PLC-Based Pneumatic Paper Cutting Machine

Paper cutting sounds simple until you watch it done by hand: a stack of sheets drifts during the cut, edges come out ragged, and every stroke puts the operator's fingers near the blade. Commercial print shops solved this decades ago with PLC-controlled guillotine cutters — programmable cut sequences, pneumatic clamping that holds the stack still, and safety interlocks that refuse to cycle unless the operator's hands are provably on the buttons. This project rebuilds that industrial machine at student scale: a steel frame carrying a pneumatic cylinder and guillotine blade, a paper stack table, and a genuine Siemens SIMATIC S7-1200 PLC running ladder logic written in TIA Portal. It is an automation trainer as much as a machine — every wire, every rung of logic and every pressure setting is something the student built, programmed and tuned.

1. The operator places a paper stack on the table against the back gauge and selects manual or auto mode.
2. In auto mode, pressing both palm buttons inside the timing window starts the cycle — the PLC checks clamp, blade-home and guard inputs first.
3. The clamp cylinder extends and a pressure switch confirms the stack is held.
4. The main cylinder drives the guillotine blade down through the stack; reed switches report stroke end.
5. The blade retracts, the clamp releases, and the retentive counter increments; the cycle repeats for the preset count.
6. Any e-stop press, guard fault or pressure loss freezes the sequence mid-cycle and latches the fault until a deliberate reset.

Tech stack:

• Siemens SIMATIC S7-1200 PLC, programmed in TIA Portal (ladder logic)
• Double-acting pneumatic cylinders (clamp + blade drive), 5/2 solenoid valves
• FRL unit (filter-regulator-lubricator), flow-control valves, pressure switches
• 24 V DC industrial I/O: palm buttons, mushroom-head e-stop, reed switches, selector switch
• Steel fabrication: frame, blade guide, paper table, back gauge
• Operator panel with cycle counter display and indicator lamps

• [Siemens S7-1200 PLC control] A genuine SIMATIC S7-1200 runs the machine; students write and download the ladder logic in TIA Portal themselves.
• [Pneumatic guillotine drive] A double-acting pneumatic cylinder strokes the blade through the paper stack; flow-control valves let the student tune cut speed vs. impact.
• [Pneumatic paper clamp] A second cylinder clamps the stack before the blade moves, holding sheets registered so edges cut clean and square.
• [Dual-hand safety start] Two palm buttons must be pressed within a short window to start a cycle — the classic anti-tie-down guard against hand-in-die operation.
• [Emergency-stop chain] A latching mushroom-head e-stop drops all outputs and requires a deliberate reset sequence before the machine can restart.
• [Cut counter and presets] The operator panel shows the cycle count and stores cut-count presets, demonstrating real PLC data handling (retentive counters, recipes).
• [Manual / auto modes] A selector switch gives manual jog for setup and automatic cycling for production, with mode-dependent interlock logic in the program.

• Assembled machine prototype (steel frame, cylinders, blade, paper table, guards)
• Siemens S7-1200 PLC with the ladder-logic program (TIA Portal project files)
• Pneumatic circuit diagram and component list
• Wiring diagram for all 24 V I/O and safety devices
• Setup and tuning guide (pressure setting, flow-control adjustment, blade alignment)
• Project abstract PDF
• Project report (background, PLC programming, pneumatic design, safety analysis)
• PPT presentation and viva Q&A document (ladder logic, pneumatics, machine safety)

• This is a student-scale demonstrator, not an industrial guillotine: it is not certified to machinery-safety standards, and the report keeps that boundary explicit.
• Cut quality depends on blade sharpness, pressure setting and stack thickness; the tuning guide covers the procedure, but results vary with the buyer's build.
• The machine needs a shop-air supply (~4–6 bar); a small compressor or lab air line is a prerequisite, not included.
• The PLC program is written for the S7-1200; migrating to another PLC family is possible as a customization, not part of the base build.
• Pneumatic cylinders and valves are wear items; seals and blade edges need periodic maintenance.