overvolted unicycle?

[1kw]

hello!

 

I have extreme ebike experience....currently have a 100v32ah/ 58 mph ebike. Looking to buy a electric unicycle to modify. Has anybody ran one on 18s lipo?(66v nominal?)

 

looking to make a 30mph unicycle for commuting.....

[cg]

ohh bugger, I just hoped for 1kv

[esaj]

I thought that @vee73 had overvolted his Gotway with Li-Po -packs, but looks like it's still 16S (but there's 900Wh worth of them ). The maximum voltage is going to be around 75.6V with 18S, does anyone know if the mainboards can take it?

[Jag_Rip]

58mph are 93kmh  I hope you have a permit to commute on Highways with that beast

The next thing I wonder, how do you plan to emergency-stop a 30mph (48kmh) EUC without bending the laws (official and those of physics) with you standing on it, unsecured.

[hobby16]

The next thing I wonder, how do you plan to stop a 30mph (48kmh) EUC without bending the laws (official and those of physics) with you standing on it, unsecured.

When I see a bike race, I always wonder if the laws of physics ever exist with those guys. Same must apply to the monobike

[Jag_Rip]

Its stated use is for commuting so there will be unsuspecting people or cars around so thats a different story.

 

OTOH: I would pay to see something like a "Veemula ONE racing world championship" With proper racetracks, safety zones and Grid Girls! wooot!

[EUC Extreme]

Gotway refuses to work more than 16S. I have tried.
But with very good battery performance improves significantly.
The torque is increased very much.
High-speed I did not have time to test before being injured. But that day will come yet.
I and one other has plans to produce EUC which would have a top speed of at least 80 kph.
It should be the body and the electronics completely self-made. Only the engine is purchased.
But this is still in the planning stage.
It would have to drive asphalt race track.
And it would have been only the use of mind. Quickly replaceable batteries, engine and tire.
The structure I already have a clear vision. Only a proper circuit board is the biggest problem.
But this is realized is considered ..
On the other hand, I hope someone manufacturer to realize that the EUC will be the future tool for many extreme sport, and that someone is a decent manufacturer starts to make a variety of purposes appropriate.
It is not always all need to do for yourself :)

[EUC Extreme]

Yet the dream I have already acquired this in mind, the charging equipment. So the battery voltage can be increased just as high as the power demand needs. I am able to download 40s battery if it is necessary. It has a total nominal voltage of 146V.
Also riding gear I acquired those that can be used even at high speeds.
A few miles from my apartment is a track that is just right for this purpose.

[1kw]

These look no diff from ebikes.. Just needs more volts for a higher speed, can also lower the amps in the process so you get a cooler motor... Should be able to swap in. A controller. How many fets are the stock controllers?

Also 30 mph is fine... Around 55km/h..

[esaj]

Should be able to swap in. A controller. How many fets are the stock controllers?

I think @hobby16 has a gallery of wheel mainboards... somewhere? Don't remember if he has posted a link... Here's one of his blogposts about Kingsong vs. Gotway MB: http://hobby16.neowp.fr/2015/07/29/king-song-gotway-comparison/   I count 6 on the Gotway-image, assuming I'm counting the right components     I did do a school project long ago that involved mosfets, and that's what they looked like   

@Jason McNeil's IPS-teardown shows 12: http://forum.electricunicycle.org/uploads/monthly_2015_06/IPS121_MOSFETs.thumb.jpg.8294e3623b00b0ae05e96efc18302dfa.jpg  Although some might be for the BMS, as it's apparently integrated into the mainboard?

6 in the Ninebot: http://forum.electricunicycle.org/topic/815-ninebot-one-e-circuit-board/

 

Firewheel might have only three, hard to say as they're covered by the heatsink, but by judging from the size:  http://forum.electricunicycle.org/topic/613-firewheel-pcbs-connectors-battery-wiring-older-gen/#comment-6719

http://ezbe.underkround.fi/unicycle/fw/mainpcb-frontside.jpg

http://ezbe.underkround.fi/unicycle/fw/mainpcb-backside.jpg

Most generics seem to have the mosfets covered by the heat sink, so hard to say if they might have only three (for 350W motor)? There are probably more pictures in the forums also, these were the ones I remembered/found fast.

 

[hobby16]

The minimum number of mosfet for a bldc controller is 6 ( 2 mosfets/half-brige *  3 half-bridges). So you'll find multiples : 12, 18 or 24.

But modern mosfets have amazing performances (several hundred amps continuous current, less than 1 milliohm drain-source resistance, low Q gate...), one can replace 5 or 10 mosfets just 10 years older ! So the total number of mosfets doesn't mean much anything.

A quite easy solution to have high speeds without developping a new electronics is to take the mainboard of the Gotway 10", put in more beefy mosfets and connect it to a 18" wheel motor, max speed is increased by +80% thanks to the bigger diameter.

Another idea : for competition racing at quite high speeds, I wonder if getting back to geared motors like the Rockwheel would not be the thing to do.

Where high power/weight ratio is needed and replacing a part with too much backlash is not a problem, geared motors reign.

Geared motors already use rather low voltages, it's much easier to double their voltage from 32V to 64V to double max speed than to double voltage of a BLDC already at 64V.

Well, much ways to explore...

 

[1kw]

Yup. How to build your own? Can I use a pre existing electric bike hub motor? I have a mxus 3kw.... Can lace into 18" wheel...

 

where to buy the parts to build one?

[EUC Extreme]

If you put Gotway 14 of the circuit board 18 inches, I wonder if the torque is sufficient.
As already own 18 inch torque near the maximum speed will begin to decrease. And if the rate still rises .. I doubt its performance.
I have also made it faster circuit board factory. But the torque is quite unhappy. Downright dangerous.
That is, the speed has been at the expense of torque.
Really fast circuit board should be so much over-sizing that it almost starts to wheel spin during acceleration empty, even if though from a large speed dares to accelerate dramatically.

I would therefore really overkill system. I would like to put money and time just a little bit faster and better. But it should be soon so incredible that it is not none of holding a.
Just as mentioned here .. Veemula 1 style: D

Terrain Enabled be sufficient to slightly higher performance than my current Gotway. But the track should be a device different planet. Heavy it should be. But I do not think that it is a problem on the track.