Coffee Table #3 Design
Note: The links on the left side of this page and the other Model CT-3 pages will take you to detailed information about the new coffee table's design and construction.
Coffee Table #3 is designed so that the layout can be operated under a glass top (similar to Coffee Table #1), or the glass top can be removed and the layout can be raised 6.5 inches, so that it appears to be resting on top of the coffee table. This “out of the box” position allows the viewer to see the entire layout from any angle.
The lift mechanism that raises and lowers the layout is shown in the raised and lowered positions in the two photos below. The major parts of the lift mechanism are the lift table, four drawer slides that attach the lift table to the equipment box, and the linear actuator that drives the lift table up and down. The layout (not shown) rests on top of the lift table.
The driving force that raises and lowers the layout is a standard automotive part. It is a linear actuator—the type used to operate tailgates, etc. The linear actuator runs on 12 VDC and is capable of lifting 120 pounds. (The layout and lift platform weigh a total of 40 pounds.) The photo below shows how the linear actuator is mounted in the equipment box. The actuator is firmly bolted to two heavy-duty square aluminum tubes, which are mounted firmly to the sides of the equipment box.
The linear actuator is actually taller than desired, so the top of the actuator must protrude through the lift table. A special bracket (photo below) is used to connect the linear actuator to the lift platform.
The bracket protrudes through the lift table (photo below), and the linear actuator pushes on the raised center of the bracket. The photos above of the complete assembly show how the actuator fits into the bracket.
The photo below also shows one of the four drawer slides. In addition, the photo shows (far left) the aluminum track that a rolling micro switch travels on. The micro switch acts as a limit switch to stop the lift mechanism when the layout reaches the correct height.
To see how the lift mechanism was constructed, click here.