400€ Build | ebay Deck | SK3 149kv 20/28t | 6S Lipo | 150A Car ESC

Hi guys,

after riding my build for a couple of weeks now I wanted to show it to you and get some (hopefully nice) feedback. It all started with a lot of reading here, on endless sphere and in a German esk8 forum. Due to limited funds and the not so perfect supply in Germany I basically did as much myself as I possibly could. So I made the mount myself (first out of 12mm PVC and then after it broke out of 10mm aluminium), modified industrial pulleys to fit, used a friends 3D printer for small stuff and put it all in a Tupperware box under a cheap ebay deck.

My goal was to create a commuter board - so size was also an issue. I wanted to keep it as short as possible so that I could still carry it and settled on a 40inch bamboo deck with a 67cm wheelbase. I cut the kicktail off. It has almost no flex - so perfect for this kind of thing. The deck was 34€ including shipping. https://images-na.ssl-images-amazon.com/images/I/31e-A0N7PhL.jpg

My Hobbyking order then included an SK3 149kv motor, 2x3S Turnigy 5000mAh batteries, an X-Car beast 150A ESC, a Reaktor 250W charger and XT90S plugs -> ~200€ I should have ordered a programming card with the ESC as the settings are not perfect - but it works. I removed the plastic housing and cut the fan to make it silent and reduce the height of the ESC. No problems so far with overheating!

The remote is a badwolf mod GT2B for which I only had to pay for the actual remote -> 25€

As you can see in my other thread I had some problems with the selfmade motor mount but this should be solved now.

The pulleys and the belt I got from industrial supplier hug. I calculated the theoretical top speed and settled on a 20/28t gearing. To fit the motor shaft and the 80mm Kegel wheels I had to use a lathe and drill press. Basically I only made the center holes wider and drilled 5 holes in there for M6 screws to hold the wheel. M6 fits through the kegel rim without any drilling necessary. A grub screw holds the motor pulley in place with a filed flat spot on the shaft -> ~14€ for 9mm belt and both pulleys

For the longboard parts I settled on the popular stuff: 44° 180mm Caliber II trucks and Orangatang 80mm wheels -> 118€

This brings the total to ~400€.

Over the weekend I put a battery indicator in there as well which works quite nicely with the semi transparent plastic lid of the box. For the electronics I put a selfmade 2x3S y-cable in and connected the balance leads to a selfmade D-Sub 9 connector (similar to what @oriol360 showed). That way I still have to open the case to charge but it is less of a hassle. Range is ~10-15KM - at full speed obviously less but I have only ever ridden it once at its top speed of ~40km/h (38 according to the GPS but the batteries were already a little lower than 4.1V at the time I reached that). I charge them as soon as they drop below 3.7V and up to 4.1V at 0.5C to keep them healthy.

For a power switch I was lucky that the Beast ESC has its own small switch. I cut the red +line and soldered a flip switch in series that I could place through the box. this is also where I connected the voltage meter (the ESC switch lines are provided with the full battery voltage :thumbsup:) so that it does not drain the batteries when the board is turned off.

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Nice Board! Where in Germany do you live?

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Thanks!

Close to Stuttgart.

Me to, i live very close to metzingen and Reutlingen

Hey, i am from Schwäbisch Gmünd

Nice work!

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@longhairedboy you recommended a similar voltmeter in one of your threads and I was just wondering if you know how they actually compute the capacity. What voltage is “0%” and can one change the thresholds somehow?

as far as i know, you cannot modify them to calculate the voltages differently. But based on what i’ve seen, they calculate based on the standard thresholds for lithium-ion, which is a 3.6v nominal per cell group. the 18650s i use have a max of 4.2v and a min cutoff at 2.6v, so i expect that’s more or less standard and that it falls in line with that. I have seen the meter read 1% when the BMS cuts off power, and it usually takes a little longer past 100% to get the charger LED to turn green, meaning when the BMS cuts off for high voltage.

All of that is to say they seem to be operating within a safe margin of the cells actual capacity, but all it is is a monitor. Even if they are measuring based on 3.7 nominal such as a lipo pack, the BMS if set to lipo will still cut charge/discharge like it is supposed to, but if you’re using them without a BMS, i think you’ll be fine because like i said they seem to work within a safe margin and if set correctly will tell you when its time to get off the board and turn it off.

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thanks - was just wondering if there is actually a way to like set them to show 100% at 4.1V and 0% at 3.5V (or similar). But I guess I just have to wait and see and measure how the reading corresponds to the actual voltage.

How did you wire the lcd battery display?

I am from Kirchheim unter Teck xD

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That’s really clever! Thanks for the answer.

Where did you get the remote from? Thanks in advance.

It is in the text: a badwolf mod gt2b

Sorry I didnt know what that was :joy:!

I think it is this thing in a 3D printed case.

how far/distance/time can you skate with these lipo 5a 3c in series?

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Hi, I am a new builder/user to this forum and I am very excited to be getting into such a fun project. I live in SF where there are plenty of hills and weigh about 145-150 lbs and was wondering what components I needed. I will be running a single motor with the VESC, with 2x 4s 5000mah 20c Lipo in series. I bought DIYelectricskateboard’s 16T/36T motor mount kit as well. SO what I don’t know is what motor I need (been told 230kv is good) and does anyone have suggestions for a comparable but cheaper alternative to DIYelectricskateboard’s on/off antispark switch.