I was able to cobble together a hand held seeder out of PVC pipe and a few other pieces of hardware. I’m expecting that it will work for medium to large-sized seeds like beans, corn, peas, pumpkins, squash, and, most importantly for me, sunflowers.
Here’s how it went.
With a table saw, I shaped one end of a 1/2 inch PVC pipe to a V-shaped point. I’ll call this the downpipe and its length will depend on how tall you are. I was shooting for it to end up a little above waist level, and I’m fairly tall, so mine ended up being 41 inches long.
Out of a piece of 4 inch PVC pipe I shaped a strip to close off one side of the V-point at the bottom. I used PVC cement to attach it, and I’m thinking that it may be the weakest link in the machine. Time will tell if it will withstand repeated jabs into the soil.
Edit 9/1/16: The glued-on strip is still there doing fine.
To close off the other side of the V and, more importantly, to open and let a seed drop out, I fashioned a flipper out of a piece of steel. Getting a useful piece of steel is probably the hardest part of the project. You want to be able to bend it, but not so easily that it will come unbent halfway down a new row of corn. It helps if you’re a bit of a pack rat and collect odd materials for future use, but hardware stores will probably have something you can use. Using a jig saw is an easy way cut the steel, but a hack saw is fine too.
The flipper starts out being cross-shaped. The side arms are drilled for a pivot bolt and then bent down to wrap down over the pipe. The top arm is then bent up to make a lever to attach a pull rod. This rod will pull the flipper open to drop out the seed.
Some shiny paint has been added and you can see how the flipper fits on the bottom and attaches to the pull rod.
The funnel is to guide a dropped a seed into the pipe, and next to it is a cup made out of a 2 inch PVC coupling sitting on a 2″ male x 1/2″ female PVC bushing. A 4 oz Yoplait yogurt container fits perfectly into the cup, closing off the hole in its bottom and holding the seeds. The cup is only to hold the seeds. There is no automatic drop of the seeds. Sorry, I’m just not that clever. You have to hold seeds in your fingers and drop them one at a time into the funnel. You drop a seed, then squeeze the handle to open the flipper and release the seed in the soil.
Edit 9\1\16: I’ve long since lost the yogurt cup and I’ve cut the 2 inch coupling down to about half height to make it easier to get my fingers in to grab the seeds. I closed the hole in the bottom of the coupling with good old duct tape. Also, the funnel is totally optional. It works just fine to drop the seeds into the top of the down pipe without the funnel there.
The handle is made of two parts. The lower piece is attached to the top of the pull rod and to a spring, so that squeezing it upward pulls the flipper open and drops a seed. When it’s released, the spring pulls it back down, closing the flipper. This piece is made of 1 inch PVC so as to be big enough to wrap around the 1/2 inch downpipe. The ends of this were angled in the table saw in the same way as the bottom of the downpipe.
The individual pieces are shown above, and all together below.
Edit 9/1/16: The worst part of this design is that I ran two screws all the way through the down pipe to pivot the flipper and the lower handle. It works fine for medium seeds, but big seeds can get caught on the screws. A better way to do it would be to run a short screw threaded into the plastic pipe from each side just enough to screw into the plastic, but not protrude inside. The downside to this is that the plastic pipe is not really very thick and i think it would be easy to strip the threads in the plastic. That’s why I didn’t do it that way.
If I were going to build it now, I think I would glue an extra thickness of plastic on the outside where the screws go and then use the short screws as mentioned above. This will change dimensions of the flipper and the lower handle. Smarter people may have smarter ideas.
Requested close ups of the flipper Sorry they’re blurry.
Here’s a crude sketch of the dimensions of the flipper to help answer a posted question. The 2 inch section is the top part that is bent to attach to the pull rod.