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Lesson 18

Card 2.3: Wire Prep, Splicing, and Waterproofing

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Unit: Electricity Format: Bench demo + hands-on practice (this is a studio skill card, not a seminar card) Time: 30 to 40 minutes plus practice Prerequisites: None. Pairs well with Card 2.7 (Connection Autopsy), taught later, once you have splices of your own to inspect.

Core Question

Salt water is conductive, corrosive, and patient. Every splice on the ROV is a place it can win. How do you make a connection that carries current, survives strain, and keeps water out for an entire season?

Resource (~10 minutes)

  1. Teacher bench demo: strip, splice, solder, adhesive-lined heat shrink. Watch for the three failure points called out: nicked strands, cold joints, heat shrink that is not adhesive-lined.
  2. Read the “Cabling and Connectors” portion of the MATE safety inspection requirements in the 2026 manual. Note what inspectors reject on the spot.

The Skill Ladder (each step checked before you move on)

  1. Strip 5 wires of two different gauges with zero nicked or cut strands. Nicked strands fail inspection: a nick is a future break.
  2. Splice two wires using a lineman or Western Union splice. It should hold your full pull strength BEFORE solder.
  3. Solder the splice. Shiny, wetted, no blobs. A cold joint is gray and dull.
  4. Seal with adhesive-lined heat shrink, sized so the adhesive squeezes out slightly at both ends.

Clearing This Card

Your artifact is a finished splice sample tagged with your name. It clears when it passes all three tests:

  • Pull test: teacher pulls hard on it. It holds.
  • Dunk test: 24 hours submerged, then multimeter continuity check and visual inspection for water intrusion under the shrink.
  • 90-second oral check: name the three failure points from the demo and explain which test would catch each one.

Passing samples go on the studio wall as the reference standard. Future students judge their work against the wall.

If You Miss This Class

Watch any reputable soldering and splicing tutorial (search “lineman splice heat shrink”), then complete the same skill ladder during build time and clear with the same three tests. The tests do not care when you learned it.

Why This Matters for Competition

Safety inspectors physically examine your wiring and can fail connections on the spot, which costs you pool time to fix at the venue. And in the water, one flooded splice can end a run. This card is also a gate: students who have cleared it are the ones authorized to make permanent electrical connections on Godzillah. Everyone else breadboards.

CC BY-NC-SA 4.0.