New "Lingbei MM28.250 torque sensor mid drive"

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maitilupas   100 W

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by maitilupas » Nov 03 2019 3:00pm

perfect , going to do that, thanks allot for your support chito!

Chito   10 mW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Chito » Nov 03 2019 3:30pm

maitilupas wrote:
Nov 03 2019 3:00pm
perfect , going to do that, thanks allot for your support chito!
You can also arm the bottom bracket without the spring, which will only work the pass sensor and not the torque + pass sensor. I tell you if you can't find material to make a new spring. You can arm without spring and calmly look for a suitable material, then you put it

fifthbro   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by fifthbro » Nov 03 2019 5:03pm

Chito wrote:
Nov 02 2019 7:33pm

What is happening to you is due to an incorrect offset between the sensor magnets. When you feel the intermittency is when you lower the left pedal because the natural torque of the bottom bracket axis helps to further offset the magnet that is more central, however when you lower the right pedal, it does not contribute to offset the magnet due to the torque of the axis because chain transmission is more direct. If you also feel loss of power when you lower your right foot it is because the angular offset between the magnets is very large.
The solution to this problem is to rotate the magnet (the one inside) a little (VERY LITTLE) counterclockwise if you look at it from the side of the chain. Or rotate the magnet that is outside, in favor of the hands of the clock, but it is more difficult.
Thanks a lot, will give it a go and experiment a little bit. Sounds like there is no point bothering with software update that I have been advised by the seller.

Also, given some of the problems with the spring described in few recent post, I can foresee and opportunity for someone to offer an aftermarket replacement.

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giannidipie1   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by giannidipie1 » Nov 04 2019 9:18am

my experience: I bought the 36v engine a few days ago.
As soon as I started pedaling on a slightly steep climb and applying more force on the pedal, I felt some engine power drops, as if the current suddenly stopped and then resumed.
Could this problem be due to an incorrect sensor magnets allineament?

Chito   10 mW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Chito » Nov 04 2019 4:23pm

giannidipie1 wrote:
Nov 04 2019 9:18am

Could this problem be due to an incorrect sensor magnets allineament?
Yes
what happens is that the torque sensor works with the angular offset between the magnets, the more force you apply to the pedals, the more angular offset there is between the magnets and the motor helps more. But if the angular offset is very large, the motor stop. This is due to the following: the sensor registers a pulse every time there is a change of poles in the magnet; there is a reference magnet and a measuring magnet, when force is applied, the measuring magnet gives a delayed pulse with respect to the reference magnet and this is used for torque calculations, but if the delay is very large, the sensor registers the Pulse of the previous pole shift as the true one (in the measuring magnet), so the sensor interprets that the measuring magnet is advanced rather than delayed so it is interpreted that force is not being applied. That is why the measuring magnet has to be advanced a little to prevent this from happening

Chito   10 mW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Chito » Nov 04 2019 4:59pm

Therefore, it is necessary to advance the measuring magnet a little to prevent the above described from happening.
In the video that was shared previously, it is indicated how the magnet should be rotated

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stancecoke   100 kW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by stancecoke » Nov 05 2019 2:51am

This doesn't seem to be a reliable system. Broken springs, displaced magnets....
A good idea, but badly implemented.
Has anyone a proper working system? :-)

regards
stancecoke

maitilupas   100 W

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by maitilupas » Nov 05 2019 3:02am

stancecoke wrote:
Nov 05 2019 2:51am
This doesn't seem to be a reliable system. Broken springs, displaced magnets....
A good idea, but badly implemented.
Has anyone a proper working system? :-)

regards
stancecoke
nothing from China is reliable.
BUT:
This motor is small ,
this motor is silent,
this motor doesnt heat up,
this motor doesn't hang under the bottom of the bike
this motor has allot of torque.

Displacement magnets in the axle or a spring can be upgraded.

casainho   1.21 GW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by casainho » Nov 05 2019 3:22am

maitilupas wrote:
Nov 05 2019 3:02am
stancecoke wrote:
Nov 05 2019 2:51am
This doesn't seem to be a reliable system. Broken springs, displaced magnets....
A good idea, but badly implemented.
Has anyone a proper working system? :-)

regards
stancecoke
nothing from China is reliable.
BUT:
This motor is small ,
this motor is silent,
this motor doesnt heat up,
this motor doesn't hang under the bottom of the bike
this motor has allot of torque.

Displacement magnets in the axle or a spring can be upgraded.
Maybe they can improve this motor over time, maybe they read this thread and see the users issues.

TSDZ2 had also silently being improved over time, with changes that really make difference like reducing the motor noise and more robust torque sensor (mainly in side play of the axle). We can find in the market the repair parts and the different versions of the gears, etc.

The thing is that DIY mid drive motors may be stopped in development, seems the popular ones are not for DIY (I mean even Chinese). So let's hope that at least they are willing to invest more to improve this issues.
Developer of the Flexible OpenSource firmware for EBike motor controllers (TSDZ2 and KT) and displays (Bafang 850C color, SW102 Bluetooth and KT-LCD3).

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

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giannidipie1   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by giannidipie1 » Nov 05 2019 3:40am

Displacement magnets in the axle or a spring can be upgraded.
could you better explain what you mean by upgrade?

maitilupas   100 W

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by maitilupas » Nov 05 2019 3:47am

giannidipie1 wrote:
Nov 05 2019 3:40am
Displacement magnets in the axle or a spring can be upgraded.
could you better explain what you mean by upgrade?

You can offset the magnets and upgrade the spring , seems that this spring (it just a metal part) but is week and tend to break on some users like me.
Chito produced this in 2 thinner parts. I would go for a good quality harden steel

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giannidipie1   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by giannidipie1 » Nov 05 2019 4:21am

maitilupas wrote:
Nov 05 2019 3:47am
giannidipie1 wrote:
Nov 05 2019 3:40am
Displacement magnets in the axle or a spring can be upgraded.
could you better explain what you mean by upgrade?

You can offset the magnets and upgrade the spring , seems that this spring (it just a metal part) but is week and tend to break on some users like me.
Chito produced this in 2 thinner parts. I would go for a good quality harden steel
:thumb: I will try to rotate the magnets and make new more solid spring. I let you know the result

Dorph   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Dorph » Nov 15 2019 12:46am

Anyone know if this motor will work with pedal-brake systems (gear in hub)?

maitilupas   100 W

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by maitilupas » Nov 15 2019 12:56am

Dorph wrote:
Nov 15 2019 12:46am
Anyone know if this motor will work with pedal-brake systems (gear in hub)?
Yes of course you can adapt that but probably you need to run the ebrake wire from the front of the bike till the rear wheel where you can adapt a sensor on the moving part of the brake hub

Chito   10 mW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Chito » Nov 16 2019 9:22pm

Dorph wrote:
Nov 15 2019 12:46am
Anyone know if this motor will work with pedal-brake systems (gear in hub)?
if you mean the brake system that works when you turn the pedals back, the answer is no, because when you rotate the pedals in an anti-clockwise direction with this engine, the chain does not move

casainho   1.21 GW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by casainho » Nov 16 2019 9:38pm

Chito wrote:
Nov 16 2019 9:22pm
Dorph wrote:
Nov 15 2019 12:46am
Anyone know if this motor will work with pedal-brake systems (gear in hub)?
if you mean the brake system that works when you turn the pedals back, the answer is no, because when you rotate the pedals in an anti-clockwise direction with this engine, the chain does not move
You can use TSDZ2 as there is a specific version for that kind of brakes, coast brakes.
Developer of the Flexible OpenSource firmware for EBike motor controllers (TSDZ2 and KT) and displays (Bafang 850C color, SW102 Bluetooth and KT-LCD3).

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

fifthbro   1 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by fifthbro » Nov 26 2019 4:57pm

I am trying to replace the spring and move the magnets as per suggestion from Chito. However, I am unable to remove the bearing that seems to be stuck to the shaft. All DIY methods failed, does anyone have any good advice on how to detach it to get to the screws underneath?

Image

Chito   10 mW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Chito » Nov 29 2019 1:40am

there are holes in the back of the piece of the image. through those holes you can push the bearing

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Metaller   10 µW

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Re: New "Lingbei MM28.250 torque sensor mid drive"

Post by Metaller » Dec 01 2019 11:46am

I realized that one of the magnets sometimes shifts in the torque sensor, which leads to problems... it is not likely that the sensor spring always breaks. If anyone is working out the firmware here - it would be good to add a software adjustment to this sensor by introducing an adjustable software delay of the signal from one of the magnets. Add a timer with a shift constant to the interrupt processing, then it would be possible to fine-tune the sensor without disassembling the engine. Image

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