3.2KW / 6KW inline skates (updated June 16th 2017)

Lightweight / Folding / Portable EVs - seats optional
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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Aug 20, 2016 2:05 am

i can't imagine doing powered skates! a quad skater i know was asking me if 4 motors would be a good idea. no way. when you gunna have them running? dying to see these running. how are you going to control throttle and brake? the thread has gotten long now and I don't want to spend all night digging.

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Vanarian » Aug 20, 2016 8:29 am

Haha I get your feelings! I've been waiting for so long it is killing.

I pretty much harass Uwe with my files so his friend's factory can give me updated quote accordingly to the updated files ; after it is a matter of making and ship the parts. I got some of the electronics, and since I don't have definitive quotes for the parts, I've kept the money I saved just in case it would be more expensive than I think. I can't think that I'll get running before October since the frames are not ready and I also need to think about shipping delay. I lost 5 weeks before getting my RE-VESCs thanks to "La Poste" which sucked up...

That's a shame I actually need them to ride accross the city!

For control I purchased months ago two acceerometer/gyroscope chips, I still need couple force sensors, and probably couple hall sensors too. I want an average board to calculate the different forces applied through the skates so you ride them like classic inlines, but you get boost!

AWD is rideable if it respects one rule : the front motor starts driving first then the rear motor can follow, both must not start at the same time. Even if delayed by small timing, it can do the trick and prevent the "kick in the heel" effect. Plus with the sensors, getting the rear motor to slow down before the "kick" acts is a piece of cake, you can never achieve this kind of analog feeling with a remote.

Nah my main complaint is weight, I'm lightening my frames currently. The lighter, the better... After gaining on the frames weight, I'm also searching light freeskating/slalom boots. Trying to make 10S2p under 2.5kg :lol:
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Aug 20, 2016 11:35 am

Wow that's awesome I didn't know all that's going into these. Really like how ur going for a smooth natural ride. I hate when people tell me to be careful so I won't :D


We might end up using the same mold factory!

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Vanarian » Aug 20, 2016 1:32 pm

Thanks! Yea that would be pretty cool. :wink: Molding is also a tight research, hard to get the less possible molds. For now I fear I'd need at least 4...

As for the frames, I just realized something is basically wrong, if I want to get badly the "speed slalom" layout working I need to rework EVERY parts, I'm even thinking of making from scratch... could be quicker than before, maybe stronger design also.

I thought of it after finally succeding to slim the frames to 295gr with motor mount, and down to 240Gr non motorized. That was precisely my aims, I don't think I can make lighter without compromising too much structure.

Bit off topic, seeing your motor developments makes me think of asking curved magnets to E-Max, for now it is flat magnets and it would surely benefit to the efficiency (less drag) ?
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

Hummina Shadeeba
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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Aug 20, 2016 1:44 pm

unpowered motor drag I guess you mean. I think if you have more poles on the stator it's less drag when unpowered but curved magnets maybe a little. I dont know. but doubt youd want to ride those unpowered anyway

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by chinyp » Aug 22, 2016 12:57 am

Hummie, since you are experienced on getting prototypes, ya think aluminium will just cut the job? or just go for steel? Any suggestions of type and grade of materials? I'm now searching for local CNC for convenience (if its affordable)....
Van, I'm still waiting for my parts lol, the 68mm stator was said to come this week (tho delayed for a month already)....and most probably im gonna get square connecting cuts to construct my frame for the time being....delay, delay, delay....I'm dying here :cry:

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Aug 22, 2016 1:58 am

Honestly I never rode the aluminum shafted motors I have long enough for them to show deterioration and they even got run over by an suv and it's on video. It depends who u ask and if you ask a machine shop it's steel all the way. The cost difference was surprising close and with steel there's no question and not going to deform for sure. I use 1020 steel as it has great flux ring characteristics too and strong enough and almost as cheap as aluminum. I'd thought it'd be nice to have pressed parts instead of slide and steel is necessary for that but now I'm not so into that with the high heat retaining fluid and even if they do loosen a bit it's steel and it doesn't matter. There's stronger aluminum out there but I didn't want to risk it. The thermal expansion of aluminum can be a problem too especially as you can hit high temps with little motors

I don't know both your plans but i know vanarian has small motors. Heat will be an issue unless it's kept to lower power, but then maybe you don't need much power on skates, I wouldn't want it. I just spent moments ago spent my bucks getting bigger motors made instead. Longer. If you're going to go to the trouble of making a sound mechanical structure I now feel it's worth it to make it a decently powered motor too. What I have now I can kill anything, the evolve gt is no match on hills and definately not on a flat but I can't sustain it because the motors are small and I have to rest after a while of continually pushing them. the heat causes problems as polyurethane will deteriorate. I'm getting nitrile and hydrogenated nitrile tires made. Car tires. Can take heat and have great physical characteristics. I use two motors with 4725 stators now but just went to 4770 and bigger bearings.

But maybe look at other motor designs other than standard radial outrunners. More torque could be had and maybe it would suit ur designs better. Radial or some cutting.edge transverse flux or something.
Anyway my final thoughts are if you go to the trouble to make the mechanical structure it seems worth it to fill it with enough motor so you're never thinking about it. Running hot is inefficiency. 20celcius vs 120celcius you increase the copper resistace by 40%. And who knows what mechanical problems it could cause ...plastics don't do well with heat. You'll want to do those mountains or something and u don't want to be limited. Then again on skates I wouldn't want to go over 10mph. I say that now but if I had some high powered skates under me I bet I would want to do mountains

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Vanarian » Aug 22, 2016 8:47 am

Keep going chinyp, I know what it is to wait for a long time, it is killing inside but keep going!

Well Hummi we have and don't have same problems at the same time. For example I don't need to think about heat deteriorating my wheels because there is no direct contact with the motors, so there won't be abnormal heat. With my design the wheels will sustain the regular heat of non motorized wheels.

I can afford to run aluminum axles instead of steel axles because :
-it is tightened on both ends of the motor, so basically it acts like a standard aluminum axle, which is already what is used in normal skating. It won't bend unless all the wheels bend axles or break them. That's not the same than having to face forces through only one end like a skateboard axle.
-it is also the same 8mm dimension so that's a direct fit.

As for heat, tests will tell me what I can expect and what I can't, I want to run them at factory rated power in the end.
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

Hummina Shadeeba
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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Aug 22, 2016 4:04 pm

do you have a drawing of how the motor will be mounted in the wheel? I don't see it in the thread and am wondering. Please take my thoughts as constructive criticism only because I want you to succeed with this and my thoughts and questions are with the intention of getting it to be the best it can.

3.2kw or 6kw is a huge amount of power. the motors may be rated for that but that's surely a claimed peak power only that will be far far from what they can do continuously. Peak power claims are questionable as how are they defining it? I will hit 2000 watts as seen on a wattmeter when pushing up hills and that's to two motors and far from sustainable. that's two motors that are 4725 stators and you'll be using (2) 4020 I think. How to define the motor's continuous ability is also questionable. all motors. IN Antarctica you might be flying along all day.

heat will transfer through whatever is around. If it's an aluminum shaft that the stator is on that's an easy transfer and that's what it will be going through. and then from there...maybe use ceramic bearings? the hottest part will be the windings, that will transfer to the stator, and then to whatever the stator is sitting on. I don't know if you're going to print your parts or use a mold and pour them but maybe look for super high heat material, and it's out there, because it could be the weakest link and will ultimately be the limit on the sustained power you can put to the motor. you definitely don't want to have the structure compromised by heat.

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Vanarian » Aug 23, 2016 8:03 am

It's alright I didn't take it on defensive POV, you've always been helpful with me :P I'll pm you the structure pics.

Eventually when you ride, bearings get hot from friction but there is plastic between a regular inline wheel rubber and the bearing, and thermal conduction of the plastic is not very good either so the PU mainly fights it's own constraints.

I get clearance between the plastic of the wheel and the motor (some time even more space), at worst there is still clearance between the motor and the rim can, plus airflow pumped through this empty space. I think of putting some thermal paste to channel heat specifically there, so it is chased out by low pressure.

I got two motors in mind, first is 1.6kw (smallest), second is 3.2kw (largest) and I'll always run either 2WD or 4WD. So smallest setup is good for 2x 1.6kw, next is 4x 1.6kw, then 2x 3.2kw and finally 4x 3.2kw ; there is a mid way motor good for 2.5kw but price and size wise it may not be worth adding it.

I can't tell how much of the power I'll be able to pump continuously with weight, tests will tell me.
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

Hummina Shadeeba
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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Hummina Shadeeba » Sep 03, 2016 2:34 am

Was thinking about powered skates. I used to skate a lot commuting.

I feel like you can go one way or the other: a light skate with small range and working as an "assist"as u skate with the cool controls u planned, or someting that weighed more with batteries/power but the weight making it not be worth trying to lift feet to actually skate them and you'd be standing there on the throttle the whole time. ID like to see the former. someting that could allow u to skate normally with maybe 2 pounds more max per skate and just a low power assist. Maybe 5mph max unassisted.

Maybe super high charge and discharge lipos u could easily charge with a plug into the skate.

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Re: 3.2KW / 6KW inline skates (updated August 13th 2016)

Post by Vanarian » Sep 03, 2016 11:06 am

I feel you there, lighter is better.

It is difficult to determine when a skate becomes heavy, for example I started skating seriously with skates weighing 4.4 lbs each, then since the Doop I must be more or less at 3.8 lbs each.

My current 1600W setup is at 5.5lbs and 3200W at 5.9lbs, so I remain somewhat in the 2 pounds overweight you like :wink:

The more heavy versions would be for 6Kw and 12Kw and for these I was thinking of maybe a tweaked version with longer wheelbase (same than racing skates)? Still need to determine it.
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

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Re: 3.2KW / 6KW inline skates (updated June 16th 2017)

Post by cocoon » Feb 08, 2018 12:32 pm

Hi! nice job man! im also developing engine for inline skates.

I hope i will have working prototype assambled in next week. It is special kind of motor.. wheel is part of motor. Stator is mounted on the chassis. Setup is very light.. we will see about power and efficiency. I managed to mount powerfull neodium magnets 4,4 kg on wheels.

I will make my own controller from arduino uno. motor will have 2 hall sensors.

simple way would be to contact u-motor company and order custom 100mm x 20mm hub motor. They are quite flexible as i know 😀

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Re: 3.2KW / 6KW inline skates (updated June 16th 2017)

Post by Vanarian » Feb 08, 2018 8:40 pm

cocoon wrote:
Feb 08, 2018 12:32 pm
Hi! nice job man! im also developing engine for inline skates.

I hope i will have working prototype assambled in next week. It is special kind of motor.. wheel is part of motor. Stator is mounted on the chassis. Setup is very light.. we will see about power and efficiency. I managed to mount powerfull neodium magnets 4,4 kg on wheels.

I will make my own controller from arduino uno. motor will have 2 hall sensors.

simple way would be to contact u-motor company and order custom 100mm x 20mm hub motor. They are quite flexible as i know 😀
Hi cocoon, thank you for your support ! :wink: God I realize I haven't updated this thread in ages.

I'm curious to see which solution you came with, and also which layout / wheel sizes you're going to use ? Will it be a 1WD ? Stator directly mounted on the frame may be a nice solution to dissipate heat, but your frame needs to be strong ! Will it be remote or remoteless ? Did you settle already for a battery ?

When you mean 4,4kg, do you talk about weight or torque? I look forward to learn more about it !

I've kept working on my skates pretty much continuously for the past years and damn there were (somewhat still are) challenges. Should update here ASAP :D
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

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B

Post by cocoon » Feb 09, 2018 4:58 am

Hi cocoon, thank you for your support ! :wink: God I realize I haven't updated this thread in ages.

I'm curious to see which solution you came with, and also which layout / wheel sizes you're going to use ? Will it be a 1WD ? Stator directly mounted on the frame may be a nice solution to dissipate heat, but your frame needs to be strong ! Will it be remote or remoteless ? Did you settle already for a battery ?

When you mean 4,4kg, do you talk about weight or torque? I look forward to learn more about it !

I've kept working on my skates pretty much continuously for the past years and damn there were (somewhat still are) challenges. Should update here ASAP :D
[/quote]

Hi!

motor will bi similar like this. https://www.youtube.com/watch?v=JkwLpAAfBVI But i will have rod magnets in the wheel hub and coils outside. Magnets are neodium 10mm x 20 mm. Magnetic force 4,4 kg. I will have 2 C shaped coils (they work like 4 coils) driven by hall sensors and arduino. If my calculations are right motor will have high amout of torque.

One coil force at 4mm from iron (magnet) is 156.008(Lbs), :shock:

wheels are 110mm. Skates are https://goo.gl/images/Rkw4YA (i got them cheap from my brother :))

For test there will be only 1wd per skate, but system is upgradable. First i must find out if this works at all :). This weak i will assable it and put it on test bench.

Im playing with idea for long time but project is in beggining phase, so i dont have all details figured yet. But with arduino controller posibilities are not limited.

For battery im leaning towards battery backpack. I dont like skates to be heavy. 10 Ah 36V should be ok for start.

Please update your progress :) did you already drive on them?

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Re: 3.2KW / 6KW inline skates (updated June 16th 2017)

Post by cocoon » Feb 10, 2018 3:25 am

https://www.youtube.com/watch?v=6m_iIbX0gmA i see the future in this type of motors (axial flux with permanent magnets). It is very easy to cool the coils becouse they are on each side of the rotor and not moving. Even some cryogenic cooling is possible in future. This can boost engine peak power to 1000 kW :shock:. This can be possible in hybrid LNG (liquid natural gas) semi trucks or cars. The liquid lng has to be avaporated before use in combustion engine and this can be done in engine similar like YASA. In this way motor can be cooled to -158°C. Than you just need monsterus battery with approx 1500A peak and 700V. ehhh daydreaming :lol:

https://www.youtube.com/watch?v=lS1fWUg2oDY

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Re: 3.2KW / 6KW inline skates (updated June 16th 2017)

Post by Vanarian » Feb 17, 2018 7:07 pm

cocoon wrote:
Feb 10, 2018 3:25 am
https://www.youtube.com/watch?v=6m_iIbX0gmA i see the future in this type of motors (axial flux with permanent magnets). It is very easy to cool the coils becouse they are on each side of the rotor and not moving. Even some cryogenic cooling is possible in future. This can boost engine peak power to 1000 kW :shock:. This can be possible in hybrid LNG (liquid natural gas) semi trucks or cars. The liquid lng has to be avaporated before use in combustion engine and this can be done in engine similar like YASA. In this way motor can be cooled to -158°C. Than you just need monsterus battery with approx 1500A peak and 700V. ehhh daydreaming :lol:

https://www.youtube.com/watch?v=lS1fWUg2oDY
Sorry for late reply! Motors look a bit big to me but sure there's something to be done with axial design :wink:

If you look into a backpack solution think of adding a caps bank to smooth down the surges. Sure it can be a quick solution. I focused on integrating everything around the skates themselves for compact and ease of use, but performance wise shifting the weight upwards is good. Could do something about it and keep the cables short.

Haven't ridden mines yet, I got parts split around the house!
I needed to turn Air Gear stuff into reality so I am making this!
-+Electric inline skates - no remote control - weight / angle sensor - hub motors - one frame for all wheels sizes between 80/125mm - from 3.2 to 12 KW :mrgreen:

Rollo Ergo Sum!

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