Bafang torque sensor mod?

[Deleted member 33385]

The Bafang BSS01b is great but could be better with a torque sensor. How about pressure pads (perhaps piezo-electric?) on the pedals, connected to the unused throttle cable via a measuring circuit? The measuring circuit design and output wouldn't need to be too sophisticated, because the throttle response parameters can be adjusted in the firmware already. Keeping the pressure pad circuit connected despite rotating pedals would be tricky.

 

[Woosh]

it's simpler to change the BBS motor for a TSDZ2 than to design an add-on torque sensor but if you want to do it, I suggest you mount a chain tensioner somewhere and convert its angle to a throttle voltage.

 

[Deleted member 33385]

it's simpler to change the BBS motor for a TSDZ2 than to design an add-on torque sensor but if you want to do it, I suggest you mount a chain tensioner somewhere and convert its angle to a throttle voltage.

The pressure sensors could be connected to a Raspberry P and coded in Python, at which point the possibilities could include a phone connected app to control a wide variety of behaviours, delivered through the throttle control, including remote shutdown and GPS positioning via the internet. Whether I do this depends on how annoyed I get about the lack of a torque sensor on the Bafang. If it becomes a relentless niggle, I'll schedule the time. I did look at the Tongsheng, but I doubt the long term reliability of small motors, how reliable are they compared to Bafang?

 

[Woosh]

I find some design issues with the TSDZ2 not to my liking* but overall, the TSDZ2 gives you extremely good value for money.

* the bottom bracket axle is held into position by circlips. There is a significant lateral movement, that has no impact on performance but still unrefined design.

 

[Woosh]

The pressure sensors could be connected to a Raspberry P and coded in Python, at which point the possibilities could include a phone connected app to control a wide variety of behaviours, delivered through the throttle control, including remote shutdown and GPS positioning via the internet.

where would you put the pressure sensors?
If you put them on the pedals, how are they connected to the controller?

 

[Deleted member 33385]

where would you put the pressure sensors?
If you put them on the pedals, how are they connected to the controller?

Like they do on rotating screen laptops. Or you could embed a piezo electric circuit into the each calf-muscle and connect them to the bike - wireless torque transmitters (Pis) built into the soles of the shoes would be less bloody, then connect via wifi via another Pi to the throttle cable connector.

 

[Deleted member 33385]

* the bottom bracket axle is held into position by circlips

That certainly seems a bit of an odd design choice - is it a bodge/fix?

 

[Woosh]

it's simplistic and customers expect better design.
you can see the groove where the circlip goes:

It wouldn't cost Tongsheng much to add a wing nut to stop lateral movement like on the BBS bottom bracket axle.

 

[Deleted member 33385]

it's simplistic and customers expect better design.
you can see the groove where the circlip goes:

It wouldn't cost Tongsheng much to add a wing nut to stop lateral movement and a rubber gasket to stop dirt and water like on the BBS bottom bracket axle.

From it's positioning (bear in mind I've just started on some wine - Echo Falls Shiraz, it's a blend but very drinkable and actually very very nice for a £6.50 bottle [Note: I know absolutely nothing about wine]), it's there to prevent lateral movement. It'd wear sidewaysover time though, and I'm sure that could have been designed better - but how exactly escapes me at this present pleasantly relaxed moment.

 

[Woosh]

it's not structural but there is no simple way to correct it.
You can pad the gap behind it with some shims but customers ignore it. The circlips limit the movement to about 2mm, 1mm on each side. The long term problem is some people put more lateral force in their pedalling than others.

 

[Deleted member 33385]

it's not structural but there is no simple way to correct it.
You can pad the gap behind it with some shims but customers ignore it. The circlips limit the movement to about 2mm, 1mm on each side. The long term problem is some people put more lateral force in their pedalling than others.

Gosh, I'm actually too drunk to comment but may think about it later - all I can suggest is using a lathe to make room for bearings contained in a circular ring, but I think your padding is the most immediate and sensible solution. Plus with a deeper channel for bearings it'll just break in use lol.