BIG TORQUE - Reliable board for the larger rider - - - Trampa Street - Dual 6374 + FocBox - Custom battery + Enclosure





No carbon at all I believe, it’s glass fibre composite. Just looks like CF


nice… i was thiking of doing a hybrid build using s-glass and carbon… since carbon is stiffer and s-glass is “stronger”


yeah its a fiberglass like composite. unlike carbon fiber its not conductive which makes things easier.


so my fault on my master focbox is weird.

Im getting “FAULT_CODE_DRV” show up in the app but only when i try and run the motor, as soon as i stop it goes back to normal. Also “ESC Monitor” app by @Ackmaniac is showing “invalid command: can_member” followed by “Error : Unknown fault”.

But the CAN seems to be working as i can control and connect the other focbox. any ideas anyone?


FOCED FOCBOX . . . again.

Had another focbox fault recently. This is my third failure so far (admitted one was my own fault caused by water damage). anyways i ordered another DRV and when it arrived i opened my board to investigate.

First thing I found was that all of the hot glue / silicone round the capacitors has broken. This has resulted in one of the caps breaking both legs.

I think our rural English countryside provide to much vibration for many eskate components.

The second thing is that it looks like one of the fets has released the magic smoke. I assumed this was going to be a DRV fault so had a replacement chip ready but unfortunatley it looks like it might not be the driver that caused the problem :frowning:

At this point im thinking it might be a better idea to wait for the unity or a dual vesc6 than to buy another focbox. I dont seem to be having great luck with them. I dont think they can handle my current requirements and local road conditions.

I guess i will just have to ride slow on mono for the next few months :cry:


Just had some time to look at this in more detail. This is what the FET damage looked like under the TIM.

After cleaning up I start to get some clues as to whats happened.

Looks like the PCB has corroded and copper had been exposed on some areas. Also the edge of the FET seems to be corroded here. Maybe a short between the FET housing and copper has occurred.

Decided to remove the fet and asses the damage.

Yep, that defenatley looks done.

The board dident look great either. So I tried again to clean it up.

This actually doesn’t look too bad. It looks like the PCB has worn down to the copper in a few areas. Maybe this is caused by vibration or maybe water ingress? not 100% sure. also cant work out how to check the other FETS without removing them which i don’t really want to do if i can avoid it.

So I plan to re coat the bare copper areas again some how then replace the FET. Wish me luck :slight_smile:



So today i fitted the replacement FET and rebuilt the focbox. after conecting it on the desk it seems that everything is working again. Hopefully i can get some time so to put it back in the board and try it out under some load :smile:

Also finally got round to uploading the cable riser to thingiverse if anyone else wants to make one.

Hope this is useful to some one :slight_smile:


I’m currently printing something similar… it’s based on the unikboard riser and it’s coming along swimmingly


Is that cable riser not aluminum, it looks it in the picture, although there’s no way it is cause that would short your phase wires for sure.

Actually, come to think of it, are you sure it’s not water getting in the cable riser and shorting your phase wires that’s killing your focbox? I know shorted phase wires during operation will cause a dry error on any vesc


The cable riser is milled from poly-carbonate. I think its the rough finish that makes it look like aluminium but if i bothered to polish it up it would be clear. its not conductive and the only other thing the wires touch is the composite deck.

Also after looking under the fets in my focbox im 100% sure issues were caused by water ingress from somewhere.


@ducktaperules how have you found the truck riser with the motor wires? I’m thinking of my options at the moment and my main concern with doing it this way is the connectors are held static to the board so the connectors would potentially vibrate on the motor side a lot and break. I’ve heard of some members having issues with solder joints breaking at the bullets.
I might still use the riser but have the connectors outside so the cables just bend with the vibrations to hopefully not transfer them to the joints as much.


its actually held up surprisingly well. I ride abusive roads and have broken 3.5 to 5.5mm bullet adaptors before but since switching to this its been very reliable. 100% one of the lowest maintenance parts of of my build :slight_smile:


Absolutely love this thread - It’s super inspiring to see how your build progresses!