40,000Watt Muscle Ebike - Hardstart twitchy throttle[SOLVED]

[lionschasing]

Dear everybody

I have been lurking for a while and need some help with a current project that I am finishing. I need to regulate the hardstarts because the throttle has a great deal of sensitivity and the bike is not currently useable in public.

Firstly about the problem: I have soldered the shunt on a 36fet controller, and the result now is that I am getting close to 400A hard start, the result is that despite the 14.5kg battery that I have slung on the front handlebars the bike still wheelies almost vertically on takeoff.

What value cement resistor can I install inline with the throttle 4v so that I can have softer starts?

I attach photographs of my muscle bike.
(I welded the frame with the help of a very experienced welder, I am currently installing a freewheel and crank arms to suit the wider tyre)

---
Solution was to request a very soft start controller (softest start) from greentime.... the acceleration is insane and it doesn't wheelie unless you lean back...perfect tame power yet wildly fun

Best wishes

Adam

 

[Gregory]

HUGE!

Many controllers support a 3 speed switch to allow you to start easier on level #1 then switch to full power #3 once at speed.

Methods/Methtek sold a universal throttle 3 speed switch that uses a resistor network to achieve the same thing you're talking about on controllers without a 3 speed plug, you can find a post here somewhere if you want to DIY.

And zombiess is selling a cheap micro based throttle tamer that allows you to dial in the takeoff with greater resolution, soft starts etc.

There may also be an option in the new CycleAnalyst but I'm not up to date on that.

Good luck, get us some videos of the beast in action.
Greg

 

[liveforphysics]

That bike should be awesome!

 

[ambroseliao]

This is the Methods 3 speed switch you're looking for.

http://www.methtek.com/2012/07/03/universal-3spd-switch-works-with-any-controller/

I picked mine up during one of his vacation sales...

http://endless-sphere.com/forums/viewtopic.php?f=31&t=50605

Sounds like it could still be going on!

 

[Cowardlyduck]

That's freaking insane
Perhaps having the weight of the batteries high on the handlebars doesn't help either. You might find better results with a lower center of gravity if you put the batteries in the triangle.
For a beast like that, I'd go with the CA v3 over other approaches to throttle control. Makes for a much more customizable setup.

Cheers

 

[zombiess]

Soldering the shunts isn't the greatest idea, but to works. Its much better to just add additional shunts so that the controller is able to limit current at least a little. I usually put 6 shunts on my 36 fet controllers that I build. As mentioned I developed a $35 throttle tamer to fix the problems you have, problem is I don't have them for sale yet because I am waiting for my PCBs to be delivered.

Make sure you have block time set to 0.0 as well. I have posted my hacked version of the eb2xx software I'm my 24 fet controller for sale thread if you want a copy.

Do you know what your shunt resistance is? If not you should measure it so you know how to program the controller somewhere close to you desired settings.

 

[lionschasing]

Does the 3spd switch wire in with the throttle? where do you solder it to on the 36fet? I'll get some videos of it soon.

HUGE!

Many controllers support a 3 speed switch to allow you to start easier on level #1 then switch to full power #3 once at speed.

Good luck, get us some videos of the beast in action.
Greg

 

[lionschasing]

thanks, I realized I bought this 3 speed switch from leo here http://www.aliexpress.com/item/Free-Shipping-Chinese-Electric-Bicycle-3-Speed-Control-Switch-Ebike-Three-Speed-Switch-3-wires/753911955.html

This is the Methods 3 speed switch you're looking for.

http://www.methtek.com/2012/07/03/universal-3spd-switch-works-with-any-controller/

I picked mine up during one of his vacation sales...

http://endless-sphere.com/forums/viewtopic.php?f=31&t=50605

Sounds like it could still be going on!

 

[lionschasing]

It'll take a lot of work to fit the batteries low in the frame and unfortunately this wheelie machine will keep pointing at the sky anytime I twist the throttle, I will be changing the setup soon so it fits in the triangle, i've got 3 packs, two carry 40v and one carries 13.8v. fresh off the charger everything was 95.7v, I'll just have to figure out a goodway of installing the batteries in, am still waiting for my luggage straps to arrive.

That's freaking insane
Perhaps having the weight of the batteries high on the handlebars doesn't help either. You might find better results with a lower center of gravity if you put the batteries in the triangle.
For a beast like that, I'd go with the CA v3 over other approaches to throttle control. Makes for a much more customizable setup.

Cheers

 

[Gregory]

Depends on your controller, but the one I have is pads X1 and X2. That switch looks ideal.

Connect X1 to GND for Speed 1
Nothing to GND is Speed 2 (Default if there is no switch)
Connect X2 to GND for Speed 3 (full speed)

Also depends on what % throttle the controller is programmed to allow for each speed. Seems it is different on the Greentime/Leo controllers

 

[Martin A]

What kind of motor is that?

 

[Bluefang]

3 speed switch wont help much if you want to be able to use the bike on the full power setting. Just another limit on the bike.

Best way i have found is using a Cycle Analyst V3 to controll your throttle. By doing that you can use a mangura throttle which allows you to use some simple resistors to change the throttle from linier to parabolic. ie at the start of the throttle turn very very small changes in voltage output will be produced and as you approach a full turn on the throttle the voltage changes much faster till max.

http://www.endless-sphere.com/forums/viewtopic.php?f=4&t=37964&p=690137#p690080

I have used this with a fair amount of success. Also it depends on your controller too, some controllers dont have the fine adjustment for throttle and seem to work in chunks of like 10% vrs 1%

 

[Trackman417]

Bluefang, no disrespect but the three speed switch will help. Have you bought one? When I use mine taking off in the medium and slow setting allows much greater sensitivity. It will definately help. granted I have a much much much lower powered setup it should provide a good amount of throttle control. :wink:
What I am going to do is install my three speed switch in line with Zombiess' throttle tamer. That would smoothe out the throttle indefinitely. :wink:

 

[Bluefang]

at 40kw in to the hub on the bike he posted a pic of.. well a slight twitch to far of the throttle puts him on his back i would guess. I had a 14kw ebike that was very hard to controll at anything below walking speed, the idea behind changing the throttle curve is to be able to ride the bike ultra slow but still be able to go full power with out having to use a switch to get there.

3 speed switch is a compromise, it works in its own way but......for him to have built a bike with that much power you really think he wont want to use it

 

[Gregory]

The 3 speed switch is a start.

He doesn't have a CA V3 and magura, he has a switch.
Try the switch to get you going, then step up to the CA + Magura (which is a nice bit of kit but will cost $200).

Simples.

 

[lionschasing]

Thanks Gregory, do you know which pads to solder onto the 36 fet controller? many thanks

The 3 speed switch is a start.

He doesn't have a CA V3 and magura, he has a switch.
Try the switch to get you going, then step up to the CA + Magura (which is a nice bit of kit but will cost $200).

Simples.

 

[lionschasing]

I got a reply.
"sorry for my late reply! Please try to solder K1, K2 and GND pads, any questions, please feel free to contact me, thanks!" this was from Leo Liu from Greentime Controllers for the 36 fet.

Has anyone tried twin controllers with a single 3-phase hub motor successfully?

The 3 speed switch is a start.

He doesn't have a CA V3 and magura, he has a switch.
Try the switch to get you going, then step up to the CA + Magura (which is a nice bit of kit but will cost $200).

Simples.

 

[jansevr]

lionschasing- nice looking build so far

if you could tell me - i am curious as to what motor that is and where you might have purchased it from?

 

[lionschasing]

Thanks I appreciate the compliments about the bike guys, it's terrifying to ride it right now given the complete lack of torque ramp the controller is effectively an on/off switch till I solder the 3spd switch.
The reason I went for a setup that's actually a motorcycle is because it is easier to cut back power by desoldering shunts than it is to keep upgrading parts. This way I get to enjoy the full power this frame can handle without the worry of blowing the controller or motor as they are designed for much heavier applications.
This is a QUANSHUN motor. you will find that QUANSHUN MOTORS manufacture a lot of the high power hub motors out there like this one and the ones on the kelly controls website, and some that come with a freewheel that are even heavier than this one like the 16352 model which weighs 23kg. Quality-wise they're very well built.

The person I spoke to was Jason, he's selling them for $250 + shipping customized for a mountain bike all ready with ceramic bearings installed.

Jason wang
Skype: jasonwang.1234
Tel: + 86-13196702312
http://www.cnebikes.com
CNEBIKES CO.,LTD
http://cnebikes.en.alibaba.com/

Controller goes for $150 from Leo at Greentime. the sensored/sensorless combo in one 36 fet is the best controller bang for buck, greentime controller does regulate current through the shunt solder method, and with the shunt modded can supply 400A+ at 100Volts or 150Volts 40kw or 60kw if you install the IRFB4115's. I had Leo install the irfb4110 mosfets.
here: http://www.aliexpress.com/item/36FET-IRFB4110-s-3000-5000W-42-98V-100-120Amax-BLDC-motor-controller-EV-brushless-speed-controller/578300665.html

Batteries I used were a123 but I wish I'd used LIPO as they're lighter, i'm currently using a amp20ah a123 setup...
here:http://www.hobbyking.com/hobbyking/store/__15521__turnigy_5000mah_4s1p_14_8v_20c_hardcase_pack.html
and
here:http://www.victpower.cn/

BMS you want to go for these strictly for charging, bypass them for discharge.
http://www.aliexpress.com/item/LiFePO4-Battery-Manage-System-BMS-PCM-24S-72V-30A-For-1000W-moto-Limpo4-UPS-LiPO-LiFe/731059280.html

One thing to mention about the controller that i asked for was full reverse/Hi level braking/pas/ and 3speed switch.

I might be going for a twin 36fet setup in the future.

lionschasing- nice looking build so far

if you could tell me - i am curious as to what motor that is and where you might have purchased it from?

 

[circuit]

So I guess controller is only "variable speed"? check if there is an option to control torque instead of speed. Common problem with chinese controllers...

 

[liveforphysics]

So I guess controller is only "variable speed"? check if there is an option to control torque instead of speed. Common problem with chinese controllers...

Most ebike controllers don't even have a method to know phase current. They simply extrapolate from battery current and duty cycle, but the true average current ringing between the caps and body diodes in the phase current loops is unknown.

 

[Martin A]

Is the wheel an integral part of the motor case or is it bolted on?

 

[Arlo1]

Bad ass! I like it!
Yup you will want to use zombies throttle tamer or another controller with phase current sensing and torque throttle.
You can also use the CA with the torque throttle out put but I have only used it up to ~6hp at the wheel and ~8kw going in to the system....
If you can set the phase current lower it would help... OR You can mod the shunt with a bypass so you can increase it once you are moving, on that note maybe someone should hook the throttle tamer to the shunt output signal and have it trick the controller as its going?? Zombies?

It truly is purely amazing what 6 little 4110 mosfets can do... If you pull 400 amps off the line that's not 400 amps at the 6 mosfets flowing power in and the 6 mosfets flowing power out. Its more a calculation of the back emf x the battery voltage and current... So as a crude way of calculating it if you are at 10% of the wheels top speed then you have ~10x the phase current minus losses. So 400 amps x 10 = 4000 amps in the motor..../6 = 666.6 amps per mosfet. It wont last long at those settings.
Yes again that's a crude way of calculating it but something to bare in mind.

 

[lionschasing]

The wheel is an integral part of the motor case.

Is the wheel an integral part of the motor case or is it bolted on?

 

[zombiess]

Phase amps would only be that high until current limiting kicked in. Who knows how long that takes on this controller or the xie changs.. I am ordering a 300a shunt setup so I can measure the phase amps... I hope.

Op, how did you calibrate your shunt? How many mOhm is it?