The lift is comprised of two iterations of four bars: one mounted onto the other, with the bottom four bar driving the top via gears attached to the top of the bottom, and bottom of the top.
The ‘reverse’ portion of the four bar helps to maintain purely linear motion. The purpose of which is to increase the ease of use in driving.
Powering the DR4B
Our DR4B has two REX shaft 30rpm motors. We switched from D shaft 45rpm motors because it wasn’t supplying enough torque, and thus caused overheating of the motors. The linkages transfer power and torque from the motor to the arm allowing it to move. We also switched from COTS metal linkages to custom steel rods to reduce bending.