Safety in robotics
What you’ll learn
- The main hazards in hobby robotics and how to avoid them
- A safety checklist to use before every build session
Electricity
Beginner robots run on low voltage (usually 3.3 V–12 V). That is not dangerous to touch, but it can still cause heat and fire if wired wrong.
- Never connect a battery’s + and − directly together (a short circuit). Wires and batteries can get very hot in seconds.
- Unplug power before changing wiring.
- If anything gets hot, smells burnt or smokes: disconnect power immediately.
- Never open or experiment with mains electricity (wall sockets, 110–240 V). Use plug-in adapters exactly as sold.
Batteries
- Lithium batteries (LiPo, Li-ion, 18650) store a lot of energy. Don’t puncture, crush, bend or overheat them.
- Charge only with the correct charger, on a non-flammable surface, and never leave them charging unattended.
- A swollen (“puffy”) battery is damaged: stop using it and recycle it properly.
- AA/AAA batteries: don’t mix old and new, and don’t try to recharge non-rechargeable ones.
Tools
| Tool | Main risk | Rule |
|---|---|---|
| Soldering iron (~350 °C) | Burns, fumes | Use a stand, ventilate, never touch the tip |
| Hot glue gun | Burns | Rest it on its stand, glue is hot for a minute |
| Craft knife | Cuts | Cut away from your body; use a cutting mat |
| Wire cutters | Flying wire ends | Point the clippings away from your face |
| Drill / rotary tool | Cuts, flying debris | Wear safety glasses; clamp the work |
Moving robots
- Keep fingers and hair away from gears, wheels and propellers.
- Test new code with the robot’s wheels off the ground first.
- Know how to stop it fast: a power switch you can reach.
- Robot arms can swing suddenly. Stand outside their reach while testing.
Workspace checklist
Before each session:
- Clear, dry, tidy workspace
- Power switched off while wiring
- Tools in their places; soldering iron in its stand
- Safety glasses for cutting, drilling or soldering
- You know where the off switch is
Example: the coin in the pocket
A student carries a 9 V battery in a pocket with coins. A coin touches both terminals: that’s a short circuit. The battery and coin get hot enough to burn. Fix: keep batteries in their packaging or put tape over the terminals.
Example: the puffy LiPo
A robot’s LiPo battery looks slightly swollen after a crash. Swelling means gas inside a damaged cell, which can catch fire when charged. Fix: stop using it, keep it in a fireproof container away from anything flammable, and take it to battery recycling.
Example: the surprise servo
A robot arm’s code is uploaded while someone’s hand is near the gripper. The servo jumps to its start angle at full speed. Fix: upload with the arm’s power switched off, then switch on with hands clear.
Spot the hazardsEasy
A workbench has: a hot glue gun lying on its side, a battery pack connected to a half-finished circuit, and coffee next to the laptop. List what’s wrong. The glue gun should be on its stand; power should be disconnected while wiring; drinks should be kept away from electronics.
Your own checklistMedium
Write a five-line safety checklist for the space where you’ll build. Make each line something you can check in a second. For example: power off while wiring; safety glasses on for cutting; soldering iron in its stand; workspace clear and dry; I know where the off switch is.
A safe charging stationHard
Plan where and how a school club should charge its LiPo batteries. A fireproof LiPo bag or metal box on a non-flammable surface, the correct balance charger, never charging unattended or overnight, swollen packs removed, and a smoke alarm in the room.
Quick check
Finished this lesson?