Resurrecting an Ultra Motor A2B Metro with 20S power

mr.pibb said:
Ok you said you were getting max temps of 110C. Are you running at the full 40A or only like half?
I will be also buying a controller probably this weekend too. Are you pretty happy with the crystlyte and data logging?
It seems like the best route to go from what I see.
Click to expand...

I am running the full 40A on the crystalyte controller. The temperature datalogger was separate from the controller and was only being used as a display for current winding temps.

I am not sure the Crystalyte is the best solution if you want to start without pedaling first. I chose sensorless because I did not want the possible reliability issues of hall sensors since having to replace them was difficult due to the motor design. If one fails you have to completely disassemble the wheel, fix the sensor and then reassemble the wheel. The bike as-is has been bulletproof but the pedaling start is not an option for some folks. Personally, it is not too big a deal but it would be nice to start without having to pedal. This bike is a commuting tool and is often ridden in 100F+ temps so the option of not pedaling at all would be nice. I have a pedal bike that weighs 25 pounds for excercise so the 95 pound A2B Metro needs to be self powered.
 
Thanks to edamane I have a blueprint for my A2B.
The cool part is that since there are but 50 miles between us we will be able to compare our ebikes.
I ordered a Lyen edition 12 fet controller and decided to retain the hall sensors.
I dug out the hotglue and epoxied everything that had been held with it (HG).
a2bwrdn.jpg


So it should be interesting to see what difference the sensors and controller make, compared to edamane’s.
I searched around and have (almost) concluded that I’ll also go with the 72V approach…copying the stock rear container concept and other things as well.
I plan on running the bike on the stock 36v frame pack until the hobbyking batteries arrive and the rear pack is ready for prime time.
wj
 
I'll be real interested to see how it works with the sensors. The winding configuration looks similar to a BMC motor so there is a potential for timing advance issues but the A2B motor has the halls located differently so this may solve that.

A good test will be the no-load/full speed current at a given voltage. If the timing is incorrect, the no-load current will be higher than it should be. A sensorless controller gets its timing from the BEMF, so inherently has the proper timing.
 
What a great writeup! When my A2B finally quits will definitely keep this in mind.

Do you have the wiring diagram on how you had the motor rewired after the internal controller was removed?
 
If you are talking to me the OP then all you have to do is crimp and solder one 12AWG or 14AWG wire to each pair of winding wires and then get them out of the hub through the axle window. There's not much to it really. -Jim
 
There is an A2B Metro in Brooklyn, NY on ebay for a decent price that has a "bad" motor. There is a decent chance it has a bad controller inside the motor and can be modified like my bike.

http://www.ebay.com/itm/A2B-Metro-Electric-Bike-Ultra-Motor-lithium-battery-powered-/300807589704?pt=Road_Bikes&hash=item4609878f48
 
Hey Guys,
Just wanted to say a quick hello. I just bought this A2B from the EBAY seller on Ebay. The seller says the motor just stopped working one day as he rounded a corner. I'm hoping to bring it back using the existing 36V batteries at first to see if I can manage the commute on the bike before investing lots more. First step starts tomorrow - removing and opening the motor. Wish me luck. I'll keep you posted and I'll be back shortly looking for advice.

Regards,

Jim
 
don't try to drive it home on a dead battery pack. put it in a truck and wait to find out why the battery will not charge. this could make a substantial difference in your repair costs.
 
Dnmun. The battery may be OK. I haven't checked it yet but it charges to full and the charged light turns green. I'm hoping it is a controller problem like edamame and a few others have seen.
 
Hey Guys,
Work has kept me too busy to make much progress on the bike. I found a few minutes today and went though the electric troubleshooting steps in the manual and everything seems to check out (brake switch, key switch, relay). The motor voltage reads 41.5 volts 1 day off the charger. The one question I had is that the manual states you need to run the throttle to test the voltage. Throttle input makes no difference (no change in voltage) does that indicate I may have a throttle problem as well? Thanks for the help.
 
OK - I got it apart but now I'm not sure how to remove it from the hub. Suggestions?
hub1.jpg
 

Attachments

  • hub2.jpg
    hub2.jpg
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It takes quite a bit of force to overcome the magnets. If you're really strong, you might be able to just push down on the outer ring to separate it from the stator. Otherwise I've seen people use a large 3 jaw gear puller. Once the magnets clear the stator it should come the rest of the way off easily.
 
Thanks. Apparently I'm not really strong as I can't make it budge. I don't have a 3 jaw puller but I may be able to rig something up. There is nothing else I need to unscrew right?
 
To get the motor out of the hub I drilled a hole in a 2x4 (you can see it in the picture above) and placed blocks between the hub and the 2x4 and simply tightened the axle bolt. It worked well. Let me know if that is not clear.
 
Excellent! Good approach. Like using the axle nut as a gear puller.
Once you get the magnets away from the stator a bit, the force needed drops way down so you can get it the rest of the way by hand.
 
That motor is pretty awesome, but sorry fechter it's just .5mm laminated steel, no fancy ferrite. The stock wind is 2x31 in delta with 20g wire. Rewound they can be a REALLY awesome motor.
 
I had hoped to have my a2b back together with the Lyen 12 fet but the flu took my down.
As I’m coming back to life I see another jim in the fray of it!

One observation,
The current hall sensor location in your unit is not what I have nor is it what edamame had.
Also it looks as if two of the halls have been relocated already…
hallvar.jpg



wj
 
Interesting. I did notice the magnets were numbered so I guess the previous owner had taken it apart. Maybe he had tried to relocate them and then abandoned the project. I think I'll pull out the halls and go sensorless.
 
well after edamame described his sensorless conversion I concluded that sensored was what I wanted!
weird thing about your unbit is that the controller has the sensor leads soldered directly to it and then potted...so manybe the unit had a replacement controlled installed?
I await the outcome of your conversion as I think you'll be up and riding before I'm up and walking.


wj
 
I have done a motor and controller upgrade on my a2b and was wondering if these are the batteries that you used in the rear battery case?
ZIPPY Compact 5800mAh 10S 25C Long Lipo Pack

I am going to be ordering a set soon.
 
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