A light electric stand up scooter

[nyx]

Hy Ferias,

I just weighted my scooter, Decathlon annonce it a 4,7kg, mine with the brand new 3S 6000mAh nanotech wich fits perfectly in the frame weight a bit less 6kg.
I took the subway with its and i can't see the difference its really good.

Concerning the range its really hard to say as it is very variable. For going from my garage to my home, its about 1km, and i generaly pull about 600mAh using a lot the motor as the Pavements are free and I can go fast with the motor.
I've been two times in the center of the town(Lyon) with lot of people on the pavements, then i can't go fast with the motor, and i am often pushing with the foot. There i consumed about 300mAh for 2km...

well to conclue i think that at the max consumption, so in the worst conditions, the range is about 5km. But by using the motor Intelligeament, not for launching, I can easly reach 15 or 20 km.

Finally its not a lot but as the battery can just fit in the frame, and as its more than i wanted, i am really happy with it.

I think i found a way to make a freewheel with 11Tooth, I just need to find a sprocket like This 11 Tooth 10mm Bore Sprocket For #25 Chain
http://www.electricscooterparts.com/sprockets.html
But I wouldn't pay $30 of shipping just for it. Does anyone has one to sell to Me ???

Thibaud

[ferias77]

Thanks for the information about wheight and range.
How do you will make the 11 tooth freewheel? I am very interested. On electricscooterparts, it is a sproket and not a freewheel, no? I don't know where you could find it...

And I asked adrian_sm if it was necessary to add extra capacitors on the controler in order to eliminate voltage bursts. His answer, which could interest other people :

You should post this stuff in your thread. Then everyone can benefit from the answer, and I might write a more complete answer. anyway....
I haven't ever put extra caps on. But I always peddle first, and will soon have protection from people hitting the throttle at standstill.
But they can't hurt, and will help keep ripple voltages in check.
Remember my aim is to make a robust system with minimal mods to stock parts, so I will only do mods like this if REALLY required.

- Adrian

PS feel free to copy this answer into your thread if you wish.

Eric

[ferias77]

I received my motor !

So I mounted it on my scooter with the modified motor mount :





Eric

[adrian_sm]

Stop making this look so simple. You are making me want to build one.

Nice job.

- Adrian

[nyx]

Whoawo its really nice job Eric, your Support is really clean. I don't know the word for "CNC" in english, but do you have one ?
its definitively a bigger motor than meine, but i am happy with it. I am coming back from the post office, about 2km, and I used a lot the motor, lot of acceleration and nice speeds, I consume 1Ah so its pretty good, and the motor was not too hot

By mounting the motor like this, are you not affraid to shoot it with the foot when you while push the scooter with it ?

I look forward to see the next

nice job

[ferias77]

No, no CNC, only my hacksaw, my file and my power drill.
I push the scooter and I brake with the right foot. That's why I put the motor on the left on the scooter. So I think it won't raise any problem.
I soldered all my plugs and started the motor. It's ok, it works ! But the motor is not very well balanced...
I think your motor is ok for riding on the flat. Do you tried to climb a hill?

Eric

[walls99]

Salut Eric,

Nice work! how are you going to attached the sprocket to the wheel? do you have any picture?

Merci,
Laurent

[ferias77]

Hi Laurent,

The sprocket is attached to the wheel thanks to 2 spacers and 4 screws. I could have made a picture... but my laptop decided to die this week end... So I don't have more access to my CAD model... We can see the spacers on the pictures on the previous page. The 4 screws are fixed between the spokes of the wheel.

Eric

[nyx]

Hi all,

I am sorry for your laptop Eric, i hope you'll be able to finish your scooter without difficulties...
you're right, my motor is just enough for flat and very light climb... but that enough for me.

Since yesterday I have something strange on my scooter. I'll try to explain the problem :
so since yesterday for the same speed/power I have to put more throttle. for example before, for about 10kph and 200-300W, the throttle was at about 1/4. now for about same speed/power the throttle is more than 1/2.
I can push the throttle at 100%, I reach 45-50A. Before I couldn't push the throttle at 100% whitout pulling more than 50A.
Its not a real problem as now at full throttle, I can't burn the motor. But I hope the power will not reduce again, and i'ld like to know the reason...

I am sure its not the battery, I made a new test just after a full charge...
can it be my servo tester ? Or my motor which has lost power?

Thanks for help

[ferias77]

Hi,

My scooter is progressing... but not as fast as I would like, I would need 48 hours / day
I machined almost all the parts (with my hacksaw and my file ), it is ok. Photos soon.

And I installed the wattmeter, the controler, and the servo tester. I made the cables longer between the battery and the wattmeter, between the wattmeter and the controler and between the servo tester and the controler. With normal length cables, the start of the motor is very soft. With my longer cables, it is really harder, there is a "clack" when the motor starts. After, it runs very smooth. Any idea why ?

[ferias77]

Some photographs :

I machined the wheel in order to use the ball bearing to center the sprocket :





I machined the motor shaft to put the sprocket :





Next step soon !
Eric

[ferias77]

Hi,

That's ok, the scooter has made his first run !!!
Top speed = 37 km/h ! See the photographs and the video :







Eric

[adrian_sm]

Awesome. I so want to make one now.

Any plans to put a real throttle on it? I always found using the pot as a throttle on the servo testers pretty dangerous.

- Adrian

[An average human]

well done on your scooter

i think i should warn you about the length of the leads between your battery and esc and lack of capacitors on the input to your esc, i personally ran in to trouble with this issue http://endless-sphere.com/forums/viewtopic.php?f=28&t=17675

anyway good luck

[ferias77]

Awesome. I so want to make one now.
Any plans to put a real throttle on it? I always found using the pot as a throttle on the servo testers pretty dangerous.
- Adrian

I'm happy you like the scooter. I agree with you, the servo tester is very dangerous... I think I will buy the beta cycle analyst and use a hall throttle. It will replace the servo tester and the wattmeter.

well done on your scooter
i think i should warn you about the length of the leads between your battery and esc and lack of capacitors on the input to your esc, i personally ran in to trouble with this issue http://endless-sphere.com/forums/viewtopic.php?f=28&t=17675
anyway good luck

Thanks for the warning. I was aware there was a problem with theses long wires... I will look your link. I thought it was ok because I run 5S and the ESC is 6S max.

[adrian_sm]

Cycle Analyst is cool, but if you want to go cheap, you can make a simple mod to the servo tester to run a hall throttle.

I have done this, really simple.

viewtopic.php?f=28&t=12196&start=15#p313413

- Adrian.

[ferias77]

Cycle Analyst is cool, but if you want to go cheap, you can make a simple mod to the servo tester to run a hall throttle.
I have done this, really simple.
viewtopic.php?f=28&t=12196&start=15#p313413
- Adrian.

Thanks for the link !!!
I bought the same servo tester but without the aluminium case : http://www.hobbyking.com/hobbyking/stor ... duct=14774
I'm not sure to have well understood, and I would like to be sure...

I remove the potentiometer, I plug my throttle on the power supply of the servo tester, I connect the signal of the hall throttle to the center pin for the potentiometer, and that's ok? It is so simple??? I hope !

Eric

[adrian_sm]

Yep. Pretty simple. Here is a (corrupted) pic of mine.

[ferias77]

Thanks for the photograph Adrian. I will do it asap.
I would like having a thumb throttle and a button for cruise control. I have this button on my e-bike, and it is very usefull for long rides. I think the only one simple solution to have this cruise control is the cycle analyst, no?
I made other tests with my scooter to be sure it is ok. And no... Starting full throttle, I have to push on the handlebar, otherwise the front wheel stands up !!!
And I finished by coming to the limits of the machine : the pressure screw between the motor and the small sprocket in not enough. I have to work on this. I will too order a 35 teeth sprocket to limit the top speed : 26 km/h will be enough, 37 km/h is really too much. So there will be more torque during the start...

[adrian_sm]

You should be able to add a button fairly easily to hold it at a specific throttle posistion, ie full throttle. A momentary push button and a resistor should do the trick.

I have also used this little guy to smoothly ramp up the throttle, for a push button input. I just plugs in between the servo tester and the ESC. This was great for implementing a push button as a throttle, without flipping the bike.

http://www.hobbyking.com/hobbyking/stor ... oduct=8863


I have also got an Arduino based throttle interface I am working on. Just in the debugging phase at the moment.

It accepts a button input as the throttle, has a power or speed PID loop (users selectable on the fly via the button), a turbo mode, SD data logging, LCD display (speed, power, dist, wh/km etc), temp sensor, wheel sensor, voltage, current... can't remember what else. This is being purpose built for my frcition drive project, but it is looking like it will be very usefull for other applications too. : ) Not ready for release yet, but it is looking really good.

- Adrian

[ferias77]

Hi,

I bought this Turnigy speed regulator with my motor, but I don’t have tested it yet. I thought to a problem : it smoothly ramps up the throttle, but it smoothly ramps up down too, no? If it is the case, it is very dangerous… There is a solution?
For the button, I will try to draw something.

Eric

[adrian_sm]

Np. There is separate adjustment for up and down. So no problem.

Just try it on the bench first.

- Adrian

[fechter]

Great job on the scooter!

How hot does the motor get?

[ferias77]

Np. There is separate adjustment for up and down. So no problem.
Just try it on the bench first.
- Adrian

I tried it this evening, really great ! As it works, I won't need any thumb throttle : I will try with only a push button and a potentiometer to choose the top speed.

Great job on the scooter!
How hot does the motor get?

I didn't ride for a very long trip but I made a lot of stop and starts, and I think the motor temperature was about 35°C. Not too warm to the touch, but I don't have any thermometer. Peak Power was 1900W

Eric

[adrian_sm]

I will try with only a push button and a potentiometer to choose the top speed.

If you want this sort of setup. I would keep the standard servo tester, and use that to set the top speed. Then cut the 5V leg on the pot in the servo tester and put your button in the break. Then I think you need to add a pull down resistor between the signal leg of the pot and ground, so it makes sure it goes to zero when you let go off the button. Then off course use the speed regulator thing.

That should do the trick.


Oh. I have been meaning to ask. How on earth do you stop? Only brakes I saw in your video was your foot. That almost scares me as much as using teh servo tester on it's own as a throttle.

I still have a nagging urge to build one of these... urrgggh... must finish other projects first.

- Adrian