This instructable will show you how to build an electric seed hopper, and give suggestions on ways to use it.
Step 1: Materials
Small geared down electric motor
Piece of plastic (about 4mm thick)
Small jam pot
About 2.5cm diameter pulley
Some nuts and bolts of various sizes
A couple of washers
For the motor i used a nice small motor with an included gear box that was liberated from the auto focus mechanism of an old video camera.
The pulley was taken from part of the mechanism of a flat bed plotter (i REALLY wish I'd held onto the rest of it, it would of made an excellent x/y table for a simple CNC machine)
And the jam pot was "liberated" from a hotel (i guess they technically where free, but I like to think of myself as a bit of a badass sometimes.)
Step 2: Cutting the Plastic
I recommend using a sharp point to score a line on the plastic rather than trying to mark it with a pen or pencil.
If your feeling neat and tidy you can file the edges straight and make it look all pretty. (I didn't, but I might clean it up a bit when I get around to using it)
Step 3: Mounting the Motor
You'll want to mount the motor towards one edge of the piece of plastic, leaving enough room to mount the jam pot at the other side.
Drill all the holes and mount it on with a couple of nuts and bolts (the mounting bracket on mine wasn't quite flush so I had to use some washers to make it stand out from the plastic a bit).
Step 4: Mounting the Jam Pot
Then put a bolt through the jam pot lid, the plastic, a washer, the pulley, another washer and finally put the bolt on top. (if you don't use the kind of pulley I used that has a built in bearing you may have trouble with this because the pulley needs to be able spin freely, use whatever method works to make the pulley able to spin, but you need to make sure that the pulley is as flush with the plastic as possible otherwise seeds will get lodged between the two and the pulley wont be able to spin.)
If all goes well you should end up with something like the second picture bellow, and the pulley should be able to spin freely.
Step 5: Making the Seed Shutes
Firstly, with the pulley and jam pot lid bolted to the plastic, drill a hole down through the pulley, the plastic, and the lid of the jam pot. Now as the pulley rotates all the holes should line up periodically allowing anything placed into the jam pot to fall through.
(you'll need to adjust the size of the hole depending on how large your seeds are, I recommend starting off small and slowly enlarging the hole until it's large enough to allow the seed to fall through)
If your motor does not turn very fast you can spin the pulley round to a different position and drill more holes through the plastic and lid using the hole already drilled in the pulley as a guide, (see the second picture)
Step 6: Attach a Belt, and Finish!
If all goes well when you put seeds into the jam pot and turn on the motor seed's should fall out the hole in the pulley whenever it lines up with the hole in the jam pot.
And that's pretty much it!
Step 7: Ideas for Use
So my idea was to attach this hopper onto an R/C car (soon as i pick mine up from home I will be) fill it up with seeds from a plant that's really hardy and grows quickly (Suggestions anybody?) and go for a drive around the empty quarry beds (.....i would of course be obtaining permission from the relevant party's before hand and taking correct safety measures...), this means you wouldn't have to wander around on foot in damned dangerous places (seriously, you hear quite allot about kids/adults dying/hurting themselves in quarries) , and could stay at a safe distance (off the premises).
You could also attach this to an R/C helicopter and go for a fly over your "favourite" building site (I might make a smaller/lighter one for putting on one of those little cheap helicopters that are around nowadays.)
If that doesn't take your fancy you could always wander around your garden with the hopper and a pack of batteries in your hand planting seed wherever you go :)