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Hydrogen Properties for Energy Research (HYPER) Lab ME316 Spring 2015

Tree Preliminary Designs

Designs and Process

Design Parameters:

  • Rotating trees both become smaller in size and rotate slower the further back the tree is in order to create the illusions of movement and depth
  • Tree branches interlock with each other when rotating
  • Tree branches rotate above the user’s head for immersion

Each design will include both a tree assembly design and a rotation design that can be easily mixed and matched to the customer’s preference.

PVC Trees / Pulley






The base of the tree will be made of a combination of PVC pipe wrapped with wire or zip ties for the core trunk and limb structures. The leaves will be made out of PVC cut into small sections which are then glued together.

The trees will have a pulleys of varying sizes wheel underneath their trunks that will sit on bearings to allow the trees to spin at different rates. The pulleys will be connected by belts.


  • Flexible but sturdy
  • More realistic looking
  • Pulley system is cheap and easily executed


  • Complex design makes it challenging to rotate and interlock branches


Wire Mesh / Gears




The main body of the tree will be made of wire and chicken wire mesh so that the client can customize the appearance to their specs. The wire will run vertically and separate into branches as shown above.

The trees will have a gear and chain system underneath their trunks to rotate the trees which will ride on ball bearings. The gears will vary in size in order to change the speed of rotation for each tree.


  • Appearance is easily changed
  • Gears can withstand higher forces


  • Heavy
  • Not easily disassembled


Flexible Tube / Pneumatic



The base and trunk of the tree will be made from a PVC plastic with rebar reinforcement if needed. The branches of the tree will be made of a rubber or other flexible hose material.

The base of the trees will be connected to small pneumatic motors that will spin each tree.


  • Branches are modular
  • Increased safety due to rubber branches


  • Branches hard to interlock
  • Potentially heavy depending on branch material
  • Pneumatic system is overkill
Washington State University