Best Variable Regen Input ???

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John in CR   100 GW

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Best Variable Regen Input ???

Post by John in CR » Oct 07 2019 4:57pm

My new Nucular controllers will be my first chance to employ variable regen, and I'm wondering what have you guys found is the best method of input? My thought is to use a thumb throttle for regen, though I'll probably need to add some kind of extension to extend the thumb pad to the right so it's easy to reach.

With the Nuk's once the input goes above 0V will that alone engage the ebrake and regen, or do I also need to squeeze a brake handle?

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amberwolf   100 GW

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Re: Best Variable Regen Input ???

Post by amberwolf » Oct 07 2019 10:51pm

Assuming the controller supports single-input braking* then you could use a cable from your brake handle to one of those cable-operated potentiometer throttle units, which can be used to create whatever voltage range your controller requires for the regen braking. (including reversed voltage, starting high and going low, simply by reversing which outer leg of the pot is connected to + and which to - .)

If your brake handles are already used for cables, you could add a second brake handle for this, either with a custom mount to put it exactly parallel above or below the existing one, or just inboard or outboard of it. (like I presetnly have on SB Cruiser's left handlebar).


Alternately, you can use a lever throttle that is "under" the handlebars, it's like a thumb throttle (and usualy thumb operated) but it doesn't rotate circumferentially around the bar tube, it pivots left/rigth under the bars.

Or just use a thumb throttle, but it's harder to make room for on hte bars; forces moving other controls inboard, or have to put it inboard and use a longer thumb tab to get "around" the other controls without moving your hand on the grips.



* meaning it doesn't require a switch to turn on braking and then a separate voltage input, usually the actual throttle, to control the amount of regen

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Re: Best Variable Regen Input ???

Post by Grantmac » Oct 08 2019 12:00am

A few guys are using a pressure transducer in the rear brake line. 500psi seems like the sweet spot.

John in CR   100 GW

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Re: Best Variable Regen Input ???

Post by John in CR » Oct 08 2019 2:00pm

Interesting solution, but I'd prefer independent operation to minimize brake wear. Plus I am a cheap and simple type.

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Re: Best Variable Regen Input ???

Post by BlueSeas » Oct 08 2019 7:26pm

I'm on test setup ride #3....but on a Phaserunner/CA3 setup, I'm using a thumb throttle on the left side for variable regen. I like it. Also moved the rear disc brake to the left too. So ala motorcycle, left is rear and right is front.

On the Phaserunner it only required cutting one wire on the throttle input. Cheap and simple. Not sure about interfacing with the Nuclear setup.

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NCC1941   10 mW

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Re: Best Variable Regen Input ???

Post by NCC1941 » Oct 08 2019 7:53pm

I use a separate brake lever for variable regen, similar to Amberwolf's setup by the sound of it. It took a small bit of doing to get it working with my CA3 (which only has one throttle input), but here's how I set mine up:

I took a typical ebrake lever with the built-in cutoff switch, and cabled it up to the converter box in this thread: viewtopic.php?f=2&t=100859#p1475133.
That box has an output signal range from 0.85v-ish to 4.2v, which was perfect for my use, because it creates a bit of a deadzone at the beginning of the lever travel before the throttle output from the CA kicks in at the default 1.1v. That deadzone is enough for the ebrake signal to trip before the throttle kicks in, telling the CA to convert the 1.1v-4.2v throttle signal into a 0.8v-0.0v regen signal for my controllers.
From there I installed my twist throttle in parallel, and it "just works" because I didn't have to do anything weird in the CA3 settings to get the brake lever working.

This setup doesn't really replicate the feel of a lever hooked up to a physical brake, because it's just a consistent light resistance through the full range of lever travel, all the way down to the handlebar. But it doesn't take much, if any rewiring of muscle memory compared to the simpler / more common method of using a second throttle for braking, which I never quite got fully comfortable with.
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amberwolf   100 GW

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Re: Best Variable Regen Input ???

Post by amberwolf » Oct 08 2019 9:32pm

NCC1941 wrote:
Oct 08 2019 7:53pm

This setup doesn't really replicate the feel of a lever hooked up to a physical brake, because it's just a consistent light resistance through the full range of lever travel, all the way down to the handlebar.
Easy enough to fix, using a spring either between the lever and the bars in compression, or in tension between the other side of the lever at the "top" where it pivots away from the mount as you squeeze, to some other point convenient to there. Might take experimentation to find the right spring tension to give a good feel.

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Re: Best Variable Regen Input ???

Post by ZeroEm » Oct 08 2019 9:34pm

I have a tadpole with no rear brake just front disc. Put both disc on one lever on left side. right side has throttle lever and a horn button to activate regen and vary it with the throttle thru CA3. I made sure the breaks do not drag at all and only used them to complete the stop or hold the trike. I run the throttle/regen with the lower palm of my hand, only use the thumb to hit regen/rear brake.
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Alan B   100 GW

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Re: Best Variable Regen Input ???

Post by Alan B » Oct 09 2019 9:55am

The feel of a real brake can be emulated pretty well with a spring to feel like initial takeup, followed by a stop or a much heavier spring at partial lever position. The braking force can be measured with a strain gauge as there's not much motion once the pads or shoes are in contact with the surface, what changes is the pressure. Arlo made a strain gauge brake lever setup, though his was solid and did not have the initial spring or switch as I recall. It would be nice if someone would manufacture something nice and professional along these lines. It would not be too cheap due to the small signals from the strain gauges, a high gain strain gauge amplifier is required. But for this purpose it doesn't need to be high precision. The mechanics and electronics could be packaged in a small box or cylinder and be cable actuated, then any brake handle could be used. This box could also contain the switch at initial motion which some regen / ebrake systems need to trigger them and/or the brake light if desired.

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