MOD seated scooters up to 72V 5kW dual motor: VESC + modular DIY OpenSource electronics and software

[Zambam]

Yes, my frame is aluminum.

Did you weigh it before modding?

Edit: checked the rest of the scooter with a magnet. Even the basket, front shocks, handle bar and fenders are steel. Only parts not magnetic are the handlebar stem, wheel spokes and hub motor case.

@casainho , a steel frame i12 may be a better choice to hop up than the aluminum Fiido Q1S that you had frame crack issues with.

 

[casainho]

I updated the display design and it is now generic, so it should fit most handlebars.

It requires only two wires (5V) for power and three wires for the remote buttons: power on/off and lights.

Communication with the main board is done wirelessly.

The information displayed comes from the motor, battery, and wheel speed. It also shows the current time and includes RTC hardware to keep accurate time.

The display is now rounder and more robust, and it uses M3 screws and nuts to ensure a strong and secure fixation to the handlebar.

 

[casainho]

I am now using the tubeless 90-degree valve (PVR40).

The straight valve I used before forced me to bend it almost 90 degrees during inflation, which made the process difficult and always left me worried about damaging the valve.

With the PVR40, inflating the tire is now much easier and stress-free.

Tubeless 90-degree valve (PVR40):


Previous straight valve I used:

 

[mrmojorising]

I updated the display design and it is now generic, so it should fit most handlebars.

It requires only two wires (5V) for power and three wires for the remote buttons: power on/off and lights.

Communication with the main board is done wirelessly.

The information displayed comes from the motor, battery, and wheel speed. It also shows the current time and includes RTC hardware to keep accurate time.

The display is now rounder and more robust, and it uses M3 screws and nuts to ensure a strong and secure fixation to the handlebar.

View attachment 382344

View attachment 382343

View attachment 382342

Display looks great! I often use heat inserts for similar printed mounts, but this is a super simple and robust design too

Just got hold of a fiido and will be taking lots of inspiration from your build

 

[casainho]

I am being reorganizing and trying to improve the firmware a bit, on the display I am adding small progress bar that appears only if motor is being limited due to temperature.

Today I was lucky to watch careful my Fiido Q1S and found this!! The frame broke again!! so, I am thinking what should I do next... should I move to another EScooter model / frame or try to solder again this frame with bigger reinforcements on the front side?

 

[Zambam]

That does not look good!

I'd suggest not "soldering" it again and find a another frame that can handle the power. My iScooter i12 frame is definitely steel even though support@iscooterglobal.com insists it's made from an aluminum alloy that is magnetic. I think they are telling me a lot of BS! Have you checked your's iscooter frame with a magnet?

 

[casainho]

My iScooter i12 frame is definitely steel even though support@iscooterglobal.com insists it's made from an aluminum alloy that is magnetic. I think they are telling me a lot of BS! Have you checked your's iscooter frame with a magnet?

I just check my iScooter i12 frame with magnets, and on different places, when there is a strong attraction so the frame is steel!!

Well, I am happy to know it is steel, so this means this iScooter frame should be way stronger comparing the the Fiido Q1S aluminum frame. So this means forgetting the Fiido Q1S and going to iScooter i12 is a safe option for me. Let's see...

 

[casainho]

I bought a Lunyee 12 inch 72V 5000W 60H 1200RPM motor to install on the iScooter i12. The motor is strong!! but will heat after 10 minutes of riding... but this scooter is for my son, that weights 30% less then me, so maybe it will be enough for him, otherwise I will need to install a second equal motor on the front, just like I have on my Fiido Q1S:

Since the motor overheat, I made the display firmware to show a bar only when the motor starts to overheat. Like at half of the scale of overheating, the motor power is limited by VESC to half of the power:

 

[Zambam]

I just check my iScooter i12 frame with magnets, and on different places, when there is a strong attraction so the frame is steel!!

Well, I am happy to know it is steel, so this means this iScooter frame should be way stronger comparing the the Fiido Q1S aluminum frame. So this means forgetting the Fiido Q1S and going to iScooter i12 is a safe option for me. Let's see...

Glad I kept asking you to check your i12 with a magnet. Iron-ically I wanted my frame to be aluminum- for lighter weight better corrosion resistance but that's not the case.

I only rode my i12 for about 10 miles total so far. It felt under powered and sags to 38V full throttle (with fully charged battery @ 42V). I need to rig up a phone mount to check top speed with GPS app.

Do you know if the i12 controller will run a 48V battery w/o blowing up? I can borrow the 7.5 Ah 48 V battery from my TSDZ2 ebike.

 

[casainho]

Yes, iScooter i12 is very weak, that is why is so cheap.

My only experience is with VESC.

 

[casainho]

Farewell, my beloved Fiido Q1S



I was ready to weld the Fiido Q1S frame again, but then I found more cracks—this time on the upper side around those holes, on both the left and right sides. At that point, I figured the frame was already fatigued and would likely fail again soon.

I just bought another iScooter i12, this time for me, to replace the Fiido Q1S. I wound if the Fiido frame did break because of strong forces from the front motor, pull and push the fork, when I accelerate and regen brake.

I just bought 20% higher torque motors (more torque but lower max speed in 20%, about 60 kms/h). I want my scooter more agile and with less higher speed. So, I will try to see if I can solder the iScoter i12 frame to make it more robust and probably build a box-like structure in the middle of the frame, like the one the Fiido had, so I can put the battery inside and even a few more things like small shopping bag.

 

[casainho]

Bought a new motor, this time with 900RPM at 72V, while previous were 1200RPM. The idea were to get more torque, but in the end, and AI did explain it very well to me with calcs, that to get higher torque, the motor will get hotter, so, I need to keep the same torque to not increase the heat that were alry on the limit. The only adbantage is the motor phase decreases and with that the lost power on the controller and so the controller can be smaller / cheaper VESC of 100A and don't need to be the big of 200A.

So, there is no way for me, I must install dual motor on this scooters.

This scooters are small but don't need to be weak, they are strong, they have a very fast acceleration!!

I also bought on Aliexpress may favorite 3.00-8 ChaoYang H-570 tires but unfortunatly the seller sent me instead ones marked as 3.00-8 H-796 ChaoYang, which are smaller overall. At least they work well as tubless!!

 

[Zambam]

I've been wondering about the small hole where the crack eminates. It's not from the factory I assume? What's it for?

 

[casainho]

I've been wondering about the small hole where the crack eminates. It's not from the factory I assume? What's it for?

That holes on the frame are original, for cable routing, including the brake "cable".

 

[Zambam]

That holes on the frame are original, for cable routing, including the brake "cable".

Bad design IMO. If there was no hole, probably there'd be no crack. Curios how many miles total you have on that Fiido frame, RIP.

 

[casainho]

Bad design IMO. If there was no hole, probably there'd be no crack. Curios how many miles total you have on that Fiido frame, RIP.

I don't know how many miles, but not much anyway, maybe only 30 a week, for over 1 year, or 2 years??

 

[Zambam]

Do you know that the iScooter i12 has been discontinued? That's what iScooter told me in an email about a month ago.

Plugged the 48V battery from my mid-drive into my i12. Powers up fine, spins the wheel. Have not test ride it yet to see what gain in power or speed.

 

[casainho]

Do you know that the iScooter i12 has been discontinued? That's what iScooter told me in an email about a month ago.

Plugged the 48V battery from my mid-drive into my i12. Powers up fine, spins the wheel. Have not test ride it yet to see what gain in power or speed.

I just got my new one, this time I got a big promotion on Aliexpress and it costed only 200€ (shipping and tax included)!!

 

[Zambam]

How does the i12 ride and handle compared to the Fiido Q1S? I think the i12 has a slightly longer wheelbase.

 

[casainho]

Oh men, the frame head tube of iScooter i12 is shorter than the one on the Fiido Q1S, so I can't reuse this wide fork needed to install a front motor - 147mm VS 93mm:

 

[glennb]

You have options to use that fork in that frame:
1. Threadless headset
2. Spacers under threaded lock ring
3. Have a bike shop cut more threads on the steerer

 

[casainho]

Current state. The fork is good and bought it on Aliexpress: https://s.click.aliexpress.com/e/_c4Bmtidz

 

[Zambam]

Current state. The fork is good and bought it on Aliexpress: https://s.click.aliexpress.com/e/_c4Bmtidz

View attachment 385238

Seat post on left scooter is more vertical than the one on the right. Is that an illusion?

I've come to accept the steel frame and will keep it. Maybe do some mods to make it go a little faster.

For testing, I had a broom stick lashed on with inner tube for foot pegs. It moved around too much. I have this long aluminum pipe laying around outside. Just cut a piece off it, secured with hose clamps. It's on solid now! On my full size moped, I like to ride with my feet on the passenger foot pegs. The pipe put my feet in about the same position.

After more test rides and if I decide to keep it, I will paint the pipe black.

 

[casainho]

Seat post on left scooter is more vertical than the one on the right. Is that an illusion?

I've come to accept the steel frame and will keep it. Maybe do some mods to make it go a little faster.

For testing, I had a broom stick lashed on with inner tube for foot pegs. It moved around too much. I have this long aluminum pipe laying around outside. Just cut a piece off it, secured with hose clamps. It's on solid now! On my full size moped, I like to ride with my feet on the passenger foot pegs. The pipe put my feet in about the same position.

After more test rides and if I decide to keep it, I will paint the pipe black.

Seat posts are equal.

Yes, I think the must upgrades are adding foot pegs and more powerful motor(s) and battery. I think the frame is good.

 

[casainho]

Finally I got my IScooter I12 with dual motor!!
Rear motor Lunyee 72V with 900RPM and front motor Lunyee 72V with 1200RPM.

VERY STRONG torque!! is so much fun

VESC detected parameters for the Lunyee 72V with 900RPM:

Parameter	Value
Motor Resistance ®	105.9 mΩ
Motor Inductance (L)	277.42 µH
Motor Inductance Difference (Lq − Ld)	44.46 µH
Motor Flux Linkage (λ)	28.378 mWb

VESC detected parameters for the Lunyee 72V with 1200RPM:

Parameter	Value
Motor Resistance ®	74.0 mΩ
Motor Inductance (L)	183.90 µH
Motor Inductance Difference (Lq − Ld)	26.26 µH
Motor Flux Linkage (λ)	23.135 mWb

As you can see, the higher torque motor I used on the rear, has also higher resistance. This means it has higher torque but can only be used for peak like at startup otherwise it will heat faster. So, has higher torque but to keep the same heating, needs to run at the same torque as the other. In practice, I just give burst of higher torque at startup.
If anyone is interested, just past this motor parameters on AI and ask and it will explain with technical calculations.

Issues annoying me:

1. I can't put inside my car as I did with Fiido Q1S

2. The steering is unstable and does not tend to return to the center.
This happens after installing the 14-inch fork for front motor, which has more forward offset (wheel advance).

Trail​

The trail is the distance between:

• the point where the steering axis (fork axis) intersects the ground
• the point where the tire contacts the ground

This distance creates a self-centering effect in the steering.

Trail value	Steering behaviour
More trail	Wheel self-centers strongly → stable steering
Less trail	Wheel wanders → nervous / unstable steering

Parameters that affect trail​

Trail is determined mainly by three geometric parameters:

1. Head / fork angle (α) — defined by the frame geometry
2. Wheel radius (R)
3. Fork offset / axle advance (O) — how far the axle is positioned forward relative to the steering axis

Solutions I am thinking of:
1. Cut the frame at the middle to make the length shorter (and with soldering reinforcements)
2. Bend a bit the frame to increase the head / fork angle (and solder reinforcements)

On a Sunday, carrying our baby on the IScooter I12, while my wife did a run and our daughter rode his bicycle.
This was near our house. I want to be able to easily carry on our cars the scooter, so we can do this moments far from home, on way more beautiful tracks!!