Well, I can speed check and brake the analog way, so I’m not too scared of this part.
As stated the motors will be more of a chairlift & emergency brake
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you don’t like the club rules?
You can calculate the exact kv by taking erpm, dividing it by poles (or pole pairs. I don’t remember) and then dividing it by voltage.
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Been really considering this for the deck. Seems perfect for my needs. Also very appropriately named for this “planning phase” lol
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35" is fucking small for a drop deck. You’ll be lucky to fit 12s2p on there
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I was actually considering 12s2p for a config.
I tested this the other day on a vesc powered drift trike. Went down a big hill and got up to 115% duty cycle and hit the regen brakes.
I discovered a few things.
With the throttle at full, it will stay at 95% duty cycle and won’t speed up when going down the hill. If I let off the throttle it will speed up and applying full throttle will slow it back down to 95%
Hitting the brakes at 115% duty had a bit of an initial jolt then worked normally. I’ve noticed the same behavior on an esk8 a while back, but I was only slightly over 95%
What I’m not clear on, is if the motor spins so fast it surpasses the mosfet voltage rating, what will happen. Does it immediately blow or do you have to apply throttle/regen for it to blow, or does nothing happen? In my tests I was well below the mosfet voltage rating even at 115% duty.
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Not expert on that part, but the big issue I see is the lack of current control, depending on your system, you weight, motor Kv, wheel size, gearing, hill grade, that sudden brake when you hit the point it start braking can be way over the it’s current rating
For a board I can see this ending badly, the first jolt because it started braking followed by a release because it blew up
There’s a solution here just build normally.
You want a high top speed, so use a high voltage battery and esc.
18S or 20S that’s the question.
There’s always the solution to use a higher Kv motor to make sure you’re airways under limits but climbing hills with say 2WD and high Kv without reduction can be a bit… Complicated
Example : see Carvon 2WD old models, these were 149kv.
Good for high tolerances in top speed but torque wasn’t made for hill climbs compared to what you want to achieve!
What if I want high speed due to gravity and no rolling resistance?
I think you’re missing the entire point of this build thread.
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I don’t find much difference between 6353 190kv on bn drives and my dd. There’s a bit more rolling resistance, but with straight cut you’d be fine.
My gear drives did hit too many stones on 85mm wheels so may go 90mm or 100mm and a big drop down. Maybe an evo deck could fit your needs.
Keep in mind there have been issues with the stormcore 100d at 205kv.
Yeah but that’s from the perspective of motors pushing a board to a certain speed. Not at all the ethos of this build.
This whole thread is about going a speed that’s probably higher than what the motors could do when powered and still wanting to use them for brakes.
No, I can freeroll down small hills and pickup speed
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this is about freerolling down large hills over 40km long, and picking up a lot of speed. like a lot.
This whole thread is about going a speed that’s probably higher than what the motors could do when powered and still wanting to use them for brakes.
Your asking for something that can’t be done safely. The rules don’t change for your use case, you need high voltage, high kv, low ratio, and big thane. You can probably pick 3 and achieve your speed goals you cannot safely push a board beyond it’s electrical limits.
low diameter is better for DH actually. as stated multiple times, yet I guess not explicitly enough, I’m aiming for 1:1 ratio.
this can totally be done safely. if you read the OP it references where you can watch people do this safely. (but without motors)
I have read the whole thread the options presented are high kv direct drives and low ratio (1:1). This can work, but I have doubts about safety. A high kv dd will not give you strong enough breaks, which you seem fine with, however i would never take DDs to these speeds due to durability issues. DDs are loads of fun, but not exactly known for their safety.
With DDs take into account that if you do a lot of sliding, the wheel diameter becomes smaller. As you already have very little clearance with most DDs (as they are 68-70mm in diameter iirc), you might need to replace wheels much more frequently than usual.
This board and these DDs seem like exactly what you are after. The motor diameter is smaller than with other DDs
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