Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: Nickosha on December 03, 2009, 10:00:13 AM

Title: Considering a DIY segway
Post by: Nickosha on December 03, 2009, 10:00:13 AM
Hello, I am considering building a DIY segway with my class and I was wondering if anyone has some advice or if anyone could help us with some of the questions we have.

1. How strong of motors do you think would be necessary? Atleast how much torque do you think we need?

2. About the motor drives, are there any relatively inexpensive commercial products we could use or is it difficult to build our own. I understand that an h-bridge isn't a very complicated design, but are there important features we'd miss out on by going that route?

3. From our initial research, it looks like you need to use a 2-axis gyroscope and an accelerometer for control. We are not sure what to look for in the specs though. Are there any someone could recommend?

Thanks for any help. We're really excited about this project.  ;D
Title: Re: Considering a DIY segway
Post by: definitionofis on December 03, 2009, 10:50:55 AM
I'm new here. But check out the tutorial section on torque calculations.
It is very good.

I guesstimate the motors will need 14 amps at 12 volts or more.

I posted some questions which led me to windshield wiper motors,
electric scooter motors and bike motors and chain drives.
24 volt, 150 to 800 watt bike motors are a possibility, too. had the best sprocket and chain prices.
Some electric bike and scooter stores were good for parts selection too.

I bought my H-bridge (14 amp, two motor, $65) for bigger amperage after building a
2 amp one for stepper motors.  That wiper motor link,
which I posted, had some cheaper regulators. I'm not sure if they
did two direction and PWM speed control.  I doubt it.

I think you can do a lot with sprockets and chains at slow speeds on weak motors.

It is interesting to ponder the acceleration and torque required to
raise a 180 lb. man from 40 degrees falling position to upright using a home made segway.

I wonder if any scooter or bike could be modified into a uni-cycle
and then put two in parallel for a segway imitation.
I can see this project getting expensive, even from scratch.
Title: Re: Considering a DIY segway
Post by: Webbot on December 05, 2009, 10:47:12 AM
The July/Aug/Sep 2009 copies of Elektor magazine had a design for a DIY Segway - the Elektor Wheelie

see (

If you buy the back issues then you will see circuit designs etc. Its also available as a complete kit (all mechanics, electronics, etc) for a 'mere' cost of: £1380 / € 1599 / US $2275