Lifts are assembled to lift other manipulators vertically or to lift the robot off the ground. Lifts are usually activated using motors attached to a gear system or sprocket/chain system and are usually attached to the robot chassis. Scissor lifts and chain lifts frequently use rubber bands or latex tubing to assist with the lifting.
Lifts can be assembled using a variety of the Motion, Structural, and other products from the VEX Metal system. Lifts are capable of reaching extreme heights. However, they require a great deal of planning and time to assemble.
Some common types of lifts include:
Scissor lifts are assembled by creating a pivot point at the midsection of two structural pieces of metal which are crossed. Typically, the end of one piece of metal is fixed to a pivot point on the chassis and the end of the other piece of metal can slide towards the first end across the chassis. This closes the scissor, raising up the two pieces.
These lifts are nearly always assembled as pairs to equalize the forces on the lift. There is usually a platform on the top of the lift which is attached in the same manner as the bottom. One side is fixed to a pivot point and the other side can slide. The sliding ends of the scissor lift often use the Linear Slide Track and the Acetal Slide Truck from the Linear Motion Kit.
A scissor lift can be activated by using a spur gear on a motor and the Rack Gear with the Linear Motion Kit to pull one side of the scissors, sliding it towards the pivot side. Another method to elevate the scissor lift uses an 84T High strength Gear mounted to one piece of the metal at the pivot point between the two pieces of structural metal. This gear can be driven by a12T High Strength Gear attached to a motor. The 12T Gear drives the 84T Gear lifting the assembly.
Scissor lifts may require extensive cross supports to provide stability.
The more scissor sections assembled on top of each other, the higher the lift can reach. However, it takes more torque to lift them and it becomes more difficult to stabilize the lift. The lower a scissor lift compresses, the more difficult it is to raise it.
Due to the many linkages necessary within a scissor lift and the variety of forces acting on the lift, it can be among the most difficult of the manipulators to assemble as an effective functioning system.
Linear Slides are assembled using the Linear Motion Kit. Rack Gears are mounted to the Linear Slide Track. A Rack Bracket is attached to an Acetal Rack Truck. Then a motor is assembled in the Rack Gearbox Bracket with a spur gear on its shaft. This will allow the rack bracket assembly to travel up and down the linear slide track as the spur gear drives over the Rack Gear.
The Linear Slide Tracks are usually attached to the chassis and a manipulator, additional rack track, or platform can be attached to the Rack Bracket.
Telescoping lifts are assembled using the Linear Motion Kit and the Winch and Pulley Kit. Telescoping lifts are powered up and gravity brings them back down.
They work by placing a pulley at the top of a Linear Slide Track. The Linear Slide Track is attached to the chassis. An Acetal Rack Truck is mounted to the bottom of a second Linear Slide Track. The Rack Truck/Linear Slide Track assembly is slid into the first slide track. A rope from a winch assembly is run over the top of the pulley and attached to the bottom of the second rack. When the rope is pulled in by the winch, the second rack track moves up.
This assembly can be repeated allowing the lift to quickly reach extreme heights.
Chain lifts are similar to telescoping lifts except they can be powered up and down. Chain lifts are sometimes called cascading lifts.
These lifts are nearly always assembled as pairs to equalize the forces on the lift. Chain lifts are assembled by nesting pairs C-Channel together and attaching one set of C-Channel to the chassis with a sprocket and chain system between the pair of C-Channels. The next pair of C-Channels are attached to the chain and sprocket system. As one or more motors spin the chain and sprockets, the second pair of C-Channels slide up the first pair.
This assembly can be repeated to reach extreme heights. Spacers are necessary to keep the C-Channel sections nested together and allow them to slide up and down one another.
Note: Another option for lifting objects are robotic arms.