Build the Lawnadillo

Parts:

• RadioShack Hummer H2 Featuring Mattracks (#60-4418) $69.97

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• RadioShack 7.2V Hi-Cap Battery & Charger (#230-322) $24.99
• 9V Alkaline Battery $1.99
• Black & Decker Cordless 12 Volt Trimmer (#CST1200) $49.98
• 1†x †Bushing PVC Schedule 40
• 1†Elbow 45 PVC Schedule 40
• 1†Elbow 90 PVC Schedule 40
• 47†x †PVC Schedule 40
• (2) †Tee PVC Schedule 40
• (2) pipe hose clamps
• Assorted cable ties, sticky-back cork, tape, electrical wall switch, wall switch cover plate

*Before you begin this project, test both the cordless line trimmer and the RC truck for proper operation. There´s nothing worse than discovering that you have a â€dead†part after you´ve finished building your Lawnadillo.

1. Remove the battery, switch, and charging harness from the plastic handle/grip housing of the cordless line trimmer. Carefully insulate all exposed metal electrical connections with common electrician´s tape.
2. Remove the body from the RC truck. If the truck chassis has front-end suspension, like the RadioShack Hummer H2, then you will have to either remove the two front spring-shock absorbers or fuse the two front-wheel upper control arms to the lower control arms. This will prevent the trimmer head from nosing down and scalping the lawn.
3. Use the various pieces of PVC schedule 40 tubing and connectors to fix the trimmer shaft to the top of the RC truck chassis. Make sure that the cutting head remains parallel to the ground.
4. Replace the original momentary switch from the cordless line trimmer with a standard household wall switch. Dress this switch up with a color coordinated switch cover plate.
5. Check all your fittings and connections to make sure that they are rock-solid. This remote-controlled lawn mower can generate a lot of vibration that could shake things loose if you're not careful. Also, thoroughly check your wiring work prior to operating the Lawnadillo.
6. It´s time for a real test. Locate a piece of overgrown lawn, drive the Lawnadillo over to this area of disheveled grass, flick the wall switch for powering the line-trimmer head, and mow that sucker. It´s fun and addictive-when´s the last time you said that about mowing the lawn?

More Assembly Tips

• Be sure to keep your batteries full charged.
• If your Lawnadillo seems to be nose heavy, counterbalance the RC truck chassis by adding some extra weight to the rear bumper.
• As you might have guessed, with a swath of only about 10-12", the Lawnadillo can take a long time to mow a standard lawn. Therefore, the ultimate goal would be to have several of these critters scampering around your yard (using different RC frequencies), each cutting in an irregular pattern while avoiding obstacles-e.g., rose bushes, dogs, kids and each other.
• On my first Lawnadillo I was able to interface the main circuit board from a WowWee Roboticsâ Robosapienâ to my RC truck. This type of brain transplant will mow the lawn without needing your direct control. You can learn more about Robosapien´s circuitry inside my book, The Official Robosapien Hacker´s Guide (McGraw-Hill, 2006). Furthermore, a $10 Robosapien rebate coupon inside this book could be the best incentive for experimenting with this optional project enhancement.