Raw Black - Slim | Single 6355 | 12s3p 30Q | 40T/15T | FOCBOX | Nano-X | 100mm MBS wheels | VGA charging | Fused XT90S

Highlights: 36" kicktail deck Caliber II 50 degree 10" trucks MBS black 100mm wheels Custom 17.5x6x1" ABS enclosure Enertion all aluminum motor mount 40/15T 15mm wide pulleys from @Titoxd10001 Single TB 6355 190KV 12s3p Samsung 30Q FOCBOX w/ Ack firmware VGA charging Fused XT90S Nano-X controller HM-10 bluetooth VG15S headlights

This will be my third build, second build thread. It blows my mind how much I have progressed in terms of build quality and reliability in the < 2 years I’ve been building. My first build was downright ugly honestly. :laughing: I swear I opened up the guts of my first board two dozen times, it was terrible; wires coming loose, switches blowing up leaving me to push home, broken enclosure, etc. It was a wonderful, yet painful experience. My second dual board (pictured below) was opened maybe twice in 500 miles of riding, huge improvement over board #1. This build (#3) should be damn near perfect in terms of aesthetics; my enclosures have vastly improved, and the 3D printed VGA, XT90S should make mounting super clean. This build will be nearly identical to the board on the left, all black with raw aluminum trucks/mounts.

Also want to make note of these cool fuses I found! I have no BMS, so I’d like to add short circuit protection for you know, obvious reasons. These fuses are cool though, rated at 58V up to 200A and the biggest thing is…they fit male 5.5 bullet connectors perfectly! You don’t really need a holder like blade fuses and they have a much wider (higher) amperage rating than blades. They’re the BF1 fuse from Littelfuse. I picked up 30, 40, 50 amp varieties. Here’s a link: http://www.littelfuse.com/products/fuses/automotive-passenger-car/high-current-fuses/bf1-58v.aspx#

3D printed XT90S holder (much easier cutting a rectanglular hole)

3D printed VGA holders

The XT90S and VGA are printed out of ABS so I’m going to flush mount them, and ABS slurry them into place.

I have a REALLY good connect at a machine shop! :grinning: Thanks @onloop for the mounts!

Here’s a dry run with everything mocked up in the enclosure, it’s tight!

Not pictured is 225 Samsung 30Q to power these babies! Board #4 will be on the heels of #3; planning a dual 6355, FOCBOX, 12s6p long range cruiser after I finish this 12s3p build.


Your motor mounts look like they where cut with a water jet. Am I correct?

What a crazy good build! Do you still have the files for the motormounts? Like in pdf file or any file type?

You got it @Namasaki. He waterjets the pieces while I drill and tap the holes.

Got a little bit done on the enclosure today. Cut out the holes for the XT90S, VGA, and volt meter. ABS slurry was used to hold the XT and VGA, will dry hard as a rock in a day or two. I’ll sand the outside down, and brush it with acetone to bring back the glossy finish. Will probably make the battery pack tomorrow and get the FOCBOX in position. Still undecided whether or not I want to make a square cutout in the bottom of the enclosure to expose the FOCBOX heatsink to open air. I’ve never seen my dual drive VESC-X above like 60-65 C. Might see how it does without a cutout first, then cut if deemed necessary.

I also painted the board today but I’m not all too happy with it. I sprayed it with a matte black, but its too much of a difference in gloss between the deck and enclosure, even with two coats of gloss clear coat. I need to pickup some gloss black and respray it. But you get the idea.


Problem with a vented enclosure is that it will get a lot of dirt inside. I had that problem on my first build. Then I re-built using a sealed enclosure and now it’s stays nice and clean inside and no problems with Vescs overheating

UPDATE Forgot to mention that my Vescs have heat sinks.

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Your build is looking amazing! I’m a little confused about the VGA connection though. Is it for your battery’s balance wires? What made you decide to go against just using a BMS inside the enclosure?

I guess your XT90 plug isn’t there for good as it’s not wired. I don’t know if it’s really important or not, but I think putting a female XT90 would be better. It’s possible to accidentally make a short between the 2 male pins, that won’t happen with a female plug. I know it’s not that important as it’s a loop key, but I thought I’d share.

@cosmicc89 Thanks! Yes, the VGA will have 7 wires for the balance plug, then a main positive and negative…I bridge two pins on the VGA for the main lines just to handle more amps. I am not really a fan of BMS, I have a lot more flexibility without one. My two other boards have been sitting for 2 months now without being used; I put a storage charge on them and they’ll be good come spring time. With an external balance charger I can: see individual cell voltages while charging, storage charge, adjust end of charge voltage (I like 4.1V/cell), and it’s just easier to diagnose problems. And with a good charger, charge at higher amps (5A+).

@louwii Yeah, thanks for pointing that out. I am fully aware of that possibility, it’s alright as long as the operator knows what they’re doing. :wink: It’s slightly easier to mount the male connector, and if the resistor ever goes out in the female, I don’t have to open the enclosure to replace it.

That’s 2 good reasons, I totally didn’t think about that.

Very cool, thanks for the insight. Using something like a VGA connector for an all in one charging connection is a brilliant idea!

Made lots of progress today! Battery pack and soldering work is 90% done…I’m going to have to wait until midweek to finish the VGA connections as I don’t have any 18 AWG silicone wire for the main + and - cables, I use 22AWG for the balance leads. I used 14 AWG before, but as you can see, I have no room left in this enclosure. :roll_eyes:

Hot glued the cells together and used adhesive insulators on the positive terminals.

I use a Sunkko 788H welder and sunstone engineering .375" wide x .005" thick 100% nickel.

First layer (parallel connections) done.

Second layer (series connections) done.

If you figure a single nickel strip can do a MAX of 10A, I need more current carrying capability to do 40-50A. I use 1/4" tinned copper braid which can do 35A soldered on top of the nickel strip, between cells (not directly on top). Flux is a must here.

A little bit of solder…

And melt the braid on top.

Replaced both the 3.5mm phase wire connectors and power connector with 5.5mm bullets on the FOCBOX. Also got the Littelfuse BF1 30A fuse in place right after the XT90S on the positive cable. Put everything in the enclosure to get a feel of how things fit and to test fire it up. Successfully powered the FOCBOX and all looked good.

I have to do a lot more insulation and isolation of connectors and stuff, pay no attention to the bare connectors and solder joints, was only a test fit. :wink:


Decided to go for the idea of exposing the FOCBOX heatsink to outside air. It turned out much better than I thought it would. Essentially I cut a profile in the 1/8" ABS enclosure and replaced the same cut profile with an 1/8" piece of aluminum, basically a cut and fill. Mounted the FOCBOX to the enclosure with the two M3x6mm button head bolts in the two corners opposite from each other. The other two M3x6mm bolts mate the two heatsinks together. I ordered some Arctic MX-4 thermal paste to go in between the heatsinks. For anyone wanting to do something similar, the FOCBOX is exactly 2.5" square and the two cutouts on the diagonal is 3/8" each side.


I am also in the process of building a no-BMS setup with a VGA connector for balance wires.

A couple of questions:

Why do you use two VGA connectors? Is seems that a single 15 pin VGA should be enough for all balance wires and main battery terminals.

Are you using a fuse for charging? On which wire do you put it? (I don’t want to use a fuse between the battery and VESC. But I’d like to protect the charging port with a fuse.)

Also, do you use any cover to protect the VGA port from water, etc?

@sash Sorry I missed this. I use two VGA due to how my battery is setup. I use 2 6S batteries in series to get to 12S. When I plug/unplug my XT90S, not only is it turning the board on/off, it also takes the battery from a single 12s3p into (2) 6s3p. I balance with two 6S external balance chargers.

So I completed this build about a week ago, finished up the final touches on the enclosure, drilled the deck for the M4 inserts, setup the FOCBOX with 2.54FW, setup bluetooth, Nano-X, etc. I really could have used an extra half inch in the enclosure, it was TIGHT. I lay 1/8" neoprene between the battery and enclosure, and then between battery and deck. I don’t need to use velcro or adhesive for anything, everything fits just right so there is no space in the enclosure for anything to move. I can violently shake the board and it is silent, nothing rattles around.

Also, we have had a “warm” spell here in PA recently in the dead of winter. It’s been around 40-50 degrees F, and we had a decent rainstorm to wash the salt off the roads! Took it out for the first ride yesterday and it was awesome, the board really left me wanting nothing more. I compared it to the other board in the pictures. They have very similar stats, a few differences, but MAJOR differences in performance.

The differences are: TB VESC vs. FOCBOX 12s3p HG2 vs. 12s3p 30Q 97mm clones vs. 100mm MBS all terrain Air cooled heatsink vs. enclosed w/o heatsink DirectFET vs. MOSFET fundamentally I guess?

Using @Ackmaniac app to monitor things, here’s the performance difference. Climbing a 3/4 mile long hill ranging from 5-13% trying to maintain 15mph, TB VESC reached 91 degrees C a little over halfway…I had to stop and wait a minute for it to cool down. I had to stop to do this 3 times with the TB VESC until I reached the top. Now with the FOCBOX…climbed all the way to the top maintaining 15mph, no stopping, pulled a max of 22 amps, and reached a max temp of 68 degrees C. About 21 degrees C cooler, unbelievable difference. The other surprising thing is how quickly it cools down, the second you get to flat ground, even while still applying power (5-10A draw), the FOCBOX was cooling down. It cools down incredibly fast once if your moving. Now granted it was 35 degrees F outside, so the external heatsink was probably sinking cold air in more than hot air out. In 90 degree weather, it won’t work AS well, but it won’t be useless. I think from 30-70 degrees air temp it will work great.

As far as range goes, I did exactly 18 miles on the 30Q battery and was at 3.38V/cell when I put it on the charger, should be a solid 20 mile board. Only did 8 miles on the HG2 because it was cold and I got my fix in. :slightly_smiling_face:

I am going to redo this heatsink vs. no heatsink test in the future and video it with the telemetry overlayed. But seriously, if you are running a single drive, get a FOCBOX or similar equivalent, and air cool your motor controller! :metal: