I don’t know if you guys recall hackaday post entitle “1480W scooter motor guarantees head trauma“?  There was a pretty intense debate on helmet use! 79 comments in total! Charles from MIT also had is word on the use of helmet. He also has more crazy rolling device but does not wear a helmet.

I was able to stick my GoPRO on it. I had my GoPRO for more then 1 year now. Very useful and great video quality.  I do have a lot of videos of the scooter but did not edit them. Working on it. I am right now working on something else… look at the picture and tell me what you see…

What I love about this design is the way it folds up into this very small footprint. Have a look at the video:

www.youtube.com/watch?v=vAoI78p2p1M

It’s about 20kg (44pounds) and the max speed is 25kph (16mph).

I like the very simple graphic interface.

There website is here: http://www.voltitude.com/ and they have this neat video in french: http://www.voltitude.com/news/voltitude-on-swiss-national-tv.html
They say, they spend a lot of personal money on the project.  They have 800 pre-order and the Chinese are interested!

In the video they talk about the price and it should be between 4000 to 5000 Swiss Franc (CHF) so that is $4782 to $5980 US.

I then send it back to Hobbyking to get a new one. Took a while until I had to send them a email go get feedback on this return. They explain that they tried it and it was working. Here is is 1 out of 3 pictures they took.

Ok fair. I have proof it does not works and they have proof it works. What happen next?

This mean that the charger has some intermittent problem. I tried to explain that to hobbyking customer service and they told me that I need to pay $23.59  for shipping to get it back or they can send it with my next order. I said no, your product is defective, send me a new one!

But check this out, I when in the reviews of the items and found this:

Thought I found the perfect charger.. Worked great for 2 days charging 4x 7 cell nimh packs at 5.3 amps each! Fan was quiet, temps were good, then port#1 failed for no apparant reason. Waiting on HK’s response. Hoping I can return to US warehouse.

First, within a day of receiving one of these chargers, one of the LCD readouts went bad (Port 4). I have confirmed that the problem is with the LCD unit and it needs to be replaced. Contacted HK to see if hey could send me a LCD module but they said no I would have to return the unit. By the time I get done with shipping both ways, this unit is no longer a good deal.

I also had problems with output 4. If I started charging the display shows error messages, unknown characters or nothing, and it stops immediately charging.

This charger works. It’s not the best balancer, but it works. I did have a temporary glitch with the 4th port display, which seems to have sorted itself out somehow.

I have had this charger for several months. It worked perfectly for quite a while, now charger port 4 does not function correctly.

You can clearly see that there is a problem. That problem is intermittent. I did mention those review but they said nothing back in return.

Who is going to win?

I just send one last email explaining all that in a very simple way… Let’s wait and see!

It’s also much more fun doing my own parts then doing tutorials.

Oh I love Solidworks! I can’t believe I have been using Google Sketchup all that time, what a shame! All my friends where saying, try it, it’s easy! Yes it is easy!

I’ve use Charles technique to parallel a part on the mill. You place a perfectly rounded bar in the T slot of your table. Then take you part and touch that bar. It will be parallel with the table. (You like what I use for circular rod? yeah I know!)

Look at the bearing placement. The best way is the bottom picture. It is impossible for the aluminium bracket to pop out of the assembly since the lip of the bearing is holding everything. On the first picture, vibration could will make the bracket come out.

I bought that spring saying “Thats the ONE!”. I then brought it home and my dad start laughing at my spring saying it’s scrap. I didn’t believe him… Ok DAD your RIGHT, it’s a piece of crap, it’s loose and way to flimsy! I need to find a better one, aka Stiffer. I need to figure a way where I could screw to adjust the tension on the spring. Something that pulls on one end.

Since I wrote this post in august and took me time to post it, I was able to show this to a guy at work and he told me that it should not even be a spring. It should be adjustable rigid link. When I roll with my scooter, you can see the thing vibrate and follow every movement of the belt.

The thing is, I thought that having a belt tensioner would get tension on the belt without consuming more current. I can use the bolts that connects to the shaft to tight the belt and that will  be very stiff . This also makes the motor consume so much more current then having a little loose on the belt corrected by a belt tensioner. I still have time to think about it.

<EDIT> After posting on facebook, my friend Louis Moreau said the same comment on the static pressure and not using a spring. Here is his drawing!

Thanks Louis!

I just tested the scooter with one battery and I am more then happy with the speed! I hit 30km/h (18-19Mph) which is perfect!

I have a nice video and great data. I am writing a post about it.

www.youtube.com/watch?v=0wTfQiGFAKE

www.youtube.com/watch?v=t7uvv7EYqg0

www.youtube.com/watch?v=wBgt0wj3Hzk

Here are the specs of the prototype
Range Up to 30 miles
Max Speed 25 mph
Recharge Time LiFePo4 1 ½ hours
Tire Diameter 25”
Weight of Bike 125 lbs.
Footprint 16” x 34”
Max Hill Incline 30%
Max Rider Weight 250lbs
Turning Radius Zero to 3 ft.
Estimated Retail Cost $3,500

You can find more informations on there website
http://rynomotors.wordpress.com

This looks like the Bombardier Embrio concept. The Embrio has smaller front wheel that acts like a stability control when the Embrio is stopped or traveling below 12mph.

Or the Canadian Benjamin Poss Gulak, with his one unicycle with two wheels.

Here is the new U2 version. It is a hybrid between a motorcycle and what you see there. I opens like scissors and unfolds into a motorcycle. (Not really like scissors, more of a  linear motion)

I just notice that Ben has a blog! http://bpgulak.com/

He his working on this neat track scooter call DTV.

www.youtube.com/watch?v=hh2nLWYnxkM

www.youtube.com/watch?v=7s0guJrle_8

Thanks to Hung Chang for is cool blog wackyboards where I learn about Ryno motors. http://wackyboards.blogspot.com/2010/08/ryno.html

PS- It is RYNO motors and not Rhino like the url

I have a tonne of video to upload because I have been using the scooter a lot!! I have a couple of miles on it. I broke the belt a couple of time and I am right now waiting for a new belt, got 2 this time.
I am also working on a belt tensionner, I realise it is important (but to lazy to build one) since the belt slips a lot due to high torque when starting the scooter.

I bought these new Turnigy Nano-Tech battery from hobby king.

Here are some of the highlight

• Fast charge capable, up to 15C on some batteries.
  Longer Cycle Life, almost double that of standard lipoly technology.
• Internal impedance can reach as low as 1.2mΩ compared to that of 3mΩ of a standard Lipoly.
• Less Voltage sag during high rate discharge, giving more power under load.

Since V = RI, and we have a 3mΩ resistance per cell  in my standard battery and consume 80Amp at peak.

When you have 14,8V, that is 4 time 3,7V cell. Since they are in series, we should then have a 3mΩ * 4 = 12mΩ for a pack.

V = 0.012A * 80
V = 0,960V of drop out. (960mV)

With the 1.2mOhm
V = 0.0048A * 80
V = 0,384V of drop out.   (384mV)

There is a difference of 576mV. 40% difference.

That is theoretical, how does it stand up in real life?
Here are the measurement I got from live test.

82.51A Peak Amp
Nominal Voltage 16.52V and the minimum voltage sag was 15.58V

16.52V-15.58V = 0.940V
0.940V/82.51A = 11.393mΩ

77.83A Peak Amp
Nominal Voltage 15.65V and the minimum voltage sag was 14.71V

15.65V-14.71V = 0.940V
0.940V/77.83A = 12.078mΩ

81.04A Peak Amp
Nominal Voltage 16.67V and the minimum voltage sag was 15.37V

16.67V-15.37V = 1.3V
1.3V/81.04A= 16.041mΩ

72.85A Peak Amp
Nominal Voltage 15.23V and the minimum voltage sag was 13.95V

15.23V-13.95V = 1.28V
1.28V/72.85A = 17.57mΩ

70.03A Peak Amp
Nominal Voltage 15.98V and the minimum voltage sag was 14.88V

15.98V-14.88V = 1.1V
1.1V/70.03A = 15.708mΩ

I realise after looking at those results that in some test I have the initial voltage and some the “after the ride” voltage. That make my result not consistent and semi false.

There is difference between the voltage read at the beginning of the test and the one at the end. In my notes I had some results where I am not sure it that is the voltage are at the beginning or the end of the ride.
I will be careful during my next test.

There is many test to be done again with the new batteries. Can’t wait to see if I spend to much money on those batteries!

Here are the hall effect sensor. There is 3 sensors.

Here you can see the slot inside the shaft where the wires can travel.

There was also this neat battery. 48V 10.5Ah lithium battery. It weight 3.4Kg (7.5Lbs)

That could fit in my scooter. The only draw back of those specific battery is the continuous current discharge. It is very low. I think it is 2C so 20Ah… the motor consume about 4Ah with no load and I get surge current of 70Ah.

Here is the work on the new revision of the original scooter. The original scooter is very small in length (29 inch). To select the new size of the new scooter, it was really easy. I just place my feet on the ground at a distance that I felt good and stable. Like on a snowboard.  So I added around 11 inch for a total of 40 inch (wheel to wheel).

Here is how I did.

This is the frame I found at St-Eustache flea market, one of the biggest in Québec.  I paid 10$ for it. Just the frame no motor, no battery. They are in very good condition and normally, when found online, they cost 18$ for the front wheel and 20$ for the back one. So 10$ was a good deal.

I have to go again to that flea market this summer! I will bring my dad, he loves flee market just like me!

Saw the entire frame in 2.

I also made 2 of  those plate you see in the picture so I can give tension on the belt with the left end screw. When I turn the bolt, the washer (big circle)  is move to the left, it pulls the axle of the back wheel.

To have a longer frame, I will use aluminium  L bracket. To mount them to my scooter, I drilled hole in the frame.

Here I cut the L bracket.

I also added other metal bracket to hold all the electronics in the middle of the frame.

Here is the progress. It feels stables when I get on it.

The new 11 inch makes a huge difference!

After I installed the motor, I saw this. Look closely, the outher shell (black) is touching the gold piece. There is suppose to be a gap between them.

I machined this like spacer.

Without the spacer.

With the spacer. See the difference?