My family and I just changed from renting apartments to renting a house on a little acre lot. For the first time in our married life, we found ourselves in need of lawn care equipment. Having just paid all those deposits and moving fees, we had enough left over for a push reel mower and a rake. If you have ever used a push reel mower, you know tall weeds and crabgrass just laugh at you as you roll over the top of them. The management company had no done much to maintain the lawn so I needed to find a way to knock down all those smug, 3 foot high crabgrass stalks. They weren't laughing when I cranked out my RDNK-2000 grass whip/ weed cutter!
Step 1: The RDNK-2000 Frame
I laid hands on a 3 foot section of wood plank from a pallet as well as a 4 foot section of 1/2 dowel rod. I cut a circle out of the plank using a drill and holding it at one end. The circle needs to be little smaller than the 1/2 dowel rod. I drilled down at a slightly obtuse angle to make swiping the base at the grass easier. A little tapering of the base of the dowel lets you twist it into the board hole for a snug fit and leaves a little dowel rod underneath to stop you from hitting the ground with the plank and breaking it. A wood screw inserted into the dowel rod and pressed against the the plank keeps it from coming apart on you.
Step 2: The Cutting Edge
For the cutting side of the grass whip, I took some spare blades for a carpet cutting knife and screwed them to the plank, leaving about 3/4 - 1 inch sticking out. These blades are readily available, inexpensive, very sharp and have the perfect groove down the middle in which to insert the screw. I left a little less space than the length of the blades between each screw. I wanted to recreate the effective slicing angle that the serration provides on commercial grass whips. I turned the blades to one side and braced them against the screwed down end of the next blade. In practice, I found the most effective angle was to pull the blade end toward the handle.
Step 3: Putting the RDNK-2000 to the Test
I only had enough blades on hand for one side so I commenced to hacking up the lawn. As you can see, it was perfectly effective and knocked down the weeds and grass very efficiently. I found holding the handle so that the end of the plank turned slightly forward created the best sweep and cut. Very much like the proper way to swing a golf club. All together, the whip probably weighs 3 - 3.5 lbs so it doesn't wear on you terribly. I have topped the weeds this way a 3 times without losing any effectiveness. When the blades go dull, I plan to flip them over and use the other side. All together, this probably cost me about $5 USD including sales tax. The blue in the photo is a little painter's tape I added to the handle for comfort. What do you think?