Energy density?

I’m probably putting 24 cells under a board with 34’’ from wheel to wheel and an average clearance of under 3" so I’m kinda worried, do you think a thin fiberglass enclosure with standoffs in the middle is enough? I doubt puncture risk is high but I can put 1/32" galvanized steel plates in if need be

I’d recommend using lipos (if you use lipos) that already come in a plastic case. That in combination with your enclosure should be more than enough protection.

If you use bare lipos, I would suggest using adhesive tape and permanently mounting them onto a hard plate that you can put “road side” inside your enclosure.

I wouldn’t use a metal plate for that, you don’t want metal near your high power electronics.

1/16th polycarbonate would be great though. That’s what I did for my first build and it worked pretty well. The cells stayed safe.

Should I tape the batteries to the underside of the deck and the plates to the batteries with a gap between the plates and enclosure? I can space it with squishy foam or conform the enclosure to hug each cell

Ah I can’t seem to find the thread, but there was a very relevant discussion recently about whether you should mount to the deck or to the enclosure… Anyone else care to chime in?

Depends on preference. its almost 50/50 now

If I had to guess, you misunderstand battery current vs motor current. What calculation gives you 40A cont and 130A burst?

The motors are rated for 65A each and maintaining speed on hills is 1.75kW based on bike calculators which would be 40A at 12s

Just so you know batt current and motor current are different.

ratings are bogus. if you ride in the arctic you’ll be able to stay cool and produce more power. worth knowing what temp the magnets in the motor can get to.

Try riding 1000 miles on a board with the build quality of that robot, it will break. A skateboard may be mechanically simpler but the stresses and environment it is subjected to are much harsher. This is what makes it a very challenging problem if you want to build a board you aren’t constantly having to repair.

I’m a robotics PhD student and I also started out underestimating the complexity of the problem.

4 Likes

Sure, but it’s way more difficult to make an electric skateboard last. This thing would break in 30 seconds under the vibrations that electric skateboards have to endure their entire existence.

2 Likes

I mean that thing wasn’t meant to go 1000 miles so we never tried making it that robust

It’s more of an exercise in dynamics than material science and kinetics

Well when you say “difficult to make” you act like it’s easy to make an esk8. It’s really easy to make one that goes 1km. Make one go 2000km, I dare you. Including water and snow. I bet you can’t do it.

I know I can’t, and I suck a sarcasm :man_shrugging: I thought it would be fun to share a story of fire and stupidity

LoL and I thought the thing you’d say is why am I using metric incorrectly :rofl:

It’s 2Mm, not 2000km

The full name is 2*10^6m excuse you

1 Like

That’s 2E6m where I’m from

2 Likes

Oof, what kind of calculator display heresy is this

Were you two seperated at birth?

3 Likes

Is there a prize for the most confrontational member? Mr @b264 I’m thinking you’d win!