My latest project in organizing the herp room is a rack that supports two 55 gallon tanks.
This rack is nearly the same as the three tier rack, located
HERE and the assembly techniques are the same as used on both the 3 tier and the screen lids, which are located
HERE.
For this project, I used the synthetic glue, same as the other rack, for extra strengt in the joints.
The basic design of the 2 verses the 3, is obviously on less shelf. The center shelf of the 3, lends to extra stability and support in order to remain square and to not fall sideways under the weight of the enclosures.
The solution to the extra strength for the 2 level rack is with a simple cross brace, from corner to corner in the back of the rack.
The bracing in the back has a compound miter cut that is actually easy to make. Once the rack is togerther, make sure it is squared and stabilized with someone else holding it steady, so that the brace can be marked for the first cuts.
The easiest way to make the marks is to hold the wood in place against the rack and mark on the inside direclt along the leg and the shelf section, similar to the red pencil in the pic.
As you can see, the red marks aren't where I made the cuts. I simply moved them about two inches off, to ensure that I would have enough length for the brace to make it into the opposing corner after making the cuts.
This is a view of the back side, showing the brace in place.
This rack is also a bit wider and thicker than the 2 tier rack.
The thickness is determined by the thickness of the tanks that will reside on it, so that the tanks front and rear edges will sit directly on the 'shelf' with no underhang or overhang.
(Although I do have a slight overhang on the bottom tank, it is doubtful that it will decrease that tanks stability due to the 50 pounds of sand added to it, which further stabilizes the entire structure against tipping.)
Finally, a pic of the rack with the tanks set up and occupied
