The 36" cage was my first attempt at this, but the larger 48" enclosure is how I will do it from now on.
- Get five 2x1 8' untreated boards at the hardware store (mine were $2.50 each)
- Ask for 48" pieces (5) and 23.5" pieces (6)
- Attach the long pieces on the outside of the enclosure
- Drill a spy hole in the aluminum frame before screwing them in
- Put the 23.5" pieces on the inside and screw them in from the exterior
- You can screw large horizontal branches directly into these cross supports and use them instead of the screen to prop up other diagonal branches