Fliess - Bulletproof DirectDrive

@uigiroux, hard to say about speed, because I never used dedicated (read accurate) gps to measure it. I always use Endomondo though, and I tend to trust the measurements now, because I always hit 62-63kmh max exactly. It’s on 83mm wheels. Don’t remember how was it with 90mm Flywheels. KV - sk3 149kv switched to star one motor. Another one rewound, so cannot say exactly. Please check hobbyking for watts if you trust the data there :slightly_smiling_face:

Get someone to ridea car next to you and add remove 2-3kmh from that

@Acido, well, then if ~40kmh on 90mm wheels going up 20% hill is possible https://youtu.be/zg72OSutHYI, then I think my phone doesn’t lie. It just cannot do it so precise so many times in row :smile:

Hell thats steep, I would basically die going by foot anywhere , like my max hill is 10% and that road leads to the edge of the city where is nothing :smiley:

Great project man, really like it I would love to reproduce it but its just way too much of time and effort for me, and im lazy…

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I know it’s early, however I would like to nominate this for thread of the year. Amazing work. @fliess would you be willing to commission a set?


Yeah about how much would these run? I should have Working prototype in a month max and it’s gonna be crazy powerful, and I’m planning on selling sets as well. Curious what the cost will be around, though my stator will be really high quality with silver windings and one single wire so very thick and perfectly wound. Can’t wait!


I’m curious now if I should go above 100kv for mine at 4000W…

Uuhm… Do you have any idea of how expensive that silver windings would be? Silver cost around $0.5 per gram, and you’ll need around 75g of silver ( eqalient to 50g copper) if i remember right.

And also you cant just have one strand of wire, thats not how it works. (Again not 100% sure)

Yes, the company I’m dealing with does that and it’s not as expensive as you’d think, and it cools by 30% better. Also they do use one stand.

Dude keep me updated on these I’m in if you need a beta tester with super hilly surroundings to really put them to the test

Thanks I’ll keep that in mind. I was just thinking about that just yesterday how I’ll need beta testers to give feedback.

@ATLesk8, haha, let it be then a thread of let’s say 2012 year, because there is no innovation here… No sets to commission is possible dude, at least not by me.

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Just made a short ride to see again how’s battery performance when cold and measure a speed. Interesting thing - I was pushing to limits 50-60% of the time, so the battery itself was always slightly warm. Still, the range is ~20-30% less than usually.

Not as shiny as before anymore :smile: But I think I finally have my dream machine…


You mean silver transfer heat 30% better than copper. Do you have a source for that?, cause its completely wrong.

Silver windings is usually just used in small motors, where the weight/performance ratio is vert critical…

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are you sure…? (I know it is in german, please dont flag it, it can be understood even if you dont know the language)


Die Wärmeleitfähigkeit in W/(m*K) Kuper ist 401, Silber ist 429 wobei hier der grössere Wert die bessere Wärmeleitfähigkeit darstellt.

The Heat transfere rate in in W/(m*K) Of Copper is 401 Of Silver is 429 The larger Value in this example in the better Heat transfere rate.


According to the sources I’ve used, silver only transfer heat better by 5%.

30% seems ab bit off :D, according to @bimmer’s numbers it would be 7% better

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best build log I’ve seen yet; thank you, @fliess. This extractor is absolutely brilliant.


That’s what it says on the motors that use it in their stators. I have two screen shots, the first addresses the silver, and the next, though it talks about their copper in a different motor, it shows the winding of thick, 1 strand wire winds.

I may be wrong, but I was going with what the site claimed.

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