Adult size Folding Kick Scooter E Conversion

[Kepler]

I have been lurking around on this forum for some time now and really enjoying the discussions and wealth of information available. I decided on a simple project to ease into this hobby and figured the simplest solution was an RC motor setup on an adult size folding scooter. Being an active Electric RC Helicopter enthusiast, I had most of the parts lying around ready to go, I just needed a platform to fit it all too.
I quick search on EBay located a suitable adult size folding scooter which I ended up picking up for $40 second hand.

Selection of parts were as follows:
Turnigy C6463 230 kv motor
Turnigy 110 amp ESC
Rhino 6S 4900 mah LiPo

Raided the parts bin and found a suitable gear and pinion for the drive. Turned up some adapters and built a freewheel unit using an 18mm sprag bearing. Gear ratio ended up being 4.35:1 which worked out nicely for a 180mm wheel and 6S LiPo.
Next item on the agenda was a control unit. Whipped up a quick 555 based servo driver circuit and added a few extras like a kill switch and speed limiter switch so the kids could have a go. Also added an Eagletree data logger and power panel to monitor amps and mahs so I didn’t kill ESCs or LiPos. Also added front brakes and some micro switches to cut out the ESC when the brakes are applied.

So that’s about it. Very happy with the result and probably ended up better then I expected. So now some performance results.

Top speed unlimited: A brisk 32 km/hr measured via GPS.
Limited speed for the kids and beginners to use: 12 km/hr.
Acceleration: Enough to easily lift the front wheel even when traveling at 10 km/hr
Average distance at a comfortable pace and coasting where possible: 8 km (4000mah back into the LiPo)
Maximum amps drawn: 101 amps. This was up the steepest hill I could find at full throttle. This hill is so steep, I need to use first gear on my 27 speed mountain bike to get up it. The scooter didn’t drop under 25 km/hr going up this hill.
Maximum Power absorbed: Just over 2 kW
Scooter weighs 11 kg in total and fits easily into a car boot.
The only addition needed is a second 6S pack to give me 10 ahs and about 16 km range.

So that’s my first project under my belt. Ended up being not too daunting and I only spent an extra $80.00 plus the parts I had lying around to complete the project. Here are a few photos of the completed project plus a data logger readout from one of my rides. If you are looking at the data log, its setup to log only if the amps are above 2 so the graph is kept compact.

[def215]

I like your build a lot Kepler. I always enjoy seeing things that don't belong that work like your rc drive scooter. How many volts is the system running? Very nice work.

[Kepler]

Thanks def215. The pack is a 6S 5000 mah Rhino LiPo from Hobby City. Around 22V under load and can handle 100A draw with ease. Got a second pack on its way to double the the range but its not really necesary on this type of ride. 8 km on a scooter with solid tires is plenty far enough. I have really good chargers for my Helis so I can charge the pack in 35 minutes without a problem.

[tostino]

I'm very impressed with your build. Looks really good on that scooter. When you get a chance, care to do some acceleration testing? Like time to 20km/h or something like that to give us an idea of how it pulls?

[Kepler]

Thanks Tostino,

Did a few acceleration runs. The power is just silly. I need to ease the throttle on to stop it doing a wheelie and keep my weight forward as much as possible. Managed a best 0 to 30 km in 5 seconds and peaked at 120 amps. Need to fit a set of wheelie bars on it to see what it could really do.

[Robomaniac]

Hey Kelper,

Nice scooter! Really nice, you should get yourself Arduino microcontroller to replace the 555 timer. You will be able to get a acceleration curve and other stuff. Arduino are very easy to program, I could even send you the code I use in my scooter.
http://www.hvwtech.com/products_view.asp?ProductID=682 it cost 26$ US
http://arduino.cc/


I saw that scooter at my local sear, it is expensive, I will wait until the price falls down. Did the pinion came from the original scooter?

Keep up the great work!

ps- don't forget a video

[Kepler]

Hey Kelper,

Nice scooter! Really nice, you should get yourself Arduino microcontroller to replace the 555 timer. You will be able to get a acceleration curve and other stuff. Arduino are very easy to program, I could even send you the code I use in my scooter.
http://www.hvwtech.com/products_view.asp?ProductID=682 it cost 26$ US
http://arduino.cc/

That controller is just what I have been looking for. Thanks for that Robomaniac. I will order a couple of those today. If you could send me the code that you are already using, that would be much appreciated also. I will PM my email address to you.

I saw that scooter at my local sear, it is expensive, I will wait until the price falls down. Did the pinion came from the original scooter?

Keep up the great work!

ps- don't forget a video

I was lucky to pick up the scooter for $40 on Ebay. It was a bit sick but the parts I wanted were fine. The pinion, main gear, and one way bearing were all salvaged from the original scooter and re configured into the current drive unit. Also the back tire was flat spotted from a big brake lockup. I fixed this by just putting the wheel in the lathe and removing a bit of tire material until it was perfectly round again.

I will try and get a video together.

[kfong]

Nice build, I was planning to modify a Xootr, but the Scooter you picked out would be really easy to convert. I really like the long deck, good reuse of the kick plate. I might end up doing the same if I can't get a Xootr for a good price. Only downside I see is the height, seems too high for manual pushing, something I need if the packs go dead on a long trip. I'll look for these locally and see how they feel when I push them around.

[Kepler]

Bit of an update.

Some how managed to break a tooth on the main gear. It was badly worn and I dont think the material was particularly good. Managed to pick up a new gear from a local gear supplier who had a suitable gear off the self. The gear is a Mod 1.0 70 tooth with a 10mm bore. About an hour on the lathe had it re configured to suit the scooter. Also made some new steel brake shoes for the front brakes. These work really well with the hard rubber tire. Just ordered a really cheap speed controller from Hobby City to try on it too. $27 US and rated at 90 A with 100 A peak. Will fit some big heat sinks to it and some extra Caps to the battery side and see how it handles the load.

[chemicalpro]

Hey Kepler, nice build mate!

Can I ask, how did you get your sprocket onto your brushless motor? And does the motor create a high buzzing sound? Also, sprocket to sprocket, is it noisy?

Cuz I'm looking to get a motor onto a Xootr MG and using their older EX3 wheels: http://www.xootr.com/Merchant2/graphics ... elBack.jpg

These wheels don't look to take on a #25 chain, maybe another numbered chain. Any idea which it might be from the looks of it?

Cheers!
-Damien

[Kepler]

The pinion gear is pressed onto a harded shaft. One end of the shaft is suported by a roller bearing, the other side is goes into a oneway bearing so it can free wheel.

This is a complicated setup that I configured only because parts from the stock scooters suited the conversion. Gear to gear is a bit noisey but no louder then a chain setup.

I would not recommend this setup though. A chain to a back spocket with a bike style free wheel is a much better solution. My second scooter has this setup.

In regards to fitting a sprocket to the brushless motor, The sprocket hole is machined with two flats on each side. To mate it to the brushless motor, I hand filed 2 flats on each side of motor's 10mm shaft and resessed the flats about 6mm. This gave the sprocket a positive key to shaft. I then drilled and tapped a 4mm hole in the end of the motor shaft and turned up some spacers so the sprocket would lock up against the motor's front bearing. All quite easy to do if you have a lathe.

Hope that makes sense.

[chemicalpro]

Hey Kepler, thanks!

I was looking along the route which required the least machining and frabrication, of which I stumbled upon the Xootr eX3 wheel which they still sell.

Mounting a sprocket onto the MG wheel would require me to alter the board for clearance for it and the chain.

The eX3 wheel looks doable, just need to figure out which #number chain to use on it and perhaps keep the entire motor to wheel belt device within the circumference of the wheel i.e. eliminating the need for frabrication on the base board on a whole.

I'll probably find a suitable, powerful and hopefully not so buzz noisy brushless motor so as not to add too much buldge onto the sleek frame. Hopefully I can find a contractor to lathe the a chain sprocket onto the motor shaft.

Will order the MG and eX3 wheel and play by ear when it arrives

Thanks again mate!

[Storm]

Chemicalpro that wheel looks like it's for a geared drive and looks simple to adapt, I would make a mount for the motor on the deck and couple a gear direct to the wheel gear, depending on the makeup of the wheel gear determines the power it can handle, the small gear from the motor may strip the wheel gear.

[chemicalpro]

Howdy Storm, good to see you here mate!

Yup, I was trying to figure out if it was a ring gear on the wheel, couldn't really tell from the face angle of the picture.

Yes it would definitely make my progress that much easier! Find a suitable ring gear to mount on a brushless motor shaft, mount the motor onto the deck and the rest would be electronics and stuff!

Was looking at the TURNIGY range brushless motors, looks pretty alright. However I've watched a couple videos on it and some give up a high pitched buzzing/screeching sound.

Any brushless motors you've used before mate? Any to recommend maybe?

[Jay64]

Why are you linking to one specific company, for kids scooters, when asking for advice on purchasing a kick scooter for someone older than that companies products are designed for?

[sk8norcal]

weird...
I think those are spam posts...

[tuurb]

Hello,

Really really nice built kepler!

I recently bought an adult kick scooter to convert it and am still a bit stuck on how to mount my rear sprocket on the wheel of the scooter.
I think I have almost the same wheel as you have on your scooter but mine is 200mm.

I saw on the second picture that you really connected your sprocket very well.
Is it a custom machined piece in between the wheel and sprocket? If so would you happen ta have any cad files maybe please?

My idea for the moment was to fill the triagular spaces with aluminium and to use spacers on the wheel to get both parallel. But your setup is much nicer!


Thanks in advance,
Tuur