ARTICLE 01Your radial line is not slow at insertion, it is slow at the bench feeding it
The station that sets your line rate is usually the one that has never appeared on a line layout.
Ask a production manager for the cycle time of a through-hole line and you will get a competent answer about insertion, wave soldering and test. Ask for the time it takes to hand-form and hand-load the radial parts that feed that inserter, and the conversation changes shape. Nobody measured it, because it never appeared as a station on the line layout. It appeared as headcount.
That is the whole problem. Hand insertion does not fail loudly. It absorbs whatever volume you throw at it by absorbing more people, and because the cost arrives as wages rather than as capital, it never shows up as a number anybody has to defend in a budget review. The line rate is therefore set by a bench, and the bench is invisible in every report you have.
The way to make it visible is a three-line calculation. Take the number of radial components on one board, multiply by the boards you build in a month, and divide by the insertion rate of one person. That gives you person-months. Multiply by the fully loaded monthly cost of that person - not the wage, the wage plus contributions, supervision and floor space - and you have the annual cost of a station that does not appear on your layout.
Then do the same division at machine speed and subtract. What is left is the labour the machine releases, and it is usually the smallest number in the comparison. The larger numbers are the ones the bench hides: the reels you bought because you could not insert fast enough, the rework on boards where a lead span was formed to the wrong gauge, and the warranty claims on parts that passed every check you ran in-house.
The reason this matters beyond the first year is that the calculation repeats. Component counts per board go up as designs add bulk capacitance and more through-hole connectors. Volumes move with demand. Every time either changes, a bench absorbs it by hiring and a machine absorbs it by running. One of those two scales, and the other one accumulates.
There is a second effect that rarely gets written down. A bench staffed to meet the peak is idle at the trough, and a bench staffed to the average misses the peak. So the bench does not just cost money, it adds a scheduling constraint that shows up as expediting, overtime and the occasional air freight. None of that appears in the labour rate either.
The practical move is to measure the bench before you argue about the machine. Count the radial parts on your three highest-volume boards. Time one operator inserting them for an hour, with a stopwatch, on a real board. You will get a number somewhere between 8 and 20 components a minute depending on lead span and how much forming is involved. That single measurement turns the whole decision from an opinion into arithmetic.
If you want the arithmetic done with your own numbers rather than a generic example, the calculator on this page takes the component count, the board volume, the insertion rate and the wage, and returns the hours released and the payback period. It is worth five minutes before the next headcount review, if only to find out whether the bench is as cheap as it feels.
















