Question 1

What factors affect actual SMT placement rate versus the rated speed?

Accepted Answer

Rated speed assumes optimal conditions (single nozzle type, adjacent feeders, zero rejects). Actual throughput is reduced by nozzle changes, feeder spacing, vision inspection time, component rejects, and head travel distance. Real-world efficiency is typically 50–70% of the rated CPH.

Question 2

How does takt time relate to line balancing in a multi-machine SMT line?

Accepted Answer

In a multi-stage line (printer → pick-and-place → reflow), the bottleneck machine sets the line takt time. If the placer takes 77 seconds but the printer takes 30 seconds, the line throughput is limited to the placer's 77-second cycle. Line balancing aims to equalize cycle times across all stations.