BBS02 PAS using chainring instead of crank?

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Reflector   1 W

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BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 13 2018 2:20am

After all my work (building my velomobile and designing the 12V electrical system, fabricating custom parts etc.) I have discovered that the BBS02 motor's PAS is triggered by crank movement rather than chainring. I have the motor installed in the Alleweder velomobile (see picture) and due to the Bafang motor's width (and also to avail myself of an extra low chainring), I decided to mount my pedals on a freewheel jackshaft between the motor and the rear wheel. The thumb throttle works fine but the PAS does not and now I know why.

My question: Is it possible to still use the installation (pictured) and activate the PAS by some other method?
This machine has taken many moons to create as I have a few health issues.
All thoughts on my conundrum gratefully received.
Attachments
BBS02 and freewheel.JPG
Alleweder A4 velomobile.JPG

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Re: BBS02 PAS using chainring instead of crank?

Post by Chalo » Mar 13 2018 2:36am

Power from the motor will continue as long as the crank is turning, and for another second or so after it stops. If you can't stop the crank, you can't signal the PAS to shut off. I don't think PAS will work with what you have arranged; the chaining must be able to move separately from the crank.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 13 2018 5:04am

It looks like I'm going to have to measure the widths again and hopefully attach the cranks to the motor, dispense with the freewheel and slide the whole lot back towards me.

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teklektik   10 GW

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 13 2018 8:24am

Reflector wrote:
Mar 13 2018 2:20am
My question: Is it possible to still use the installation (pictured) and activate the PAS by some other method?
Sure - a couple of options come to mind:
  1. First - I have no experience with this motor so this recommendation is a little generic...
    PAS is activate by pulses that typically derive from magnets passing a couple of hall sensors. The two sensors allow the controller to determine both crank rpm and direction. In this case the sensors are internal to the motor but it's unlikely they are unusual from an electrical perspective. You could attach a conventional PAS wheel to your freewheel BB in standard manner and wire it into the motor controller to replace the internal sensors. Here you would like to arrange for the same number of magnets and the same signals which in all likelihood are coming directly off a pair of halls. There are folks here on ES who have extensive knowledge of these drives and can answer many questions about the halls, wiring, connectors, etc - you will likely need a thread titled specifically to acquire BBS02 hall/PAS hookup information.
  2. A second option is to bypass the builtin PAS entirely and use a CA3 with separate PAS wheel to provide assist via the throttle connection. There have been a couple of projects with this motor in this vein here - notably by Kepler and electricwheels.de.
Option 1 will require opening the motor case and patching into the existing hall wiring, while option 2 is more of a bolt-on fix and would involve external wiring changes and the added expense of a CA3 - which might be nice to have for other reasons. In either case you can likely squeeze in a standard PAS wheel on the crank spindle, but from the looks of your fabrication skills, this should not be an issue. If you are not comfortable with opening the motor or tinkering with electronics, then option 2 might be a good path to pursue in that the CA will afford some advantage in its own right even if you later decide to adopt another strategy.

Reflector wrote:
Mar 13 2018 2:20am
This machine has taken many moons to create...
This is a control problem and it frankly would be a shame to back out of so much thought and effort by re-imagining the mechanics at this late stage of the build.
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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 13 2018 7:44pm

Thanks Teklektik,
I had thought of the advantages of a CA3 (especially after reading Fastolfe's description of what he had achieved).
Does the PAS wheel fit to the motor crank or my freewheel crank? The idea of not cracking the motor case appeals to me.
I imagine that the PAS wheel would fit to the freewheel to detect the crank rotations and then somehow send this data to the CA3 and thence to the motor controller; am I right with my train of thought on this one? If so, what would I buy (and from where) and how would I hook it up?

The beauty of the CA3 is I can probably dispense with the C961 Bafang display.

My fabrication skills certainly took a steep upward curve while building the velomobile and I have reasonable electronic ability, but in this case I could do with a bit of a 'leg up' as they say in horse racing.

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 13 2018 9:43pm

Reflector wrote:
Mar 13 2018 7:44pm
I imagine that the PAS wheel would fit to the freewheel to detect the crank rotations and then somehow send this data to the CA3 and thence to the motor controller; am I right with my train of thought on this one? If so, what would I buy (and from where) and how would I hook it up?
Yep - that was what I had in mind. The idea would be to mount the PAS wheel here and then follow a more or less standard hookup for a CA3 with a generic controller as outlined in "Appendix D. Adding a CA-DP Connector to a Generic Controller" of the Unofficial Guide. The only difference being that you would use a CA3-DPS with wheel speed sensor instead of wiring the yellow wire up to the controller hall sensor as described in Appendix D.

freewheelJackshaft.png
freewheelJackshaft.png (248.58 KiB) Viewed 1564 times
CA-genericController3.png
CA-genericController3.png (82.05 KiB) Viewed 1564 times

I did quick search back on the folks who have tried this - I know Kepler may have been the first to try this some years back but he had difficulties with the CA/BBS controller interaction. However, electricwheels.de subsequently released a kit that essentially was the the same setup but no issues were reported. I would encourage you to contact these guys as well as Grin Tech to get a better feel for the present evaluation of this scheme. Certainly the CA3 has evolved and has one or two improved PAS features which may well prove helpful and were unavailable to Kepler, but the BBS situation is outside my area.

Although the CA3 can use many PAS wheels with a little finagling, I would recommend getting one from Grin or one of their distributers so at least that part is plug and play. They have several models including on kind that doesn't require removing the crank and a new miniPAS version with 24 poles (!) that promises to give quick start stop response. You would also likely want to start with an auxilliary pot to adjust assist level although I would recommend also getting one of the DigiAux button assemblies so you could also switch presets on the fly. There a variety of configuration options for what the pot, digiAux buttons, or three position switch can do so a little reading might be in order. And of course, you would need a CA3-SA (equivalent to a CA3-DPS + Shunt-CA3).

Here's some links about the stuff I mentioned to help get you started:

https://endless-sphere.com/forums/viewt ... 31&t=60433
https://endless-sphere.com/forums/viewt ... 0#p1019353
https://endless-sphere.com/forums/viewt ... 1#p1322541
https://endless-sphere.com/forums/viewt ... =2&t=83439

Anyhow, this looks like it should work fine since it's essentially a plain vanilla generic controller installation, but the reports of problematic CA/BBS controller interaction need to be investigated - particularly if you really don't want to get into a research project...

All that said - in one of the links above, Kepler pointed out that the internal BBS sensor was a 24 pole two-wire sensor which is what the new Grin mini PAS-24P sensor provides. If that physically fit your rig and cracking the BBS case wasn't too scary, it holds promise of being a good external replacement that would allow you to keep the original BBS PAS system operation intact. The Grin version has been altered to run on 10V instead of 5V, but that can be worked around or one of the original unmodified units is likely workable. Justin at Grin can fill you in if you decide to pursue this approach. :)
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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 14 2018 4:45am

Thanks for all the links and information. I will contact Grin, Keppler et al to see if they have any idea where I can source a plug and play solution for the Bafang BBS02 drive.
Yes I agree that the space at the left crank of the freewheel looks like the location for the PAS wheel.
Now I have a lot of reading and learning coming up.
Attachments
space for PAS wheel.JPG
space for PAS wheel.JPG (128.42 KiB) Viewed 1542 times

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teklektik   10 GW

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 15 2018 10:08am

BTW - there is another strategy available that you might like to consider which involves replacing the BBS controller as well. This frankly seemed like it might be a bit more of a handfull than you might want to pursue, but here's a thread on the conversion that you might like to check out:

https://endless-sphere.com/forums/viewt ... =4&t=91775 (thread)
https://endless-sphere.com/forums/viewt ... 5#p1364846 (post discussing PAS hookup a bit)

Case 3.
  • Here the idea is to remove the BBS controller (!) and then attach the CA3 and a Phaserunner controller to the BBS motor and PAS sensor. This buys a more powerful controller and sidesteps any CA3/BBS controller issues. There's a post or two by Reinhard (electricwheels.de) on page two. He's a supplier of quality CA add-ons - his stuff is always meticulously designed and implemented.
Anyhow - this may not be a direction in which you wish to go, but the posts are contemporary and the option might be worth a quick read. :D
Last edited by teklektik on Mar 16 2018 9:41am, edited 1 time in total.
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Electric Bicycle Union   1 µW

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Re: BBS02 PAS using chainring instead of crank?

Post by Electric Bicycle Union » Mar 15 2018 2:06pm

Hi,

You should contact Alligt in Dronten (Holland) This company make cranks for left side drive to the Bafang axle. Check out the Ice fat trike in the link bellow.

http://www.ligfietsshop.nl/ice-full-fat ... #more-2839

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 15 2018 8:21pm

Would I just buy the CA3, shunt and a generic controller (as per the schematic) and somehow patch in a new PAS wheel to the motor?
With your option 2 can the new components be connected to override the motor's existing PAS pickup (i.e. with cracking the motor case)?

So many questions, but I've just received a 'no can do' from Reinhardt (I asked about a plug and play solution), almost the same response from Joseph at Em3ev and awaiting responses from Kepler and Grin.

See if I've got it right this time;
1. New PAS wheel to the LHS of the freewheel crank
2. New shunt between batteries and new controller
3. Throttle plug (3 pin) from new controller goes to an unseen connection on CA3?
4. New PAS wheel connects to 'Halls' input 5 pin plug on new controller
5. Then output somehow to BBS02 to override the internal Halls sensor?
6. does step 5 require the poles of the new PAS wheel and the BBS02 to be matched?

Dang blat...more questions I hadn't counted on.

Then of course I have to think about a heavy duty switch to alternate between the two batteries to obviate the need to unplug them as they become depleted.

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Rassy   1 MW

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Re: BBS02 PAS using chainring instead of crank?

Post by Rassy » Mar 15 2018 9:07pm

I've had good luck with marine style two battery switches. I would recommend only switching between the two batteries when not actually using them to avoid arcing:

http://www.boatstore.com/0462dp0red-bat ... PAQAvD_BwE

I've followed your thread and believe the basic BBS02 is a very clean and relatively trouble free system. I've installed six of them on my own and friends bikes at this point. Even though I understand the width is an issue within the velo shell, my preference would be what you stated near the beginning, to just adjust the location of the BBS02 and put your crank arms/pedals directly on the BBS02. No extra expense, no possibly troublesome hacks, retention of the BBS02 control/display system, and who knows what else. Just my two cents worth, good luck with your project however you do it. :D
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 16 2018 4:53am

The reason I went with the freewheel is that it is symmetrical and narrower than the BBS02 (which is asymmetrical and wider). Even with the 152mm straight unicycle cranks fitted to the motor the right pedal is so close to the inner wheel well that it guarantees a shoe strike most of the time. The bigger Q factor plays havoc with crook knees and I can't use my egg beaters (narrow) due to awaiting ankle reconstruction so there won't be any shearing movements to snap out for about a year.

Meanwhile hopefully I can get Tek's option 2. to work.

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teklektik   10 GW

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 16 2018 10:00am

Reflector wrote:
Mar 15 2018 8:21pm
Would I just buy the CA3, shunt and a generic controller (as per the schematic) and somehow patch in a new PAS wheel to the motor?
The generic controller in the Case 2 posted above is the BBS controller. You would buy/add a new PAS wheel + CA3 + external shunt.
Reflector wrote:
Mar 15 2018 8:21pm
With your option 2 can the new components be connected to override the motor's existing PAS pickup (i.e. with cracking the motor case)?
You would not be using the built-in BBS PAS so it doesn't get 'overridden' -- the CA + other parts provide an alternate PAS - the BBS just thinks the CA PAS is you on the throttle. Without cracking the motor case.
Reflector wrote:
Mar 15 2018 8:21pm
So many questions, but I've just received a 'no can do' from Reinhardt (I asked about a plug and play solution),...
The important question was not if he could provide a plug and play solution - since he used to - it's "did he have control problems with CA and BBS interactions".

Please re-read my post above. Hooking up the CA to do PAS is simple. However, Kepler had problems with unforeseen interactions that appeared unique to the BBS controller. Reinhard subsequently sold a kit to do this, but now doesn't. 'Why?' 'Did he have interaction problems?'. The problem here is not the CA hookup - it's whether or not the BBS controller has some issues working with the CA (read kepler's thread for that discussion). If you cannot get a positive response that Reinhard resolved the problems Kepler had (and how he did it), then there is no point in pursuing this strategy if the whole CA installation works fine EXCEPT for the PAS part which is why you are doing it. I'm a big fan of the CA3, and think there is value in having it there anyway, but you need to clear up this outstanding compatibility issue with the BBS re: PAS.
Reflector wrote:
Mar 15 2018 8:21pm
See if I've got it right this time;
1. New PAS wheel to the LHS of the freewheel crank (yes)
2. New shunt between batteries and new controller (yes)
3. Throttle plug (3 pin) from new controller goes to an unseen connection on CA3?
As noted above, this is the BBS controller and its throttle connector goes to the CA shunt breakout cable as shown in the diagram. The present throttle goes to the CA.
4. New PAS wheel connects to 'Halls' input 5 pin plug on new controller
No. The PAS wheel connects to the CA3 PAS connection as per normal CA installation.
5. Then output somehow to BBS02 to override the internal Halls sensor?
You will not be using the BBS PAS. You are not turning the BBS cranks so no BBS PAS gets generated. Or disable it by programming.
6. does step 5 require the poles of the new PAS wheel and the BBS02 to be matched?
No. The PAS wheel goes to the CA. The BBS doesn't know about it.
Here's a summary of the three cases:
  1. Low risk, retains the original BBS PAS performance/operation.
    add an external 24 pole PAS wheel (same poles as the BBS), open the BBS case, unplug the internal PAS sensor, attach the external sensor, close the case.
  2. Higher risk, use a CA to provide PAS be alternate means.
    Do a stanard 'generic controller' CA hookup with any new PAS wheel. Don't open the BBS case. BIG QUESTION: were reported CA/BBS interaction problems resolved?
  3. Low risk, use CA to provide PAS by alternate means + add Phaserunner controller to eliminate CA/BBS interaction question.
    This is reported to work well. Open the BBS case, remove the controller, extend the motor phase/hall wiring, close the case. Plug the BBS into the Phaserunner like any other motor, plug the CA into the Phaserunner, plug the new PAS wheel into the CA. This arguably gives the best resulting system but has high cost and a lot of DIY unless you can get a plug and play kit (Reinhard?).
Frankly, the least expensive easiest change with the lowest special knowledge threshold is #1 if you can get by the part about opening the case. You might be able to get Samd or Hyena to handle the BBS mod for you (they have OZ shops) or perhaps another OZ ES member...
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Rassy   1 MW

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Re: BBS02 PAS using chainring instead of crank?

Post by Rassy » Mar 16 2018 10:10am

Okay, I have a better understanding of what your problems are now.

Someone did mention using a left side chain wheel. Why wouldn't it be simpler to just add a "fixed" chain wheel to the left side of both your crank and the BBS02 with a chain loop around them. Then when you pedal you are just turning the crank axle on the BBS02. And you would need to remove the pawls in your new freewheel crank so that your chain wheel on the right side would just be an idler and not turn directly from the pedals.

Again, the advantage of a fix of this sort is that you would retain all the functioning of the BBS02 without having to hack anything.
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 16 2018 4:10pm

Considering that the only reason the PAS isn't presently working is due to the motor crank not turning; after looking at the picture at the top of the thread how plausible would it be to construct a bracket joining the Lekkie chainring fixing screws to the motor crank?
Then the movement of the chainring would subsequently induce movement in the motor's crank and then PAS.

Thanks again for all your research and advice Teklektik, option 1 is after all he most straight forward approach.

Still searching for the BBS02 number of poles and wire colour codes / connector types.

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Re: BBS02 PAS using chainring instead of crank?

Post by Rassy » Mar 16 2018 6:01pm

Considering that the only reason the PAS isn't presently working is due to the motor crank not turning; after looking at the picture at the top of the thread how plausible would it be to construct a bracket joining the Lekkie chainring fixing screws to the motor crank?
Then the movement of the chainring would subsequently induce movement in the motor's crank and then PAS.
Even though this would be fairly easy to do (essentially eliminating the freewheel between the chain ring and the crank axle on the BBS02), I don't think it would work, because once PAS kicked in it wouldn't stop when you quit pedaling since the crank axle would keep turning. However, you could still stop the motor be holding down a brake lever (with a cutout switch) or holding down a cutout button. I have a latching button installed on my tadpole that is plugged into the brake cutout circuit so that when I just want to pedal for a while I don't have to switch to PAS 0. Relating this to your case it would be like turning off cruise control in your car be hitting either the brake or the cancel button on the steering wheel. On the bike, your PAS would resume when you released the brake or hit the latching button again and then resumed pedaling. No idea how all this would feel or how safe it would be without actually trying it.

Once, with the drive wheel off the ground, I was testing a replacement throttle and engaged the PAS by giving the crank a turn by hand. When I let go of the crank (and throttle) it kept turning and I thought the throttle was stuck in an on position. Turned out there was just enough drag in the freewheel that the motor running in PAS mode kept turning the crank axle. With my feet stopping the pedals this wouldn't have happened, but it does prove that with the crank axle and chain wheel connected the PAS system will keep going.

This is a cutoff button that plugs into either the brake circuit or the gear sensor circuit:

https://em3ev.com/shop/bbs0102hd-push-b ... rrency=USD
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 16 2018 10:07pm

Sounds like a dangerous path to go down. I hadn't thought of that; it would be like having the old stuck throttle on a 2 stroke bike on a cold morning (and I don't want to go there again in a hurry).

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teklektik   10 GW

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 17 2018 10:17am

At the end of the day, you need to assess you comfort/skill level with these various approaches. It may be that a mechanical solution will be the most doable for you.

Anyhow, to finish up a few details on the Option 1 solution:

As mentioned above, Kepler reported that the BBS PAS sensor was 24 pole with 2-wire quadrature encoding (two streams of pulses slightly offset so the controller can tell both rpm and direction). The Grin mini PAS_24P is also 24 pole with the same encoding. Justin reports that although rated for 10V for use with the CA3, it will work fine on 5V which is what you need for the BBS. I mic'd one up and it's 5mm thick - a little fat so you might have to clearance the inside of the crank to fit it.

pas_24p_1.jpg
Grin PAS_24P PAS sensor
pas_24p_1.jpg (11.68 KiB) Viewed 1363 times

Here we see in one of Kepler's images, a hookup of the BBS PAS sensor to an ebike tester. This shows a standard JST-SM-4M connector and gives us the pinout. We see the same pin order and some color coding in a shot from a vendor for a replacement BBS sensor part.

PASconnectorJST_closeup.png
Thank you Kepler! (ebike tester L<-->R BBS PAS sensor )
PASconnectorJST_closeup.png (207.7 KiB) Viewed 1363 times
pasCkt.png
BBS PAS sensor with attched male JST-SM pins
pasCkt.png (154.13 KiB) Viewed 1363 times

So, it remains to hook these together with a little adapter cable that would look like this:

GrinPas24PToBbsxPas.png
GrinPas24PToBbsxPas.png (7.84 KiB) Viewed 1363 times

So the plan would be:
  1. Open the BBS case (see many YouTube HowTo videos)
  2. unplug the internal PAS sensor from the controller
  3. Either
    1. drill a hole in the bottom or rear/downward in the case
      (attach the pins to the cable for the inside connector but don't add the plastic shroud until after you thread the pins through the hole) OR
    2. use a small round file (chainsaw file or similar) to file a small D shaped notch in the lower case edge
      (this is handy since you just plop the finished cable into the notch.)
  4. fabricate and route the adapter cable so there's about 8" or so external to the case
  5. sleeve the adapter cable with a layer or two of heatshrink where it contacts the case.
  6. plug the adapter into the controller and button up the case, sealing it with RTV where the cable runs through.
  7. power the controller and check the +5V/GND pinouts on the external adapter connector.
  8. plug the Grin cable into the adapter cable
  9. Spin the cranks to see if PAS kicks in. If it detects reverse pedaling instead, reverse pins 3 and 4 in the adapter cable external connector (Dir and RPM).
Correcting pinouts on the external adapter connector is pretty easy: press the wire into the plastic shroud to relieve pressure on the tang, then using a small flat blade screwdriver, press in the tang on the side of the connector. Holding the tang depressed, pull out the wire with connector attached. Use a small pointy object like a compass point to press into the side of the pin opposite the tang to lift the tang outward and restore its holding ability. When reinserting the pin, the tang goes to the side of the shroud hole with the little square notch. Easy-peasy.

You can get a bag of JST connectors and a JST crimper from Grin. Since the PAS sensor has miles of cable, you can start by just cutting off the connector then cutting off a foot to use as the adapter cable, then you can shorten things as you see fit and attach new connectors to the CA PAS sensor and both ends of the adapter cable. I'd get a spare sensor while I was at it so you have an unmodified one to test with (above) before you bother to shorten and put a connector on the 'tidy fit' one. If you don't feel comfortable fabricating the adapter cable, you can probably get an ES member in AU to do so and mail it to you.

With the same number of poles and no extra electronics, this should leave the BBS performing normally. You can restore it to stand-alone operation by removing the adapter cable and plugging in the internal PAS sensor. As I said above, I have no experience with these motors, but this PAS sensor stuff is pretty generic so this mod should work fine. It's actually quite lucky that Grin just released this new PAS sensor for the CA3 - I'm unaware of any other PAS sensor that sends the required quadrature encoding.

Anyhow, that's about all I've got on that scheme - hope you find a solution that works out for you. :D
Last edited by teklektik on Mar 18 2018 9:15am, edited 1 time in total.
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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 17 2018 9:51pm

Whew, what a lot of effort you've gone to in the step by step instruction for me. Now I understand :idea: the what, where and why and have just sent off my order to Justin for the 24P PAS (x2), JST connectors and crimper. The left freewheel crank arm has 5mm clearance and if that's not enough I'm not averse to grinding a tad off it.
The least invasive approach makes sense to me especially when I am able to leave all other mechanicals and cabling in situ.

This exercise has been an education for me in the functioning of the various components of the motor; something which is directly attributable to the eagerness of ES members to share their knowledge and ease the way for those of us who are less knowledgeable in some areas.
Thanks for all the time, effort and research you've dedicated to helping me solve this; I really appreciate your patience.
I will make a final post when I have received the parts and completed the job. :mrgreen:

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Re: BBS02 PAS using chainring instead of crank?

Post by Chalo » Mar 18 2018 1:10am

There's a much less complicated way to resolve your issue. Fit two left side tandem cranks to your velomobile, linked by a timing chain in the usual way. That should allow the pedal cranks to drive the BBS02 normally.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 18 2018 7:12am

Due to the width and asymmetrical way the motor sits on the boom, there was no way I avoid shoe contact with the inner wheel wells even using straight unicycle cranks. I then bought another bottom bracket shell, clamps, cranks, chainrings and a bottom bracket to fit a new freewheel. This way at least I had shoe clearance; then a Lekkie Bling Ring on the motor brought the driven chain into line with the freewheels chainrings. There are two chain tensioners (one for motor chain and a sliding pulley on the final drive just rear of the freewheel to compensate for lateral chain travel when changing between the two ratios available on the freewheel).

The tandem cranks would have been a ripper of a solution if only the motor and freewheel drive shafts had been equidistant from the left side of the boom. Unfortunately the motor shaft protrudes further (that's where it all began...) therefore a timing chain would never be perpendicular to the shafts and as a result unviable.

It was a good idea Chalo.

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 18 2018 9:54am

Hey R-
No problem on the posts - you have beautiful build and it just needed a tiny assist to help realize your vision.

So here's a couple of last points:

I suggested above that you could cut off the end of the Grin PAS cable and use that as the internal BBS PAS connector. Wrong # of pins, My Bad. I fixed the post to rewrite history and hide the mistake. But - to be honest, crimping is a skill that comes with practice. Some folks even like to buy connectors with wire tails on them so they can just splice the wires instead of crimping. You should give crimping a few test tries (here's a post that may help). If it's proving a little elusive, you might cut off about 6 inches or so of the end of the PAS cable and then just splice the wires when eventually shortening it. Just put some 1/16" or 1/8" heat shrink over the splices and sleeve the whole cable with a couple of layers of 1/4" shrink (short, then longer lengths). Your call there if you want to swap a splice in lieu of crimping a new connector.

Now for the weasel words.
The adapter connections above look correct but in the absence of authoritative BBS documentation were winged from photos. You need to verify the pinout on the BBS end when you open the case and can eyeball the wiring for real. The only two wires that are important are the red (+5V) and the black (Gnd). The other two carry hall signals and there's really no way to know which way they need to be connected a priori so you may have to swap them (one will way with trigger PAS pedaling forward, the other will work in reverse). Anyhow just to state the obvious - make sure the red and black wires and up connecting to the PAS connector the proper way and be sure to measure with a meter before plugging in the PAS (measure on the side of the PAS connector where the tangs are - should be +5V across the red/black). So short form - the wiring on the adapter illustration is a 'best effort' but the BBS side really needs to be verified.

Anyhow - looking forward following your progress. I see you've been working on this project for some years - you really should post up some photos in a build thread - it's really quite a vehicle.... :D
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Build Thread: 2WD Yuba Mundo V4

Reflector   1 W

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Mar 18 2018 8:27pm

Thanks T-k-k-k,
I'm so out of touch I've forgotten how to reply with a quote.
Would I start a build thread in E-bike photos + videos / Topics?
On the alternative splicing instead of JST; in my 12V electrical system there are only connectors used for( the horn and computer fan which cools the motor (and also 4 'd' computer connectors to connect the parts of the loom to the electrical control box. I read somewhere years ago that NASA used the Linesman Splice rather than connectors and I thought if it was good enough for them....
I've ordered the crimpers now so it will make for easy removal of the motor if needs be. You do mean that the joiner for the short lead is outside the case and not inside?

Attached is a plan view of the 12V supply and distribution and I try not to think of bad scenarios as this sits directly under my seat! The cell logger sits on top of the turn signal relay and provides a boundary for the battery which is such a tight fit that I had to make a sling so that it can be dropped in vertically.

Just part of the thread to come.
Attachments
lunch box 2.jpg

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teklektik   10 GW

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Re: BBS02 PAS using chainring instead of crank?

Post by teklektik » Mar 19 2018 9:34am

Reflector wrote:
Mar 18 2018 8:27pm
Would I start a build thread in E-bike photos + videos / Topics?
yep.
Reflector wrote:
Mar 18 2018 8:27pm
I've ordered the crimpers now so it will make for easy removal of the motor if needs be. You do mean that the joiner for the short lead is outside the case and not inside?
I was just suggesting a way to avoid an extra crimp if you were having trouble with the crimper. No big deal.

BbsExternalPasCableFab.png
BbsExternalPasCableFab.png (8.01 KiB) Viewed 1253 times

The details and your personal preferences should guide you here and are really governed by considerations other than electrical (ease of construction, serviceability, etc).
Visit Grin Technologies at www.ebikes.ca
Build Thread: 2WD Yuba Mundo V4

Reflector   1 W

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Re: BBS02 PAS using chainring instead of crank?

Post by Reflector » Sep 03 2018 5:25am

I've made and installed my patch lead to the controller and verified that the controller output is 4.7V
Also I've inserted a temperature probe to work with my thermostatically controlled computer fan.
1. Upon powering up, the C961 display has power but throttle is inoperable
2. Spinning the cranks does not cause the external PAS to induce any motion at the BBS02 spindle.

Nothing else has been adjusted; the 2 front wheels are locked down and the driving rear wheel is raised up to enable movement.
I have no idea why neither the throttle or PAS is not functioning as they should. I bought 2 PAS units from Grin and have tried both of them so I don't think the problem is in that dept.

Does this picture show that my connections are correct?
(external PAS at top of picture, temp. probe prior to fitting at the bottom of picture)
Attachments
external PAS cable copy.jpeg

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