Rad2Go E36 Build

[milesinfront]

This is my E36 scooter:-



It's been mentioned on a few other threads... Much progress has been made so I've decided to start this build thread.

I bought this scooter s/h from ebay about 4 or 5 years ago. In it's stock form it consisted of a Unite 1020 36v 800w brushed motor sucking amps from 3x 12ah SLA's. Out of the box is was pretty fun, with exceptional torque and a very reasonable 40km/h top speed. Stopping was done by a rear band/drum brake. Range was about 6kms when ridden hard.

The first upgrade was LiPo power. After quickly destroying 2 sets of SLA's the scooter was ignored for about 18 months. I was regularly looking at lithium packs for e-bikes but the price was always just too much to bear. Eventually I discovered HobbyKing and their Zippy 30c 8ah LiPos. The price was too good to be true so I decided to give them a go! I bought two 5s packs and ran them in series into the stock controller. The scooter was back to life with a vengeance! The reduction in weight and voltage/amperage increase was quite noticeable. Acceleration was much better (esp midrange) and peak speed rose to ~41km/h. The increase in range was amazing!

Prior to getting the LiPo's I added a CA computer. Was staggered to see 120amps max!

The next upgrade was a Kelly controller. I wanted to try upping the voltage. I bought an extra 3s pack to see what 50v would be like. The moment I connected 50v to the stock controller the motor fired up (zero throttle) and that burning smell was released. So I got a higher voltage Kelly, and also upgraded the high current wires to big audio power cables. The results were mixed... While testing with the 10s pack, peak amps rose to 152 but the initial hit from the throttle seemed softer. Midrange acceleration was once again improved, but top speed was unaffected.

So now it was time to add the extra 3s pack... With 50volts max accelleration seemed about the same, but for longer, and the wind noise just keeps getting louder! Top speed went from 25.5mph (41kph) to 32.3mph (52km/h). That's a bit scary on this rig... But after a quick test ride I could smell the smoke getting ready to escape from the motor. I'm sure it wouldn't go for much longer at that voltage. (36v Motor)

Here's a quick youtube:- http://www.youtube.com/watch?v=SCv1-DKJoCU

I did some mechanical upgrades next:- I switched to pneumatic tyres (lighter, less rolling resistance), upgraded to 8mm chain and upgraded to a disc brake



Performance was starting to go backwards... It seems the motor never recovered from that 50v test run and some time later it finally melted.

I'm thinking R/C brushless power next...

[milesinfront]

Coming soon! C80-100 + 18fet Lyen powered E36! Better call an ambulance...

[E-racer]

Ive never seen that label on an 80-100 before!? where did you get it? do they still have any? Awesome dog btw!

[milesinfront]

Bought the motor s/h from ES member Bluefang just this morning. Sticker has the following web address:- www.electricmodelpower.com All company info is there, but no pricing or ordering...

Rufus has been a faithful companion for nearly ten years now!

[E-racer]

Thank you! I emailed them I'll be interested to see what they have to say.

[milesinfront]

Wolf in sheep's clothing!

[milesinfront]

I have ~18mm of space inside the front of the motor to mount the optical board and trigger wheel. (c'mon Burtie, get another batch done!) Radial slots will allow external timing adjustment. I would like to incorporate a cooling fan with the trigger wheel also.

The original Unite output bearing is still there, and is perfect at 12mm. Sprocket load shouldn't be a problem!

It's a pity the threaded output shaft will 'unscrew' under torque. I still think it will be okay to thread the drive sprocket to match and use a retaining bolt on the internal thread of the shaft...

C'mon Burtie, c'mon Burtie...

[Bluefang]

Damn i wish i had a mill like that

Now i under stand why you thought it would be very easy to fit the motor into the old motor face plate. FYI be careful about having metal within like 1-2cm of the can of the motor as that will cause problems with the running of the motor increasing current draw and heat, so having the complete case of the old motor around the new one may not be a good idea

[parabellum]

milesinfront, how is all the kv thing working out? Was original motor about 180kv?

[milesinfront]

milesinfront, how is all the kv thing working out? Was original motor about 180kv?

At ~38v, with the scooter on the stand it was turning at around 5krpm, so the kv must have only been slightly higher than 130... I will run a 9/63 sprocket combo and see how it goes. I was running 11/54 with the brushed motor... I do plan to go to the full 18s battery or higher. I worked out the 9/63 set-up yields ~70km/h @ 9.5krpm. I'm hoping for 50-60km/h on the road.

Damn i wish i had a mill like that Now i under stand why you thought it would be very easy to fit the motor into the old motor face plate. FYI be careful about having metal within like 1-2cm of the can of the motor as that will cause problems with the running of the motor increasing current draw and heat, so having the complete case of the old motor around the new one may not be a good idea

My 'mill' is actually an old industrial engraving machine. It's very heavy for an engraver, but on the weak side for a mill... I hope I don't have an issue with the motor case, but could switch to alloy as a plan B.

[Bluefang]

I think the problem with metal been too close to the motor can is electrical so you would have to change it to something none conductive. All i know is metal close to the motor can results in heat in the metal and a motor drawing alot more amps I didnt pay attention to the technical reasons for it.

[milesinfront]

I can understand the iron content doing something with magnetic fields etc, but I can't see aluminium would have any effect other than it's effect on air flow. If I'm wrong I'm sure someone will provide an explanation I'm sure...

[Burtie]

Spinning magnets in rotor of the outrunner cause moving magnetic flux which will interact with any nearby stationary electrical conductor (i.e. the old aluminium motor case.)
This will induce eddy currents in the conductor which generate heat, and also cause mechanical drag on your motor.

Note that the conductor does not have to be iron, any decent electrical conductor will be affected.


Best to keep any metalwork a good few mm away from the spinning rotor for best efficiency.

Burtie

[milesinfront]

I have a 10mm gap, all the way round. Should I be concerned?

[Burtie]

I dont know.

Unless we know lots of stuff, like the flux leakage, conductor resistance, area, rotor speed, (and how to work it all out ), it would be difficult to say.
You may well have no problem, but it sounds like a good excuse to do an experiment

[milesinfront]

I'll push on... This is such an easy mounting option that I can't ignore it unless I have to. If it doesn't work out I'll just mount it 'stand alone'...

I'll let you know how it goes! (but I need some optical sensors first! )

[Burtie]

I'll let you know how it goes! (but I need some optical sensors first! )

working on it.

I will pm you soon.

[milesinfront]

As I'm waiting for Burtie's next batch of optical sensors I've decided to do some work on the frame... I'm going to add a gusset to the head tube where a crack has appeared. (actually the crack has always been there) I've also disassembled the fork in order to add a disc brake mount. The fork will actually need to be widened also...

[milesinfront]

some progress....

[milesinfront]

I decided to scrap the 'motor inside the motor' idea. I figured the frame is stripped, and is having some welding done anyway, so might as well just make a mount for the outrunner... It'd suck if I got it all back together and found that the surrounding metal did in fact cause problems.

Here's a pic of the final prototype laser cut from wood:-

[E-racer]

Do you have access to a laser or did you outsource it?

[milesinfront]

I sell them... Just wish they'd cut metal...

[parabellum]

Just wish they'd cut metal...

Did you try it?

[milesinfront]

Did you try it?

No, but I would not try cutting metal with a scalpel either...

[milesinfront]

Trigger disc and sensor board is now mounted to the motor. The bracket is NOT my best work, but will hopefully do the job or be upgraded later... (3mm bent aluminium)

Here's the trigger disc being laser marked:- http://www.youtube.com/watch?v=Tky067KKlhw

And laser cut here:- http://www.youtube.com/watch?v=wAyoG6I_lhI

Material is 1.5mm engraving laminate. The 'body' of the disc was milled out of 10mm aluminium and fixed with 2x 4mm grub screws.

Just need to wire up the sensor board and will fire up the c80100 for the first time. (first time for me at least...)

Drive sprockets are still on their way from the UK. They are coming pre-drilled to 12mm, but without any means of fixing to the shaft! With the smallest being only 9t, I'm yet to decide how to do it...