An automatic vertical sheet metal storage tower is a dense, self-contained warehouse for flat material: a steel frame, a stack of trays, one lift and a PLC that coordinates the whole movement. Its purpose is simple to state — store sheets vertically and deliver the right one to an access bay on command — but the engineering details decide whether it runs for years without trouble or becomes a maintenance burden.

This article looks inside the machine: the structure, the lift mechanism, the tray designs, the control logic and the options that make each Herochu tower fit a specific shop. Knowing how the hardware behaves makes the buying decision easier and daily operation safer.

Tower Structure and Vertical Lift Mechanism

The tower is built around a steel frame that carries the entire weight of the stored stock. Inside the frame, trays are stacked vertically, and a motorised lift travels within the tower’s central column, moving trays between their storage positions and the access opening. The operating principle is goods-to-person: rather than an operator navigating a warehouse with a forklift, the system brings the required sheet directly to the access bay at an ergonomic working height — or, on a fully integrated line, directly to a gantry robot waiting to take it.

When an operator requests a specific material via the control panel or connected software, the PLC identifies the correct tray, retrieves it and delivers it to the access bay. The entire cycle typically completes in under 60 seconds. That speed is what makes the tower feel instant on the shop floor: the person or the robot never stands idle waiting for stock.

Trays: Solid Bottoms, Lattice Bottoms and Load Securing

Tray construction follows the load. Solid sheet-metal bottoms suit lighter materials such as aluminium, composite panels and timber sheets, where a continuous surface protects the stock. Reinforced latticed steel bottoms handle heavier duty — bundled bar stock, thick plate and the dense material that would sag or distort a thin tray. Mobile load-securing supports prevent material from shifting during handling, so a tray arriving at the access bay holds exactly what it left with.

The lift’s transfer speed of 5–15 m/min is set to keep trays stable through both vertical and horizontal movement. Sheets up to 500 kg can ride in the tower, which covers the practical range of laser-ready plate without stressing the mechanism.

PLC Control and Goods-to-Person Operation

The PLC is the brain of the tower. It manages tray indexing, tracks which position holds which material and sequences retrieval commands so that two requests in a row do not collide. Interlocks are built into the logic: a tray is not released while the access bay is occupied, and the lift does not move until the bay is confirmed clear. Position verification happens on every cycle, which is why tower systems earn a reputation for reliability — the machine checks itself before it moves.

Control can be as simple as a panel with a material-code keypad or as connected as a link to the company’s ERP or WMS. On a Herochu line, the tower also talks to the gantry robot and the material cart, so a retrieval request can trigger the whole sequence of storage → handling → loading without a second command.

What the Tower Can Hold

Steel, aluminium, stainless steel, copper, composite panels, timber sheets and plastics are all standard stock for tower storage. The practical limits come from the tray and the access bay: sheets from 3000 × 1500 mm up to 6000 × 2500 mm can be accommodated, and clear space between sheets is set at 350 mm as standard, customisable when the material mix needs more room — for example, for coated stock or panels with protective film. The four standard Herochu models cover the common sizes:

Layer counts run from eight to ten as standard and are customised upward for shops that store many grades of the same gauge.

Configuring the Tower to the Shop

Configuration work is where a tower earns its keep. A shop cutting 3000 × 1500 mm plate every day needs a different tower from one that stores 6000 × 2000 mm stock for a heavy fabrication line. Layer count sets the storage density; clearance sets the material envelope; load rating sets the weight ceiling; and the number of towers — one or several — is decided by the material mix and the pace of the cutting schedule. Herochu engineers take the sheet list, the gauges, the batch sizes and the available ceiling height, then specify the tray layout accordingly. The result is a tower matched to the stock it will actually hold, not a catalogue default.

Operating Notes That Keep the Tower Reliable

Tower maintenance follows a short list of recurring checks: keep the guide rails clean and lubricated, inspect the lift drive components for wear, confirm the sensors that verify tray position and bay clearance, and review the PLC fault log weekly. Operators should be trained on the interlock behaviour — what happens when a bay is blocked or a request references a missing material code — because most “tower failures” turn out to be operator actions that the interlocks correctly refused. With these basics covered, a tower typically runs years between major interventions, and Herochu supplies the checklist with every installation.

An automatic vertical sheet metal storage tower earns its place through density and discipline: dense storage above the floor, disciplined control over every cycle. Herochu builds the structure, the lift, the trays and the PLC as one unit, then configures each tower to the shop’s real material list. That is the difference between owning a tall rack and owning a working system.