AEVA Forums

Hi Guys,

This is our little "EV" project.

12KW powerboard, currently construction under way.

Main features include:

• 4WD
• Independent & dynamic suspension
• Independent steering
• Servo controlled damping
• Top speed ~50km/h
• Weighing in the order of 15kg, compact enough to fit in the back of a car
• Designed to take a pounding from jumps

You can check out more photos and our video here.


Thoughts or comments welcome

PingaAus wrote:Thoughts or comments welcome

umm WOW

Looks nice but since you asked for comments...

Ok so a car uses about 10-15kW to do 90kph.
So the 50kph is an intentional speed limit right?

Even at 1kW it's likely you will fall off or have your feet ripped off from a standing start.

Where do the batteries go?
Any estimates on run/fun time?

Well done

Cheers Richo.

We actually have a proof of concept prototype up and running. (video here)
It can theoretically do ~75-80km/h on 12inch wheels. Having said that, we've only tested it up to ~55km/h before some sensibility came into play to slow down :p
It's unlikely (or at least not advisable) that a board rider will go that fast on off-road trails (not to mention any legal aspects). So we've designed the one in the pic for a lot more low end torque for those uphill runs, instead of top speed.

The acceleration is "intense", but we've got a way to control it.

Batteries will be covered under the board. Run/fun time is dependent on how hard you ride I suppose. We've ridden the proof-of-concept model at about 20-30km/h on a trail for over 2.5 hrs without needing a recharge if that's any indication. Recharge time is just over an hr.

wow, looks great and innovative.
But I have to agree with Richo.

My BLDC 10wk hub motor can push my 230gk motor bike to a speed of 115 kmh.
And thats only on short test runs so far.

Wouldn't it be cheaper to use less wk's?

Thanks Glenn.
Power doesn't necessarily corrolate top speed.
We are designing the board more for low end power, because it's going to have to accelerate pretty quickly in some pretty boggy terrain. Plus it has no gearbox.
With the particular motors we use, we can actually increase their speed if we increase voltage. So, 50km/h is with our current 22V batteries; if we went with 44V batteries, speed doubles.
All will come out in the wash in testing, so you never know, maybe we can reduce kw's and achieve the same outcome:)

Very cool
reduction gear stuff is available for a pmdc outrunner such as the lrk torquemaster open source design made with rewound cd drive stators up to 2.7kw which have been used on bicycles etc and is a very high power to weight ratio system and easy enough to build/wind how you want it to perform check this group
http://www.rcgroups.com/forums/showthre ... hlight=FAQ

Well it all sounds great.
I had a look around yesterday at similar items and I think yours is unique enough to have a good go in the market place.

Perhaps a revamp of the wheelman for the 2 wheel version could be worthy too?

I think we are on Wackyboards somewhere haha.

unheardofinstruments wrote: Very cool
reduction gear stuff is available for a pmdc outrunner such as the lrk torquemaster open source design made with rewound cd drive stators up to 2.7kw which have been used on bicycles etc and is a very high power to weight ratio system and easy enough to build/wind how you want it to perform check this group
http://www.rcgroups.com/forums/showthre ... hlight=FAQ

Thanks unheardofinstruments. We'll check it out.

We just also uploaded some raw video footage of the test rig in action.

http://youtu.be/E_smy0xWFu4

its really a pity that ridding this an any public land (non privately owned and with permission) will/could land you in jail in QLD

how do i know this? my friend with his 800W bike

he almost got a jail term and they did confiscate his bike because he didnt get it back

link

Adverse Effects wrote: its really a pity that ridding this an any public land (non privately owned and with permission) will/could land you in jail in QLD

Oops! Perhaps should've checked the VIC regs as well before making our video (link)

It is a shame. On the other hand, if we did get arrested it would be good for publicity. Maybe we'll write-off a board and some fines as marketing budget haha. jk jk.

What I have done is govern my 6000w Etrike recumbent to 200w through a ebike cycle computer. That way you can have a off road mode 6000w and street mode. Its perfectly legal in QLD. There is a difference between a motor consuming 200w and actually putting that to the ground so a e bike dyno is a handy thing to make the most of the 200w rule.   

They key is having a drive system that is light weight and free wheeling so that even using the bike non powered you are not hampered and 200w can actually be quite useful. There are lots of places to have fun off the street. prticularly thus off road board or a dual suspension Mountain bike.

Great board by the way. is it a full custom build of are some of the parts of the shelf 1/4 scale rc car parts?

Kurt

offgridQLD wrote: What I have done is govern my 6000w Etrike recumbent to 200w through a ebike cycle computer. That way you can have a off road mode 6000w and street mode. Its perfectly legal in QLD. There is a difference between a motor consuming 200w and actually putting that to the ground so a e bike dyno is a handy thing to make the most of the 200w rule.   

They key is having a drive system that is light weight and free wheeling so that even using the bike non powered you are not hampered and 200w can actually be quite useful. There are lots of places to have fun off the street. prticularly thus off road board or a dual suspension Mountain bike.

Great board by the way. is it a full custom build of are some of the parts of the shelf 1/4 scale rc car parts?

Kurt

Cheers Kurt. Pretty much all custom parts. Only off-the-shelf stuff are the tyres and fastners. The shocks and motors are also bought, but we modify them.

Looks great but I would be sitting down, not standing up with that kind of performance.

Haha, I can see the image now. Clutching onto the board like a bob sled!

AAhhhhhhhhhh

PingaAus wrote: Haha, I can see the image now. Clutching onto the board like a bob sled!

naaa

if it has re-gen you could street luge up and down the hills

Absolutely!
And especially as the board has pretty low rolling resistance with the thin tyres, whenever you are going downhill, you don't actually need any power...unless you want to go crazy fast.

Quick update: most of our fabricated parts are finished. Assembly day is coming pretty soon. We are psyched!

Very cool... with a built in parts replacement business for when people stack it :O)

Lol. Never thought of it like that, but a good point!

Gen2 approaching testing phase!
www.facebook.com/bajaboard

Take-off Practice Youtube Clip

Link above to a short clip showing us practicing launching on the BajaBoard. No bindings were installed at the time of filming, so had to be a little careful.