Arythmia 4WD - Boundmotor Octopus

Long time reader and searcher, this is the first time Ive got any serious content to share. Ive undertaken a 4WD as my first complete build (except for battery) and it’s fair to say that Ive learned a great deal on the journey, also noted is a serious up-skill required in soldering skills for this sort of thing, I was challenged, I persisted.

The biggest item on the needs list was for the enclosure to be watertight with each entry point having at least 2 types of protection, if possible, 3 types (for example, washer seal, hot glue and then silicone) This in itself presented some challenges… I set about playing with various connections and assessing the viability of them. The Second need was to make jumpers for every connection so that I could access the enclosure without having to remove it from the deck. These two items probably presented the greatest challenge by far.

The Goal

Ultimately, I chose MT60 connection as they fit the enclosure easiest without further mods required so into the soldering rabbit hole I went…

This still left a faint possibility of water issues so I went another level here adding liquid electrical tape to all the internal sections of the connection, there will be no shorts and no water ingress there…

I also needed to create an external connection for the Sensor wires so I set about making a jumper cable passing through a waterproof cable gland (also back filled with liquid tape)

Prior to this assembly, I also had to cut in and seal the heat sink plates into position, more silicone and liquid electrical tape…

This got me to a pretty solid place as far as cables go.

Last to go in was the charging port, Power button and the USB jumper through the enclosure, here, I leaned that all the holes in an enclosure for proposed penetrations should be marked out and cut in advance of assembly :woozy_face:

Boundmotor Octopus Deck and Enclosure
12s6p 21700 moli’s + Smart 12s BMS
Hoyt Puck Controller
4 x Radium 178kv 6485 + 4 x 78t pulleys + Radium Mounts
Boardnamics 270 Precision Hangers on Adjustable plates (*edit to add)
Radium Heatsink x 2 (For maker x)
2 x Maker x DV6
2 x 120a fuses
2 x Radium Antispark

I really underestimated the amount of work that goes into making these bespoke machines by a long shot, buying parts that dont/cant work, ordering more parts that dont/cant work, breaking or melting parts that do/did work :crazy_face: Changing direction and buying more parts that dont/cant fit… so on and so forth… endlessly putting it together and deciding I hated it and stripping it all out again. It’s taken months of effort and to look at it on the bench, it looks like it could have been thrown together in an hour. Im incredibly happy with how it’s gone and I cant wait to rip the trails around here a new one on it. Im reasonably happy with it so far, next up is to get the battery done and installed, fit the motors and spin it all up.

Big love to @glyphiks, Nick, Tye, Liam and everyone else whose put up with my uneducated nonsense, it’s a hell of a journey and if this has proved anything to me it’s that that journey has really only just begun and I’m still a baby at this game


Welcome to the rabbit hole. I think we all know too well buying things that don’t workout lol, I know I do. Maybe I missed it but what trucks are you going with? Looking good so far though.

shit, I knew I missed something… BN270 on adjustable BN plates


Omg that internal wire mess… Honestly becoming one of my least favorite parts when building a DIY board. The struggle is REAL. Glad you made it work!

Super keen to see it in action! Got the next build planned yet? :grin:

Oooh I like this idea and I’m going to steal part of it for my own build now lol

Only difference being I’m using the MR60 (easier to make rectangle holes) and I’ll likely solder the VESC phase wires directly into the MR60 and only use extra bullet connectors on the motor side. Not enough room in my enclosure to fit extra bullets + I don’t want to buy more bullets

It’s actually really tidy, there’s enough length in all the cables to get at any component, it’s all been designed with maintenance in mind. Ive seen enough enclosures with shit jammed in all over the place that I knew I wanted to be thoughtful about where I ran cables.


as it turns out… I was thinking about something 18s perhaps…

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MR60 was my first choice too, it would have meant further and a more complicated enclosure panel to be fitted, I know you can just buy one that would do the job - Panel Mount - but that wasnt going to help with this enclosure and the penetrations it already had, just would have made it messy, I chose these as they snug fit into the existing hole.


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I’m making all of my own panel mounts for my enclosure which works better than buying preexisting stuff that might end up being too big anyway. Also I have perfection issues where if I’m making something it has to be done right and well without cutting corners :sweat_smile:

The power button has its own o ring for sealing it, the USB-A port is fitted very snuggly around the female ports with custom cut notches on them so they can’t be pushed out of the enclosure + custom gasket on the port to give an even tighter fit on the epoxy added on. The the micro usb port is still being made and I am working on getting it to be able to screw into the side of the enclosure since it already had the inserts built in. I don’t want to screw it through the front of the enclosure since it would look bad

I’ll probably epoxy the MR60 permanently into the enclosure so long as they won’t get in the way when removing the VESC. The usb ports and button all stick out to far into the enclosure to epoxy them in place permanently.

It’s been a while since I’ve been able to do much to this, the deck is away for Skin and Frit and I was awaiting the battery from my Man Tye who has built 2 for me now… legend… anyway, as all build go, this has had a steep learning curve, I discovered that I needed to split off the main feeds from the battery to go to the Radium Performance antisparks and then to the controllers, this filled me with enormous amounts of dread… but tonight was the night…

I then moved on, with slightly less trepidation, to put some blobs of solder onto the Anti-spark, wasn’t so bad here as I wasn’t going to kill myself, just possibly destroy some shit… I’m relatively new to soldering so I spent an hour or so last night trying to get some down onto tin cutouts to practice and wasnt unhappy by the end so into the breech I went.

I’m not terribly dissatisfied by the result, tomorrow I can solder the XT90 connectors to go to the controllers from the anti-spark and then Im nearly done till the deck comes in and I can assemble the beastly thing… I’m really hoping to have a ride of this for Xmas


I’m doing the deck tomorrow! Was all set to start last week until i realised the bastards sent me the wrong frit. But i ordered more and it came today :partying_face:



Faark!! Thats coming out pretty damn sweet!

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Coarse frit is huge :sweat_smile: no barefoot on this one


dunno how to quote an image, but regarding thise phase wires, why not get rid of the bullet connectors and just do straight to mt60?

@poastoast Mostly because it means I can plug and play most motors with little to no modification unless I need to change cable length or some such in which case I’d be soldering anyway I guess but hay, bullets are easy.

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I’m not some sort of reckless heathen that rides barefoot so no biggie there :crazy_face: :rofl:

Looks a little less vicious with it’s final coat but i still wouldn’t ride it barefoot :rofl:


@glyphiks Dude! thats sick, it should make it easier to keep clean (snigger, like thats gunna happen)

Love ya guts ya mad bastard!

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