kaezone's first build | simple street longboard | build planning

DIY Builds
#1

Howdy, everyone. I’ve reached a decent stage of the planning process for my first build, and I’m now looking for any comments/criticism/advice.

This is a relatively long-term project which I’ll be doing in multiple stages - mostly out of necessity, due to being a uni student with only a part-time job :stuck_out_tongue: I don’t expect to have this build finished until the end of the year, but no matter how long it takes, it’s gonna happen.

I’ve been interested in esk8 for a long time now, but put it off for years due to high prices and the complexity of DIY, especially since I live in New Zealand. At the start of this year, I picked up a Black Hawk Electric longboard (I know, I know). It’s been pretty damn fun, and I still enjoy it, but I’ve quickly outgrown the relatively underpowered 7S2P pack + hub motors. At this point, with a bit of damage to the motors, I don’t get anything higher than 20km/h.

The plan, then, is to rip out practically everything, and replace it with a fully custom setup. The only thing remaining will be the deck.

GOALS

The primary goal for this project is speed. Probably a common goal, of course, but 20km/h just isn’t enough for me anymore. My minimum speed target is 40km/h, with 50km/h being the ideal. As 50km/h is the speed limit on most New Zealand roads, this will make it a truly street-capable board. Torque isn’t a huge factor for me - the city I live in is about as flat as it can get.

The second is reliability. The existing Black Hawk drivetrain is okay, but it’s obviously not very good. It has an epoxy-potted black-box ESC, unknown-cell 7S2P battery pack, and relatively fragile hub motors. Replacing the whole thing will give me a better understanding of what’s actually going on under the hood, and the ability to easily replace anything that breaks.

STAGE 1

The first stage of this project involves replacing the drivetrain. I’m scrapping the existing trucks and dual hub motors, and replacing them with a single 6374 belt-drive.

I’m planning on using dickyho’s hardware kit, with a Flipsky 6374 190kV motor. The kit has 97mm wheels, a 36T wheel pulley, and a 15T motor pulley.

In terms of the electronics, I’m still slightly mixed on it. I’ve been considering Flipsky’s “Group S3” kit, which comes with the motor, an FSESC 4.12, 2.4GHz receiver, and VX1 remote. However, I know Flipsky has a somewhat mixed reputation. I’m open to any suggestions for alternate electronics.

At this point, I won’t be replacing the battery pack. While using a 7S2P pack with a system like this is a bit odd, I won’t be able to afford to build a new pack until later - that comes under Stage 2. Using the existing pack will allow me to re-use the existing enclosure and ride the board while I build everything else.

STAGE 2

This is the point where the board will properly come together. Once I have the board running on the new drive-train and electronics, I’ll start assembling the cash and materials for a new battery pack build, and a new enclosure.

The battery pack will likely be a 12S2P flat-pack design, with Molicel P42A 21700 cells. Sourcing cells is quite an issue here in New Zealand, due to air freight regulations. Thankfully, after being tipped off by a user here, I found that 18650BatteryStore stocks them for an acceptable price (about half the local price!), albeit with some high shipping prices. I considered using Samsung 30Q cells from a local supplier, but the difference in price works out to be roughly NZ$70, which IMO is acceptable for the benefits of the P42As.

I’ll likely be building the battery myself, unless I can find somebody in New Zealand to build it.

The next thing to tackle will be the enclosure. My plan is to whip up a custom CAD design once I know the dimensions of the battery, then 3D print it in ABS. Since I’m a little worried about cracks or impacts, I’ll then be applying some fiberglass cloth and resin. Hopefully, after sanding and painting, it’ll be a good-looking and strong enclosure. Additionally, I’ll be adding a silicone gasket to the deck to ensure water can’t get in. I’ll be using a GX16 connector for charging, and an XT90S loopkey.

At this point, the board should hopefully be capable of speeds around 50km/h. Before I call it “finished” though, I’ll be filling in the old drill holes, sanding down the deck, painting it, and applying a clear-coat. I’ll also be using some plain-black grip-tape, and spray painting some white stripes on it.

EXTRAS

I’m pretty interested in adding LED strip lighting to the bottom of the deck, with acceleration/braking changing the light states. For example, when accelerating, I’d like the LEDs to slowly light up in segments based on the speed - one block at 10km/h, another at 20km/h, etc, acting sort of like a speedometer. Whenever I brake, the LEDs should all change to red. I’m not entirely sure how to implement this - I imagine I’ll need a custom board sitting between the receiver and VESC that receives the throttle/brake states and adjusts the lights accordingly.

I’ll also be re-using old front and rear lights from my bike, since I often ride at night. It should provide plenty of visiblity for me in the front, and plenty of rear visiblity to people behind me, especially combined with the under LEDs.

BOM (tentative)

Hardware:

  • 2x 8" trucks (dickyho)
  • 4x 97mm wheels (dickyho)
  • 205mm hanger (dickyho)
  • motor mount (dickyho)
  • 5M 36T wheel pulley (dickyho)
  • 5M 15T 15mm motor pulley, 8mm bore (dickyho)
  • drive belt (dickyho)

Electronics:

  • Flipsky 6374 190kV motor
  • FSESC 4.12 VESC
  • Flipsky 2.4GHz receiver
  • Flipsky VX1 remote

Battery:

  • 24x Molicel P42A 21700 cells
  • 12S LithiumBatteryPCB smart BMS
  • 50.4V/3A YZpower charger
  • 0.2mm nickel strip, fish paper, kapton tape, etc.

Enclosure:

  • ABS filament
  • Fiberglass cloth and resin

Let me know if you have any critique or advice. This project’s gonna take a long time, and I’ll update as I go along.

11 Likes
#2

Plan sounds good! My only suggestion would be to pay more for a more reliable, and more powerful ESC. I know you don’t need torque, but at 50km/h wind drag becomes noticable. On a small hill, going up at just 42km/h I use 30 battery amps on my brother’s single drive 6374. Running the flipsky 4.12ESC at above 30A for long will cause it to thermal throttle, if not just die :laughing:

So yeah, I would look into getting a better ESC if I were you. And always try to buy used parts to save some money :slight_smile:

2 Likes
#3

Interesting, I hadn’t considered that. Do you have any suggestions for other ESCs? I’ll probably get the Flipsky kit anyway just so I can get up and running + use all the other parts. I’m not really sure where to go about buying a used ESC here in NZ…

#4

Apparently I’m blind, because the Flipsky Group S3 package comes with a 6354, not a 6374. Is there any appreciable difference?

1 Like
#5

6354 will heat up faster under the same load, and its torque output is probably limited at about 50A, whereas the 6374 could do about 70A. For a single drive board I would highly suggest the 6374, just for better braking capabilities, if nothing else.

Waiting for something used to pop up in NZ or Australia would be your best bet, but following that, maybe a Mini Foc plus from MakerX?

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#6

Btw, maybe local builders can help you:

1 Like
#7

Are you using a vesc 4, with 190kv motor and a 12s battery? You definetly want a vesc 6 ASAP, this is a recipe for black smoke.

This will surpass 60k ERPM which is the limit of a vesc 4 based esc

#8

Ah, gotcha. Guess it’s probably better for me to part everything out seperately, instead of using a kit.

#9

Gotcha, thank you. By any chance, do you happen to know how the braking power of a single 6374 would compare to 2x hub motors?

#10

Personally I’d say it’s similar at higher speeds. But at low speeds the belt motor will easily outperform the hubs. Hubs only slow you down to 2ish mph. They can’t fully stop

1 Like
#11

Nice, that sounds like it’ll suit my needs.

#12

I have a single 5065 motor on my second board with 25a of motor current. It stops quite well, except down a hill

On a hill it takes it’s time slowing down

1 Like
#13

For a single drive on 97’s I would suggest a larger than 36 tooth wheel gear. 40 or 44 for all around better brakes and acceleration

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#14

I used a 36t on 83mm wheels and it was good.

#15

Why are you planning on re using the deck? Is it great, or a cost thing?

Gnartearaoa FB groups or trademe can have some good used longboard deals and would be worth checking. Example - there’s an old LY switchblade on Surf rodz rkp on there at the mo which would be an awesome donor (offers)

If you’re gonna go to the effort to FG skin a printed enclosure, maybe have a look for second hand longboard on trademe or FB marketplace which you could skin to add stiffness or tidy it up aesthetically. You’ll be buying resin etc already and might end up with something better.

1 Like
#16

To be honest, there’s no real reason to keep it. It’s pretty cheap, but I weirdly kinda like it - maybe I’m just used to it. It’ll also be good to practice sanding/painting on.

Also, there’s the comedy value in a 50kph drivetrain being tacked onto a deck with the Black Hawk logo :stuck_out_tongue:

#17

Might pick up both then, just to see what works for me.

Out of curiosity - how reliable are 3D printed pulleys? Not very, I’m assuming?

1 Like
#18

Unfortunately I can’t edit the topic yet (new user), so I’ll have to reply each time.

Here’s why you don’t buy Black Hawk Electric boards:

image
image692×62 3.67 KB

Granted, I’ve kinda fucked the hub motors a bit, but still. Gonna buy some replacement hub motors so I can keep riding this for now.

#19

I dont know how much this is but for reliability you might be better off with Boardnamics M1 Drive + hanger (184mm) for 110 dollars. And then buying some wheels for it.

Also that flipsky Variable ESC its not very reliable, i think you can find something better for not much more second hand or even new! Check out maker X

1 Like
#20

I second this…it is a good shout!

1 Like