I’m still waiting on mine and I am local…but unless there is a miracle in the production timeline, I don’t see it happening. If I do get it in time, happy to share so that you can ride a familiar board.
Im sure any of is local guys mynself included would host your board until your arrival if you wanted to ship it here via ground before the event.
OMG what the hell have I missed here?
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Too Much… My best advice will be to go back to sleep 
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To find which hubs have more torque?
It’s tough to compare boards when we all weigh different weights. But I really wana race whatever you’ve got up your sleeve. I could always crank my settings way high, haha. But they are nice as is right now.
I’ll try to figure out if I can attend or not. Hope so, should be able to drive down. Says 7 hours, 403 miles… I’ve driven to LA before, and I love rode trips. Just depends were my school is at the time and if I can find a place to stay for Friday and Saturday night.
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We started with why small hubs have issue, which turned into why belts are more efficient then hubs, which turned into a debate about whether 4wd is less efficient than 2wd, which turned into lets do more tests and show real world data, which is where we are now.
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Excellent summary lol!
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At 280lbs I have big sleeves, you sure you wanna see what I got hiding? Hahaha.
If some other people are coming in from out of town too it might be worth pitching in for an AirBNB.
CHURCH*
*depending, there is always a but… but the rule of thumb unless you have tech is 1C
Oh I’ve got tech… Lots of tech. The best tech. No one has better tech than me. Who wants some tech? lol
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Well the answer is most definitely that there are too many variables.
I guarantee that with the same motors and the same rider 4 motors is less efficient than 2. But with 4 efficient motors vs 2 inefficient motors… who knows? Belts vs hubs? Yeah again… the only way to prove it is to get out and ride. From my experience I think the dragless costing ability of hubs would put them into the high efficiency zone. I know that I have done a really long ride on a dual hub board and simmilar rides on belt drive and not made it as far… but then wheel compound comes i to it too. Softer rubber wont be as efficient as hard thane. There are pros and cons of every setup…
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if you have a bigger motor you are more efficient. more motors is the same as a bigger motor.
motor inefficiencies worth mentioning are copper or iron losses
starting at the dragstrip with 50volts:
if you have one giant motors with .02ohms resistance doing 100 amps the copper losses in the windings,decided by I2R are 200 watts. 100x100x.02 equals 200 so 200 watts wasted…and since the total elctrical input with 50v and 100a would be 5000watts, the major loss in the motor under heavy load, copper, is 200 watts and it’s …95percent efficiency.
if you have 4 separate quarter sized motors then each will have probably .08ohm resistance, and the 100 amps will be devided between them, so 25 amps each. current squared times resistance… 25x25x.08 is 50 watts loss to copper losses. times that by 4 for the four motors and it’s the same 200 watts and 95 percent efficiency.
maybe the math is off but the idea I think is right. soon will see.
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I hate to wade into this conversation, since I’m just another non-engineer with an opinion but I’m gonna do it anyway-- lol. From what I’ve read KV doesn’t change torque. Copper mass changes torque at the motor and gearing changes torque at the wheel. The more copper mass you have the more torque the motor can produce. The more gearing you have the more torque the at the wheel you can produce or you can look at this as the motor needing to produce less torque required for a scenario – effectively you’re exchanging RPM for torque. People here keep conflating torque output at the motor with torque at the wheel which makes it especially confusing to then talk about efficiency because only motor torque matters when we’re talking about motor efficiency. If what Vedder is saying is true, that these electric motors are most efficient at low torque and high rpm (but not exceeding 60 k erpm) then lowering the torque needed at the motor is the the most efficient way to run the motors because the motors simply need to produce less torque when ramping up to an efficient RPM, or in other words, gearing allows you to exchange RPM for torque because the wheel needs high torque lower RPM and the motor is more efficient at lower torque higher RPM. For a rider of the same weight and style looking to achieve a certain level of performance, the only way to lower the amount of torque needed at the motor shaft is through mechanical advantage. Increasing the motor size don’t reduce the amount of torque needed at the motor, it just produces more torque at the motor, which I guess is becoming more efficient because you spend less time in high torque low rpm and they’re better suited for higher torque scenarios than small motors.
I’m getting this from: Chosing the right BLDC motor and battery setup for an electric skateboard | Benjamin's robotics
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There’s 2 big factors that effect torque, which is the amount of copper and actually, the size of the stator. The iron in the stator places an important role in the whole thing. Just increasing the stator size while leaving copper amount the same will increase torque. A smaller factor is magnet size. Bigger magnets can create stronger magnetic fields, can being the key word. This does depend on copper and stator size too, and theirs a point where more magnet in a small motor will do nothing more for it.
kv just tells you how many amps you’ll need to get the same amount of torque, higher kv, more amps needed to get the same torque (assuming no gearing). This means more heat, most importantly at the speed controller level. With smaller motors that are inefficient, this will make them worse. With larger motors, not necessarily. The carvon v2’s/v2.5 are actually a similar stator size to our motors now (wider and shorter instead of thin and longer). Longer means bigger magnets, which should help with torque to some degree too. The v2’s though, at 149 kv, did not get really hot at all. But they would overheat 2x 4.12 vescs in under 2 miles, even with heatsinks… The range was also horrible for the same reason. As it is now with hummies new motors, my vescs seem not go above 120 F, way below their limit. So not an issue anymore, though I have my amp limits very high.
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Can’t say it better. Took me time to finally understand the “torque per amp” instead of “torque” thing…
BTW which seller can you recommend to get 20AWG insulated high heat copper wire ? I wanna upgrade my windings. Opened my motors and was like “Damn it is 29AWG or what ???” The real question is : how can I be sure that I’m keeping the same kv ? Should I count number of turns and make it the same ?
Once I’m done I’ll do the redneck way : add more magnets like I’d add cubic inches inside a small block V8 !
EDIT : I got an APS 3300W motor to be delivered. I’ll check the wire diameter since I’ll hack through it.
I use Remington Industries 20 awg high heat wire. Great stuff, and works well.
To figure out how many turns you want, the best is if you can count it while unwinding.
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if you have an inductance meter, or that feature on a good multimeter, you can see what the inductance is per phase and that’s a lot easier than trying to count the windings that are on there already especially because it’s likely a multistrand winding and maybe 4 thin wires doing all the same amount of turns. find what the inductance is and you can replicate it as you put the new on. be prepared to spend many hours removing and winding.
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Thank you for the tips.
Another question : can I bind strongly around the stator or I risk damaging the iron? BTW I have to look how the 3 wires go all around (beats my common sense)
I’m thinking of crafting a tool with the 3d printer to make the turns less difficult (make walls between phases) and pack it tight.
A tool made on the printer I’d be interested to see. So far the best tool I have beyond bamboo skewers is the hole cover on either end that holds the wires from blocking the shaft hole ehen putting it together after winding. Done that too many times. U won’t damage the stator winding. U could damage the insulation on the wire but if the stator is well insulated its unlikely you’ll scratch the wire. The danger is a bare corner on the stator that scratches the insulation on the wire and then u short through the stator.
lve been doing tons of the dlrk winding and terminated wye. A classic u can find a guide for
The biggest reason I don’t like putting these MOTors together and am hoping to slow peoples roll till the new show is theres 1.5mm less room for the end turns to fit. Everything must be perfect and adding the leads is surgery
hadn’t anticipated getting as much copper on had to put the “transits”( wires going between teeth you can see in the photo, on the other side of the motor) to make it fit. but these just sit here and I’m not going to put them in the oven or waste magnets on these. we’re all going for the better big gamble with the new design. god forbid it has a problem I’ll send the 15 of these I have to people I owe. we will see. I’m drinking beer waiting till this coming week. I hear from @evoheyax that the tire’s core are a bit subacceptable and gunna get an aluminum done for sure. thanks and @ralphy for saying it and showing it I think you’re right and don’t want to mess with the pu core… a relief really. ill get those designed and ordered. aluminum is of course the best, and the huge contact area for the urethane to adhere, that much shows true. but I don’t even ride with this and that and wait for the new and it’s just @evoheyax and I translate to the custys
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Your welcome man. Keep at it and im happy to share what i have learned to make this sport safer and more reliable. Once you get everything worked out id like to get a pair myself.