NOTE : Last updated by April 2018 - for quick infos please scroll down to "III/Current state of the build" or last page; if you have time look through my development or my thread for more detailed updates.
Hi guys, welcome to my build thread
I/ What is this thread all about
Updated pictures to be posted shortly!
Thanks to ES awesome community who generously shares key knowledge. Special thanks to JohninCR for his teachings in motor, Vedder for his awesome work in micro ESC, torqueboards for his help on understanding power distribution/use with multiple motors layout, and everyone who kindly helped me on the way !
I've decided to create what I call Ariane Treks (and for this build thread, AT-One). Shortly, a realistic and practical application skates imagined in the manga Air Gear (yep). It consists in highly powered electric inline skates. Take everything you love in skates. Then boost it all. When you want something and you can't buy it, you build it.
B/Without control, power is nothing
You should not control inline skates with a RC transmitter or a command like you do with a longboard. It is not intuitive, your reactions are delayed, you can't predict what you are doing because your legs suffer from an artificial rythm you try to control with your finger... instead of putting up the rythm like you normally do when you ride classic skates.
Thus I aim to develop a hands free control for my skates. Simply let your body do the job and focus on riding. The skates must obey this rule. That's my actual goal, to make the rider forget about the electric stuff and just enjoy the adrenaline.
C/So, let's talk numbers, what power do we talk about? New edit
My current rig is built around 2x custom E-Max GT4020 50mm. More motors options and layouts in the trunk, but you have to start somewhere.
The controllers used are now based on Vedder's VESC hw6.4, which is pretty much unkillable (even more at this limited power level).
The GT4020 are 1600W factory rated at 8S / 33v. Nice power to weight ratio and top speed of 50km/h capable ; 0 to 40 in 5 seconds capable and you remain under the 1600W limit. Now I'm tempted to prepare an upgrade to 12S /50v because f*ck yea this voltage gives awesome specs on compact sized drivetrains. BTW my mule units are under mods. Wider gauges, extra cooling. Should define a high continuous power rating and nice torque.
Honest, it is more a matter of weight and end cost here. Still need to determine the max climb ability.
D/Going fast is cool. Being able to commute for the day and ride back home is cooler. 2018 edition
Let's talk batteries ! This is specific to AT-One.
1) LG HB2/HB6 1500mAh are what I currently have at home. It remains my first choice for pack assembly.
Why ? The LG HB cells are very cool, I mean cold. They are capable of 30A continuous discharge while keeping a temp lower than a Samsung 25R at 20A continuous discharge. You can easily hit the sweet spot for powerful compact and travel-safe packs with them. You can manage cooler temps and get longer cycles.
2) Samsung 30Q 3000mAh ; once higher voltage has become relevant, this cell has too ! Nice voltage pack, and good discharge with enough parallel. Range is more than doubled.
Realistic battery layouts based off these cell models are :
- 2x 8S2P HB2 (2x 33v 3Ah)
- 2x 12S2P HB2 (2x 50v 3Ah)
-2x 12S2P 30Q (2x 50v 6Ah)
Note that with the last iteration, space has been raised so bigger batteries are possible. What remains is weight, I don't want heavy skates.
More stuff on the table to finish, like a break chopper to never be bothered by regen braking under full charged battery.
E/Custom it like you stole it. Hub motors and one frame to size them all. 2018 edition
Have you ever wanted to not be limited by any choice of boot? Be it 165, 180 or UFS standard? If so, why compromise ?
I'm bringing "Universal" to a new standard. Just choose your favorite style boot, from aggressive to slalom-like, marathon or freeskate boots. I personnally started from Roces M12 and now am working on Doop Freestyle 3, that's how versatile it is.[/u]
The frame is also designed to accomodate the powertrain, not the other way around.
It comes loaded with a quick swap system, so mounting different boots with minutes (or seconds ? depends how fast your hands are) is now possible.
Up there I said I was developing hub motorisation. I worked my way through to get motors with low profile between 20-30mm width to fit right inside the skate wheel. That's where the custom GT4020 and siblings models come in play.
Hubs have serious qualities. Non-existant drag. Smoothness. Compact and little maintenance needed.
As for wheels sizes ! I'm a streeter, I like short wheelbase. And I still want my ultra low center of gravity. So I ended up with the following compatible sizes :
- 4x 84/72mm wheels (and a mighty H-block
... yea, it's back in the game !)
- 3x 110mm wheels (243mm and a sexy slalom style base!)
These offer a gorgeous geometry under the feet and ultra low center of gravity.
What is also straight compatible but less interesting from a handling POV :
- 4x 84mm flat
- 3x 125m
F/Last for the least, what does it weight : In progress
I started this with Roces Majestic 12 from my good old days. Then I upgraded to Doop Freestyle 3 because I needed more versatile and lighter ride. Yet a bare boot is 1kg100. With a Supra sneakers inside it rockets up to 1kg600. That's heavy right.
So with my heavy 1600gr boots the 8S version accounts for 3Kg per foot without lightening mods. Seems too fat right ?
Here is the feat : weight of March 2017 hit 2.55kg per skate for 8S model without lightening mods with a light freeskate boot.
It has become, in fact, lighter than most EVs I know. So the difference in sensation between a classic skate and these will mainly be about the motor power, not the extra weight.
That's all for now, thank you for reading till there
II/ Current state of build
-Custom 85Kv low profile motors mounts are working
-Hub rims are SLEEK as EFF
-Hub motors DONE
, aluminum version on the way
-Frames got re-updated
, new frame is at home ; alu proto frame is being produced
-Soul plates and added height are... gone ! Lowest possible achieved (just like non moto skate), and purest handling.[/i]
-8S4P LG HB2 batteries at home
-Custom solderless battery modules ready to roll
-New controllers based off VESC hw 6.4, these are monsters in the size of a CB card
Need to update this topic... with pictures and more stuff.