▶What is a robot teach pendant and how do I use it?
A teach pendant is a handheld control device (looks like a video game controller) that lets you manually move the robot arm and teach it positions and movements. Buttons or a joystick move the robot in X, Y, Z directions (Cartesian) or by rotating individual joints (joint coordinates). Once you've positioned the arm at a target location (a part pickup point, for example), you press 'Record' to save that position. You repeat for each waypoint in the program: pick, move to station A, place, move to station B, weld, return to start. Then you run the program in slow-speed 'teach' mode to verify the path doesn't collide with obstacles. Once verified, the robot runs at full speed, often in a cycle that repeats 50-100 times per hour. A good robot tender can program simple tasks (pick-and-place, material handling) in an hour; complex paths (welding seams, surface finishing) take hours.
▶What is a gripper and what are the common types?
A gripper is the end-of-arm tooling that handles parts: it attaches to the robot wrist and grabs/releases objects. Vacuum gripper: uses suction cups, great for smooth, flat parts (sheets, boxes, machine doors). Parallel-jaw gripper: two fingers close together, good for parts with defined grip points (boxes, cylinders, engine blocks). Magnetic gripper: for ferrous metal parts (no suction or finger surfaces required). Specialized grippers: needle gripper for fabric, adhesive grip for fragile parts, multi-finger hands (expensive, for complex manipulation). A robot program calls a gripper command: 'GripOpen' releases parts, 'GripClose' clamps. Tender job: check that the gripper is operating (fingers moving, suction holding) and replace worn pads or damaged fingers. Gripper failure stops the entire cell, so tenders inspect and maintain them religiously.
▶What is a PLC and how does it integrate with robots?
A PLC (Programmable Logic Controller) is a dedicated computer that controls the logic of the entire manufacturing cell: robot movements, gripper commands, conveyor speed, vision-system triggers, safety interlocks. The robot sends signals to the PLC ('I've completed pick'); the PLC responds with commands ('activate conveyor, move part to next station'). The integration is critical: the PLC synchronizes the robot, material handling, vision inspection, and output signals so everything happens in the right order. A robot-cell failure often originates in the PLC logic, not the robot itself. Tenders need to understand: how to read a PLC ladder-logic diagram (the program), how to use diagnostic software to see signal states (is the sensor triggered? is the gripper getting power?), and basic troubleshooting (re-seat a connector, reset a signal). Advanced tenders can program simple PLC logic (IF sensor is triggered, THEN activate gripper).
▶What does 'teach a robot program' mean and how long does it take?
Teaching a program means manually guiding the robot through the required sequence of motions and recording those positions. For a simple pick-and-place: (1) move robot to the part-pickup point using the teach pendant, (2) record that position, (3) move to the placement location, (4) record, (5) return to home. Total time: maybe 10 minutes. You then add gripper commands (open, close), delays (wait for part to stabilize), and test in slow-speed mode. For a complex task like spot-welding a car body, you teach dozens of positions (one for each weld point), and the program takes 2-4 hours. Modern robots support 'drag-and-drop' visual programming (a 3D simulation of the robot cell where you drag the robot to positions instead of using the pendant)—faster and less prone to error. Pre-planned simulation software (like DELMIA or RoboDK) lets engineers pre-teach the program on a computer, then download it to the real robot, reducing teach-time from hours to minutes.
▶What is a collaborative robot (cobot) and how does it differ from industrial robots?
Collaborative robots (cobots) are designed to work safely alongside humans without protective fencing or interlocks. Industrial robots are dangerous (high speed, high payload, no force-limiting): if the arm hits a person, injury or death results; they're caged in protective cells. Cobots have: force-limiting technology (if they hit an obstacle, they stop or slow immediately), rounded corners (no sharp edges), and lower speeds (still fast, but manageable). Cobots are more expensive per unit but save money because you don't need the safety infrastructure (cage, interlocks, emergency stops in specific places). Cobots are growing in small manufacturers and job shops where flexibility beats absolute speed; industrial robots dominate high-volume, repetitive production (auto assembly, consumer electronics). A cobot tender has fewer safety restrictions (can work in the cell while the cobot is running, with caution) but must understand force-limiting behavior.
▶How do I troubleshoot a robot that's stopped?
Logical steps: (1) Check the teach pendant or control screen: what error message is displayed? (Common: 'Collision detected,' 'End of reach,' 'Joint limit exceeded,' 'Communication lost'). (2) Verify physical causes: Are safety gates closed? Is the gripper jammed? Are there obstacles in the workspace? (3) Check electrical connections: Is the gripper power cord plugged in? Is a sensor cable loose? (4) Review the program: Did the robot try an impossible position (beyond its joint limits)? Is the teach data corrupted? (5) Contact the integrator or manufacturer: Complex issues (internal faults, servo failures) require expert help. In the meantime, isolate the cell to prevent dangerous restart. Good tenders keep a troubleshooting log (date, symptom, fix); patterns emerge (always jams at position X = gripper wear; always fails at 3 PM = temperature issue).
▶How do robot cells increase throughput and reduce labor?
A robot cell replaces 1-2 human workers, producing 10-50 parts per hour (depending on task complexity). Advantages: robots don't get tired or distracted (100% cycle-time consistency), work 24/7 (three shifts vs. one human shift), produce zero scrap (if the program is correct), and fit in tight spaces (a 6-axis arm in a 1-meter footprint does work that would require a large machine). Disadvantage: high capital cost (a robot cell with gripper, vision, PLC integration = $200,000–1,000,000+), requires skilled programming, and inflexible (if the product changes, the program must change). ROI depends on volume: a cell producing 10,000 identical parts per year easily pays back; a cell producing 100 different parts per year in small batches is harder to justify. Smart companies use robots where they do best: high-volume, repetitive, dangerous (welding fumes), or precise (medical device assembly) work.
