Crimping and Connectors Done Right
Why connections matter most
Section titled “Why connections matter most”The weakest link in robot electrical reliability is almost always a connection , not a wire. A cold crimp or loose terminal adds resistance, heats up, drops voltage, and eventually fails - often during a match. Learning to make clean, repeatable connections is the single highest-value skill in this branch.
Anderson Powerpole and SB connectors
Section titled “Anderson Powerpole and SB connectors”Powerpole connectors are genderless plug connectors used for motor and device power; SB50 connectors are the larger battery connectors.
Crimping tips:
- Use a crimper that keeps the contact’s round shape - cheap crimpers deform the barrel into an oval and weaken the grip.
- Position the contact with the barrel flush to the jaw and the Anderson logo facing up so the cores aren’t twisted when you insert them into the housing.
- For SB50 , use a 6 AWG crimp die even on smaller wire - it just makes thicker walls on smaller conductors.
- After crimping, tug the wire firmly to confirm it won’t pull out.
WAGO lever connectors
Section titled “WAGO lever connectors”The PDH uses toolless WAGO-style lever terminals: lift the lever, insert the stripped wire, close the lever. For inline splices, WAGO 221 lever connectors are popular - strip about 11 mm , insert, and clamp. They are reusable and far more reliable than twisting wires together.
Ferrules
Section titled “Ferrules”A ferrule is a small metal sleeve crimped onto a stranded wire end. It bundles the strands so they can’t splay or work loose in a screw or lever terminal. Strip an appropriate length, slide on the ferrule, and crimp with a ferrule crimper (a four-indent / square crimper gives the best grip). Use ferrules anywhere stranded wire enters a clamping terminal.
Ring and fork terminals
Section titled “Ring and fork terminals”For screw-stud connections (like motor controller input lugs or the main breaker studs), crimp a ring or fork terminal sized to the wire and stud. Use a ratcheting crimper so every crimp gets full pressure, then heat-shrink the barrel for strain relief and insulation.
Habits of reliable teams
Section titled “Habits of reliable teams”- Tug-test every connection after making it.
- Heat-shrink exposed barrels to insulate and add strain relief (and to satisfy the R607 insulation rule on battery/breaker terminals).
- Strain-relieve wires so vibration loads a zip-tie, not the connector.
- Keep a crimper, spare contacts, and heat-shrink in the pit kit.
Sources
Section titled “Sources”Key takeaways
Section titled “Key takeaways”- Connections, not wires, are the usual point of electrical failure - crimp them well and tug-test each one.
- Use a round-barrel Powerpole crimper; for SB50 use the 6 AWG die regardless of wire size.
- WAGO 221 lever connectors (strip ~11 mm) and ferrules make stranded-wire terminations reliable and reusable.
- Crimp ring/fork terminals with a ratcheting crimper and heat-shrink for strain relief and insulation.
This lesson was adapted from learnfrc.com.