Has anyone heard of or tried Toseven mid drive?

[guerney]

Not quite sure how that is relevant to my comment though.

You must have had your reasons for holding off buying one, and I was curious as to what those were.

Hopefully will have one soon.

Glad to hear it. I hope you'll post about your experiences, upload photos etc. You'll really have fun when they eventually release the software, particularly if it's open source. I'm hoping for something without external libraries.

 

[Woosh]

So that’s a DIY install motor? Must be if it’s the competition.

Oh hang on… it’s not.

A good motor will find its way onto bikes which compete directly with Bosch bikes.
In that sense, Bosch compete with other motor manufacturers.

 

[Woosh]

From a crank sensor being used for motor advance angle, to the TDSZ2 torque sensor being a coil (hint: it’s actually a hall sensor).

let's not fight over that again but correct me please if I am wrong.
The rotating part acts as a passive load. The Hall sensor, the one stuck on the shaft, is used as an amplifier. It is powered by the rotating coil by induction. The latter (induction) is produced by the fixed coil. When a twist in the bottom bracket shaft happens, the Hall sensor varies the passive load, which varies the current in the rotating coil which varies the current in the fixed coil. The controller uses the change in the fixed coil as torque signal.
You can replace the Hall sensor with a strain gauge or elastomagnetic strip.

Now, can the pedalling torque, field weakening and cadence be used to make the motor more efficient?
yes. It seems to me that many people think so. Would you insist that I must go through field equations to relate torque to field weakening?

 

[Blacklite]

let's not fight over that again but correct me please if I am wrong.
The rotating part acts as a passive load. The Hall sensor, the one stuck on the shaft, is used as an amplifier. It is powered by the rotating coil by induction. The latter (induction) is produced by the fixed coil. When a twist in the bottom bracket shaft happens, the Hall sensor varies the passive load, which varies the current in the rotating coil which varies the current in the fixed coil. The controller uses the change in the fixed coil as torque signal.

Now, can the pedalling torque and cadence be used to make the motor more efficient?
yes. It seems to me that many people think so. Would you insist that I must go through field equations to relate torque to field weakening?

The hall sensor has a magnet near it, and it is the movement in the magnet in relation to the hall sensor that senses the torque. The coils are an inductive method of transfer of this information allowing for crank rotation.

Your original comment was that

to measure the displaced angle, a Hall sensor and a magnet or an IR LED and a photocell (Suntour HESC) or an induction coil in the case of the TSDZ2 are the most straightforward methods.

You stated the induction coil did the torque sensing in a TSDZ2. It is clearly a hall sensor not a coil.

Field weakening is a process to increase the rotational speed of a BLDC motor beyond that of its unloaded maximum RPM given by its motor constant. Torque is reduced but rotational speed increased for the set maximum voltage available. Obviously this can lead to a higher possible cadence at the pedals, but with a reduction in efficiency in the motor.

Field-Weakening Control

Learn about the field-weakening control techniques for increasing the speed of an electric motor above its rating at the expense of reduced torque. Resources include videos, examples, and documentation.

au.mathworks.com

The supplied torque from the motor in its field weakening region will be less than in its constant torque region, so you’ll have to pedal harder. Beyond that please tell me how pedalling torque relates to field weakening?

 

[Woosh]

You stated the induction coil did the torque sensing in a TSDZ2. It is clearly a hall sensor not a coil.

You are hairsplitting. The controller picks up the torque signal from the torque sensor, in this instance, the fixed coil.

Field weakening is a process to increase the rotational speed of a BLDC motor beyond that of its unloaded maximum RPM given by its motor constant. Torque is reduced but rotational speed increased for the set maximum voltage available. Obviously this can lead to a higher possible cadence at the pedals, but with a reduction in efficiency in the motor.

I learned that stuff when I was 17 for my bac and I am now a pensioner. It was a long time ago. I wasn't educated here but the courses are about the same.
Let's go back to that issue of diminishing torque when voltage drops while he wants to maintain his cadence (about 90rpm). How would you code a solution to his problem? Vary the pulse width? Vary the phase? I'd like to see your code.

 

[Woosh]

If I am not mistaken, I think Bosch measures both the pedalling torque and the motor output torque through their gearbox.

 

[Blacklite]

You are hairsplitting. The controller picks up the torque signal from the torque sensor, in this instance, the fixed coil.


I learned that stuff when I was 17 for my bac and I am now a pensioner. It was a long time ago. I wasn't educated here but the courses are about the same.
Let's go back to that issue of diminishing torque when voltage drops while he wants to maintain his cadence (about 90rpm). How would you code a solution to his problem? Vary the pulse width? Vary the phase? I'd like to see your code.

You continue to say the torque sensor is the coil - “the torque sensor - in this instance - the fixed coil” - when it’s demonstrably true that the torque sensor is the hall sensor. The coil is just a transmission mechanism.

I would code field weakening exactly as how it is done one of the OSF’s. When you hit max duty cycle on the PWM drive, but there is still demand for more speed, increase the advance angle on the motor drive, effectively creating field weakening. You can’t increase torque and motor speed at the same time. It’s one or the other.

If you mean to limit the max torque at lower cadences so there isn’t a drop off when weakening kicks in and reduces torque the most efficient way would be to have a current limit at lower cadences. Doing it with changing the advance angle at lower cadences would be inefficient in terms of power draw.

 

[Woosh]

I would code field weakening exactly as how it is done one of the OSF’s. When you hit max duty cycle on the PWM drive, but there is still demand for more speed, increase the advance angle on the motor drive, effectively creating field weakening. You can’t increase torque and motor speed at the same time. It’s one or the other.

He wasn't interested in increasing torque and speed at the same time, he wants to maintain his cadence (about 90rpm, at that cadence, the OSF would have applied field weakening) and speed but does not want the drop in assistance when the battery is sagging.
if you followed my posts on the other thread, I suggested reducing the field weakening angle when the voltage drops to compensate.
The proper solution is to oversize the motor and have two torque sensors.

 

[Woosh]

Doing it with changing the advance angle at lower cadences would be inefficient in terms of power draw.

no, you are wrong on efficiency and we can discuss this later, I need to go back to sleep. At my age, I wake up for a few hours in the night and usually play chess to get back to sleep but still need 6 hours sleep.

 

[Blacklite]

He wasn't interested in increasing torque and speed at the same time, he wants to maintain his cadence (about 90rpm, at that cadence, the OSF would have applied field weakening) and speed but does not want the drop in assistance when the battery is sagging.
if you followed my posts on the other thread, I suggested reducing the field weakening angle when the voltage drops to compensate.
The proper solution is to oversize the motor and have two torque sensors.

If the voltage is lower, you need more field weakening to maintain a higher speed. The max speed of the motor is limited by voltage. Reduce the field weakening when the voltage lowers will just lower the rotational speed.

Ironically even though you made a big point of of saying above

I suggested reducing the field weakening angle when the voltage drops to compensate

what you actually suggested with your code in the other thread is

I imagine that you would want to apply a FW angle that depends on voltage instead of cadence, something like FW_angle = 0.5 * (54- battery voltage)

which increases the angle as the voltage drops. You claim you said one thing and then when I look it up find out you said the exact opposite.

Anyways. This has taken this thread completely off topic.

I’m excited that the new To7 motors have a proper FOC controller. The TSDZ2 firmware, both stock and open source, does not. It doesn’t have the processing power, nor the required phase current sensors to do so.

 

[pxl666]

I will be honest it was late at night and i didn't give any time to read it. I currently have no input on the website and had not seen this i think it must be quite new. Maybe i come across as defensive and i probably am

We are a small, close knit very hard working team. It isnt easy to start up a new company and bring new products to market, often in start-ups you have people doing jobs outside their normal roles. The person working on the website has a lot of other work she's doing and is working really hard. I have a lot of appreciation for the work shes putting in.

I understand your feedback and i have written you a PM

Thanks

did you sell any motor ? do you know is anyone using it for mtb and can give honest opinion ? why didn't you bother to open motor and show some pictures from inside ? i don't recall from you a clear statement that motor has any thermal safety built in and will prevent itself from overheating . every modern smartphone is capable of delivering good quality video and you provided none showing motor installation , servicing or setting up things from display .
how do you want to convince me to spend 372$ over 275$ to get your motor over tsdz2 ? and i'm not eager to do so mostly because i hate large tv-like display ... why on earth there's not dz41 / vlcd10 / sw102 option to buy ???
really ... i want to see change in small conversion - motor world , a want to have a choice and to7 seemed to something , but you attitude is at least repulsing .
instead of focusing on providing tsunami of information you focused on pointless flamewar with other people...
hell... send me your products and i will install them , test them in various conditions , open and service them and film this in 4k uhd and post on yt so the rest of the world can see how good they are ...

 

[Woosh]

You claim you said one thing and then when I look it up find out you said the exact opposite.

agreed. The old post was at 10AM, the new post was at 4AM. Brain fade? I don't know.
I rarely post at 4AM. FOC is a very interesting subject but I agree that it is off topic here.
Which model did you order?
I hope you'll post a review soon.

 

[pxl666]

can you be more specific?

This is what I am talking about:
Thermal Putty Kit for TSDZ2 - Eco Cycles

why bother with stuff like that when you have this :

 

[Raboa]

This is the link to the above information.

TSDZ2/TSDZ2B motor cooling improvement kit - premium

TSDZ2 motor cooling improvement kit - premium The kit consists of: motor housing heatsink for TSDZ2 to improve heat transfer (heatsink, thermopad 68x24mm, screws M3x4 - 2 pcs) body radiator for TSDZ2 to improve heat transfer (radiator, thermopad 63x37mm, screws M3x8 - 2 pcs) thermal conductive...

e-bikestuff.com

This works out at roughly £80.

Could you put holes in the outer case and not fully cover the holes with a cover to stop water ingress but still allow airflow.

Make the outer case out of carbon fibre.

 

[alexfnoble]

This is the link to the above information.

TSDZ2/TSDZ2B motor cooling improvement kit - premium

TSDZ2 motor cooling improvement kit - premium The kit consists of: motor housing heatsink for TSDZ2 to improve heat transfer (heatsink, thermopad 68x24mm, screws M3x4 - 2 pcs) body radiator for TSDZ2 to improve heat transfer (radiator, thermopad 63x37mm, screws M3x8 - 2 pcs) thermal conductive...

e-bikestuff.com

This works out at roughly £80.

Could you put holes in the outer case and not fully cover the holes with a cover to stop water ingress but still allow airflow.

Make the outer case out of carbon fibre.

The DM-02 removes the need for any of this

 

[rik111]

@alexnoble my humble suggestion for UK success would be to send Woosh bikes a free sample for them to test and review. They have far more experience to help than anyone else. You never know if it is as good as you say, they may start stocking and selling it.

 

[Woosh]

The DM-02 removes the need for any of this

Your motor is arranged in the same way as the TSDZ2 judging by the pictures.

Can you show us how your DM-02 remedies the heat dissipation problem?

This is the amount of effort to deal with overheating when you want to push the motor. The video takes half an hour to watch, the guy spent much more time than that.

 

[alexfnoble]

Your motor is arranged in the same way as the TSDZ2 judging by the pictures.

Can you show us how your DM-02 remedies the heat dissipation problem?

This is the amount of effort to deal with overheating when you want to push the motor:

You are the only person whos seen this picture that i know of who cant comprehend what you are looking at

 

[Woosh]

You are the only person whos seen this picture that i know of who cant comprehend what you are looking at

You are the only rep I know who answers by ridiculising those who want to talk to you. I have no problem dealing directly with Chinese sales and tech support people, they are always curteous, detailed and helpful.
If you don't know or have not got the information, just say so instead of beating about the bush.

 

[saneagle]

Hopefully will have one soon.

Not quite sure how that is relevant to my comment though. Seems as though

It’s not about grovelling for forgiveness. There were multiple points that you were completely wrong about, and most pointed towards someone with barely any understanding of how modern BLDC motor control works. From a crank sensor being used for motor advance angle, to the TDSZ2 torque sensor being a coil (hint: it’s actually a hall sensor). So it’s worth mentioning to all that your critique is not based on someone with solid engineering knowledge in this field.

For things to improve this would be my top four -
Heat management between stator and case
A proper FOC controller.
Less play in the axle / better and smoother bearings.
A more consistent torque sensor that doesn’t have wildly variable values between units.

Notice how a lot of these are things that To7 have claimed to have addressed.

I personally can’t wait to use one and see if they have.

What about waterproofing, which is the bane of after-market mid motors? Most of those other things are what technical masturbators on forums get off on. Real people just want a motor that works and gives the power they want with a user-friendly way to control it.