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3D-Printed Battle Tanks (1:40)

Six self-driving printed tanks, blue team vs orange team, in an IR laser-tag style battle game.

  • 3D Printing
  • Electronics
  • Coding
  • Motors
IdeaBUILD LOG #12

// What I'm building

Six autonomous 1:40-scale battle tanks that drive themselves: a blue team (Tiger II, Leopard 2, M1A1 Abrams) against an orange team (T-80U, Panther, Tiger I). Each one gets its own scaled speed and acceleration.

They battle with infrared laser tag: hit zones on the armor, 5 lives, 150 shots, and smoke (virtual smoke grenades). Low on ammo? Drive back to base to reload. Teams capture three command posts (Crush, Nebula and Bust) by pushing a lever, and a live map on my computer shows the whole battle.

The plan: print the tanks in PLA+ on my Bambu, with Heltec LoRa32 V4 boards, N20 gear motors, LEGO Technic tracks on printed sprockets and wheels, and 624ZZ bearings. The first two prototypes will be the Leopard 2 and the Tiger I.

  • 6 tanks: blue team vs orange team
  • IR laser tag: hit zones, lives, ammo + reloads, smoke
  • 3 command posts + a live map
  • Heltec LoRa32 V4 · N20 motors · LEGO Technic tracks
  • 624ZZ bearings · PLA+ on the Bambu
  • Budget: about $250
A short row of dark gray LEGO Technic track links on carpet.
LEGO Technic track links. These will be the tank treads.
BATTLE TANK · 1:40 · SIDE VIEW 360° TURRETIR "SHOT" LEGO TECHNIC TRACKS · N20 MOTORS · 13 mm BEARINGS HELTEC LoRa32 VS

// Build Log

  1. Try #1 — bearing size

    WHAT I TRIED
    Picked 624ZZ bearings for the road wheels.
    WHAT BROKE
    The bearing size was first written down as 30 mm. That's way too big!
    THE FIX
    Corrected it to 13 mm (4 × 13 × 5 mm), with 13.2 mm pockets and 4 mm axles.

  2. Try #2 — where's my tank?

    WHAT I TRIED
    Planned GPS so the live map knows where every tank is.
    WHAT BROKE
    GPS doesn't work indoors.
    THE FIX
    Swapped GPS for LiDAR, plus distance sensors and a shared map.

  3. Try #3 — the battery

    WHAT I TRIED
    Checked the small battery I already have.
    WHAT BROKE
    It's too small to power a tank for a whole battle.
    THE FIX
    Get a bigger battery.

  4. Try #4 — no soldering

    WHAT I TRIED
    Planned how all the electronics connect.
    WHAT BROKE
    I'm not soldering for this build.
    THE FIX
    Use plug-in and screw-terminal parts instead.

  5. Try #5 — first two chassis

    WHAT I TRIED
    Getting ready to build the Leopard 2 and Tiger I prototypes.
    WHAT BROKE
    Nothing printed yet!
    THE FIX
    Get the no-solder parts and check the motor specs first.
NEXT STEP

Get the no-solder parts, check the motor specs with a grown-up, then design the Leopard 2 and Tiger I chassis.