Lesson 10 put a number on the flow. This lesson hands the student the steel that number lives in. The outcome you're after isn't a memorized parts list. It's the instinct that a part a student can name but can't say what wears in is a part they don't really understand. Two things have to land: every component answers back to a decision the product already made, and every component wears and has to be reachable by whoever keeps the building running. Protect one deferral above all others: the moment the room starts picking a conveyor category, stop them. That's Lesson 12. Here they diagnose machines, they don't select them.
| Segment | Min | What happens |
|---|---|---|
| The machine that has to survive the customer | 6 | Read the hook. A conveyor isn't a drawing, it's a machine that runs two shifts a day in a real building with a maintenance team that might be one person. Put the frame on the board: knowing why each part is built that way beats taking a vendor's word from a spec sheet. |
| Anatomy walk, guessing-game style | 16 | Draw a simple powered belt conveyor. Component by component, have the room name the part and its job out loud before you reveal it, the way the Three W's are run. Frame, rollers, belt, drive, drive and end pulley, take-up, guards. For each one, tie it back to the product decision that drove it: frame width from belt width from the package analysis, roller centers from the smallest package. |
| What fails, and where the wrench reaches | 14 | The key teaching moment, below. Same sketch, harder pass. For every part just named, ask two questions: what wears in it, and can the customer's one maintenance person reach it. Run the access discussion hard: two units butted together, can you get a wrench in, can you pull a motor. This is where the lesson lands. |
| Calculations as a starting point | 6 | Kept short on purpose. The rate they carried in from Lesson 10 was calculated for a perfect world. Name the four real drifts, belt stretch, product orientation, roller wear, temperature, and the margin principle. Don't run the margin method. That's Part VI. |
| Riverside failure read | 12 | Read Michael's two SCENE 4 failures aloud in his voice. Ask the room to name what kind of machine failed in each, without naming the replacement. Facilitation note below. Collect the component-and-maintenance read note. |
| Forest, close, and the VFD Controls Corner | 6 | Tie the anatomy to the rest of Part IV: everything ahead is built from these parts and every one of them wears. Close on the Controls Corner, the VFD sets and ramps belt speed and some conveyors require it. Name that the how is Part V. Don't teach it here. |
| Total | 60 | Baseline session. Expand with the stretch options below if you have 90 minutes. |
Draw one powered conveyor and use it twice. First pass is the guessing game: name each part and its job before you reveal it, exactly the way you run the Three W's. Frame, rollers, belt, drive, pulleys, take-up, guards. Get the room naming and reasoning, not copying.
Second pass is over the same sketch, and it's the one that matters. For every part they just named, ask two questions and make them answer both: what wears in this part, and can the customer's one maintenance person reach it. When a student can name a component but stalls on what wears in it, that's the moment the maintenance lesson lands. Don't rescue the stall. Let it sit. Your job this session is to close the gap between naming a part and knowing what kills it.
Three failure modes to catch, and one redirect that fits all of them. Push every one back to the same question: what fails, and who fixes it.
Read Michael's two SCENE 4 failures aloud, in his voice, the pneumatic accumulation system that died when the shared compressor's air pressure dropped during peak, and the system where anything downstream slowing stopped the whole line. Then ask, don't answer. What kind of machine failed in the first story? Steer them to the air dependence: a machine whose zone behavior leaned on an air supply the building couldn't keep stable, built from parts nobody on site could service. What kind failed in the second? Steer them to the missing capability: a machine with no way to hold product on its own, so one slow spot took everything with it.
Hold the line on the replacement. Don't name it, and don't let the room name it. That call is Lesson 12. The grade at this point is only whether they can hear the mechanism inside the story. A student who says "it was the wrong technology" has skipped the work. A student who says "it depended on air this building couldn't hold, and nobody could service it" has done exactly what this lesson teaches.
Question 1, three real-world conditions on the hardware and how an engineer accounts for each. Look for any three, each paired with a real accounting move. Belt stretch and tension drift, handled by an adjustable take-up and a retension on the PM schedule. Products arriving in varying orientation, handled by designing for the worst-case presentation instead of the ideal square carton. Roller wear, handled with durable rollers, tool-free replacement, and PM. Temperature changing belt stiffness and motor pull, handled by specifying for the environment and verifying with the manufacturer. Belt slippage below commanded speed, handled by carrying margin on the rate. The accounting move is the same shape every time: build margin, verify with the manufacturer, document the assumption so the field can trace what drifted. Grade the pairing of a real condition to a real response, not the specific three they pick, and not arithmetic.
Question 2, the shared-air, reactive-maintenance, two-shift facility. The three facts and the read each one forces. Shared air compressor feeding production and material handling: any air-dependent mechanism inherits the whole building's pressure drops at peak, so anything pneumatic, fittings, bladders, filters, dryers, is a problem candidate here. Reactive maintenance with a small team: complex or air-dependent hardware degrades faster than a one-person reactive team can catch, so the read favors simpler, more durable, tool-free-service parts. Two shifts: sixteen hours a day of wear, so retensioning, bearings, and roller wear all arrive sooner and access has to be quick. On service access before committing a layout, they should want to see room to get a wrench between side-by-side units, room to pull a motor or a shaft, room to swap a bearing, and single-person reach to every wear point. Don't accept an answer that names a recommended conveyor category. If they jump to a motor-driven roller or an electric solution, it's the right instinct but it's Lesson 12's call. Here the task was the component-and-mechanism read only.
The component-and-maintenance read note the students write on Michael's two failures isn't a warm-up exercise. It's a project-folder artifact they'll lean on directly in Lesson 12 when the read becomes a technology selection, and again late in the program when they scope and quote the maintenance conversation for Riverside. The students who keep an organized project note from this first Part IV beat walk into those lessons with their reasoning already on paper. The ones who treat it as a throwaway rebuild it under pressure later. Make the note a real deliverable today. Don't tell them where it pays off. Let that land when it lands.
Protect the deferral, because the pull to diagnose the technology in this lesson is strong precisely because the failures are such clean technology stories. Hold it anyway. Lesson 12 is where the mechanism read turns into a selection, and it lands harder if the class arrives having named the mechanism but not yet the machine. Your win this session is a student who can look at any conveyor, name every part, say what wears in each, and ask who has to reach it, all before anyone opens a catalog.