Brushless dual 6kw ALIEN Power system - electric longboard

[simonjook]

Some of the ESCs supported ... https://docs.google.com/spreadsheet/ccc?key=0AhR02IDNb7_MdEhfVjk3MkRHVzhKdjU1YzdBQkZZRlE#gid=0

Yeah, very few car ones and neither of the 150A variants.

This might be a dumb question, but how do you get to 40mph using 83mm wheels, a 2.133 pulley ratio, 170KV motor and 10s batteries

Ah, I thought most including Beetbocks were using 240 or 270kv motors not 170kv. I use a 190kv because I have a single motor and live in hilly central and I rarely see anyone mention a motor with lower kv than mine.

We have the new custom Nunchuck in hand now though and as Bruno says and we just need to test them..

I've played with two - they are painfully flaky especially with all the motor noise ... I would have to use one on the road ... would result in much loss of skin.

2.)Why use HTD belts instead of GT2?

I know why I have used HTD more than GT2 in projects - it's a pain to get them outside the US and it's also annoying to get the specs for milling your own pinions ... not impossible but painful.

 

[rf]

We have the new custom Nunchuck in hand now though and as Bruno says and we just need to test them..

I've played with two - they are painfully flaky especially with all the motor noise ... I would have to use one on the road ... would result in much loss of skin.

The 'Wiichuck' seemed a bit strange with the cruise-control interface. Apparently that was done because the joystick has such low resolution. Sounds equivalent to a car gas pedal with only one inch of travel. :-(

There are some inexpensive addons for the Arduino for remote control. Simple transmitter and receiver boards that you program youself. They run about $2 each. I've ordered a couple to test. I suspect they will be better controllers than Wii or R/C.

 

[dirkdiggler]

As to the HK 150a. I wouldn't recommend it after my experiences. I would go with the alien or hobbywing. The 200 amp from Hk looks good, but I havent heard from anyone using them. Plus the hobbywing esc was only about ten dollars more.
I looked at those pages about flashing the esc. That is a bit much than I want to do. Seems like a potential disaster if you dont know what you are doing. I have flashed plenty of things and it is usually a fearful experience on whether you will end up bricking your device.

 

[rf]

As to the HK 150a. I wouldn't recommend it after my experiences. I would go with the alien or hobbywing. The 200 amp from Hk looks good, but I havent heard from anyone using them. Plus the hobbywing esc was only about ten dollars more.
I looked at those pages about flashing the esc. That is a bit much than I want to do. Seems like a potential disaster if you dont know what you are doing. I have flashed plenty of things and it is usually a fearful experience on whether you will end up bricking your device.

I have the 200 amp on order ... no telling how long it will take to get here. Hope it's still Atmel based! It was $30!

There's a ton of net chatter about flashing ESCs among multicopter enthusiasts. A number of them offering to flash ESCs for others. Once you flash one you get a boot loader that makes doing it again much easier, through the servo connector.

 

[Nikimce]

What is the purpose of the new universal drive hub? Im sorry but I cant seem to find it.

 

[dirkdiggler]

Where did you get it for thirty bucks? That is a sweet price.
After flashing phones, xbox and routers. I agree it gets much easier the next time. Most of the time i just do it for the experience. Sometimes it is worthwhile, like when the manufacturers are no longer providing support. Could be good in this situation where you need some better response.

 

[yelnatsch517]

Some of the ESCs supported ... https://docs.google.com/spreadsheet/ccc?key=0AhR02IDNb7_MdEhfVjk3MkRHVzhKdjU1YzdBQkZZRlE#gid=0

Yeah, very few car ones and neither of the 150A variants.

This might be a dumb question, but how do you get to 40mph using 83mm wheels, a 2.133 pulley ratio, 170KV motor and 10s batteries

Ah, I thought most including Beetbocks were using 240 or 270kv motors not 170kv. I use a 190kv because I have a single motor and live in hilly central and I rarely see anyone mention a motor with lower kv than mine.

We have the new custom Nunchuck in hand now though and as Bruno says and we just need to test them..

I've played with two - they are painfully flaky especially with all the motor noise ... I would have to use one on the road ... would result in much loss of skin.

2.)Why use HTD belts instead of GT2?

I know why I have used HTD more than GT2 in projects - it's a pain to get them outside the US and it's also annoying to get the specs for milling your own pinions ... not impossible but painful.

270Kv makes a lot more sense, but from the Alien Power site, the 63mm motor is listed as 170Kv.
I didn't realize the Nunchuk had such low resolution. In our build, we didn't use one. We used a pot connected directly to an Xbee transmitting to another Xbee connected to a Teensy.
We ordered our belts and pulleys from SDPSI. They have a fairly decent selection, but can be pricy. We spent $20 per pulley.

 

[rf]

Where did you get it for thirty bucks? That is a sweet price.
After flashing phones, xbox and routers. I agree it gets much easier the next time. Most of the time i just do it for the experience. Sometimes it is worthwhile, like when the manufacturers are no longer providing support. Could be good in this situation where you need some better response.

Hobbyking.

All the Atmel-based ESCs are pretty similar. The code inside is 80% of the battle. And the SimonK code is free and modifiable and better than the stuff in most of the commercial controllers. Seems like the best way to go, especially if you can find a cheap Atmel-base ESC. Or even throw one together ...

 

[simonjook]

As to the HK 150a. I wouldn't recommend it after my experiences. I would go with the alien or hobbywing. The 200 amp from Hk looks good, but I havent heard from anyone using them. Plus the hobbywing esc was only about ten dollars more.

Well the HK150A has done a happy 110km for me now without a fuss (except a stack on the first day testing different timings) and I live in a very testing area - lots of decent grade hills so lots of of it pushing up and braking down. I can't find the Hobbywing for anything close to that cheap - nothing below $99 versus $66 for the HK150A.

I thought the 200A one was a heli one - remember we have much more demanding braking behaviour than the non car ESCs were intended for - reports I read elsewhere suggest non car ones go pop easily when too much braking is done. I have done nearly 1km of just solid braking without a failure yet.

Not defending the HK150A and I'll definitely try something better if I do blow it but so far so good and at a bargain basement price when doing your first board, you don't know how well things will turn out and you don't want to waste a whole lot of cash.

 

[Vapology]

Hey simonjook,

Where there any cogging issues? How was the start up harsh or pretty smooth? What settings do you have your 150 set up to?

 

[rf]

For the most part the only thing different about the various ESCs is the software inside. Car ESCs often have fans -- that's a little different. Planes create their own cooling breeze and don't need them. Skateboards have room for a larger heatsink and don't need fans either. Other than power handling differences everything is controlled by the program inside. The software is the heart and soul of the ESC.

So a plane ESC can become a car ESC with some good braking software. An ESC with great braking becomes a skateboard ESC.

We really need to find a good schematic and have someone build some ESCs for us. Otherwise a source of cheap Atmel-based units that will handle plenty of power should do nicely. The big long list of supported units gives an idea how easy it is to adjust the software to a new ESC. The differences are small.

 

[simonjook]

Where there any cogging issues? How was the start up harsh or pretty smooth? What settings do you have your 150 set up to?

I get cogging if I try to drive off from a standstill. I give it a little push up to about 3km/hr (ie hardly any - just a single lazy push) and drive off from that speed without any cogging. Just a little bit of movement is enough to get sync. I had to set the timing to high on the HK150A - I went back to the default (normal) to see if it would make a difference to range - it stalled on hard acceleration and hurled me into the pavement at 20km/h without any warning. I'm sticking with high now.

For the most part the only thing different about the various ESCs is the software inside. Car ESCs often have fans -- that's a little different. Planes create their own cooling breeze and don't need them. Skateboards have room for a larger heatsink and don't need fans either. Other than power handling differences everything is controlled by the program inside. The software is the heart and soul of the ESC.

So a plane ESC can become a car ESC with some good braking software. An ESC with great braking becomes a skateboard ESC.

Not really. Many planes have ESCs inside the fuselage away from the breeze and the same for copters and boats - one of the reasons the dont NEED a fan is they don't hang to apply heavy braking for long periods. Heavy, long braking requires dumping a lot of energy - that energy needs to be dissipated and if its not being dumped into the battery through regen it needs to be poured off as heat ... hence the fan. On a plane braking just means the energy of a light prop spinning is all that needs to be dissipated.

Braking on a skateboard is and even more extreme case and well beyond what the car ESC was designed for ... plane ones without being designed for a lot of braking will burn up. Read around and you will see this is the experience of many skateboard, ebike projects experiencing this. If you are not intending to use braking though then there is a much greater ange of good high current ESCs at good prices and then the plane options represent a good opportunity. For me - I love the braking on my board - it's essential to my use and enjoyment and for me one of the main advantages of having an eboard!

 

[yelnatsch517]

For the most part the only thing different about the various ESCs is the software inside. Car ESCs often have fans -- that's a little different. Planes create their own cooling breeze and don't need them. Skateboards have room for a larger heatsink and don't need fans either. Other than power handling differences everything is controlled by the program inside. The software is the heart and soul of the ESC.

So a plane ESC can become a car ESC with some good braking software. An ESC with great braking becomes a skateboard ESC.

Not really. Many planes have ESCs inside the fuselage away from the breeze and the same for copters and boats - one of the reasons the dont NEED a fan is they don't hang to apply heavy braking for long periods. Heavy, long braking requires dumping a lot of energy - that energy needs to be dissipated and if its not being dumped into the battery through regen it needs to be poured off as heat ... hence the fan. On a plane braking just means the energy of a light prop spinning is all that needs to be dissipated.

Braking on a skateboard is and even more extreme case and well beyond what the car ESC was designed for ... plane ones without being designed for a lot of braking will burn up. Read around and you will see this is the experience of many skateboard, ebike projects experiencing this. If you are not intending to use braking though then there is a much greater ange of good high current ESCs at good prices and then the plane options represent a good opportunity. For me - I love the braking on my board - it's essential to my use and enjoyment and for me one of the main advantages of having an eboard!

I was wondering how much energy is recovered from regen. Has anyone tested? I live on a hill and it's roughly 600ft over 1.5miles to get to the bottom. How would the Alien ESC cope with that?

 

[simonjook]

Not speaking for the Alien ones core to this thread most of the other ESCs (RC hobby) mentioned dont do regen. The Alien ones, I don't know - perhaps someone can chime in. The ebike community has been debating it's value for a while as you dont seem to get enough back to justify the higher cost of regen.

 

[Silenthunter]

Guys,

I have bought a 6s - 12000mAh Headway cell pack. I was wondering if I can use B6AC 80W Dual Power Charger. Maximum I can set is 6A and 19.8V for 6S. Anyone has any thoughts if this charger, is good for Headway Cells?

Thank you.

 

[rf]

Braking on a skateboard is an even more extreme case and well beyond what the car ESC was designed for ... plane ones without being designed for a lot of braking will burn up. Read around and you will see this is the experience of many skateboard, ebike projects experiencing this. ...

More good reasons to buy higher capacity ESCs than your motor's rating suggests. And reason to install larger heat sinks and test carefully with ammeters and thermometers. R/C equipment wants to be small and light -- that tends to make their heat sinks marginal. Few R/C ESCs seem to have built in temperature control and current limiting. (Many ebike controllers do.) If you're selecting your own parts, having an ammeter and a temp-gun seem like musts to me. And proceeding with caution until you know how much power your setup is consuming and how much heat it produces.

I've played with various kinds of dynamic braking on my ebike. I live up a 2-mile hill with a 900-foot rise. Regenerative braking doesn't seem very useful when I tend to leave the house with a full charge. Connecting a resistor across your motor can stop you in a hurry, while generating lots of heat. Incorporating that into a skateboard seems messy. (If you have a loose motor sitting around: short the leads together and see how much harder it is to turn ...)

I'm thinking seriously about building an ESC. I like programming Atmels and I like logging lots of data. Using Bluetooth between ESC and phone for temp., amps, RPM and other things would be cool -- and help to build a better board. The ebike folks use more efficient MOSFETs for controlling power -- less power wasted, less heat generated, more capacity.

 

[simonjook]

More good reasons to buy higher capacity ESCs than your motor's rating suggests. And reason to install larger heat sinks and test carefully with ammeters and thermometers.

The capacity of an ESC has absolutely no correlation to its design intent with respect to how it intends to dump energy only how it delivers it. Although improving sinking will increase the ability to slough it off as heat it does not improve the electrical design which may not be appropriately designed for dealing with a full braking situation down a steep hill as heat is not the only factor.

 

[yelnatsch517]

Not speaking for the Alien ones core to this thread most of the other ESCs (RC hobby) mentioned dont do regen. The Alien ones, I don't know - perhaps someone can chime in. The ebike community has been debating it's value for a while as you dont seem to get enough back to justify the higher cost of regen.

If the ESC does not regen brake, all the energy must be dissipated somehow. How does the EBike community deal with that energy?
I can imagine going downhill for 2 miles can generate quite a bit of heat if all the energy is dissipated via resistors.

 

[rf]

Not speaking for the Alien ones core to this thread most of the other ESCs (RC hobby) mentioned dont do regen. The Alien ones, I don't know - perhaps someone can chime in. The ebike community has been debating it's value for a while as you dont seem to get enough back to justify the higher cost of regen.

If the ESC does not regen brake, all the energy must be dissipated somehow. How does the EBike community deal with that energy?
I can imagine going downhill for 2 miles can generate quite a bit of heat if all the energy is dissipated via resistors.

Most ebikes just use normal bicycle brakes. Very few do regenerative braking. Besides the difficult task of sending energy back to the batteries without damaging them, regen braking needs to be controlled. It's not nearly as easy to use as brake pads/drums/disks, etc. The stopping action from regen braking tends to be 'lumpy', having a different feel to the driver in different conditions and at different speeds. The driver usually needs to modulate two different controls for stopping since regen braking doesn't work well at slow speeds.

 

[Venus]

I just wanted to add my board to the list.

It uses an SK3 6354 260 KV motor, 6S 6000mah Lipo and 150 A Hobby wing ESC. I just did a 16 km ride and arrived home with an average cell voltage of 3.75v. I was cruising relatively slowly, maybe 20 kmph, but carving the entire time. So I would estimate I could get 20 km if I drive efficiently and not go too low to hurt the battery.

With the 76 mm wheels it has a calculated max speed of about 45kmph, I have taken it up to 38. I would estimate it will do 40-42 under ideal conditions. I am a wimpy skater and prefer to cruise at 25 or so. Final weight is 6kg.

It is much even better than I expected it would be. The entire time, I have to fight the ridiculous EV grin.

There is very little I would do differently. Perhaps the new 12 tooth pinion gear to limit top speed some more. I wouldn't buy the hard case 2s batteries next time. The wires are bulky with the required 90 degree input angles. 5s would also help limit top speed and make my cruise throttle setting easier. A slightly lower KV motor would be another way. For me a top speed of 35 would be ideal. I have found from my electric bikes it is much more relaxing to cruise at full throttle. I am quite sure I could get away with 3/8 spacers instead of 1/2.

I would like to thank Richard for putting together such a nice kit. Everybody should own one of these!

 

[simonjook]

It uses an SK3 6354 260 KV motor, 6S 6000mah Lipo and 150 A Hobby wing ESC. I just did a 16 km ride and arrived home with an average cell voltage of 3.75v. I was cruising relatively slowly, maybe 20 kmph, but carving the entire time. So I would estimate I could get 20 km if I drive efficiently and not go too low to hurt the battery.

Awesome range - is that all flats or hills too? I am running 190kv because I need hill climbing ability. That means I top out about 30km/h on flats and get 16km range on 6s 5000mah if there are no hills.

Can you tell me how you starts from a full stop are with the Hobby Wing ESC? Can you also (others reported) drive off from a full stop or do you get a little cogging (jittering) from a standing start?

 

[simonjook]

Some piccies of my Caliber bracket - I promised these for Caliber lovers last week. Sorry for the crappy low light photos but I keep forgetting during the day. Just the ugly prototype done with aluminium leftovers. Later versions will be neater. Bracket does not move at all and has clocked up 100km without needing any tightening. Need better bolts for the motor - didn't have and hex cap heads at the right size. There's a few bite marks from where I hung it up on a gutter but was actually nice how it stood up and protected my hanger.

View attachment 1

 

[Venus]

Awesome range - is that all flats or hills too? I am running 190kv because I need hill climbing ability. That means I top out about 30km/h on flats and get 16km range on 6s 5000mah if there are no hills.

Can you tell me how you starts from a full stop are with the Hobby Wing ESC? Can you also (others reported) drive off from a full stop or do you get a little cogging (jittering) from a standing start?[/quote]



That is all flats and not much stop and go.

It will cog from standstill, so I don't do it. I always push off. If I hit the throttle hard while slow it groans a bit. Even if it started perfectly from standstill, I would avoid doing that. That is the least efficient phase for the motor, and the most efficient for pushing.

I just finished charging, 4742 mAh back into a 6000 mAh pack.

 

[simonjook]

It will cog from standstill, so I don't do it. I always push off. If I hit the throttle hard while slow it groans a bit. Even if it started perfectly from standstill, I would avoid doing that. That is the least efficient phase for the motor, and the most efficient for pushing.

Others have reported better - perhaps a higher timing might give an improvement - perhaps it was too good to be true or perhaps it's our cheap Turnigy motors.

 

[beetbocks]

Great Venus - that's looking good .. Yes the lower gearing is needed for the 270 kv as you say .
That's why I'm producing the new 2 peice hub , so I can make larger pulleys wheels available without the cost going up too much . As a 1 peice means machining from larger blank thus meaning more machining and higher cost for the blank in the first place .
I hope in the future to offer a range of gearing solutions for different speeds/ hill climbing/ wheel/ motor size etc etc