Modern Metal Scrap Balers are sophisticated pieces of equipment that offer multiple modes of control, typically blending automation with manual oversight for safety and flexibility. 

Here’s a breakdown:

1. Semi-Automatic / Programmable Logic Control (PLC - Most Common)

This is the standard for industrial balers. The operator uses a manual control panel (often with buttons and a touchscreen HMI - Human Machine Interface) to initiate a pre-programmed, automatic cycle.

How it works: The operator loads the machine, closes the safety gate, and presses a single button like "CYCLE START."

The Automatic Sequence: The PLC then takes over and runs the entire baling cycle automatically:

The hydraulic pre-press head may descend to compress loose material.

The main compression ram advances in several stages to compact the metal.

The bale chamber may index or adjust.

Once the bale is formed to pre-set pressure or size, the tying/wiring system (manual or automatic) is activated.

The ejection door opens, and the ram pushes the finished bale out.

Manual Override: During any automatic cycle, the operator can typically press an E-STOP (Emergency Stop) or Hold/Pause button to take immediate manual control if there's a problem.

2. Fully Manual Mode (For Setup, Maintenance, and Troubleshooting)

Every baler has a manual control mode, accessed from the same control panel.

Purpose: This mode is used for:

Setting up the machine for a new bale size or material type.

Jogging individual components (e.g., "ram forward," "door open," "head down") inch by inch.

Performing maintenance.

Clearing a jam by reversing or moving rams manually.

In this mode, the operator has direct, discrete control over each hydraulic function, but safety interlocks (like gate switches) are still active.

3. Fully Automatic (Advanced Systems)

Some high-end, integrated scrap processing lines feature balers that are fully automated.

They are fed by conveyor systems or robotic arms.

Sensors monitor bale density and size, making adjustments on the fly.

Automatic tying systems bind the bale without human intervention.

These systems still require manual monitoring and have full manual override capabilities for safety.

Key Analogy: A Modern Washing Machine

Think of it like a washing machine:

Manual Mode: You select the water temperature, spin speed, and time individually (like jogging a ram).

Automatic Mode: You press the "Heavy Duty" button, and it runs a pre-set sequence (like the standard bale cycle).

You (the operator) must still load it, close the door, and press start. The machine handles the complex sequence, but you are in overall control and can stop it at any time.

Why This Hybrid Approach?

Safety: Manual override is critical for emergency situations.

Efficiency: Automatic cycles ensure consistent, fast, and optimal baling with minimal operator effort.

Flexibility: Manual control allows for handling non-standard materials, maintenance, and adjustments.

Conclusion:
You don't typically choose between an "automatic" or "manual" metal baler. You choose a baler with a PLC-based control system that provides semi-automatic cycling for production and full manual control for setup and safety. The operator's role is to manage, initiate, and oversee the automatic processes, not to control each hydraulic movement individually during normal operation.