My banner was 4 feet wide and 30 inches high. The cross piece can be longer to allow for wider banners.
The feet are a bit more complex than some of the simple ones in an effort to make it more stable. I am not sure where the original idea came from, but this YouTube Video has the idea - thanks, Julio!
(3) 10' 3/4" PVC Pipes - I used Schedule 40 since it's a lot stronger than schedule 200. 1/2" pipes might work too.
(2) 3/4" 90-Degree Elbows
(6) 3/4" Tees
(8) 3/4" Couplings - end caps might work too.
All the connectors are Slip type.
The pipes are cut into the following sizes:
(2) 7' pieces for the sides
(1) 52" piece for the top - the width of the banner + 4"
(4) 1' foot pieces for the bases
(8) 8" pieces for the bases
The sides are 7' long. The top is 52" long - 4" longer than the banner width since 1" on each side will go in the fittings, and that leaves 1" clearance on each side for the string/ties that hold the banner to the frame. I used a spool of green twist tie material for gardening.
The bases have a 12" piece of pipe on each side of the central Tee connector, and 8" pieces as the ends with the couplings or caps.
See the pictures for the base construction. The sides go in the bases and 90-Degree Elbows hold the top piece to the sides. The bases can probably be oriented in any direction, but I had the 8" pieces parallel to the top.
So far, I have not had to glue any of the pieces - friction has been enough. I leave the bases together, and pull the sides and top apart. The bases could be glued, but be careful to get the middle T pointing straight up. Tape could be used on site if the sides or top start slipping.
In windy conditions, weights like sandbags could be placed on the bases.
Low cost and quick to build - Enjoy!