7.5KW mid drive stand-up scooter build project.

[ilia-45]

It's been a long time since I posted here
I wanted to share with you my current project , this project now in design state (CAD) , it will be a stand-up water cooled , mid drive 7.5KW (up to 13.5KW peak)motor , 200A controller , 20s-12p battery monster :wink:
This will be heavy duty machine in all means , for now calculated mass is around 110 kg , all body parts will be 6061-T6 aluminum ,the wheels will be 13x6.5-6 , I design it to be my daily rider .






In current state model is still not finished , its does not have suspension (I'm waiting for parts ) , and I need to make a lot of small corrections , before it will be ready .
Most of the parts I use in this build are from motorcycle/atv word , as brake levers, calipers , brake disks, speedometer .

 

[ilia-45]

Despite the size of the scooter , there is not enough space inside for all the components , as all the component are big and bulky , for example the motor occupies almost 1/3 of the chassis space:

The motor controller is also huge :

All this creates some problems
So this machine can't be build in classic layout , when all the parts are placed under the "main plate".

 

[ilia-45]

So I had to distribute various blocks throughout the chassis

 

[BigBlock]

Very interesting design - I would be concerned about the 110kg mass. If so, it will need some serious suspension design to handle

How much is the weight of the frame only ?

 

[liveforphysics]

Why not go belt drive?

 

[BigBlock]

Why not go belt drive?

The design of the rear wheel swing arm is quite straightforward but I believe it bring some challenge. The roller tensioner cannot work with chain. A different chanin tensioning system should be designed, unless a belt drive is used.

Also it would be interesting to know more about the motor RPM and gear ratio on the rear wheel sprocket

 

[SlowCo]

Nice project :thumb:
I suspect you'll be replacing rear tires very often wit that much power and such small wheels

 

[ilia-45]

Very interesting design - I would be concerned about the 110kg mass. If so, it will need some serious suspension design to handle

How much is the weight of the frame only ?

110 kg it's a normal mass for motorcycle , this one is a stand-up version :wink:
Will be proper suspension, I'm waiting for parts now.

 

[ilia-45]

Why not go belt drive?

It's need more attention then chain :wink:

 

[ilia-45]

Why not go belt drive?

The roller tensioner cannot work with chain. A different chanin tensioning system should be designed, unless a belt drive is used.

Also it would be interesting to know more about the motor RPM and gear ratio on the rear wheel sprocket

The tensioner work very well on chain , look at aftermarket motorcycle parts :wink:
As for the motor RPM it's 4000 up to 6000 , gear ratio 3.5 to 1(final drive).

 

[ilia-45]

Nice project :thumb:
I suspect you'll be replacing rear tires very often wit that much power and such small wheels

The time will show :lol:

 

[ilia-45]

By the way , those are the tires 8)

 

[ilia-45]

Machined all the parts for my steering tube 8)

 

[ilia-45]

Some welding

 

[cheapcookie]

cool project,

you could review the fork entirely to 1) make it low profile, and gain deck length 2) maybe add front motor maybe even use smaller motor rear ?
from my experience added weight to steering not good idea.

rear foot pedal could also be modified to serve other purpose, controller, fuses...

also please consider placing the controller in the rear :|

it might also be a good time to think about mudguards

also I don't think I would have placed the motor inside the deck, outside seems like less material and same rigidity

 

[PaPaSteve]

Good looking welds.
A Demmeler welding table is a real investment.
Is that a Fronius welder hiding in the background ?

Waiting eagerly for the test ride video :thumb:
Always appreciate seeing good craftsmanship.

 

[Dino83]

You are doing a very interesting build.
I believe it would be better to use the square stabilizer than the piston one.
Are there any better looking wheels?
Better quality tires?

 

[amberwolf]

The roller tensioner cannot work with chain.

Sure it can. It'll probably be noisier and wear faster as a smooth roller like that, but it would still do the job. Rollers are used often enough on tensioners (and guides) for various chainlines on long bikes, and I've seen them on motorcycle chains too.

If you use a small sprocket on a bearing instead of the roller, it would guide the chain more quietly and "efficiently" than the roller, if that's a concern.