Twin trundle bed frame are a great way to save floor space in a small living room. If you have three children, consider using a triple bunk bed to save space.
Determine the height that you want your bed to be. You should allow at least 36 inches between brats. You can lower the total height of the bunk by placing the lower British directly on the floor. Cut your corners to that height. Mark where you want each frame to attach the corner posts. Sand all your wood smooth with an electric grinder. Measure your mattress size and cut your boards for the twin trundle bed frame to that size. Cut the slats, 3 for each frame. Screw the boards in the frame into two smaller boards within the outer boards.
Screw slats along the bottom of each frame. Each twin trundle bed frame should have at least three ribs evenly distributed along each bed frame. Use carriage bolts to attach each frame to the four corner posts of the particular brands. Stain or paint pieces of the bed. Let dry and put mattresses in place. To create more ceilings you might want my floor to protrude from the 90 degree angle from the other 2. If you do, you will need 2 additional corner posts for the center and shorter corner posts for the head of my sleeping chest. You will build the bed the same with my bed frame coming out and fastening on the shorter corner posts on the bed.