A compact material-handling trolley that moves along a rail using a rack fixed to the rail and a pinion on the trolley. Motion can be manual (handwheel) or motorized (DC/BLDC/stepper gearmotor). Great to demonstrate power transmission, gear geometry, braking, and load calculations.

Parts Used:

1. Trolley Frame & Deck – Welded frame with load bed, tie-downs, bumpers.
2. Guide Wheels/Rollers – Flanged or V-groove wheels on bearings; keeps trolley aligned to rail.
3. Rack (Linear Gear) – Steel rack bolted along rail; module m = 1–3 (student build).
4. Pinion Gear – Mates with rack; mounted on drive shaft with bearings.
5. Drive –
6. Manual: Handwheel with spur reduction or chain stage.
7. Motorized: 12/24 V DC gearmotor or stepper + gearbox.
8. Coupling & Bearings – Rigid/flexible coupling, pillow blocks for smooth pinion support.
9. Brake – Normally-on spring brake (motorized) or band/disc brake (manual).
10. Tensioner/Idler – Keeps pinion engaged; adjustable motor plate to set backlash.
11. Controls (motorized) – H-bridge/driver, PWM speed control, joystick/DPDT switch, E-stop, fuse.
12. Sensors – Limit switches at rail ends; optional overload switch (current/pressure).
13. Rail/Base – Straight rail with rack mounts; end stops with rubber buffers.
14. Guards – Pinch-point covers over pinion & chain.