"Raptor 2.1 GTX" | R-SPEC DRIVE | FOCBOX Unity | 12S3P VTC5 | 3D printed custom enclosure

[occino]

Hi guys,

I’m Nico from Berlin, Germany and I’m building electric longboards since two years now. I would like to share with you my latest and easiest build which is technically a Raptor 2.1 with at GTX deck. I’m also motivated to write this post because of the Enertion R-SPEC DRIVE KIT | Best Build Competition [link].

Specs & features:

• R-SPEC DRIVE KIT w/ 90mm wheels [link]
• FOCBOX UNITY ESC [link]
• Evolve GTX deck [link]
• Custom 12S3P battery pack w/ VTC5 + BMS [link, link]
• 3D printed custom enclosure + PVC bottom plate [link]
• Enertion Nano-X 2.4Ghz Controller [link]
• Voltage display [link]
• USB charging port module [link]
• Loop key

GTX deck

The GTX deck by evolve is perfectly suited in my opinion because it comes already with a notch for the battery pack. Furthermore it’s flexible and looks nice.

In order to use a 10S4P battery, the notch had to be enlarged by about 1 cm. I used the original screw holes to mount the enclosure.

Enclosure

The enclosure is a modular 3D printed frame with a PVC plate underneath. Due to the dimension limits of 3D printing, I decided to design a modular system which can be printed in multiple parts. To ensure water resistence, I used a tongue and groove technique which makes the enclosure flexible as well. I also used sponge rubber between deck and enclosure as well as between PVC plate and enclosure. You can find all parts on thingiverse.

Mounting

In order to mount the PVC plate underneath, I glued M4 threaded sleeves (5mm x 18mm) (link) into the parts as you can see in the picture below. This way I could use proper thread screws. The threaded sleeves pass through the entire material. This allowed the deck to be screwed on from both sides. This makes the construction pretty strong.

FOCBOX UNITY case

The rear part of the enclosure contains the FOCBOX UNITY as well as a battery voltage display and the power switch provided by enertion. The voltage display is powered by the CAN bus port (5V, GND) and the measuring wire is connected to the BATT+ pin of the AUX port. The FOCBOX sits tightly into the compartment, so there is no need to mount it with screws.

Connector box

The connector box is the middle part of the enclosure and contains receiver, 3A USB charging module (LM2596HV), XT60 charging port, XT60 key loop and all wiring. The charging port is connected to the BMS via XT30 in order to change the battery easily. The receiver of the Enertion Nano-X 2.4Ghz Controller fits perfectly in a small compartment and doesn’t need to be srewed down.

Battery pack (12S3P, Sony Konion VTC5)

12S3P or 10S4P? I chose both variants. 12S for more fun and 10S for more range. For the 12S3P pack I used 36 Sony Konion US18650VTC5 cells 2600mAh with a total capacity of 336Wh. I paid 128€ for 36 VTC5 cells on eu.nkon.nl. 36 VTC6 cells with 3000mAh would have cost 207€ for additonal 53Wh. Range is not that important to me, so I took the cheaper option.

For spotwelding, I used the amazing kWeld by keenlab powered by a high discharge lipo. The nickel strips are pure nickel (8mm x 0.3mm). I made some tests and figured out that they can easily handle 25A. In order to archive the full rated 90A of the cells, I used 4 layers of nickel (pyramid technique) at the S-transitions to be on the safe side.

The BMS is a cheap 13S circuit usable for 12S as well. It is only used for charging and not for discharging. To prevent the battery from over discharge, I used the cut off setting of the FOCBOX UNITY. As I mentioned before, I would like to use 12S3P and 10S4P battery packs in the battery compartment. In order to get the same dimensions, I printed a 2x2 dummy cell construction as your can see on the picture below.

After adding all the wires, I added felt pads on all edges which should absorb shocks and keep the pack tight in the battery compartment.

Finally I used a 200mm shrink tube and a hot air gun to close the battery pack.

After inserting the battery and connecting the XT60 and XT30, the only thing left was the bottom plate.

That’s it. Just an easy, modular build :).

What do you think? Any suggestions for improvements?

If you have any questions please feel free to drop a message.

Cheers, Nico

[mynamesmatt]

this is really well done. would be a bit concerned about water ingress but apart from that you’ve done an awesome job.

[mutantbass]

that battery is beauiful good job

[occino]

Thanks Matt! I used a lot of sponge rubber in order to keep water out auf the enclosure. The only place which is not sealed is where motor wires run into the focbox case. I’m already working on a solution for that

[Winfly]

Nice build!! I really like the compartments for electronics. Also, I’m worry about your battery. Afaik , the bamboo GT is quite flexible and the way you spot welded series connections with only nickel strip concerns me. Ignoring whether your spot welds are good or not. You will be pulling a alot of stress on these nickel strip and they might eventually give out.

[occino]

Hi @Winfly, thanks for your response. The bamboo GTX deck is not that flexible compared to Loaded decks for example. I literally jumped with my 90kg on the final board and it only sag about 1-1.5 cm in the center. To be honest, I’m a bit disappointed about the flex. With all the padding around the battery I think this should be fine.

[rey8801]

On that spot you can internally add sugru or what I do is back sealant silicone. It cures in about 24 hours and became rather strong but really elastic so it will allow to the cable to move a bit while keep everything sealed. Plus you can always remove in case of intervention.

[Superflim]

does this work on blank pcbs too? or only on sealed off wires?

[rey8801]

You can find it in the home depot. I prefer over sugro for sealing because you can always remove and doesn’t leave any residues. Sugru is fantastic to hold parts in place, but I prefer the black silicon for those part where you have a hole with wires going through. In thst case the silicon can really fill up all the gaps and then became a rubber wall really elastic.

[Superflim]

my question was will it damage electronics?

[gmurad]

That’s a cool way to build a battery case! Could be really cool and functional with a transparent bottom plate. I wonder if the tongue and groove would really stop water.

Also saw that you posted your build in Github. I guess you work in tech?

[barajabali]

Awesome build! Competition is getting good now

[briman05]

This looks very thought out I am really liking the unity printed box.

[landonkun]

I’m curious about the PVC plate. Where did you get it? How was the shape cut that way?

[occino]

Hi @gmurad, funny that you mention transparent bottom plate. I already played around with plexiglass before the 100x50x2mm PVC plate arrived. You are right, the post is hosted on github as well. Thanks to markdown the readme.md in github is perfect to prepare a longer post. And yes, I’m working as a software engineer (bachelor in electrical engineering and master in computer engineering).

Here’s an old picture with plexiglass underneath the board.

[occino]

Hi @landonkun, I bought it on ebay. Unfortunately, the seller only ships within Germany. Maybe you find something similar in Canada. The material is pretty soft and not brittle as plexiglass. Therefore I used a jigsaw to cut the shape and a file for the finish.

[Smithster]

congrats nice build

[dareno]

Nice clean build that. Love the simplicity and the thought that went into the enclosure. Awesome stuff.

[deucesdown]

@occino

kWeld by keenlab powered by a high discharge lipo. The nickel strips are pure nickel (8mm x 0.3mm)

I tried welding 0.3mm strip with a kweld to some dead 18650. Gave up at 100joules, as the nickel, the cell, and hhe electrodes were very hot after just a few attempts. This was with a 3s 65c 6000mah graphene pack. I have the crimped XT150 electrodes. I also didnt like how things were going with 0.25mm strip.

Can you tell me your settings, setup, and how it went?

I like the cell holding jig.

And how are you finding 10s4p vs 12s3p? Not many people have been able to do direct comparisons.

Thanks for posting!

[mikenyc]

can that battery flex?