But when run it runs slow, about 120 - 135 watts. It looks like there is current limiter or speed limiter. When I tried to run with stock controller it runs smooth and full power. Does anyone know how or idea why the motor run slow when using KT controller?
What is C5 set to?

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Re: KT LCD Settings

Post by deeph46 » Jan 10 2020 12:14am

C5 iscurrent limiter I believe, and I have set to 10.

I noticed the speed half of 72KM/H (37KM/H) that I setup in LCD.
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Re: KT LCD Settings

Post by aroundqube » Jan 10 2020 1:20am

deeph46 wrote:
Jan 09 2020 9:22pm
ended up take a bike speedo meter so it runs independently.

Btw, I tried to run the Yalu motor with KT controller. I managed to run it by change the Hall and Phase combination. But when run it runs slow, about 120 - 135 watts. It looks like there is current limiter or speed limiter. When I tried to run with stock controller it runs smooth and full power. Does anyone know how or idea why the motor run slow when using KT controller?
re; speed limiter : LCD3 General Project Setting ( page 17 in my manual ) max trip speed comes set at 25 kph default . Display can be set for MPH , but function settings have to be entered as kph. The magnet / poles , wheel size stuff is used to calculate the speed shown on the display. Sometimes have to fudge those numbers to get display speed to match real time GPS . I went with P2=0 and C2=0 on a geared hub motor.

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Re: KT LCD Settings

Post by deeph46 » Jan 10 2020 3:03am

aroundqube wrote:
Jan 10 2020 1:20am
re; speed limiter : LCD3 General Project Setting ( page 17 in my manual ) max trip speed comes set at 25 kph default . Display can be set for MPH , but function settings have to be entered as kph. The magnet / poles , wheel size stuff is used to calculate the speed shown on the display. Sometimes have to fudge those numbers to get display speed to match real time GPS . I went with P2=0 and C2=0 on a geared hub motor.
I have setup max 72km/h, which is max setting in the LCD8H and still slow running rear wheel in mid air. Tried P2=0 and C2=0 still running slow (mid air / rear wheel on a bike stand).
But if I ride the bike, acceleration is great. Possibly wheelie. I haven't tried ride for top speed though.

Just wondering, does KT controller/LCD8H has current limiter when running in mid air?

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Re: KT LCD Settings

Post by docw009 » Jan 12 2020 9:57am

It calculates speed from the wheel size and P1. And it doesn't matter that the speed is bogus because the controller really uses it if there is a speed limit set. I have found that the speed limit setting on KT controllers really works when you set it low. I never had a big enough motor to have it go to 72, so don't know much about the high values. Anyway, your P1 is probably holding you back.

Just experiment. Raise/lower P1 from your initial value of 184. See if no load wheel speed changes.

deeph46   1 mW

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Re: KT LCD Settings

Post by deeph46 » Jan 12 2020 8:06pm

docw009 wrote:
Jan 12 2020 9:57am
It calculates speed from the wheel size and P1. And it doesn't matter that the speed is bogus because the controller really uses it if there is a speed limit set. I have found that the speed limit setting on KT controllers really works when you set it low. I never had a big enough motor to have it go to 72, so don't know much about the high values. Anyway, your P1 is probably holding you back.

Just experiment. Raise/lower P1 from your initial value of 184. See if no load wheel speed changes.
I noticed/heard it take more speed when I put 255 in P1 but not very much. I read that if P1=255 I can setup L2 but I don't see any different.
After some testing I can get PAS 5 running at 1000W but if I ride it.

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