Hi Skylavaulter, this is my simple pop door. I purchased the metal pieces from Lowe's. They are called The Hillman Group 4-ft x 1-1/4-in Plated Steel Slotted Angle. Attach one side to the 2x4 and the other side acts like the track for the cutting board. I drilled a hole in the top for the twine. I drilled a hole on the side of the coop by the window & passed the string through. I put a dog leash clip on the end of the string, so I can just clip it to the chicken run fence to keep it open. The bottom of the cutting board ( on the inside of coop ) goes below the little porch, so no critters can lift the door from the outside. The pop door is about 8" above the floor of the coop, for plenty of shavings on the inside, and nothing gets kicked out. Good luck!!!!
