Wildflower Seed Processor / Leaf Shredder





Introduction: Wildflower Seed Processor / Leaf Shredder

About: Dad and hubby, good food enthusiast, solar energy, boating, making stuff, melting stuff, and raising chickens.

I made this to shred leaves and break apart wildflower seed heads. This instructable shows an electric weed trimmer model; another instructable to make it gas powered is Gas Powered Shredder. The gas trimmer seems to have more torque and lower rpm which keeps everything from shooting out of the top of the can.

You'll need:

A Round Trash Can
A Old Electric String Trimmer (gas if you're really good at mods)
Some Scrap wood 1x2s
.25" Hardware Cloth
1" Deck Screws or Similar Screw

Note: One picture below shows the machine upside-down; snap off the screw ends with some pliers.

Step 1: Cut Holes in Trash Can

*Sharp Edges, be careful!*

Mark and cut the holes for the trimmer shaft (actually this center hole becomes a lot bigger later on so the head spins freely)
Mark and cut holes for your hardware cloth screen. Leave enough metal/plastic to support the motor.

Step 2: Add Screen

Cut some hardware cloth to fit the bottom of the can.
Add some wood supports to hold the hardware cloth and strengthen the motor mount. Screw into wood from the inside of the can and snap off the screws if they're too long.

Also remove any shrouds on the trimmer so it can fit flush onto the base of the can.

Here I also cut the center hole bigger so the head spins they way it should.
I also added a plastic spacer at the base of the shaft so it sets the head a little higher to clear the can.

Step 3: Add Legs and Motor

I used sheet rock screws to go right through the can (from the inside) and into the wooden legs. I then snapped off the screws with pliers where they were too long.

Screw through the can and into the plastic shroud on the trimmer. Use washers.
I adjusted the trimmer head depth with wood blocks so the string is rotating .25" above the bottom of the can; any higher and it leaves large debris that clogs the screen.

(With the newer string trimmer motor shown I had to modify it with a wood donut as seen in the picture below.)

Plug it in and start tossing in the leaves.
Rules of this machine (lessons learned on some of these):
*Always unplug when adding new string or making any adjustments.
*This is a high speed low power motor; that means it can be easily overloaded. When it starts to bog down, it's too much.
*This works best with completely dry seed heads, moisture in the plant material makes the stuff bounce around rather than shatter.'
*Pulsing the trigger works best because the air current lifts the debris away from the head.
(I didn't have any leaves to shred while making the video, so I used newspaper instead. That's where I discovered it's use as a paper shredder too.)



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    29 Discussions

    "Pulsing the trigger works best because the air current lifts the debris away from the head"

    Not unlike a blender when making margaritas :)

    1 reply

    This was a great idea when I saw it four years ago: now it's an even better 'ible! Good job Rob (er, as of today your paper shredding vid is not working...). I'm going to make one of these that can shred twigs.

    Hey great project. I have an old whacker in my shed and will give it a try, although seeing this makes me wonder about beefing things up to make something that will demolish twigs too.... hmmmm...

    1 reply

    excellent idea! We live across the street from a park with a forest of maple leaves and every fall the prevailing winds blow them in my yard. I rake them together, let my kids and the nieghborhood kids beat the heck out of them by jumping in them, raking them back up and then doing it all over again for days. this really reduces the size of the pile, the kids love me, and I felt like I saved money on having to buy a shredder, although the yearly residue piles are not composting fast enough to keep up. So last year I finally bought a cheapy leaf blower that was supposed to also shred. It works fantastic ... If you feed 1, (2Max) leaf at a time. I Guess what I am trying to say is You have just given me the solution. Thanks!! Great instructable!! PS: one thought I had - With the motor underneath where all the finaly shredded leaf particles are going, wouldn't it create a hazard of clogging the motors air vents? Maybe even a fire hazard? and if so what if one made a "cage" of smaller mesh (like metal window screening) around the motor?

    2 replies

    You may want to measure to determine if a very large soda bottle could shield your motor, or a bleach jug cone cut out to slide over the motor. The shaft of the motor would go up through the neck of the cone shaped container.

    Yes, good idea. There should be some screen there to keep the motor from getting too full of stuff. I would turn the can upside-down like in the picture and turn on the motor to clean it out too.

    I was think of doing this but using a old table mount router and some sort of blade system instead of that annoying weed eater string....great instructable!

    Another alternative for supporting the trimmer motor would be to cut a circle of plywood, 1/4"~1/2" thick, that would fit inside the lip of the trash can base. Mark the holes on the plywood and remove them with a jigsaw. Then screw the support on in place of the wooden blocks you used. Plywood is pretty stiff and even 1/4" spread over the entire area would be much stiffer than the 4 wooden blocks. Just a thought... Dr. Spiff

    A variable speed rheostat control for electrical motors for $20 on ebay fixes the speed problem on this machine.


    Coming soon: Gas powered seed processor/leaf shredder. AAAAAAAAAHHHHHHH! I overloaded the electric motor too much before I learned my lesson. If you hear it bog down, that's too much stuff in the can.

    I finally got flower seed heads through this thing; man does it work well. I use a tarp to catch everything.

    Interesting idea! I wonder if you used piano wire for the blades if you would be able to make wood chips from small branches.

    1 reply

    bicycle chain or old chainsaw chain might work too, if you can keep it balanced. But this would make it more dangerous like a homemade hammermill. I'm sticking to the heavy duty trimmer string for now.

    Excellent instructable. Glad to see it after a lot of not so interesting instructables lately. I'll probably get to build this soon, as there are always old weed eaters and buckets on the curbs around here about this time of year.