Self Balancing Scooter Ver 1.0

After seeing the balancing skateboard, we thought we would built a Balancing Platform to test out the technology. We bought some rear ends of kids scooter for the drive wheel/motor and the electronics that XenonJohn suggested.
https://www.instructables.com/id/Easy-build-self-balancing-skateboardrobotsegway-/

Making a stand-on balancing unit is the same as a skateboard but the wheels are wider apart and the board is turned 90deg so the rear end of kids scooters were used. They were quite small but were quick and easy for testing.

Just don't hit any big bumps! We only had a few bit of skin missing from our shins and one hole in the wall!

Some rear ends of kids scooter were purchased for the drive wheel/motor as were the electronics that XenonJohn suggested.

Angle steel, flat plate and some tube were welded together to make an area to stand on and a handle out the front. The motors bolted on the sides and the electronics was fitted to the front. A torch was cut in half to use as a battery holder which fitted to the top of one of the motors. Now, the electrician needs a new torch! An old piece of plywood was used for the standing platform.

Now it looks like a real prototype!

It took a couple of attempts to get the polarity to the motors correct but it worked pretty much first go. The torque and power values were adjusted as we were using a 18Volt battery instead of 24volts that the motors are rated at.

It worked quite well.

Parts Needed: (remember you can try eBay for the parts)

•Arduino UNO - Check your local suppliers or eBay.
•Sabertooth 2x25 Motor Controller (http://www.dimensionengineering.com or a local supplier)
•5 DOF accelometer http://www.ebay.com/itm/181004141876?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
•2 rear end off kids scooters or buy motors and wheels separately  (www.oatleyelectronics.com or eBay) Have a look around your area.
•Batteries - SLA batteries are good and cheap, Power drills can be quite inexpensive too or LiPo's if your game!
•Shielded multi-core cable for the accelerometer and heavy power cable for the motors
•Deadman switch
•Toggle switch for turning.
•Toggle switch for adjusting balance position.
•DC connector for Arduino.
•DIL pins to suit Arduino
•Double sides tape
•Screws etc

Basic tools are needed

Also, someone with the skills and equipment to weld the frame.

And additional tools:

•Drill and drill bits
•Soldering iron and solder
•Wire cutter and wire strippers
•Heat shrink and hot air gun to shrink it

For the frame, a couple of pieces of angle steel and two plates were attached either side to bolt the rear end scooter motors onto.
Cut the 2 pieces of angle steel to the width needed for your feet. Holes were drilled in the plates to match the bolt holes on the rear-end scooter wheels. These plates were welded to the angle steel plates.

A post  was added out the front and a T-Bar handle welded onto this.

A piece of angled reinforcing from the upright handle to the second angle steel piece was added. Now, the wheels can be bolted on.

The electronics are quite simple.... just an Arduino, IMU, Motor drive and a bunch of switches.

All cabling for the switches and IMU should be shielded cable except if the IMU is right next to the Arduino.

The IMU needs to be mounted under the centre of the platform or in front if possible. We mounted ours in a box out the front.

Everything fitted in the box and the kill-switch, L/R steer and tilt adjust were run up to the handle. The battery was mounted on top of one of the motors.

The code is basically the same as XenonJohns code but some of the power/torques values needed to be adjusted because we were running 24Volt motors with an 18Volt battery.

At the start of the code there are 2 varables to alter in order to adjust the power and torque.

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Code bug updated on the 24th Feb 2012.
Issue with timing routine.
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