Molded Carbon Shuttle Side Frames.
Here is the Rhino generated solids CAD file of the Shuttle's Molded Carbon Frames. Notice that there is another larger slot in between the bearing blocks, on the side frames. That's for the push pull elevator conversion later on.
Here is an example of a Molded Carbon Frame for the Shuttle. Many of the metal standoffs, screws, and hardware required in the stacked frames are no longer required in the molded frames. So the molded frames are much lighter and stiffer. Plus, the landing gear rails are molded in, not bolted on. These Molded Carbon Frames will hold a .30 or .46 sized engine without any frame modifications. These frames with all of the boom, engine, and main shaft bearing blocks, weigh exactly the same as the stock frames. However, these are much more durable. The frame pictured, was molded and machined by Mark Diel.
These are the terrific Carbon ZXX replacement frames from Rave's in the USA. Notice all of the extra hardware required to put these frames together. That will increase their weight significantly. This is typical regardless of who makes them.