Archived: the OG noob question thread! 😀

[drone001]

cool. I’ll read up on it some more tonight…interesting stuff.

[Monomas11]

Isnt the ground on the ppm enough?

[Venom121212]

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Originally published at: http://dev.esk8.news/2019/01/25/esk8-iq-the-math-and-the-science-of-electric-skateboarding-part-3/ Hiyas, nice to see you gluttons for punishment again :). This is the final installment of Esk8 IQ. What does that mean to you, the reader? It means this is where we tie all the previous info together and make it useful. It’s important that you understand the aforementioned concepts or none of this will make sense. I am about to cover ERPM, KV, Voltage, Watts, Char…

This will help you understand what motor kv is specifically.

Motor gearing and kv work hand in hand to balance speed and torque… Changing one will affect both.

Generally speaking,

Low kv motors are better for torque
High kv motors are better for speed

[IamLee]

Tested today. The temp remained below 53c. I tested on full charge and cold run too but it just won’t climb the steepest hills like it used to. Funny thing is that I was able to zip up a hill that I’ve considered really steep (Hyde street at Fishermen’s Wharf) Oh well, it’s probably the battery showing its age.

[MysticalDork]

If it’s not temperature related, then you can also check the battery voltage under load - If it sags low enough to reach the low voltage cutoff, the vesc will reduce power as if the battery was dead.

[Customesk8]

Does this regen seem ok, is there any risk that it would be able to overcharge the battery if I’m going down hill and breaking alot?

I ask as I checked voltage after a ride and before the ride it was 38v and after it’s 41v surprised at how much it recharged

[MysticalDork]

The regen current “safe limit” is dependent on the battery pack you have. With those 5Ah Turnigy packs you’re using, the maximum allowable charge rate is 5C, which is five times the capacity. 5 times 5Ah is 25A, so that’s what I’d set your max. regen to.

When going down a long hill with a mostly full battery, if the battery reaches “full” due to regen, the vesc will stop putting more current into the battery to protect it. This has the unfortunate side effect of the board losing all brakes, as the braking energy has nowhere to go.

Moral of the story is, don’t go down hills with a full battery.

[Customesk8]

Thanks man will change that, very scary to lose brakes on the hills I am going down!

[MysticalDork]

Agree there. I live on a hill, so I learned that the hard and scary way.

[Tbone]

@Tbone

upgraded my 4.12 esc to a 6.x. It is a little bigger and does not fit in the back of my enclosure. Any concerns with stacking it on top of the battery. I may have room for a small standoff to minimize the direct contact with the esc, but I am not sure how hot the outside of the aluminum housing gets and if it is an issue for the battery. Thoughts?

Bump…

[wafflejock]

Definitely not ideal since putting the heatsink right up against anything but a fan pushing air over it isn’t really ideal over the long term, the extra mass will act as a better heat sink initially but under load over time the heat will just build up with nowhere to go. Believe the vesc default settings have soft temp set to 85C for the PCB/MOSFETs and hard temp at 90C so the temp shouldn’t get higher than that so anything touching the heatsink just needs to deal with that or you’d need to adjust the temp settings to keep it cool enough but would be giving up hill climbing and/or working in warm ambient temperature.

Running the cells warm is actually good but hot is bad it’s a balancing act for the chemistry in the cells to optimally deliver the power stored in the battery (ask any Tesla owner in a cold climate)

[Jamie42]

Yeah that should be good. What about the baudrates?

[Monomas11]

I Havent tried yet. Will do it on the weekend

[annihil8ted]

Is there a guide or tutorial on how to do conformal coating? I’m looking to conformal coat a motor sensor pcb.

[kook]

follow manufacturers recommendations, and @b264 's many posts…

[Sebi]

So, if I want to have a backup remote for my board, but don’t want to open the enclosure to re-bind every time I’d switch between the remotes, is it even possible?

I’m using a gt2b with an orange housing for better reliability.

[kook]

some receivers and remotes will allow multiple transmitters/receivers to bind with them
I “think” gt2b has the capability, but you can try it of science and learn your remote for yourself…

take your second remote and go thru the bind process and see for yourself if it will allow multiple transmitters to bind with a single receiver

[Venom121212]

I’m ordering pvc heat shrink battery wrap. The face the wrap will slide over is 18mm tall by 130mm wide ( 1 cell high, 2 cells long).

What diameter pvc do I need to have the right shrinkage and fit?

I was going to order 150mm but figured I’d check first.

[b264]

You can get it anywhere inside a motor except the bearings and it won’t hurt anything. Keeping it out of the mount threads will make your life easier.

If it gets in a bearing, it will suck. A lot.

[Ace]

@mutantbass

LMAO, I used an old camera lens case + empty coffee cardboard pack that I bent into shape. Have travelled through 4 airports with it and zero problems. They don’t even look at it twice. Its weird how I make a far bigger deal in my head than it is in real life.

Can you get more than two on at once? My trampa can take two, four or six of those guys. Six would be bad ass to fly with