My electric longboard

Quezacotl

10 mW
Joined
Jul 4, 2016
Messages
22
Location
Finland
Hello!

I'm just sharing my experiences of my build :D

I were first building an electric bicycle, and it was okay. Not so great with the usefulness, but great speed.
I were having issues with the controller and bms, so i switched to VESC. It then worked good. With that i found out that electric skateboard would be a good project, and easy to carry around instead a whole bicycle(or actually it's battery).

So, i went and bought a skateboard for 20€ from local market. Ordered all the needed things, and built the board.img_20170503_230539_34049212670_o.jpg
img_20170512_093219_33805559284_o.jpg
And i got few LiPo batteries from my friend. 2200mAh cells. I disassembled them all and soldered together. (picture doesn't have the cheap chinese BMS that i have)
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Here's the completed E-skateboard:
img_20170522_171440_34456575090_o.jpg

You might notice that the trucks are weirdly. At the time when i took to picture, i haven't ever really thought about the truck directions until now. When i took a test drive, i thought that "Have i lost my skating skills?!". Then i noticed that in order to actually drive it, the trucks need to be faced outwards(With motor outwards. No ollies :D)

I then build Vedder's NRF nunchuk. I had a little struggling with the USB chip at first, but all turned out well.
I disassembled a normal wired Wii nunchuk and installed nunchukRF with battery in it.
I had problem with the device not working. It could not connect at all. No LEDs on. I then got one step forward by installing different firmware in it that i got from some german site.
And then i found out that i need to "activate" the nunchuk by connecting it to Win7 virtual machine(probably full Win7 does the same). What is that thing? I haven't found out why it requires that? Any idea?
Here's the nunchukRF:
img_20170530_201603_34954317036_o.jpg
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Only inside pictures. I made also a hole on top of it, and hot glue as light pipe to see the status LED.

Here's the only unsolved problem so far. The motor mount and truck are not very good with eachother. The screws get loose all the time. Yeah i know i should weld or use some loctite, but i'm waiting for new trucks to arrive.
img_20170531_120226_34620372050_o.jpg

The current setup goes about 25km/h top speed. I'm quite happy about it so far. I haven't tested any hills yet, so i don't know if it is satisfactory. I might install another motor with it, since i have two VESCs.
The board it wobbling some amount when going top speed, and on top of that out of curiosity(and to feel more professional) i decided to create a longboard(yay, not mismatching thread title!). So here's my build log about it:
View attachment 6
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View attachment 4
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Battery and controller enclosured are gluing:
img_20170611_113811_35232951575_o.jpg

Here's how the batteries wil be installed:
img_20170611_130756_35067842712_o.jpg

The enclosures will be something like this:
img_20170611_131052_35193570956_o.jpg

The longboard i made is way better than i thought. Only thing i am worried about is that it's bending about 5cm down when jumping on the board. I'll just have to wait for the new reverse kingpin trucks to arrive and i'll see how tall they are compared to the current trucks. I might end up adding more thicker risers.

I bough also "roving sheet" and epoxy resin. I'll coat the board with them and the enclosures separately with them.
Should i coat the entire board? Top and bottom, or just bottom and sides? Any other things worth noting? The grip tape is on it's way also.

The final design should then be:
-100cm x 25cm longboard with 25cm RKP trucks. 70mm wheels
-Two 5065 270KV motors with two VESCs
-7S2P 4400mAh battery (later upgraded to 10S1P 5Ah or similar)
-nice clean enclosures for electronics, 21mm height, and the battery wires going inside the board

To do:
-anti spark-switch or just battery connector
-clip for the controller on board
-USB connector for charging the controller
-some graphic to decorate the board
 
I got the new trucks. They have very good turning.

Now when i installed the motor mount, i needed to file the mount round hole into square. Now it fits like a glove.
The problem now is that it hits the board when i turn. It feels like i would need an additional 2cm clearance from the board. It is now 10mm.
It was quite hard to examine it how it would work, because i needed to file the mount beforehand.

So what would be the best solution? Install a flat or angled raiser? Or just file the mount even more and then find a place that welds it? How people usually do these?
EDIT: And to answer my own question; 8mm flat riser will do for now, while i'll get to test all other things.

img_20170612_174016_35221148996_o.jpg
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Now it looks like something.

So i installed the risers. 10mm flat is good.
img_20170613_134336_34471515933_o.jpg

I buried the wires between battery and controller.
(Why this picture wont show up on the post?)
img_20170611_234900_35204668816_o.jpg

I painted the board, looks something like a star clouds/fog, then applied the cloth and epoxy coating.
img_20170613_171149_35118295432_o.jpg

No griptape. Hoping that mailman delivers it soon.
img_20170613_180633_35285522105_o.jpg

I installed XT60-connector on battery end, and soldered other end straight to VESC.
img_20170613_194547_35157289931_o.jpg


Now the biggest problem is the motor mount. I tried to weld it with low-temperature weldsticks(equivalent to Techno-Weld). It was a complete failure!
img_20170613_171037_35154442001_o.jpg

And i saw that the motor mount i have bought is very bad material. It is not kind of aluminium that i'm used to work with. Maybe some kind of mixing. No more motor mounts from eBay!
I'll just have to go to scrapyard to get a piece of aluminium and make a better mount. Or i get some steel angle-things from hardware store and screw them together.

Test drive was success, except the belt was skipping because of the bad mount.
img_20170613_190925_35246322976_o.jpg

And yes, i forgot to paint the enclosures also. Too bad i already coated them with epoxy. Well it will be a quick job to fix them and apply another coating.
 
Today i made a new motor mount. It was about a time that i bought a smirgel. It would be hell with hand tools alone.
I brought it to a welding place. I can pick it tomorrow.
img_20170615_143024_35321439545_o.jpg

I painted the enclosures, sealed them and bolted on board. I added a superglue to the bolts, so they are solid part of the board now. Now all i need to open the enclosures are few nuts.
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Allright! Now it is rideable.

The welding was perfect. I painted it afterwards:
img_20170616_104853_35171210142_o.jpg

I installed a BMS for charging, and an charging port as XT60 connector i had lying around.
img_20170616_104441_35171148572_o.jpg

Now it is finally ready, from bottom side. Except all i need now is anti-spark circuitry and caps for connectors.
I just need to find some good FETs for the anti-spark.
img_20170616_110136_34494809074_o.jpg

The controller battery dies fast. I measured the battery and it has only about 300mAh capacity. It should be enough, so it is bad anyhow. Too bad i don't have any other battery that fits in. There is room only for one AA-sized battery, or some other small cells.
 
Does anyone know what is the thing behind this?
I had a bad battery on the remote that allowed me to travel half of a day. When it got empty, the remote needed to be connected to Windows in order to function again.
Now when i changed a better battery on it, suddenly it started to function without "Windows activation".

Now i just need to use that better battery until i get a battery that fits inside the remote.

EDIT: And again, it stopped working. This time middle of a ride. Again, by disconnecting the battery didn't work, but connecting to Windows worked.
 
Okay, some updates on this. I got the remote working. All i had to do was cut the BOOT0-signal(RTS), and it started working. By cutting that, it disables programming mode, but still allows databridge between BLDC-Tool and VESC.
I got better battery for the remote too.

I got also better batteries for the board. 5000mAh LiPos. 10S2P configuration.
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I got rid of the onboard BMS, and replaced it with a connector that i use with my own balance charger.
img_20170724_234622_35332984153_o.jpg

Here's the charger. 10pcs of TP4056 modules with own power supplies charging every cell individually. Power is only 42W in total, 1A per cell. It takes about 10h to charge the 10Ah battery full. Those batteries can handle even 5A charging current safely. I'm going to make a better charger also, with 126W power = 3A per cell, which makes it about 3,5h charge.
The 10h charging doesn't matter at all, because i can ride about 30km on one charge. And i'm not planning to drain it empty every time, so little charging every day is good.

I'm adding a fan and voltage displays on the charger as soon as they arrive.
The charger does a good job. Charges in full power until some point, and slows down on end. Because of that, the voltage doesn't drop on the cables, and voltage measurement is accurate even without additional cables.

It is strange that i haven't seen even a single site in web with same idea for a charger than i do. Why's that?
img_20170726_095023_36131776576_o.jpg

I made the anti-spark switch, and it works great! I made this:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=40142&start=100

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The motor mount i made, was way too thin. It was constantly bending and causing the tooth belt to slip. I made another from thicker aluminium:
img_20170719_140851_36022724635_o.jpg

I added an additional help for the tooth belt. I have rode for a while, and it has not slipped yet.
img_20170719_140841_36022721965_o.jpg


Then i got another problem. I fried the DRV8302 when i switched to FOC control. There might be many causes, including wrong settings and incorrectly matched battery and motor. BLDC mode works good though.
The chip was fortunately a 10min job to change.
img_20170724_225128_36099797386_o.jpg
 
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