There are 28 free motorized Technic-style builds on MightyCog, and the best one to start with is the Motor Buggy: one M motor, a battery box and a direction switch, in about 30 minutes. From there, move to a motor-driven machine such as the Spinning Radar, then a car with a gearbox, then remote control. Every build has an animated step-by-step guide and a free printable booklet, and its parts list tells you which motor and battery box it needs.
The full list is on Motorised builds, easiest first. This guide groups them by what the motor does, so you can pick the next one with confidence.
The order we recommend
- One motor, one switch. Motor Buggy (level 3, 30 minutes) and Spinning Radar (level 3, 25 minutes). Learn to fix a motor, wire it and gear it.
- A strong, slow motor. XL Power Crane (level 4, 35 minutes): the XL motor and a worm gear make the hook 24 times slower and much stronger.
- A motor with a gearbox. Clutch-Gear 2-Speed Car (level 3, 45 minutes), then the Reverse-Gear Truck and the Three-Speed Car.
- Remote control. First RC Car (Servo) (level 4, 50 minutes), then the RC Tank and the RC Racer.
- Several motors. Skid-Steer Loader, AWD with Central Diff, Twin-Motor Dozer and the Robot Arm with Servo Claw.
New to motors? Read First motor build: how to add a motor and battery box before you start the Motor Buggy.
Every motorized build, grouped
First motor builds
| Build | Level | Minutes | Motor |
|---|---|---|---|
| Motor Buggy | 3 | 30 | M motor |
| Spinning Radar | 3 | 25 | M motor |
| XL Power Crane | 4 | 35 | XL motor |
| Floor Express | 4 | 40 | Train motor, IR remote |
Cars and trucks with gearboxes and clever drives
| Build | Level | Minutes | What it teaches |
|---|---|---|---|
| Belt-Drive Buggy | 3 | 35 | A belt instead of gears |
| One Motor, Knob Steering | 3 | 40 | The motor drives, you steer |
| Clutch-Gear 2-Speed Car | 3 | 45 | Two speeds with a driving ring |
| Reverse-to-Turn Car | 4 | 50 | Steering with only one motor |
| Worm-Drive Crawler | 4 | 50 | Two worm gears, four-wheel drive |
| Reverse-Gear Truck | 4 | 55 | A gear lever for forwards and back |
| Three-Speed Car | 4 | 60 | Two gearboxes in a row |
Remote-control models
| Build | Level | Minutes | Motors |
|---|---|---|---|
| First RC Car (Servo) | 4 | 50 | M motor and servo |
| Front-Drive Servo Trike | 4 | 50 | M motor and servo |
| Diff-Lock Mud Truck | 4 | 60 | L motor and servo |
| RC Tank | 4 | 60 | M and L motors, one per track |
| Skid-Steer Loader | 4 | 65 | M and L motors, one per side |
| RC Racer | 5 | 75 | L motor and servo |
| Independent Rally Car | 5 | 90 | L motor and servo |
| AWD with Central Diff | 5 | 90 | M, L and servo |
| Twin-Motor Dozer | 5 | 100 | M and L motors, one per track |
Motor-driven machines
| Build | Level | Minutes | What the motor does |
|---|---|---|---|
| Twin-Piston Engine | 3 | 40 | Turns a crank that pumps two pistons |
| Oscillating Fan | 3 | 40 | Turns the fan's head left and right |
| Nodding-Donkey Pump Jack | 3 | 45 | Rocks a long beam slowly |
| Ferris Wheel | 3 | 45 | Turns the big wheel slowly |
| Conveyor Belt | 3 | 50 | Moves a belt of parts |
| Cog Railway Climber | 4 | 55 | Climbs a toothed rail |
| Klann Walking Spider | 4 | 60 | Turns a crank that makes legs walk |
| Robot Arm with Servo Claw | 4 | 60 | Three motors swing, lift and grab |
Gearing: the motor is fast, the model needs to be strong
An electric motor spins fast but with little turning force. Almost every build above puts gears between the motor and the job to trade some of that speed for strength, which is torque.
- The Motor Buggy's 8-tooth motor gear turns a 24-tooth gear on the back axle: the wheels turn 3 times slower and 3 times stronger.
- The XL Power Crane uses a worm gear, which moves its 24-tooth gear on by one tooth per turn: 24 motor turns for one turn of the drum, and the load cannot run back down.
- The Ferris Wheel, Pump Jack, Conveyor Belt and Cog Railway all use a worm gear for the same reason: they need slow, steady movement.
Try it in the gear simulator: put an 8-tooth driver on a 24-tooth gear, turn the input three times, and count the output turns. Then swap them round and see what happens to the speed.
Interactive: Gear pair simulator. Pick a driver and a driven gear, turn the input and watch both gears mesh. The ratio, output turns and direction update as you go, and a worksheet checker sets fresh questions.
Which motor does what
The parts lists use five kinds of motor:
- M motor: small and quick. Used in the Motor Buggy, the Spinning Radar and most of the machines.
- L motor: bigger and stronger. Used in the RC Racer, the Worm-Drive Crawler and the Klann Walking Spider.
- XL motor: the strongest, for lifting. Used in the XL Power Crane and the Robot Arm.
- Servo motor: turns to a position and holds it, for steering and the robot claw.
- Train motor: a motor built into a train bogie, for the Floor Express.
Is the strongest motor always the best? Not quite: read Five motor myths before you swap one for another.
Going further
Once a motor works, add control. How does an RC car steer? follows the servo from the remote to the wheels, and One remote, several models explains IR channels so two models don't answer the same remote. For tracks versus wheels, see Tracks vs wheels.
Interactive: Check yourself. A few quick questions on the ideas in this guide, each with an explanation.
- In the Motor Buggy, an 8-tooth gear on the motor turns a 24-tooth gear on the back axle. How fast do the wheels turn?
- The XL Power Crane uses a worm gear on the motor driving a 24-tooth gear. How many motor turns lift the hook by one turn of the drum?
- Which build is the best first motorized model?
- What do the RC Tank and the Skid-Steer Loader have instead of steering wheels?
