Electric Longboard

OK, you guys have probably seen this one a lot but after doing a lot of research there are still things i don't know so i wondered if you guys could help me out.

I've purchased a Turnigy c80100-130:

These are the motor's specs:

Motor Stats: Model: HXT80-100-B Wire Turns: 8 Resistance: 32ohm Idle Current: 2A ESC Required: 130A Input Voltage : max. 48V Kv : 130 rpm/V Weight: 1570g Shaft: 12mm Voltage Range: 20-48v Non Load Current: 2.0A Maximum Power: 6500W Equivalent: 60-80cc Gas Engine

I disassembled a freeboard i had lying around and took the trucks off(of course i'm going to dismount the third red wheel):

And am going to use an old Sector 9 deck:

There is just one thing i really do not know, how do i find a suitable ESC that can be used with an Arduino:

I want to archive something like this:

https://www.youtube.com/watch?v=DMYhUHeX5Fg

I have absolutely no experience in RC cars/plains/etc, this was a pretty impulsive purchase but i'm going to have very much spare time in 3 weeks so.... :)

Thanks for reading this! Any suggestion helps!

You need to specify how many amps you need.

Ah thanks, totally forgot about that, included the specs in the first post. I'll resize the pictures tomorrow for they are unfortunately a little bit too big.

standby....

http://www.hobbyking.com/hobbyking/store/__984__182__Speed_Controllers-120_to_149_Amp.html

rutierut: Voltage Range: 20-48v Non Load Current: 2.0A Maximum Power: 6500W

6500W is about 8HP and would send that board at absurdly fast speeds. A well-trained athlete, for a short duration, is capable of about 250W of power. If you're running at the recommended 20V minimum you shouldn't need more than a 30A ESC.

The practicality of loading enough batteries onto the board to provide that motor with enough power to meet its needs is also a consideration. Even at 30A you're going to need a crapload of batteries.

Chagrin:

rutierut: Voltage Range: 20-48v Non Load Current: 2.0A Maximum Power: 6500W

6500W is about 8HP and would send that board at absurdly fast speeds. A well-trained athlete, for a short duration, is capable of about 250W of power. If you're running at the recommended 20V minimum you shouldn't need more than a 30A ESC.

The practicality of loading enough batteries onto the board to provide that motor with enough power to meet its needs is also a consideration. Even at 30A you're going to need a crapload of batteries.

Yhea i knew it would be a little bit too much but i thought it was better to have a overpowered motor instead of a underpowered one. One of the other cons is that it's a little bit to big, it fits underneath the board but i only will have a few centimeters left so i'll have to come up with something else. But i did really underestimate the capacity of the batteries, i thought i had seen a 100Ah battery for 30$ but that seems impossible looking at the prices now. Do you think i would be better of selling this one and trying to find another?

Motor Stats: Model: HXT80-100-B Wire Turns: 8 Resistance: 32ohm

Ha! 32 milliohm more like.

Without hall sensors how are you going to start under load? Or go slowly? Do you have any reduction gearing?

Well trained athletes can reach about 1kW for short durations, 450W is sustained output of a Tour de France hill climber.

The apparant friction drive mechanism in the picture cannot handle anything like the power involved, a good wide traction tyre and chain drive would fare better. The motor has little cooling in that orientation so cannot handle 8kW anyway.

MarkT:

Motor Stats: Model: HXT80-100-B Wire Turns: 8 Resistance: 32ohm

Ha! 32 milliohm more like.

Without hall sensors how are you going to start under load? Or go slowly? Do you have any reduction gearing?

I've seen a few mods where people attached hall sensors to this motor or even put them inside

Indeed - its doable for large RC brushless motors, but you'll need a hall-sensor ESC to match it.

However I think you have some other issues:

drive mechanics cannot handle the power - the driven wheel will just melt! Tread on the drive wheel is a good idea!

You want accurate torque control for such a system or you'll just be thrown off when it accelerates - RC ESCs are not normally designed for this, they are designed for powering an airscrew.

Cooling - such a motor is intended to be in the airstream of its own airscrew. However I think you won't need to put anything like full current through that motor, its over powered, so this may not be too much of a problem.

Gearing - decide on a sensible max speed, calculate the driven wheel rpm, then select a power train to match - 10mm wide T5 belt system springs to mind, or cycle chain/sprockets.

[ I should add "good luck, don't forget a helmet, pads and spine-protector!" ]

good luck, don't forget a helmet, pads and spine-protector!

(and a Will...)

OK i've decided to sell my current motor and buy another one, i've looked at several ones but what should i be looking for?

I've read that the Kv should be around 270 I know it shouldn't use to much power because that will require a lot of batteries the size is of course important it should be a brushless outrunner

What are other things that are important?

You need to work out your speed and torque requirements first, then choose the motor / gearing. Don't go for a sensorless BLDC, its not going to produce much torque from stationary and spin-up sequence may fail.

Have a look at other similar projects to see what can work, it'll help suggest realistic speed/torque values. There's bound to be at least one on hackaday!

MarkT: You need to work out your speed and torque requirements first, then choose the motor / gearing. Don't go for a sensorless BLDC, its not going to produce much torque from stationary and spin-up sequence may fail.

Have a look at other similar projects to see what can work, it'll help suggest realistic speed/torque values. There's bound to be at least one on hackaday!

Yhea i was originally inspired by a project on hackaday but this is the best build i've seen so far:

http://endless-sphere.com/forums/viewtopic.php?f=35&t=37230

unfortunally Turnigy does not sell those anymore, i can only find these:

This one from ebay: http://www.ebay.com/itm/NEW-AEOLIAN-C6364-10-KV230-OUTRUNNER-BRUSHLESS-MOTOR-100A-ESC-FOR-RC-AIRPLANE/231010720558?_trksid=p2050601.c100085.m2372&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20140211132617%26meid%3D6787391219340396284%26pid%3D100085%26prg%3D20140211132617%26rk%3D1%26rkt%3D4%26sd%3D231010720558%26clkid%3D6787399575707354288&_qi=RTM1562569

and this one:

http://www.alibaba.com/product-detail/powerful-electrical-dc-outrunner-brushless-motor_1283675712.html

will they do? The speed of papo (owns the endles-sphere thread) looks good

He uses this ESC: EZRUN 150 amp car esc (http://www.ebay.com/itm/RC-Truck-Car-Hobbywing-EZRUN-150A-PRO-Brushless-Motor-ESC-Speed-Controller-2s-6s-/321152878309?pt=Radio_Control_Parts_Accessories&hash=item4ac63406e5)