Solar-Charged Lawnmower

After searching various yard sales I found and bought this old lawnmower for $5.00. I was hoping to remove the internal combustion engine by loosening the bolts that attached it to the mower deck. No such luck. They were rusted to the deck so I spent a large amount of time cutting the deck with a rotary tool to allow the engine to be removed. I used some spray on paint remover to remove a majority of the red paint. Then I used a wire brush to remove all the rust. After that I sprayed the rust spots with a rust retardant to stop the rust from spreading.

After stripping the mower and removing the engine I was left with a mower deck with a huge hole in it. I went to a local scrap yard and found a couple of small sheets of stainless steel about 1/16" thick. I then cut the steel to the proper size to cover the hole in the deck.

When mounting the motor to the mower deck the most important thing was to make sure it was centered and properly secured. I made sure it was centered by measuring an equal distance from the sides of the motor to the outside diameter of the mower. I secured the motor to the deck with four 3/8" bolts.

Unfortunately, when removing the old blade from the old mower I was unable to salvage the piece that attached the engine shaft to the mower blade. This meant that it was necessary to fabricate my own blade mount. I found a piece of metal rod about 3/4" in diameter in the scrap pile in the HSU metals lab.

Once the motor was mounted I needed to find a place for the battery to sit. The base of the motor was facing the rear of the mower and would provide a solid mounting surface for the battery mount.

The electrical was one of the more complicated parts of this project. I had originally thought it would be rather simple, just run some wires from the battery to the motor, add a switch and that would take care of it.

After the mower was assembled and ready to go I needed a way to charge it. I used an 11 Watt Uni-solar panel that plugs into the mower when not in use. This panel is made to charge a 12V battery at 0.62 amps in full sun. I screwed a couple 4' long 2x4s to three cross supports to serve as a mount for the panel.