Build · Parts & cost

The honest shopping list.

No “starting at” games. Here is everything a first competitive bot actually needs, what it costs in ranges, and the total including the stuff other pages forget — the charger, the fire bag, the spare battery, the tools.

Electronics core

The parts that go inside the robot.

PartWhat to knowCost
Transmitter + receiver (2.4 GHz)Entry hobby TX with model memory and a bound RX. Must support fail-safe — that is a rules requirement, not a nicety.$45–60
Dual brushed ESC (drive)One board drives both motors; built-in mixing and BEC keeps wiring simple.$15–25
2× brushed gearmotors (N20-class)The standard first drive. Buy the speed the design calls for — and buy a spare pair.$12–20
Brushless weapon motorOnly if your first bot has an active weapon. A wedge skips this line entirely.$12–20
Weapon ESCSized to the weapon motor. Also skipped by a wedge.$10–18
2× LiPo battery (2S/3S)Two, so one charges while one fights. 3S is the class maximum.$20–30
Balance chargerA real balance charger, not a USB toy. This is shared family infrastructure — one per household, ever.$30–45
LiPo-safe bagNon-negotiable. Batteries live and charge in it. Required at events and at home.$8–12
Power switch / removable linkThe mechanical disconnect the rules require, reachable from outside.$5–15
Power lightExternally visible when the bot is live. An LED and resistor.$2–5
Wheels + hubsOff-the-shelf hobby wheels are legal and good.$8–15
Connectors, wire, heat-shrinkXT30s, 20 AWG silicone wire, heat-shrink assortment.$10–15
Fasteners + heat-set insertsPlastite-style screws and a bag of M3 inserts. Inserts make repairs survivable.$10–15

Core subtotal: roughly $150 for a weaponed bot, ~$120 for a wedge. Skipping the weapon motor and ESC on a first build is a proven strategy, not a compromise — wedges win events.

Tools & safety gear

One-time purchases most households buy once and keep forever. If you already own them, your total just dropped.

ItemWhyCost
Soldering iron (temperature-controlled)The one tool worth not cheaping out on.$25–40
Hex drivers, flush cutters, wire stripperBasic bench kit.$20–35
Safety glassesRequired for all pit work — one pair per person.$5–10
Battery voltage checkerCheck before and after every fight.$5–10
Digital calipersOptional but transformative for CAD.$10–20

Printing — with or without a printer

You own a printer

A 1 kg spool of PLA+ (~$20–25) prints several chassis plus spares. Filament is the cheapest line on this page.

~$25 / season

School or library printer

Many schools and public libraries print free or at filament cost. Ask — this is the most common path for our builders, and lab access days include print time.

$0–15 / season

Online print service

Upload the files, parts arrive by mail. A full antweight chassis set typically runs $15–35 per order. Slower iteration — order spares in the same batch.

~$30–70 / season

You do not need to buy a printer to compete. Nobody at an IRL event can tell whose chassis came off a $2,000 machine and whose came from the library.

The all-in number

ScenarioFirst season, everything included
Wedge, school printer, some tools at home≈ $150–200
Weaponed bot, own filament, buying all tools≈ $230–300
Weaponed bot, print service, buying all tools≈ $260–340

Plus event entry fees (kept low; published per event). Prices are honest ranges as of mid-2026 — hobby electronics drift, so treat the ranges, not the midpoints, as the promise. Second seasons cost a fraction of this: the transmitter, charger, tools, and safety gear all carry over.

Rule of thumb for parents: the first robot costs about as much as a video game console. Every robot after that costs about as much as a game.

Now follow the 30-day pathParent FAQ