Precision Pendulum Assembly: Mechanical assembly
In this section, is describe the procedure to assemble the tripod metallic structure as known as Primary Pendulums.
Order of assembly and filling with sand
- Screw the three plastic base support under the triangular base and level the base with the help of a spirit level;
- Fit together the three lower sections of each leg following the numeration presented in the figure below;
- Fix each one of the legs to the triangular base by tightening the provided screw and taking into account the letters "E" and "D", as shown in the figure below leaving the screws a bit loosy;
- Fill the legs with sand while the whole structure is standing in the vertical (use a table or step ladder);
- Fit the last section of each leg following the numeration;
- Fit the aluminum top plate and tighten it slightly to each one of the legs using the screws;
- To check that both top plate and base triangle are aligned, one can lean the whole structure against a wall and adjust the top plate in accordance if necessary. Once both aligned, firmly tighten the screws of the (i) bottom triangle followed by the (ii) top plate;
- Pass the bob cable and fix it in such position that the equatorial plane crosses the photo-gate;
- Having the bob at rest, start the pendular movement by slowly excite the fulcrum in the top.
- With the help of a flashlight in the front of the shovel and putting a white paper on the shovel other end adjust the horizontal tilt screws in order to have the launcher platform aligned with the plane of oscillation. This can be seen easily if the shadow center of the bob do not move horizontally.
Wall mount assembly
The simplified version of the pendulum is delivered as a toolkit to be fixed in a masonry or concrete wall. It do not include the tripod and consists on the launcher with shovel and the top holder to sustain the fulcrum.
The main aspects to retain on the fixture is (i) to have all structure completely tied-up and firmly secured, (ii) the launcher perfectly horizontal and (iii) aligned with the natural plane of oscillations (please refer to previous sub-section "Order of assembly").