Project Jericho – A Tank is Born or At Least Designed

Project Jerhico

Project Jerhico

The new project has begun. It has been codenamed Project Jericho, and the plans are being finalized. The boys and I have been planning this project for almost a year. It will be a track driven (tank) robot. We plan to run it from car wiper motors and some kind of timing belt or other automotive belt with teeth.

When we decided on a tank design early on because our last project “O.F.F. R.O.A.D” gave us challenges we didn’t want to face again.  First OFF ROAD was built out of an old 4 wheeled Powerwheels chassis.  We had it running forward and back, but didn’t have the time to build in steering.  Because of this, we thought a track design because it would allow for steering by just adjusting the forward and reverse of the motors.

After the tank idea was agreed upon, I scoured the Internet for track designs.  I thought there would be all kind of options, but found that unless we wanted to make something about the size of an R/C car we would have to build our own tracks from the ground up so to speak.  I am not knocking the R/C car size robots, in fact I found some really great looking tracks for that size at Amazon.  It is just we want a robot that uses a netbook PC as the brain instead of a microcontroller.  It will become clear why we needed the power of a netbook later.

Ideas for Tank Tracks

tank track designs The best site I found during my searches RC Tank Combat really got my brain thinking in tank terms.  I started looking deeply at how tracks work and how the wheels and tracks really match up to move the vehicle. It also showed me that R/C builders really understand the mechanical engineering necessary to build a custom vehicle.

At this point I was pretty set on building either the bicycle chain track or the chain and bolt track.  I was a little worried that our robot project was going to be more of a mechanical engineering learning experience than the electrical engineering project I was hoping to teach my kids with.  I have very little background in any kind of mechanical engineering and am more comfortable with electrical, so I was worried I would spend too much time learning rather than teaching.

As I was re-reading over and over the track designs at RC Tank Combat, I was also doing a lot of looking at images of real tanks in use today as well as WWI and WWII tank designs.  It was also a big help to see tracks in motion on youtube.  During days and weeks of planning and research on tracks, I came across what has turned out to be our best resource: A homemade tank on FastMHz.com. Again this was an R/C vehicle, but it was so detailed all I had to do was ignore the speed controllers and think in terms of motor controllers.  This post had all the detail I needed on not only the tracks, but the types of motors to start looking at and voltage to run.

The tracks of the FastMHz tank were made out of snowmobile drive belts.  But studying the pictures, I can probably use any kind of automotive belt with teeth.

Motors

Another big find with the FastMHz tank was it showed we could use wiper motors to drive the tracks.  What a great idea because they are strong and the gear box is built in.  I used the wiper idea to search the Internet again, and I found the site Monster Guts. This site sells equipment for building Halloween props.  Among their collection of components, they sell a wiper motor and it is only $15!  A search of ebay brought up new wiper motors in the $50 – $100 range.  I can get 2 from monster guts for less than one anywhere else.

wiper motor

Monster Guts Wiper Motor

More to come:

We are ready to move now.  We have a design and a sample tank to use as a reference.  We know how to build the tracks, and we know where to buy our motors.  Now it is time to think about sending power to the motors.  We are going to buy some parts, do some wiring, and take some pictures.  It should be fun and educational for the kids.  I hope it is inspirational to you.

 

Here is a small R/C tank chassis if that is the design you want.

Incoming search terms:

homemade tank tracks 

2 Responses to “Project Jericho – A Tank is Born or At Least Designed”

  1. One good look at my motors and you should realize why I’m weight paranoid with this project. These are late model Ford windshield wiper motors, selected because they are cheap, are readily available, and can be found in a wide variety of Ford automobiles and trucks. One of the biggest drawbacks so far will be speed. Motor shaft RPMs are a paltry 120 RPM which will make this a slow beast no matter what I do. Over-volting may be my only option eventually but we’ll stick with a safe, 12v system for now.

  2. Michael Spielman says:

    How is your project coming along? I am using the same motor from Monsterguts to control the steering on a custom RC golf cart project. What did you do to attach the threaded shaft of the wiper motor to whatever you are driving? I’m using shaft couplers from robot parts websites but they don’t fit perfectly and there is a little wobble in any shaft that is attached to the other end of the coupler. Any help (pictures) would be great! Thanks!

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