@rich I certainly do not wish to kill myself, only to have more fun than legally allowed. Considered “Widowmaker” but i’m not married yet! Then one of my friends came and after some questions said: "Dude, this thing could go into Encyclopedia Britannica as very definition of the word “OVERKILL”. So it sticked. @hazza Pictures due in few days, when progress is done and photographed. VESC 10 PCB manufactured and in route from china, also today some machining will be done due to free time.
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There’s a thin line between achieving something awesome and standing in line for a Darwin award.
That thin line is called speed wobble on a high velocity board. 
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how will you account for the heat the in hub motors will get… i can only assume 20s will absolutely kill the adhesive holding the magnets in place with the heat produced…
It is not he voltage that heats the motors but the current. And you go high voltage to decrease the current. Another beast is that at 12S i would have to wind 1/2 turn of wire per pole, which is hard to do!
Wanted some photos here you go.
Rendered design for deck mould, top and bottom. 30cm wide, 110 cm long, 3,5 cm curve.
@FullMetal_Machinist maybe I am pointing out the obvious, if so my apologies.
I just want to make sure that your truck angles front to rear are not symmetrical. This is what creates speed wobbles. And if you build the deck from scratch you can put in adjustable angles.
Standard longboard trucks with be like 50 deg front and rear. But for down hill racing people run the rear at a much lower angle. Like 50 front 30 rear. This eliminates the oscillation that causes speed wobble.
But for crazy fast maybe you can run lower angles like 35 front 15 rear for more stability.
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As i mentioned some posts ago initial setup is 30/30 degrees, if it needs adjusting then angled spacers will be cut using bandsaw and put between truck and deck. All depends on how the board will behave.
ok cool, low angle is good. 
But symmetrical angles front and rear will still be a problem, (it will just happen at a higher speed) its what induces uncontrollable oscillation.
Today was the metal shavings day. Two more hubs got machined, one to go.
As you can see hub consists of two parts - inner aluminium part and steel flux ring.
They are connected by a M90x1,5 thread which is machined directly on a lathe - no tap required. Tap of this size would have cost over a 1000$ and is impossible to use bencause of enormous torque required, so i did away with regular pointed blade. Parts will be glued together with special industrial adhesive and final 0,5mm of steel removed afer centering the hub. This is the job for tomorrow.
Test winding of 3 turns per pole was made using colored wires - each color is different
phase.
Magnets were glued inside first hub
and then motor can be test assembled
Using drill press method exact motor KV will be determined and final winding will commence in a few days.
Did i mention metal shavings? Like a barrel of them?
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Awesome stuff man! I’ve always had an eye on those big tiger motors but I never expected them to show up in an esk8 build!
Thinking of obstacles to your goal maybe you’d need two sets of tires, one super low duro for acceleration and one hard pair that could stay on the motors and not be thrown off from centrifugal force. Higher voltage won’t make motors run cooler. Someone was saying otherwise.
That’s a huge amount of poles in the rotor. Will u be able to stay under the esc erpm limit at such high speeds?
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Use the link to filled calculator data i posted yesterday. erpm at top speed will be just 88.000, about half of original vesc limit, no idea how higher my improved design will go. No problem here. Higher voltage will make motors cooler only when motors with lower KV are used, here running lower voltage was not an option for 2 reasons:
- at 20S i will run 500-600 battery amps, if i switched to 12S i would have to run over 1000amps, thicker wires etc. Max motor amps combined 1400 amps, with 12S would be over 2500 amps, wires as thick as a middle finger.
- At 20S i estimated 50 KV needed, which should be 1 turn per pole. Will know exactly on monday. At 12S i would need 85KV, and i cannot wind motor pole with 0,6 turns of wire.
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Are you going to use liquid nitrogen for cooling motors?
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All components of this build are so oversized and overpowered this is no longer a joke, just pure overkill. Textbook overkill. For “normal” riding everything will operate at under 10% rated capacity and no heat buildup is possible, i consider lukewarm is worst that can happen after long ride in woods at 50 KPH. For “racing” even 1/4 mile would take like 10 seconds. Can you burn a motor in 10 seconds from heat buildup? i dont think so.
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Well, like I mentioned in my first post on this topic this build denies physics 
My 80100 with not even reaching 20km/h heats up so badly with open ends full cooling, aluminium heat exchanging from gear drive and etc 
Your motor is under metal jacket, and aluminium hub with big ass rubber over it without any ventilation. You will be able to fry steaks on it. (P.S. you know that magnets start losing magnetism at around 80ºC)
Also learn about duty cycle your motors will consume your max current at speed zero as the weight and large pole number will make it super hard to spin it now make it 4 of them.
Another thing you know that >60V DC is lethal and you know spark gap requirements for currents over 200A on higher than 60V?
EDIT:
Magnets with the N52 magnetisation have a maximum working temperature of 65°C.
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… I love this place, that post just made me smile so much 
I considered that for hardcore vesc cooling, but just cannot imagine using it outside a bench test
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I thought thats what esk8n is. Denying physics?!
Motor will be wound with 12mm2 of copper per phase which is thicker than 8awg. It is designed for 350 amps. Casual riding at 20 amps is nothing, Entire motor loss will be like 10 watts. Imagine you drive your board at 5 amps - will it be hot? A lot depends on steel core quality - it gets no better than tiger motor. As for 60 volts you do not even make me laugh. I am certified elctrican for 10 years, got shocked more times than can remember. Once discharged big ass capacitor at 3000 volts through my hand, was missing entire tip of the thumb. Took 6 month to heal. Not my mistake. Another time through-air discharge from high frequency coil caught me from 1,5 meters afar. Took almost a year for the hair to grow back. I still live and have all limbs in proper working order. Now i own electronic assembly company and make my own vesc. You are teaching a father how to make a child.
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Well professor mechanist you know better 
Good luck
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