S7900 Odd-Form-Bestückautomat – Lösung für die smarte EMS-THT-Leiterplattenbestückung

The awkward parts are the ones still sitting on the bench

A modern line places chips at SMT speed and radial parts at radial speed. What is left over is the odd-form band: connectors, relays, transformers, trimmers, bulk electrolytics, DIP ICs and spade terminals. They arrive in five different packagings, several of them have leads that bend or polarity that matters, and they are exactly the parts a manual station gets wrong at the end of a shift. This page starts from a real customer BOM — thirty-six through-hole lines — so you can see how much of…

• Manual insertion does not scale with the order book. The customer solution document behind this page opens with the same list every EMS plant recognises: labour cost rising year on year, a shrinking general labour pool, skilled operators who take time to train, quality that drifts with the shift, capacity that cannot be promised, and floor space consumed by benches. None of those are insertion defects. They are the cost of running a manual process…
• Odd-form packaging is inconsistent by design. A single odd-form BOM mixes five supply formats — loose bulk, ammo pack, tape, tray and tube — because that is how the component makers ship. A machine that only takes tape is not an odd-form machine. The S7900 platform is documented with all four feeder families on one base: bowl for bulk, tape for taped parts, tube for relays and ICs, and tray for connectors and transformers, with a…
• Floating parts are a wave-soldering defect, not an insertion defect. A part that is inserted but not secured can lift during wave soldering, and the fault shows up downstream as a bridge, a void or an open. The S7900 addresses it at the insertion head: an optional bottom clinching unit bends the leads after insertion so the part cannot move. Four bend patterns are documented — outward, inner, circular and two turns — and the specification gives lead diameter…

Thirty-six lines from a real THT board, split by which machine should place them

This is the part of an odd-form project that decides the price. Before anyone quotes a machine, someone has to read the bill of materials and answer one question per line: does this go on the odd-form inserter, on an axial inserter, or does it stay manual? The analysis below was done line by line on a customer board — thirty-six through-hole lines — and it is reproduced here because the split, not the machine specification, is what tells you whether the project is worth doing.

• Lines for the odd-form inserter. Electrolytic and ceramic capacitors, noise-suppression capacitors, seven connectors, a spade terminal, a relay, a varistor, a sensing gauge, a transformer, a DIP IC and two trimmer potentiometers. These are the parts with body shapes, polarity and lead pitches that a tape-fed radial machine cannot take.
• Lines for the axial inserter. Four diodes and five resistors, all supplied in ammo pack on axial tape with a fixed lead span. Sending these to an odd-form head would waste its flexibility; they belong on an axial machine running at its own cycle rate, which is why the same solution document proposes the two machines together.
• Line that stays manual. A crimped ground harness. It is not a component on a feeder — it is a wire assembly that is routed and terminated by hand, and no insertion machine in this class addresses it. Being explicit about the one line you cannot automate is what makes the other thirty-five credible.
• The same board, read by packaging instead of by function. Feeder count is bought per packaging format, not per component type. Read this way, the same thirty-six lines tell you how many bowl, tape, tube and tray stations the machine needs before anyone has quoted a price. Verified material Component descriptions, supply formats and line count are taken directly from the customer component analysis supplied to Southern Machinery. Part numbers, reference…

From a bowl of loose parts to a clinched lead in six stages

The sequence below follows the machine's own description of its mechanism, taken from the customer solution document and the S7900 catalog. Each stage names the subassembly that performs it, because when a line stops you need to know which of them to look at.

Where the documents disagree — printed side by side, not averaged

Three documents describe this machine: the customer solution document that specified it, the 2025 product catalog, and a precision automation presentation. They do not agree. A page that quietly picked one figure per row would look tidier and would be wrong, so every disagreement is printed here with both values and the document each came from. None of these are averaged, and none are resolved by Southern Machinery on your behalf — the machine you buy is the machine in the contract, so the…

Four feeder families on one base — because odd-form parts arrive five different ways

Feeder choice is decided by the BOM analysis, not by preference. On the thirty-six-line board above, seventeen lines arrive loose in bulk, nine on axial ammo pack, five on tape, three on trays and two in tubes. That is a five-format problem, and it is the reason a tape-only machine cannot be called an odd-form machine. Figures below are from the S7900 catalog's feeder pages.

• Loose bulk, oriented by track and vibration. For components that ship loose: connectors, terminals, capacitors, LEDs, crystals, ICs. The bowl orients each part mechanically and the pickup point presents it to the head. The customer solution document describes a patented bowl control unit that drives up to twelve vibration sources from hardware and software in one unit, and notes that the vibration supply is DC rather than mains so the…
• Radial and axial tape, six widths plus 90° bending. The catalog lists five radial tape feeder widths — 201, 218, 207 with a 90° bend, 259 and 254 — plus a 202 axial tape feeder. The standard tape feeder is described as motor-driven with a maximum pitch of 22.5 mm and a 90° bent-lead function, accepting tape material from 0.4 to 0.8 mm, with a stated feed rate of 1.1 to 1.5 s per component and a separate electric feed figure of 0.8 to 1.0 s per…
• Relays, DIP ICs and anything shipped in a stick. Two tube feeder types are listed, 222 and 203. The catalog gives a feed rate of 0.8 to 1.5 s per component, compatibility with all brands of mounting and insertion machine, a tube size customisable up to 50 × 50 × 50 mm, and a component adaptation example of relays within 30 × 22 × 40 mm. Load capacity is quoted as up to 4 kg in one place and up to 2 kg in another on the same catalog page — both…
• Connectors, transformers and large bodies on a blister tray. The tray feeder takes components supplied on blister trays — the solution document names USB and HDMI sockets and transformers, the catalog names resistors, capacitors, diodes, small connectors, small ICs, transistors and precision resistors. The catalog quotes a structure rated for 200 kg, a drive of 0.4 MPa at 100 W in one place and AC 220 V at 2000 W with 0.5 to 0.8 MPa in another, a touch…
• Grippers and nozzles are made in the same factory. Southern Machinery designs and manufactures the pickup tooling as well as the machine. The catalog devotes two pages to customised grippers and nozzles, and the head mount is a standard fast-joint system so tools can be exchanged between spindles. That matters when a component has no flat face for a vacuum nozzle, or when a body is too delicate for a gripper — the tool is a design task rather…

What one machine produced on the project it was specified for

A rated tact speed tells you how fast a head can move. It does not tell you how many boards an hour leave the machine. The customer solution document includes the case table below, and it is the most useful figure on this page because it is the only one measured on a real board rather than on a bare head.

• Two cavities, not one board at a time. The case runs two boards per cycle, which is what turns an 11-second cycle into roughly 650 boards an hour. Cavity count is a fixture and program decision, not a machine specification, and it is usually the single largest lever on real output — larger than any difference between two models in the same family.
• Four insertions per board. The board in the case needs four odd-form insertions, supplied as one variety of four pieces per machine. At a tact time of 1.6 seconds or better, four insertions fit inside the 11-second cycle with time left for indexing and vision. Boards with more odd-form lines take longer, which is exactly why the rated tact figure should never be quoted as a board rate.
• Rated tact and case output are different numbers. The same document quotes a rated tact speed of 2,400 CPH and a case output of about 650 pcs/hr. Both are correct and they are not comparable. Before you build a business case, decide which one you are using, and ask for the case figure for your board — it is the one your finance team will recognise.

What happens after the machine lands

Southern Machinery has been designing and building auto insertion equipment since 2011 and has shipped more than fifty automatic insertion machines into Brazil, India, Malaysia, Indonesia, Thailand, Turkey, Saudi Arabia, Ecuador, Colombia and Argentina. The support model below is the one that kept those machines running.