Treadle feeders offer a way for chickens to eat while they're out in the yard, but prevent rodents from stealing their food at night. There are a number of treadle feeders available to buy, but they seem kind of expensive. Designs are available for home-made treadle feeders (including here on Instructables), but they are either made of wood (which wouldn't quite work for us), or require specialized equipment to build. I wanted something that would work to keep the hens food safe and dry, but wouldn't cost as much as a the commercial ones.
Step 1: Materials
Here are all the components, I found this metal tool box on Amazon for $20. This seemed like it would be big enough to hold a few days worth of food and it's fairly weather proof. I had intended to use the dremel tool to grind off the rivets holding the latches to the box, but I decided to leave them on for now. The picture also shows a jig-saw that I intended to use to cut the wood parts, but I ended up using a rotary saw (not shown) instead. Another thing shown in the photo, that I didn't end up using, is some "soft-close" drawer closer parts, left over from a kitchen project.
The box and the linkage (made from the aluminum bar) are the heart of this project. The wood treadles and the base parts are also pretty simple, you can see that I used I recycled lumber, and some of the pieces weren't long enough. If I find some more scraps I may make a better cover to keep the rain off.
Metal tool box with lid - 14-inch x 6-inch x 2-inch .
One 3/4 x 1/8-inch by 48-inch aluminum bar for the linkage.
Two long bolts
Four short bolts with flat heads
Two 1/4-inch spacers
Six Nylon-insert lock nuts
Four regular nuts
Six lock washers
One eight-foot 3/4 x 1 1/2-inch furring strip for treadles (may need more, depending on number of treadle parts)
Three feet of Redwood 2 x 4 for the base
A couple of pieces of 3/4-inch by 11-3/4-Inch wood for side guards
Lots of wood screws
One Champagne cork
Graph paper, ruler, compass.
You'll also need a drill with appropriate sized bits, a center punch, a hack saw, a file, wrenches, and vice grips.
Note that I haven't listed the measurements for the bolts. I just used bolts that I scrounged, and some of them aren't really long enough to work right. You'll have to select the correct size bolts for your project. Just puzzle out all the parts the bolts have to go through, and allow a little extra length for adjustments.
Step 2: Drawings
I started by making a few sketches, using the basic treadle-feeder concept. Since I'm using a pre-made metal box, I had to work the design around the box. I did this by just standing the metal box on its side on a piece of graph paper and tracing the outlines of the box and the lid, with the lid opened about as far as I thought it needed it to be for the hens to eat. From there, I played around a bit with various anchor points for the treadle pivot and where the lid attaches. I used a compass to figure out how each part would travel when the treadle moves, and I came up with something that looked like it had a good chance of working.
Note that it takes a lot more weight to get the lid to start opening than it does to keep it open. So you need to have enough leverage on the treadle to get the box to open, and enough weight on the lid to close it after the treadle is released. I used a piece of cork to limit how far the box opened, so there would still be enough weight on the lid to close it when the hen leaves. There was a lot of guesswork involved, and in the end I had to go back to the drawing board, as shown in the final step.
Step 3: Cut, File, Punch, and Drill Treadle Linkage
Once the pieces were cut to length I taped them together, rounded the ends and filed them smooth, and punched and drilled the holes. I measured the distance between the drill holes from my drawing, (2-1/16-inches for the short links) and added 3/8-inch in length to each end of each piece. The arm pieces (long part of linkage) were 12-inches long, with holes drilled for the linkage 4-15/16 inches apart (adding 3/8-inch to the end that mates with the short link). I also drilled pairs of holes for the treads. [The length I chose was a bad guess.]
De-burr the holes and do any finish sanding that's needed; you don't want any sharp edges. Then drill the corresponding holes in the box and the lid. I drilled the hole in the front of the box 1-1/8 above the bottom, and the hole in the lid at 1-1/4-inch from the back. Lastly, drill four holes in the bottom of the box (3/4-inch in from the sides) at each corner to attach the feeder to the base.
Now assemble the linkage. I put a regular nut with a lock washer on the bolts that attach to the metal box and snugged them down to keep the bolts tight to the box and the linkage square. Use the long bolt and spacer for the hole at the front of the box, and the flat-head bolts for the holes in the lid and for the linkage. At the place where the bolt attaches through the side of the lid, the bolt hits against the top edge of the box and prevents it from closing. I bent the edge of the box inward with vise grips so the bolt could clear the side of the box when the lid closes. I think it would have been a good idea to grind down the bolt head to make it easier to fit between the lid and the box. Bending the sides put some added strain on the front of the box, so what used to be a straight edge across the front, is now bowed outward, slightly. I just bent this back in with my hands, being careful not to bend the box too much.
Step 4: Mount Base Boards and Treads, Attach Sides
Now that the linkage is attached to the box, we just need to raise the box up a bit, so the linkage has room to move below the bottom of the box when the lid closes. It also needs some sides, so when one chicken steps off the treadle, the lid can't shut on a hen who may have been eating from the side.
To raise the box above the base boards, I cut two 6 1/2-inch pieces of the same material I used for the treadles. These will be lined up flush with the edge of the box.
For the base I cut some pieces of redwood that I had on hand 2 x 4 (14-1/2-nches long), and lined them up under the spacers so the base boards extend out from the spacers far enough that there will be room to attach side pieces without binding on the linkage.
I used the lines on my cutting mat for this, but you could also use a carpenter's square. Make sure to leave about a quarter-inch of clearance between where the sides will attach and the linkage parts. When you get everything lined up, hold the box down tight against the base parts and drill pilot-holes through the bottom holes in the feeder. Screw the feeder to the base, going through the spacers and into the 2 x 4s. Cut a piece of the tread material (furring strip) to fit across the two 2 x 4s at the end, below the end of the treadle l move up and down. Attach this "stop" board with screws. Don't attach all the treads until you have this stop-board in place. It doesn't matter how far the treadle goes down, this will be adjusted by attaching a piece of cork as a "stop" to set how far the lid can open.
Cut side boards to keep the hens from eating from the side. I just used scrap material I had left over from a kitchen project. The boards are 3/4-inch thick and 11-1/2-inches wide, but they turned out to be too short for the lid to work. This is just one of the problems I discovered during testing.
Step 5: Testing and Back to the Drawing Board
I found the lid wouldn't shut after releasing the treadle, but it worked better if I stopped the treadle from going all the way down. I measured the distance between the treadle and the stop board, that would allow the lid to shut correctly, and cut a piece of a champagne cork this thick for a "stop," and just glued it to the cross bar under the treadle. That helped, but the lid still didn't close correctly, so I taped a weight to the lid. The weight I used was a piece of round steel that I scrounged from my junk pile. You could probably use a rock or some other thing, as long as you can get enough weight to make the lid close when the hen steps off the treadle.
So, what did the hens think?
The feeder didn't work for them, so it was back to the drawing board. It turns out that chickens are bigger than I thought they were while I was designing this. The cover board gets in their way, and the treadle didn't extend out far enough, so the hens had to stand too close to the food when they were standing on the treadle and they couldn't easily reach under the cover to get at the food. Not only that, hens standing on the ground could reach in and get food while another hen was on the treadle; I didn't want a hen to get smacked in the head when the lid closed, so I needed to raise the cover board and make the treadle longer.
Extending the treadle part was not really a big deal. I only needed to cut some left over pieces of aluminum, and drill them for screwing on the treads. To mate the extensions to the existing treadle I removed the last tread, and clamped the extension to the existing treadle piece so I could mark the holes. Since the extended treadle would be higher off the ground when the lid closes, I decided to mount the extension pieces so they angle downward. I also decided to remove the next tread so I could match up three of the drill holes for mounting the extension. You can see the angle in the last picture.
With a longer treadle, the lid needed more weight to close, so I added another piece of steel. If I ever get a drill press, I'm planning to drill the weights so I can bolt them in place and get rid of the tape.
Step 6: Conclusion
I decided that the top cover isn't really necessary, and it seemed to scare the hens so I just left it off. It looks a little funny with the side boards sticking up, but all the sides are for is to make it so the hens have to stand on the treadle to eat.
I tied the feeder open for a few days so the hens could find the food. The first time one of them stepped on the treadle, she jumped a little when the lid opened, but as soon as she saw the food she was happy. If I had it to do over again, I think I would have drilled the front linkage mounting hole lower on the front of the box, and I would have made the original treadle longer and used fewer treads to keep it lighter.
One thing to remember is that this kind of feeder only works if the lid doesn't open all the way. You need to have enough weight on the lid, forward of the hinge point, for the lid to close and push the treadle back up. Overall, this feeder seems to work well enough for our needs, and it wasn't too complicated to put together. I don't know how much I ended up spending, but I'm sure it was a lot less than buying a commercial one.