T8 lead screw, 8 mm, 2 mm lead
Turns rotation into linear motion and, with a 2 mm lead, is self-locking — it holds a vertical load with the motor off. Slow, but it will not drop your payload.
The role it plays
Transmission trades speed for torque between the motor and the load. Every option sits on three axes: ratio, backlash and stiffness. Low ratio with a good encoder is how quasi-direct-drive works; high ratio buys torque but hides the load behind compliance and friction. Pick the ratio from the torque budget first, then the technology that hits it.
Typical use: Z axes, lift columns, linear grippers.
What the numbers actually mean
The headline figure is 2 mm / rev (lead), with up to 500 mm typical as the next most load-bearing number (travel). At $12 in the transmission tier it sits cheap enough to prototype with and replace without regret, which is the correct way to learn a new subsystem.
How it compares
Same subsystem, closest alternatives. The primary spec column is usually the one that decides it.
| Part | Price | Primary spec | Second spec |
|---|---|---|---|
| T8 lead screw, 8 mm, 2 mm leadLinear conversion | $12 | 2 mm / rev | up to 500 mm typical |
| Harmonic Drive CSF-14-100Strain-wave reducer | $1.2k | 100:1 | < 1 arcmin |
| Planetary gearbox, NEMA 17, 27:1Planetary reducer | $25 | 27:1 | ~1 – 3° (typical cheap unit) |
| GT2 belt drive, 20T → 60TBelt reduction | $15 | 3:1 (20T driver, 60T driven) | GT2, 2 mm |
| Printed cycloidal reducer3D-printed reducer | $5 | 20:1 – 40:1 (by design) | 0.5 – 2° depending on print quality |
Where it shows up
It is a component-level choice rather than a defining part of a named platform — pick it for the subsystem it serves, not to match a reference build.