Rebuilt kids electric cross to 3000w

[Dixonk]

I assume you mean .45v/sec on the throttle up speed? If so try increasing that until you get the acceleration you are after. One of my bikes is at 5v per sec. At some point that will be so fast it will feel like it used to before the CA.

I think the fast throttle up must have speed signal working to function. The idea with the fast throttle up setting is to pick a very aggressive ramp up speed but only to the amount of amps it takes for the bike to begin to pull from a roll. Its hard to guess an exact value for these amps. You can try 10v per second and see if it feel different then go up or down from there. 4 amps is probably a bit on the high side. I would guess 2amps. You will know that is too high when there is a momentary jolt when you throttle from a steady cruise state. This is the result of it overshooting a bit at the faster ramp speed. Remember the controller still thinks the throttle is speed based. So without the fast throttle up feature you would have to wait for your normal ramp speed to catch up with however fast you are going. You can try crazy high volts/sec settings for this just dont set the amps too high. If the amps are close then the overshoot will be very brief and not buck you too hard.

The AUX switch/ potentiometer cant control acceleration specifically but if you are using a watt or amp based throttle strategy then then it will have a similar effect. A 1500 watt bike wont accelerate as hard as a 3000 watt bike. So when you get time or energy to tune the throttle in watts or amps rather that simple time based ramp you can use that aux switch.

The CA allows you to have different profiles. So you can have one profile set for you and another for your son. I believe they can have completely different acceleration ramps and power settings. I have not used this feature so you need to study the manual. I have seen the profiles in the setting menu before but I only use one of them.

Most controllers default to speed #2 with the 3 position switch unplugged. Some have a simple 2 wire connection that is the highest speed. Its hard to know what you have. Most of the time the speed switches have a common wire and 2 speed wires. Wire 1 to common is speed 1. Wire 3 to common is speed 3. No wires to common is speed 2. So unplugging it is the same as 2.

3-5kw could be fun on the 125 if the trails are narrow or if its geared for a top speed of 30mph and you like trials or technical riding. A full size moto frame probably starts to get fun at 7-10kw. Thats all just opinion.

You're super helpful!! You're awesome btw, thanks a bundle!
I tried setting it to 5V per second and that flips the bike with me on it, same on 3V but I kinda like it, either way. Its not for me but my son so we settled on .5V. Dialed up the fast ramp to 5V and Amp to 2, guess a little better? Or just placebo.

Bike is pretty much dialed in now for my sons current level and its awesome, he loves it. Throttling still gives a punch or kick rather for a very brief moment and im not sure why, son doesnt like it or neither do I really, but perhaps its whats supposed to happen? Its like when you toll a car with a rope.. when the rope is not straight and you accel the second car jumps briefly, its that and son doesnt like it one bit.. but we're both novices so perhaps he gets used to it but he likes the new power alot!

Gonna try a few different profiles and see what can be done and plug in the aux pot and buttons and try something with them!

Capped the speed at 25km/h atm for testing purposes and it seems full throttle and it kinda holds the 25km/h limit but very jittery, what could be the cause of this? Or is it intended? I noticed the speed setting and you could change circumfence? The bike has 10 tires and im not sure what value to set here.. its at 2000 something at the moment - what does this setting do?

Other than above, theres just a few things left to do with the bike and perhaps you could be of assistance here too?
Im looking for a charge port to mount on the bike that needs to be somewhat weather proof and should handle 72v 5ah as that is what the charger do. Any ideas?
I used the stock one yesterday and it seemed fine but then suddenly it bursted up in sparks and fire haha! It was a 3 pin header mounted on the chassi.. the thing just melted!!

Then regarding the sparks. I have xt anti spark plug between shunt and battery now but no matter what I do it still sparks, ideas on that aswell?

I would also love to change the throttle to something more robust, sand gets into the throttle all the time when son falls off in sand. Is there some more robust electric throttles?

Best regards!

 

[DanGT86]

My responses in red

You're super helpful!! You're awesome btw, thanks a bundle!
Thanks. I don't have any projects going on lately. Its fun to watch something improve so I'm enjoying the process.
I tried setting it to 5V per second and that flips the bike with me on it, same on 3V but I kinda like it, either way. Its not for me but my son so we settled on .5V. Dialed up the fast ramp to 5V and Amp to 2, guess a little better? Or just placebo.
Guess you will just have to keep trying numbers between .5 and and 3V per sec. I prefer the absolute fastest ramp that I can still control but its all preference.

Bike is pretty much dialed in now for my sons current level and its awesome, he loves it. Throttling still gives a punch or kick rather for a very brief moment and im not sure why, son doesnt like it or neither do I really, but perhaps its whats supposed to happen? Its like when you toll a car with a rope.. when the rope is not straight and you accel the second car jumps briefly, its that and son doesnt like it one bit.. but we're both novices so perhaps he gets used to it but he likes the new power alot!
This kick sounds exactly like fast throttle up settings. Try reducing the fast throttle up current threshold and see if it goes away. If your fast up current level is set too high then the bike is using the super fast rate and overshooting the amount of current you need to "catch up" to the speed you are at. If your fast throttle up current is set too low it will bring back the dead band when rolling but that's safer than a surprise kick. I believe if you set the fast throttle up current threshold to zero it will disable that feature completely. That might at least help you identify the problem.

Gonna try a few different profiles and see what can be done and plug in the aux pot and buttons and try something with them!

 

[DanGT86]

Capped the speed at 25km/h atm for testing purposes and it seems full throttle and it kinda holds the 25km/h limit but very jittery, what could be the cause of this? Or is it intended?
The jittering is due to the PID control strategy. This is what Fechter mentioned earlier. You can tame this with gain settings. When you set a limit like power current or speed the CA has to read this data and respond quickly. As you approach the 25kph speed limit you have set the CA computer has to start reducing the throttle signal to maintain that speed. Because the controller ramps so fast the CA has to start this reduction ahead of time or it will overshoot your speed. The response time of the computer is the speed gain setting. If the gain is too high then it jitters because it is making drastic panic changes to maintain speed. You are feeling these drastic on an off changes as jitters. If the gain is too low then it will overshoot the speed then coast way down under that speed then overshoot again.

Gain too high=jitter at your limit of 25kph
Gain too low= under constant throttle the bike goes to 30kph then coasts down to 20kph then goes back to 30kph then coasts to 20 etc. but the average is what you set at 25

Somewhere between jittery and slow oscillation there is a perfect gain setting. This same thing will happen with power or current limits. This is a closed loop strategy and is the trickiest thing to tune. Some controllers are just too reactive to ever tune just right. In this case you end settling for open loop where you are just forcing a ramp rate and the CA is not metering based on current or speed input.

If you cant get this right then you can always just use the speed switch that came with the controller to limit the speed.


I noticed the speed setting and you could change circumfence? The bike has 10 tires and im not sure what value to set here.. its at 2000 something at the moment - what does this setting do?
I believe that is the circumference of the tire in mm. You may also need to tell the CA how many magnets the speed sensor has. If you bought the CA with the external speed sensor and spoke magnet then its probably already set correctly. Does the speed read pretty close right now?

Other than above, theres just a few things left to do with the bike and perhaps you could be of assistance here too?
Im looking for a charge port to mount on the bike that needs to be somewhat weather proof and should handle 72v 5ah as that is what the charger do. Any ideas?
I used the stock one yesterday and it seemed fine but then suddenly it bursted up in sparks and fire haha! It was a 3 pin header mounted on the chassi.. the thing just melted!!
Fire is bad. Sorry, I dont have any suggestions.

Then regarding the sparks. I have xt anti spark plug between shunt and battery now but no matter what I do it still sparks, ideas on that aswell?
If the anti-spark device is the last thing you connect then it shouldn't spark. Might need to see a diagram of how you are wired.

I would also love to change the throttle to something more robust, sand gets into the throttle all the time when son falls off in sand. Is there some more robust electric throttles?
Domino throttle is the top of the line in my opinion. Unfortunately its really expensive. I have one and now I hate all of my other throttles. Its over $100 USD but it is a weatherproof OEM grade throttle in the motorcycle industry.
I think Magura makes a nice throttle as well.
You could find a throttle position sensor and cable throttle from a gas motorcycle and use it as your signal but you are going to need some fabrication skills. Most throttle position sensors are 0-5v.

Best regards!

 

[Dixonk]

Oh, tons of valuable information. Hey, if you ain't got a project.. I got one for you
Does the speed/amp/power limits follow the same gain sweetspot? I mean, if I dial it in okay or perfect for speed, will it work the same way using amp/power?
What ive seen fiddling with presents, some of the values are not changeable between presents which I find to be very odd as that more or less defeats half the purpose of it.
Like throttle out amp, stays between all but throttle ramp is changeable..but not fast up nor throttle down speed.
None of the buttons work for navigation and not sure yet what the middle button is for as in the digital aux you can only select pot,1button or 2 button but mine has 3

I found analog aux pot to throttle out to be awesome (when it worked) occassionally the throttle just dies then comes back alive, all from .5 to 2seconds it worked just fine in the middle mark - seems strange to include a option that doesnt work as intended or am I overlooking something perhaps? There is a low and high deadzone % adjustment but I dont get this one at all like pretty much everything else!

Im a single parent of 2 youngsters, my son at 6 and daughter at 4. My fiddle time per day is about 30minutes after their bedtime, garage is outside the house and I dont dare be there for long incase they wake up and during the day, fulltime work and after work, shit. Well, I got my handfull

The 3 speed switch is broken, does work but.. while it does limit top speed I would like finer control and have CA limit instead, perhaps use aux pot for speed limit or throttle out control if I can get it to work and limit other things using presents or whatever.
Really, only I want top speed. There is no one at kids cross club going above 25-30kmh on the track currently and limit 1 is above 30.. I just want him to ease into things
CA is a cool device!! I wish they offered one without a display and with a program that works properly . That would be awesome.
My fardriver will stay in its package cool thing about that one is that it has bluetooth and android app to program with, would love to try but shit.. I dont want to tear down the bike again

100usd for a throttle.. time to save up some money then I suppose, got my son 2 pairs of throttles for 9usd they arent amazing but atleast theres no chinese writing on them and doesnt look horrible. Ill have to check them out!!

 

[DanGT86]

Good news. Looks like you can now use the AUX button to limit the throttle output in volts. This will give you speed control without having to deal with speed gain settings! This is probably the quickest way to eliminate the oscillations. You should watch that vid from the beginning because it shows how to setup the aux button.

https://youtu.be/IU4qWSXtJUU?t=163

Lots of good instructional videos halfway down this page.
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html#SoftwareSetupUtility

I think your 3 button aux switch is considered a 2 button because the middle one is for something else. Settings for that will be digital aux.

Settings for the pot will be analog and choose pot from the dropdown.

If you go into the help menu of the Setup utility software it explains every single parameter in the order they appear.

I'm sure you are overlooking something if it doesnt work.

If you are in POT mode then the low and high deadband are to scale your particular pot to the device. So if your pot is plugged in and is 1v to 3v then you would set those as your low and high deadbands. So all the way one direction is 0% and all the way the other is 100%

If you go to preset settings in the software and put 2 or 3 for number of presets then the preset 2 and preset 3 columns will allow editing.

Looks like the AUX switch can be used to control one of the following:
Which preset you are using
Amps limit
power limit
speed limit
throttle voltage limit
pedal assist limit

Eventually when you get good at this you will probably want to have a preset profile for you and a preset value for the kids and just use the switch to go between them.

In the meantime your best bet is probably to hook up the pot and set it to control throttle voltage limit (ThrO Lim). This will give you a precise and reliable speed limit with no gains to figure out.

When you boot up the CA it should tell you which firmware it is currently running. Perhaps the Setup utility software is not working properly because your firmware is older than the current version. Hard to know how long the CA was sitting on the shelf before you bought it.

I have never heard of a grin device not working correctly. I'm sure the problems with the software are you missing something.

When you navigate to the aux setting menu on the device it should show you a live readout. You can move the pot or click the dig switch and it should show you the corresponding values. This is where you will figure out what to set the Pot high and low deadband voltages. When its set right you should be able to turn it and see 0-100% on this display screen.

 

[Dixonk]

Good news. Looks like you can now use the AUX button to limit the throttle output in volts. This will give you speed control without having to deal with speed gain settings! This is probably the quickest way to eliminate the oscillations. You should watch that vid from the beginning because it shows how to setup the aux button.

This is what I tried, using aux analog pot to throttle out, it controls the throttle speed up rate (accerelation) it seems. The pot is 0.9 to 5V and is shown in the settings page to work the full range. Low deadzome is 15% and high 20% but full range work in settings page. However when I try it live, adjusting the pot makes the throttle unresponsive for a few miliseconds or just doesnt work at all. Thanks for the video, Ill check this one ojt for sure!!


https://youtu.be/IU4qWSXtJUU?t=163

Lots of good instructional videos halfway down this page.
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html#SoftwareSetupUtility

I think your 3 button aux switch is considered a 2 button because the middle one is for something else. Settings for that will be digital aux.
i have my buttons setup in digital aux, here I can only choose pot,1btn or 2btn. No settings for a 3third button or in this case, 2btn with a middle button. I set my buttons as Present

Settings for the pot will be analog and choose pot from the dropdown.

If you go into the help menu of the Setup utility software it explains every single parameter in the order they appear.
software works for reading and writing to the CA, but doesnt allow adjusting decimals at all. Adjusting 1,2 3,4 works fine, input 1,2 in any column and it sets 0 or 1 or 99 depending on where youre adjusting, super strange! And most columns are greyed out, meaning you cant adjust at all.

I'm sure you are overlooking something if it doesnt work.

If you are in POT mode then the low and high deadband are to scale your particular pot to the device. So if your pot is plugged in and is 1v to 3v then you would set those as your low and high deadbands. So all the way one direction is 0% and all the way the other is 100%

If you go to preset settings in the software and put 2 or 3 for number of presets then the preset 2 and preset 3 columns will allow editing.
i couldnt input 1,2 3 present in software but adding present in CA did allow the program to read there was more than 1 present

Looks like the AUX switch can be used to control one of the following:
Which preset you are using
Amps limit
power limit
speed limit
throttle voltage limit
pedal assist limit

Eventually when you get good at this you will probably want to have a preset profile for you and a preset value for the kids and just use the switch to go between them.

In the meantime your best bet is probably to hook up the pot and set it to control throttle voltage limit (ThrO Lim). This will give you a precise and reliable speed limit with no gains to figure out.

When you boot up the CA it should tell you which firmware it is currently running. Perhaps the Setup utility software is not working properly because your firmware is older than the current version. Hard to know how long the CA was sitting on the shelf before you bought it.

I have never heard of a grin device not working correctly. I'm sure the problems with the software are you missing something.

When you navigate to the aux setting menu on the device it should show you a live readout. You can move the pot or click the dig switch and it should show you the corresponding values. This is where you will figure out what to set the Pot high and low deadband voltages. When its set right you should be able to turn it and see 0-100% on this display screen.

aux setup.JPG

 

[Dixonk]

Got the pot working with throttle out when the ramp up speed was set below 2V, for some reason if I set ramp up speed to 2V/s the throttle becomes unresponsive or gets a delay when used with pot for throttle out.

The throttle out is amazing, dont have to fiddle at all with the speed, wow. Son loves his bike now and said today he dont want the 1000w one anymore because its not as strong uphill.

Its amazing, he is able to dial in the bike just as he wants.
The digital aux buttons changes present which only changes throttle ramp up speed, one at .35V second to .95V and third to 1.9V its enough for him to practice burnouts and wheelies, 1.9V Flips the bike with me on it, most likely due to my heavier weight.. but with him on it, hes able to control it.
The aux pot analog determines the max speed by throttle out
So in a way, the CA handles the speed by aux pot and the amount of kick from start.. its perfect for him, he can change and adjust to his liking.

I call this a success for now. Thanks for helping out!

Now I just have to figure out how to kill the display from a switch or something like it, get a proper charge port on the bike aswell as figure out how to connect the regen brake to the CA.

Currently left and right brake is connected together and then attached to the controller to allow both front and back brake to have regen.. should only one of them connect to the CA?

Theres a heavy brake available aswell, somehow it allows the motor to brake by using battery, not sure if I should connect it or not. Manual says its more powerful brake.

Thanks again!

 

[DanGT86]

Glad to hear the setup is working well. Being able to use the Pot and buttons together is something I didn't know was an option. Thats really great.

The throttle cut over 2v/sec is weird. Are you sure there is not a max amps or max watts setting enabled somewhere? If you have an amp or watt limit set in the CA then the aggressive ramp might be causing a brief spike in power that is causing the current or power limit to be exceeded.

Maybe check the max throttle out voltage limit. If its too close to the threshold of the controller then the CA might be overshooting it and making the controller think there is a fault. Lowering this setting will eventually limit your top speed. There is no sense in having it set higher than the max voltage your throttle puts out assuming you didnt have this problem before the CA was used. If you look at this screen when you are riding it will show you which if any limits are triggering. amps watts speed voltage temp. If you accidentally have a limit you are hitting when the ramp is too high that limit will go from lowercase to capital letter.



The power wires for the CA are in that 6 pin harness. You could put in a switch to interrupt that. There may also be a solder location on the board in the CA to install a power switch. The thing is, even with a switch you probably don't want to store the bike with the battery connected all the time. Resistors in the controller will eventually drain your battery if its left connected.

For the brakes I like to have the regen on a button separate from the brake handles. On slippery surfaces the regen is too harsh compared to precisely modulating the actual brakes. Some controllers support variable regen but not all of them. The CA supports variable so you can use a throttle or pedaling backwards to modulate the regen strength. But again its only as good as the controller's ability to do it.

Like I said a few posts back, the thing you want to avoid is having the controller brake switch hooked up and in use when the CA doesnt know about it IF you are using a closed loop throttle output in the CA. Closed loop strategies are Watt, amp, or speed, throttle. If you are using only throttle ramp time with a pass-thru throttle it shouldn't matter.

Hard to say for sure what heavy brake means to your controller manufacturer. Many controllers have a security feature that electronically locks the motor in place as an anti theft device. Might be that and there is a translation error from the original chinese.

 

[Dixonk]

Glad to hear the setup is working well. Being able to use the Pot and buttons together is something I didn't know was an option. Thats really great.

The throttle cut over 2v/sec is weird. Are you sure there is not a max amps or max watts setting enabled somewhere? If you have an amp or watt limit set in the CA then the aggressive ramp might be causing a brief spike in power that is causing the current or power limit to be exceeded.

Maybe check the max throttle out voltage limit. If its too close to the threshold of the controller then the CA might be overshooting it and making the controller think there is a fault. Lowering this setting will eventually limit your top speed. There is no sense in having it set higher than the max voltage your throttle puts out assuming you didnt have this problem before the CA was used. If you look at this screen when you are riding it will show you which if any limits are triggering. amps watts speed voltage temp. If you accidentally have a limit you are hitting when the ramp is too high that limit will go from lowercase to capital letter.
Image 1.jpg


The power wires for the CA are in that 6 pin harness. You could put in a switch to interrupt that. There may also be a solder location on the board in the CA to install a power switch. The thing is, even with a switch you probably don't want to store the bike with the battery connected all the time. Resistors in the controller will eventually drain your battery if its left connected.

For the brakes I like to have the regen on a button separate from the brake handles. On slippery surfaces the regen is too harsh compared to precisely modulating the actual brakes. Some controllers support variable regen but not all of them. The CA supports variable so you can use a throttle or pedaling backwards to modulate the regen strength. But again its only as good as the controller's ability to do it.

Like I said a few posts back, the thing you want to avoid is having the controller brake switch hooked up and in use when the CA doesnt know about it IF you are using a closed loop throttle output in the CA. Closed loop strategies are Watt, amp, or speed, throttle. If you are using only throttle ramp time with a pass-thru throttle it shouldn't matter.

Hard to say for sure what heavy brake means to your controller manufacturer. Many controllers have a security feature that electronically locks the motor in place as an anti theft device. Might be that and there is a translation error from the original chinese.

Thank you kindly for the tips, I'll be sure to tryout the throttle and see if its the limit causing issues. I do have limits set to 50A and 3000W but honestly, riding uphill on our worst hill i didnt push above 35a and somewhere around 2000w. Its abit jumpy so didnt push it max but it was well enough for me on this small bike.
Got a 40A fuse after the battery so figured I do limit it somewhere around 40-50.. cant be bothered to change to a bigger fuse atm. If it blows it blows

Regen on a button you say? Feels like my son has alot to keep track off already
So from controller regen connector to button to CA?
This project for my son.. uh, I wish my own later on will be easier

 

[DanGT86]

Yeah. My guess is that above the 2v per second the amps are spiking higher than your 3000watt limit for a tiny fraction of a second and causing the ca to cut throttle.

If you have the skills you could go full throttle uphill at faster than 2v/sec and while looking at the display to see if the status letter switches from lowercase to capital.

And yes. Simple momentary button like a horn button that is connected to both the controller brake wire and the CA brake wires blue and black.

It is simpler to just use the brake levers instead of a button for the brake switches but I would only do that with the back brake since you dont want regen when trying to only front brake. And you can still do burnouts with the front brake engaged.

 

[Dixonk]

Yeah. My guess is that above the 2v per second the amps are spiking higher than your 3000watt limit for a tiny fraction of a second and causing the ca to cut throttle.

If you have the skills you could go full throttle uphill at faster than 2v/sec and while looking at the display to see if the status letter switches from lowercase to capital.

And yes. Simple momentary button like a horn button that is connected to both the controller brake wire and the CA brake wires blue and black.

It is simpler to just use the brake levers instead of a button for the brake switches but I would only do that with the back brake since you dont want regen when trying to only front brake. And you can still do burnouts with the front brake engaged.

Hi again, I removed the limits and still happening so im not quite sure what is up - it works just fine when pot is disabled as ramp up was set at 2.5V or above default if I remember right, I emailed grin aswell as Im not really sure whats going on.

I wouldn't be able to handle it, I most often fall off the bike at 2V ramp or above, its really wierd not being able to have a quick ramp up speed without having the bike rise up in the front, bike is quite small and my weight at 70kgs is perhaps too much for it.

I didnt get around to fix the brake tonight but perhaps tomorrow, did some cable cleaning up and repainted the bike black, it looks quite nice now! Also fitted the pot next to the throttle and the other buttons on left side, felt better!

Next up is brakes, display power (did you say it was the red cable?) And hook up that to the keyswitch and somehow relocate the keyswitch (ignition) to some better place, looks way off as it sits now, need to source a battery disconnect switch aswell, some marine switch or perhaps something I can hook into the keyswitch aswell if there is even such a thing, would make it more clean and practical for my son.
Perhaps need to look over the battery aswell as see if I can fit a bigger fuse on it.
What should I look for? How do I know its safe to go with a bigger fuse? Kinda feels wierd not using the full capacity of the motor or allow peak to go above 3000w. Would be awesome if I can bring out even more power than I have now.





Thanks for everything so far!