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Blutstern - Rocket longboard, 10s6p, 4WD 58KV China Direct Drive

Welcome to my latest build :slight_smile:

This time I’m building a 4WD thing for long range (I know, 4WD typically doesn’t stand for that) with the following components:

  • Rocket longboard deck with integrated enclosure by @evoheyax
  • 10s6p battery (This time spotwelded, would have used NESE again but I got no battery scenario where I wouldn’t end up with lots of empty space)
  • Landwheel hubs for the back (at least for now, need to test out which works best)
  • Mellow hubs for the front
  • 2x MakerX dual mini ESC connected over CAN
  • Later on: Hammock baseplate in the rear (Not sure yet, doesn’t fit without modifications
  • Arduino Nano for additional features, I’ll do a LED Matrix Speedometer in the lid first, lights maybe later.
  • Flipsky Nano V2 remote, might be replaced with a VX1 which I use with the Grünstern commuter build.

Some horrible pictures:

At the moment I’m checking all cells I got from my first builds NESE modules and the ones in my battery expansion pack for the mov-e for capacity and internal resistance and then I’ll use repackr.com to calculate the best variant for the 10s6p battery. I only use a Graupner Ultramat 18 charger for external balancing so I’m sure it works perfectly :wink:
I want the whole thing as stealth and waterproof/resistant as possible. At first I’ll only have the charge port (thanks @Angeljmm ;)) and the antispark plug hidden away somewhere around the baseplates.

The drives have different kV Values, the Landwheel around 90, Mellow around 120. My plan is that they’ll support each other with what they can do best, when torque is needed the Landwheels have the main part and on speed the mellows set in making it efficient (hopefully).

I’ll keep you updated :wink:

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I just had an idea I have to write up (so why not here :D): I need to create different VESC Tool Profiles with 4WD (all motor amps to normal), 2WD frontdrive (front drive motor amps to normal, rear motor amps zero) and 2WD rear drive(accordingly :)) Brakes are always 4WD, although I have to try it out :slight_smile: free roll behaviour is very good with both drive systems, mellow even better but both feel like normal unmotorized wheels when pushing.

12 cells to go, then I can shuffle them for equal capacities in each P-Group, glue them and spotweld :slight_smile: Thanks to all of you battery builders I have a plan on how it will be really safe. First I’ll arrange them in the slightly bend deck, then I glue the P-groups together, Fishpaper rings to the positive terminals, Kapton tape between the neighbouring positive terminals, fishpaper stripes on top of the Kapton. Spotweld. fishpaper. shrinktube. Connect groups with 2x12awg, (or 2x10awg, whatever I’ll find), I’ll make nickel->wire->nickel pieces that get spotwelded on top of the group nickel with balance wires connected. TPU divider in between to make shorts nearly impossible. Route silicone balance wires to prevent overlaps.

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I just modified one of the makerx with a metr pro, a canbus cable and optimized route for the power supply. This is gonna be the one close to the battery plus and minus so no additional caps needed. The one on the other side will have a 2200uf hq cap in parallel.

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Looking great :slight_smile: Cells seem fine even though I still have 4 to check :slight_smile:

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Sanding now :sunglasses:

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Battery half done, serial connections tomorrow :smiley:
Edit: You might notice that the packs are not all straight, some are slightly bend to fit the slightly curved deck :wink: (I love when a plan comes together ;))

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Did I mention how much I love sanding…NOT!

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Older picture of the first layer of dye:

After that I changed the name to Blutstern. I love the color, as soon as I have the epoxy I’ll seal it with that :slight_smile:

I just placed the charge port:


Inside:

Of course I won’t do anything cosmetically here, only functional stuff (cable management. I had to modify a bit to use the Hammock baseplate, its slightly too big for being mounted drop-through.I’ll use low shockpads in hope for vibration reduction and I managed to get both the Paris and the Hammock baseplates to same height with a very low angle (30° I think) in the back :slight_smile:

A red (:D) 16x9 LED Matrix for speed(number) and voltage (bar):

I’ll put tape on the inside to seal and then fill the hole with the matrix with Epoxy. After that I’ll sand it down together with the rest of the lid and cover it in a final epoxy coating with glass frit :slight_smile:
Its working but only without direct sunlight, for that its not bright enough. I’ll try that nonetheless and might replace it with a slightly bigger e-Ink display in the future.

Due to the bevel routing and the dark color the board almost looks slim :star_struck:

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More progress:

I use silicone 22AWG for balancing and 16AWG for charging.

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Can you share the link again? How have these been working for you?

This time I use these with 12 pins


In the Grünstern it is the 12 poles version from here:

https://www.bulgin.com/us/products/range/circular-power-connectors/400-series.html

plus a QS-8 for the main power lines.
The new one is much bigger (more than double the size, looks like a electric car charger connector in small) but it is capable for 10A in the 12pin version. This battery is so huge I’ll never need the expansion pack, which was the reason for the big QS-8 on Grünstern, so I can use one connector for charging this time :sunglasses: :nerd_face:
The WF28 has a rubber cap but I’m planning to make a cap thats making use for the threads on the connector from the screw ring on the side (I’ll post pictures when I did that :))

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Thanks for the link and explanation. I’ve been deep in the connector hole on a few occasions.

10s means 11 balance wires, use the first and last wires for the power lines? Leave the 12th pin free?

I guess one concern is, as amps go up the skinny wires have more voltage drop, so your rate of charge gets a little wonky, but it should level out as you get into the CV stage.

WF28 means 28mm diameter on the circular part, pretty big.

One more interesting spec is the number of mating cycles the connector is rated for. Sometimes with tiny pin connectors it’s as little as 15!

wait wtf this?

https://www.rcgroups.com/forums/showthread.php?3205861-QS8-connectors-(8mm-XT-90S)

8mm version of XT90s (4.5mm)?

Gonna go dig around in your build thread again lol.

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Exactly :slight_smile: I usually charge with 4A max so it should be fine :slight_smile: They say its 500 cycles.

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Yeah, mostly because I wanted to prevent an accident like @Andy87 had, swapping the Antispark with Charge Port :wink: A XT90 would have been sufficient for that but this way I could have pulled 120A that the combined two 12s3p batterys could theoretically deliver :wink:

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Have you also found a durable sheathed multiconductor cable? Sigh I’m gonna stop asking and go check your build threads again.

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:smiley: No, I use 9 separate 22AWG silicone wires plus two awg16.
Its ok, I’m happy that my monologue I started 13 days ago has been finally interrupted :rofl:

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Just so you know, I love your build threads. All the messy epoxy, sanding, and electrical madness. You’ve not been posting in vain.

:slight_smile:

I’ve got my hands on one of these:

And I really think I should dump the bms’s in new builds.

Your builds are one of the few bringing the balance points to the outside in a serious way. So I’m always watching.

Also, I’ve been looking at stuff like this:

https://www.aliexpress.com/wholesale?SearchText=flexible+sheathed+wire+core

And also this type of stuff for power leads

https://www.amazon.com/gp/product/B0764TSZNG


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A shielded silicone multistrand wire would be best but a quick search only gave my up to 5 cores. I’d always use silicone wire for balance cables though :wink:

5 cores

btw, this one will be really organized compared to the other builds :smiley: I have to think about how to keep the batteries from moving this time :wink:


I’m gonna cut the screw ring a bit but basically this is my idea for the cap. The stock one was without threads, couldn’t trust it :blush:

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