My Torq has died

imellor

Pedelecer
Oct 25, 2006
67
4
I can't be sure on that position change without knowing all the spacing relationships Ian, but instinct tells me you should avoid it and use the simplest replacement option.

I feel sure it should be possible to chip out the existing dud sensor head and just replace that. Looking at this photo from Endless Sphere you may be able to insert a screwdriver just below a bar magnet and gently lever out the sensor. If not, cutting into it from side to side should fragment it enough for removal. A further option with care is to gently drill into the sensor at an angle from just below a bar magnet above, either to break it up or to insert a screw to give you something to get hold of to wiggle it free. If you break a little of the paxolin surround removing the sensor, you'll be able to build it back up again with epoxy resin when you cement in the new sensor.

I'd be happy to try that Hall sensor you found as it seems to match what's needed.
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Thank you, I must admit, I hadn't thought of chipping it out. Although they are deeper than shown in the picture in your post.

I'll order a sensor (and spares) and give chipping out a whirl.

Thanks, once again for your help and suggestions.

Ian
 

Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
Ian,

Have a go at getting the old one out first, but if not, your idea of using the appropriate empty slot ought to work. You shouldn't even have to rewire the other two sensors.

You can easily test it before you close the motor up to check that the 3 sensors are on different phases.

If you do have to switch sensors/phase wires around it can be done outside the motor at the cable join on the forks.

Nick
 

Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
Ian,

Just had a look as a scrap one I've got. The Hall sensors come out very easily. There is a slight recess machined in the laminations to take the sensors, so you wouldn't be able to fit the new one in a different position. Yours may be different of course. Mine is 18 windings with 20 magnets.

Nick
 

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
Ian,

Just had a look as a scrap one I've got. The Hall sensors come out very easily. There is a slight recess machined in the laminations to take the sensors, so you wouldn't be able to fit the new one in a different position. Yours may be different of course. Mine is 18 windings with 20 magnets.

Nick
That gives you an insight into how they work, Nick - you always have a multiple of three windings (so 15, 18, 21 - etc) because there are three circuits, and each circuit feeds every third winding. The different number of magnets means that only two magnets are opposite two windings when one circuit is energized - and when the controller sequences to the next circuit, the nearest magnet gets attracted to the nearest energized winding, which is only (in your case) 2 divided by 18x20 of a revolution, which is exactly two degrees of rotation.

Because the two numbers - 18 and 20 - are fairly close, and they are both divisible by 2, there will be two magnets on opposite sides of the motor in the right position.

That's how these motors manage to be so quiet - with a 180-step sequence for every revolution, the operation can be really smooth. Also, the 'target' magnet is very close to the pole of the 'target' winding when it gets turned on, so you get maximum torque.

Rog.
 
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rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
;). Stepping animation of a six winding motor with colour coded activity of poles, sensors and decoder:

Servo Magnetics
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That's pretty!

I had to take three stabs at it to get the maths right - but I think I'm now correct for the 18 windings/20 magnets setup Nick was referring to.

In a previous life writing software for the fruit machine business I learned ALL about stepper motors!

Rog.
 

flecc

Member
Oct 25, 2006
53,559
30,848
In a previous life writing software for the fruit machine business I learned ALL about stepper motors!

Rog.
I only learnt how to get more out than I should!

Still remember infuriating an arcade owner at Swanage very many years ago. :D
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flecc

Member
Oct 25, 2006
53,559
30,848
Ah found memories of the chain ferry!!!!
Yes, I've been over the Sandbanks to Shell Bay ferry many times, used to live at Bournemouth in my motorcycling teens. Incident I mentioned was a few years later though, when I'd crossed in a car.
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Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
What a small world the e-bike community turns out to be. I grew up in Dorset so I know that area well. I don't think I ever cycled there but that whole Poole Harbour/Purbeck area is somewhere I have hiked, driven, swum, sailed and canoed, and more lately flown aircraft over. I even used to go out with a girl from Swanage.

Nick
 

flecc

Member
Oct 25, 2006
53,559
30,848
What a small world the e-bike community turns out to be. I grew up in Dorset so I know that area well. I don't think I ever cycled there but that whole Poole Harbour/Purbeck area is somewhere I have hiked, driven, swum, sailed and canoed, and more lately flown aircraft over. I even used to go out with a girl from Swanage.

Nick
Certainly is Nick. I still regularly visit my brother at Moigne Combe east of Dorchester and my niece and her family at Corfe Castle. I also used to own a boat based at Littlehampton and was often along that Dorset coast, anchoring overnight at Goathorn Point, Poole; Lulworth Cove or in harbour at Weymouth.
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CDinFrance

Finding my (electric) wheels
Dec 9, 2008
19
0
Wow, I'm glad this was not a "Technical" discussion...

I look forward to the day when this type of discussion is either unnecessary, or restricted to professional e-bike technicians, rather than consumers.
 

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
Wow, I'm glad this was not a "Technical" discussion...

I look forward to the day when this type of discussion is either unnecessary, or restricted to professional e-bike technicians, rather than consumers.
Hi there!

Well, there is quite a bit of interest in the technical aspects in here, not least because there are kit bikes, mix 'n' match home-brew bikes, and of course bikes bought in good faith from now-defunct suppliers.

Obviously some members are also inclined to tinker and have the time - unlike me! Although I'm an engineer (electronics, mainly) I take the easy road and buy a bike from a reputable (hopefully) supplier, and hopefully don't HAVE to tinker, though I will if I'm pushed.

I wouldn't take my e-bike back to the mail-order place it came from if I had a problem with it unless I couldn't possibly avoid it, as it's not exactly round the corner, and I wanted to make the best price for the product I wanted to buy. 'Professional e-bike technicians' are probably just a bit thin on the ground at present, as there are not all that many e-bikes around.

Shared knowledge is always useful. What else would we discuss?

Rog.
 

Conal

Pedelecer
Sep 28, 2007
228
2
Technical aspects of ebiking

The technical "conversations" are great. I even understood the description of how the magnets in the motor work. I joined the forum to gain knowledge and it is better than Wikipedia as a reference source (and more likely to be true). I think the average age of members is over 50 so this forum is proof that it is never too late to learn, or to teach. I even think I am learning by osmosis as I look through the posts.

Conal
 

flecc

Member
Oct 25, 2006
53,559
30,848
Wow, I'm glad this was not a "Technical" discussion...

I look forward to the day when this type of discussion is either unnecessary, or restricted to professional e-bike technicians, rather than consumers.
We try to incorporate both without becoming too annoying to either interest group. To keep out some of the Technical stuff, we have a separate Technical section for permanent tech items.

Those who want to be non technical can post in here as they wish, and we even have a section where the discussion doesn't have to be about e-bikes:

The Charging Post
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wotwozere

Esteemed Pedelecer
Sep 6, 2008
280
1
Hi Conal

yes i have learned so much on this forum it changed my life.

Thanks to flecc and all the wiseguys on this place.

thx

Bob
 

imellor

Pedelecer
Oct 25, 2006
67
4
I would like to thank everyone for their assistance in getting my Torq back on the road. It isn't quite there yet, as I need to put everything back together, but the motor now runs.

I originally bought this hall sensor Rapid, but during my testing I relaised that it gave a positive output and the original sensors gave a negative output.

So I ordered one of these Farnell and everything seems OK.

I could not have completed this repair without the knowledge and help of everyone here, so thank you very much.

Ian
 

flecc

Member
Oct 25, 2006
53,559
30,848
That's great Ian, always good to hear of another broken down bike returned to health by it's owner. Thanks for the Farnell part link also, useful for any future repeat event.
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Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
Well done Ian, that's good news.

The first Hall sensor you list is a ratiometric one, good for measuring the strength of magnetic fields. It could also be used as a current sensor. The other one is a switching type, which is what you need.

While you're with Farnell, I use Binder 712 connectors for the 5 Hall leads on my motors. Together with Anderson Powerpoles for the phase wires, it makes it easy not only to disconnect the whole assembly but also to mix and match controllers, etc and swap parts between bikes.

Nick
 

imellor

Pedelecer
Oct 25, 2006
67
4
Well done Ian, that's good news.

The first Hall sensor you list is a ratiometric one, good for measuring the strength of magnetic fields. It could also be used as a current sensor. The other one is a switching type, which is what you need.

While you're with Farnell, I use Binder 712 connectors for the 5 Hall leads on my motors. Together with Anderson Powerpoles for the phase wires, it makes it easy not only to disconnect the whole assembly but also to mix and match controllers, etc and swap parts between bikes.

Nick
Unfortunately I am guilty of not paying attention to the Datasheet until I had recieved the first hall sensor, hence ordeing the switching one later!!!!
Thanks for the tip re the connectors, that's exactly the sort of thing I was looking for, it will make removing the front wheel much easier