I needed a to keep the wheels of my YAAR robot (see YAAR Instructable) off the ground for testing.

Step 1: Materials

Actobotics parts (from Servo City):

(3) 6" Channel
(2) 12" Channel
(1) 1/2" Aluminum Tubing - 6" length
(2) 1" Aluminum Tubing - 8" length
(2) 1/2" Bore, Face Tapped Clamping Hubs, 0.770" Pattern
(4) 1" Bore, Face Tapped Clamping Hub, 1.50" Pattern
(2) Side Tapped Pattern Mount C
Screws

Other parts:

Neoprene padding (sold as anti-vibration pad on Amazon)

Step 2: Top Support

0.770" clamping hub goes on flush with very ends of the 6" long 1/2" tubing. Rest the assembly on workbench before fully tightening hubs in order to align them. Attach to 2 of the 6" channel from the inside of the channel.

Step 3: Aligning Clamp Hubs on Upright Tubing

The uprights are held in place with the 1.5" clamping hubs. There is no easy way to tighten the clamps once the hubs are in place, so I got the vertical spacing right by attaching the hubs temporarily in an extra piece of channel toward the end. Use a piece of flat plate so that the tubing is flush. Then the channel can be tightened. Once both ends are done, then again rest it on the workbench to make sure the surfaces are parallel - you may have to carefully loosen one hub to let it pivot around the tubing, being careful not to change the alignment along the tubing. One I had one done, I used it to align the hubs on the other piece of tubing.

Step 4: Attach Uprights to Top Support

Use external screws into clamping hub.

Step 5: Start Bottom Supports

Flip the stand onto the finished top supports. Center 8" channel onto the aluminum tubing. Attach to outside of each channel with external screws. Instead of using screws on inward faces of the channel, use a 1 1/2" screw to go through the Side Tapped Pattern Mount Type C. Be sure the perpendicular holes on pattern mount are facing sideways for attachment of last piece of channel.

Step 6: Finish Bottom Supports

Finish attaching pattern supports to the inward facing channel - I used a ball socket screwdriver to attach the screws. If I had been smarter. I would have attached the pattern supports first with the 2 inside screws, then added the outside long screws once I had the upright tubing/clamp mount assembly in place.

Slide last 6" piece of channel over the pattern mounts and screw into place.

Step 7: Finish Stand

The frame of the stand is now done, and completely usable. I wanted something to keep the robot from sliding around (and to prevent possibly scratching future projects). I had some 1/8" neoprene padding left over from a previous project - I cut a couple of pieces and just hot glued them to the tops.