The Concept

I have the motors, I have development team (my father and I), and have the drive. Now I am ready for a concept drawing.

Since my motors have a 10.5" wheel and that long cylinder, I have to mount the motors such that cylinder is perpendicular to the ground. Mounting the motors horizontally will limit the length of the platform. I could avoid this by finding larger wheels, but that leads to another problem of finding a hub that matches the motor and a wheel that matches the hub.

I plan to have the electronics (sensors, processor, motor drive, etc) placed on the platform between my feet. Turning the Segway will be done at a joystick/potentiometer at the handle bars similar to the original Segway instead of steering with a swivel handle bar.

I drew a sketch of the concept in Google Sketch because it is free and easy to use. I sent it to my dad, so he can start working on the frame. This is an excellent start.

Its all about the motors.

Before, I layout my design for the Segway, I wanted to find motors first and design my frame and electronics around the motors.  This may seem kind of silly, but I had some logic behind it.  Motors come in all types of sizes and ratings.  I do not want to design a frame and supporting circuitry with the hope that I can find motors that can fit in the system.

I also figure that one of the biggest cost in the system would be the motors.  The motors must support a rider's weight and provide enough speed to keep the rider balanced (and provide a little show off speed).  I looked online to see how much DC motors cost for such an application and my jaw dropped to the ground.  I saw motors ranging from $150 to $600 each.  I'm trying to do this on the cheap and that is very steep.  Wheelchair motors were priced very reasonably and they are suitable for Segways based on Trevor Blackwell and other Segway builders.  They are also used on Battlebots.

There are several wheelchair motor vendors out there like NPC Robotics.  They have motors ranging from $72 and up along with tires and wheels.  I looked at Ebay for used motors because I still felt this was a big investment at the beginning of my project.  I looked and I looked and I looked, but I was running into a little trouble.  Most motors were very expensive or they did not have a matching set.  I was starting to get frustrated until my father left me a voicemail and said he found some on Ebay.  WHAT?  How did my father who recently figured out how to search on Google and attach a file on Hotmail find motors on Ebay.

Well, this is what he found:

Can you believe it?  I got two 24VDC wheelchair motors with hub and tire for $26.  I could not believe.  I told my co-worker who built a Segway last year and he said if I didn't get those motors then he would of snatched them up.  The seller stated that these motors were from a Rascal wheelchair.  He also said they retail new for $1000, but I'm thinking he is talking about the chair not the motors.  I must say, my father found an excellent set at a great price.  Now I can start my concept drawing.

Silicon Rivers

I want to make a Segway.

For the last couple of years, I have been giving presentations to encourage middle and high school students to pursue careers in engineering and science.  To keep the students' attention, I usually demonstrate a walking robot I built using an Oopic and a spider toy.  I used IR sensors to detect obstacles and a UV sensor to detect flames.  The robot was pretty cool, but it started to show some age.  We live in a world where educators and parents have to compete against the Internet, cellphones and video games, so it is tough for a small walking robot to hold the interest of young minds.

One of my co-workers told me about another co-worker at another facility who made a Segway (that was very convoluted).  I was shocked.  I never heard of a person building their own Segway, so I called up my co-worker and said how did you do it?  He told me to check out his YouTube videos.  He told me that they are very straight forward to make and require a little bit of hardware, software and some mechanical know how.  Then I realized this could replace my walking robot.  Students will love to see this versus my tiny robot (I hope). 

I called my father who recently retired from repairing and installing HVAC systems.  He now has a lot of time on his hand, so I enlisted him in the mechanical portion of the design while I would focus on the electronics.  Our goal is to build a Segway clone as cheap as possible, but of course we want to be safe and reliable.  I think it will be an awesome father and son project.

I started this blog to capture what I am doing and what I have learned and I hope whoever reads it can give me advice, feedback and be inspired to make a Segway too.

Photo of T-shirt design by Indie Tech