Yet Another Build Log

Starting with electronics, (sadly 100/250 was released the day I got these, 20S would’ve be sweet)

Battery currently planned to be 16s12p Sony VTC6 cells, planning on making a plastic enclosure similar to lift’s so I can use it as a general 16s / 360A battery.

Finding a BMS to handle discharge was difficult. I ended up buying a tiny bms because it supports an external relay + current sensor. Unfortunately these high amperage relays are ~1LB, so my new plan is use the BMS charge only and use the vesc’s e-switch as a “relay.” I think this should work great and the vesc uses about as much power as the BMS in low power mode.

I got some recycled supercaps to power my spot welder, but their current output is only 900A, so I think I’ll have to add more caps to spot weld copper strips to the batteries.

Where would you get these supercaps ? Seems to be SATA6 interface ?

slow build, some more pics

still unsure if I’m going to double down on this battery design

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motor mounted, cables routed

The caps were from some server backup boards (I think). They didn’t end up working out that well and I ended up buying 60 recycled maxwell ones and cut out some instead.

I really like the design of Trampa’s pcb battery pack because the cells are loose and you can disassemble to take on a plane. Wish it came in 16s12p.

Chose a deck design, will be 4’3. Not using a stringer, figure the walls of fiberglass cavity will give it plenty of strength.

New plan to waterproof the battery is fiberglass + cable glands.

I’m routing this antenna

to the nose of the board.

I plan to use vesc wand (maybe eventually make own remote) with the internal NRF in the vesc. The chip my 75/300 uses is the BMD340 which has a pcb antenna. There is BM341 with external connector that you can replace it with, but there’s no stock until October.

So if the signal’s too bad in the aluminum box, I will try soldering the antenna in place of the pcb antenna.

Made a little mistake routing that I made bigger by adding superglue. I see why making boards is avoided now. Styrofoam is everywhere. I imagine the fiberglass dust will be worse.

Used a router for the outline and then hotwired out the cavity. I’d do this method again it wasn’t that hard to keep the router straight and the hotwire for the bulk of it reduced the dust a bunch.

Also figured out you can use external 51822 with ufl.

Got it glassed, still need to make the lid tomorrow. After that, just need to assemble and take it to the DMV to hopefully get some uninterrupted lake time for the 4th :tada:

I also forgot to add more patches around where the mast is. So this’ll be a test if finboxes + 12oz on top, 12oz on bottom and a layer around the finbox holds up.

This test went poorly so I’m redoing the seal on the hatch. I had to do a lot of rework on the top because the vacuum bag sealed poorly and the lip had gotten uneven.