Tips on Popup Building

• Never be Cheap over Safe.
  If you can't afford to do it safely, don't do it!
• Determine the effect you're after before you build.
• Always start with the scare!
  Work the scare as the center of your design process.
• Find the simplest mechanical design that will give the movement you're after.
  Always evaluate simple manually activated levers and simple pulleys as options.
  Your scare may not need pneumatics or hydraulics.
• Prototype the design using wood scrap and PVC pipe.
• Test your design for movement.
• Move the prototype by hand first!
• Look for signs of binding, seizing, or improper motion.
• Attach a pneumatic piston (if needed) and test at low air pressure (20 psi or less) first.
• Gradually increase pressure and continue to test.
• Look for signs of binding, seizing, or improper motion in your design.
• If, at any time, you find problems with the mechanism,
  STOP! Remove air pressure from the prop, and fix the problem.
• Do not use pvc levers with air pressures exceeding 70 psi!
  Pvc is a very sturdy material, but its still plastic, its not nearly as strong as metal.
• Using pvc pipe really simplifies the testing process.
  Its very easy to cut, attach, cut again, and re-attach until you get a popup that 'pops'.
• If your prototype works well, use it - go ahead and detail it for your needs.
• If you need to move a heavy prop, use steel tubing for your final popup design.
  Use your pvc prototype as a guide to cut and assemble your final metal popup.