This Is a Work Period, Not a Lesson

There's no new concept to introduce today — you already have everything you need from your Design Packet. These four sessions are for turning your concept sketch into a physical launcher.

Teams will move at different speeds, and that's expected. A mechanism that looked simple on paper often needs a mid-build redesign once you're actually holding the materials — that's normal engineering, not a sign you did Sessions 15–16 wrong.

Bungee safety still applies every session, not just the day you got certified. Recheck anchor points and cord condition every time you test a pull.

Build

Construct Your Mechanism

Work from your Design Packet's concept sketch. If reality forces a change from what you sketched, that's fine — note the change and why in your notebook as you go, not after the fact.

Troubleshoot As You Go

Expect real problems: parts that don't fit, a mechanism that binds, an attachment point that isn't strong enough. Diagnose and adjust — this is Build and Iterate happening together, the same way Session 1's design cycle described.

Checkpoint Timing

At the Session 19–20 spot-check, your instructor checks every team: is your mechanism physically functional, regardless of polish? A team that's badly behind at that point needs to flag it now, not wait until the milestone ends.

If Your Team Finishes Early

Don't sit idle, and don't start "polishing" indefinitely. Start preliminary data collection — a few practice pulls, logged the same way you will for real in Sessions 21–23. It's a genuine head start, not busywork.

Checkpoint

By the Session 19–20 spot-check, your instructor confirms:

• Your mechanism physically exists and can complete a launch cycle
• Your team can point to your chosen IV's physical control point on the mechanism (where pull distance is measured, or where angle is set)
• No bungee safety protocol from Sessions 15–16 is being skipped

"Functional" is the bar here, not "finished" or "polished" — that distinction matters, because Sessions 21–23 need real time, not a squeezed leftover.

Reflection

Answer the following questions before submitting your work.

1. What's the biggest way your actual mechanism differs from your original Session 15–16 concept sketch? What forced that change?
2. Which of your decision matrix's four categories — Cost, Feasibility, Time, Alignment — turned out to matter most once you were actually building? Did that match what your matrix predicted?
3. Sessions 21–23 ask you to test across a range of settings for your IV. Looking at your finished mechanism, what do you expect the realistic range of settings to be?

Submit

No written deliverable this milestone — this is graded as a hard checkpoint via your instructor's direct spot-check, plus your individual reflection.

Milestone Complete