I have designed and built my own wooden frame for use in my PVC tube astromech replica. I based my design on ideas harvested from many places, of course there is nothing wholly new under the sun 🙂 The top and bottom plates are largely based on the Senna wood frame, though omitting the center foot cutout. And the construction of the vertical plates and the method of attaching the legs based mostly on Dan Baker’s wood frame design. My frame is constructed mostly from 1/2″ baltic birch plywood, and held together by 3/8″, 5/16″ and 1/2″ steel bolts and 1.25″x1.25″x1/8″ aluminum angle.
The vertical plates are made from 2 pieces of 1/2″ plywood glued together for 1″ thick plates
The bottom of each vertical is set into a routed pocket, and bolted down via the aluminum angle. THe bolts are secured to the base plate using T-nuts set into the base plate.
The top is similarly bolted, but not using T-Nuts. It is secured by wingnuts at the top for easy removal to service the droid.
There are clearance pockets cut into the base plate to make space for the resin details, these are largely in the same places as the senna design, but mine have simply been cut by hand where needed
Also, the verticals have been trimmed a bit to make room for the octogon ports
Glued to the outside of the vertical plates are small support blocks to help brace the flat ankle clearance plates at the bottom of the body, inset from the ankles.
The PVC tube is secured mechanically to the top and bottom plates via a series of small plastic L-brackets bolted to the tube (but not the plates), and places wherever they would not interfere with the resin details or skin detail.
It basically just sits on these brackets, which allows for the heat expansion of the plastic relative to the frame, and avoids being permanently attached by glue, to allow again for easy service.
The coin returns are styrene, and permanently glued to the inside of the tube.
THe center ankle is bolted to the base plate directly with 3/8″ bolts, and the base plate secures it with T-Nuts
Each legs is secured by 4 1/2″ bolts, screwed into large T-nuts set into the vertical plates
THis has all been built by me by hand, but could certainly be cut on a CNC.
My techniques for building it have been to use the 18″ craft rings from michael’s as router patterns to get good circular plates. Upon those plates then I copied the details from my drawings in pencil, and then cut into the plate with a trim router
CAD drawing may be found here: Drawings
(this folder is only accessible to members of the r2builders yahoo group…)