Selectorized (Pin) Machines

Selectorized machines use a stack of plates connected by a cable/cam; you set resistance by inserting a pin at the desired weight. The movement runs along a fixed, guided path in a single plane.

Pros

• Easy to learn and use — minimal technique; good for beginners, rehab, and circuits.
• Fast weight changes — move a pin; sessions go quickly (see free-weights-vs-machines).
• Generally safe / no spotter — you can't be pinned; you can fail safely (see free-weights-vs-machines-safety).
• Isolation — the fixed path targets a muscle with little stabilizer demand; useful for pre-exhaustion and accessory work.
• Many use cams to vary resistance through the range to better match the strength curve (see variable-resistance).

Cons

• One plane of motion — less carryover to free, multi-plane athletic movement; trains fewer stabilizers than free weights.
• Fit issues — a fixed path may not match every body size, forcing a non-ideal joint angle.
• Stack increments can be large (often 5–15 lb jumps), limiting fine progression; add-on micro-weights help.
• Takes a large footprint and is expensive — mostly a commercial-gym item.

• Load set by a pin in a weight stack; single guided plane of motion.
• Beginner-friendly, fast to change, usually no spotter needed.
• Isolates muscles with low stabilizer demand; many use cams (variable resistance).
• Drawbacks: fixed path, fit issues, coarse increments, footprint/cost.

• plate-loaded-machine — loaded with plates instead of a stack.
• cable-machine — cable resistance with a freer path.
• free-weights-vs-machines / free-weights-vs-machines-safety — the core comparison.
• variable-resistance — cam-based strength-curve matching.
• beginner — a common starting point for new lifters.