A2B Metro - www.ultramotor.com - Video Page4

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fechter
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by fechter » Jul 25, 2017 8:05 pm

Ouch :shock:

That could hurt. I have torque arms on both sides and I torque the axle nuts to the specified torque, which is really tight. Even then, I can see the torque arms are getting slightly dented on the corners, so doing their job.
"One test is worth a thousand opinions"

paul drury
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by paul drury » Apr 06, 2018 3:26 am

Good morning,
just as an update after giving up on the A2B and using a Bosch powered bike for the last year or more I decided to have one more shot at getting the A2B running reliably. I bought a 12fet controller from Power Velocity (thank you Fetcher for the recommendation) and after a little problem with my android phone not connecting with the app I now have a fully functioning bike. I can whole heartedly recommend this controller if you are looking to upgrade your A2B as it is super smooth and super quiete compared to the stock controller. I just need to tweek the settings slightly as the amp limit in the app does not tally with my power meter.
Paul

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fechter
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by fechter » Apr 06, 2018 7:34 pm

Good news. Yes, the amp limits are not calibrated very well on those but with an accurate meter you can get it dialed in where you want it. The regen works really nicely.
"One test is worth a thousand opinions"

paul drury
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by paul drury » Apr 19, 2018 2:43 am

Good morning Fetcher,
I was wondering what settings you have for your A2B as the throttle response on mine seems a little twitchy and not very linear, the initial twist of the throttle there is a dead zone on the throttle where there is no respnse then over a very small area of throttle movement the amps will go from zero to max and then the rest of the throttle movement is at the max value. Controlling the bike in traffic at low speed is shall we say interesting. Secondly may I ask where you got your torque arms as I definitely need to upgrade mine.
thanks
Paul

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fechter
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by fechter » Apr 19, 2018 9:09 am

I'll have to find those settings on my old laptop. It might take me a while to dig them up. I think there is a setting for the throttle voltage but I don't recall having an issue with mine. Low throttle should be around 1.0v. If you see a setting for this in the programming, you want it to be lower. The other way to fix it if software doesn't work is to add a trimmer pot in series with the ground wire going to the throttle. Something like 500 ohms. Then you can dial it up until the motor starts moving, then back off a little. The trimmer can be placed anywhere between the throttle and controller wherever it is the easiest.

The torque arms came from a member here, but I can't remember who. It will be in one of the A2B threads somewhere (maybe even this one). They were perfect. Edit: after a search, see this topic:
https://endless-sphere.com/forums/viewt ... m#p1297730
Ianhill
"One test is worth a thousand opinions"

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fechter
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Re: A2B Metro - www.ultramotor.com - Video Page4

Post by fechter » Apr 21, 2018 12:14 pm

I checked the programming software and I don't see any settings for throttle range. Some other controllers have this.

So the old school way to fix the problem is to place a 500 ohm trimmer pot in series with the throttle ground wire. With the wheel off the ground, you start at zero and increase the pot resistance until the wheel just starts to move, then back off a little. Typically this will be around 150 - 200 ohms. This may be what I did on mine, but I can't remember.

Here's how it looks on another setup:
Throttle smoother.jpg
Throttle smoother.jpg (58.28 KiB) Viewed 15 times
"One test is worth a thousand opinions"

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