Drive setupShiny exposed motorDrive circuitElectronics
OwnerPaul Kennelly
Owner's Other EVsBoreem Jia
Pink Boreem
Razor Pocket Rocket
Xtreme xp-707
Super-Razz SCOOTAH!!!
Power Wheels
Orange Zest
Razz the Third
Purdue Kokomo Electric Go Kart
LocationKokomo, Indiana US map
Vehicle2012 Xtreme X-140
Was a scratch n dent special. 50% off! I wasn't going to use the stock components anyways, so it was a good place to start.
Motorunknown 63-74 Brushless DC
no name brushless motor from hobbyking. This scooter could go faster than 23 mph, but I don't know the continuous current rating for the esc or motor, so it would probably all burst into flames sooner than necessary.
Drivetrain#25 chain. 11-60 ratio. The motor has a 10mm shaft and tncscooters.com conveniently sells sprockets with 10mm bores! I lost the roll pin for the sprocket, so I whacked in a 3mm bolt and bent the ends so it doesn't fall out. Works so far!
ControllerTurnigy Sentilon 100A HV
Solid controller so far. I like the programming options. The esc soft-start smoothly ramps the throttle over zero, three, or six seconds. Then it's max current all the way!!! I had it set to six seconds, but I got better controlling the wrist twist, so I disabled the soft-start.
Batteries2 Turnigy 4s 20c 5000 mAh hardcase pack, 14.80 Volt, Lithium-Polymer
These particular batteries are an interesting deal. 4s 5000 mAh AND hardcase for about $25! Plus I ordered them from the USA warehouse so shipping was faster and cheaper. Two fit side by side quite nicely.
System Voltage34 Volts
Charger Hextronik HX8080
I bought them for their reviews citing simplicity and accuracy. They charge through the balance wires, so only one connection is needed. Then, there is a switch selecting 2.0, 1.5, 1.0, or 0.5 charging amps. It takes about 4 hours for a full charge. So, I wish they pushed more current, but then they couldn't charge through the balance wires without frying...
Heaternone installed....yet
Instrumentationhandlebars
Top Speed23 MPH (37 KPH)
Rode around a 400 meter track and used a stopwatch to keep time. From there it is a simple distance=rate*time calculation
AccelerationINSANE!!! this scooter WILL pull wheelies at any speed. The high cg (standing on a 2 foot wheelbase), large torque, and sensitive throttle make this machine for experienced scooterers only!
Range4 Miles ( 6 Kilometers)
Same test as above, rode around a 400 meter track at full throttle until the esc cut out at 3 volts per cell. Range will be farther at slower speeds. I get 6 miles of range at 14 mph.
Watt Hours/Mile34 Wh/Mile
This is an average of 135.8 watt hours used for four miles at 23 mph. Uses 140 watt hours over 6 miles (23 Wh/mi) at 14 mph.
EV Miles
Current:20 Miles (32 Kilometers)
Seating Capacityone plus none
Curb Weight21 Pounds (9 Kilograms)
Not bad! I wonder if I can make one lighter...
Tires200 x 50 pneumatic
Conversion Timejust a new motor and wheels added to the old scooter
Conversion CostPneumatic wheels $50
Front Fork $15
New motor $50
Wattmeter $23
500 foot wheelies $priceless!$
Additional FeaturesUses a magura potentiometer throttle jacked into a servo tester to control the esc.

Installed bolts up through the frame to hold the deck down with wingnuts. Tool-free deck removal! I was tired of searching for a screwdriver and wrench to get the deck off to charge the batteries, turn the scooter on and off, etc.

The back hub is from andymark.com! They sell wheels and aluminum sprockets with the same bolt circle. So, mounting a sprocket to the wheel was a piece of cake. andymark also sells plastic sprocket spacers to offset the sprocket from the wheel so it lines up with the motor sprocket. Fun stuff!

Brakes? We don't need no stinkin' brakes!
I love it!

The motor and esc are mounted externally for cooling airflow.

This is the reincarnation of Super-Razz. The old fork and 6 inch wheels were destroyed. I upgraded to a bigger fork, a different ratio, and 8 inch pneumatic wheels.

Update 11/2012:

The scooter pulls around 600 watts at top speed which is about 20 amps for the motor.

Twice the rim one of the plastic wheel halves has split from the rest of the hub. Not exactly sure why it happens, but it isn't that much of a surprise. I pump the wheel up to 50 psi instead of 30, I wheelie the scooter EVERYWHERE ~180 lb load, I wheelie off curbs, and I ride wherever I want (water, dirt, gravel, cliffs, etc.)

I bought 2 8s pigtails from progressiverc.com so I can add a 2x 4s to 8s jst-xh extension to the batteries. Thus (with an 8s charger) I can charge both batteries at once to save a little time and complicity. If you intend to do the same, RESEARCH BEFORE YOU TRY IT!!! I hooked it up wrong and ended up shorting a cell through the discharge and balance wires. Luckily the 24 awg fused and opened the circuit before the battery caught fire and my neighborhood exploded.


code by jerry