On a used machine, the control is often older than the mechanics are worn. It is also the part that decides how the machine feels to work with every day — and how easy it will be to keep running in five years.

The brand matters less than three practical questions

  1. Can your people already program it, or something close to it?
  2. Are spare parts and service still realistically available for that generation?
  3. Does the machine come with a full backup of parameters, PLC and, where relevant, the machine data?

A control your operators know, with parts on the shelf and a backup in the drawer, beats a more modern one that nobody in the building can drive.

What each family tends to feel like

These are generalisations, and every model differs, but on the shop floor:

  • Fanuc — enormous installed base, conventional G-code, parts and expertise widely available across Europe.
  • Siemens — strong cycle support and shop-floor programming on the newer generations; older ones need someone who knows them.
  • Heidenhain — conversational programming that many toolmakers strongly prefer for one-offs and moulds.

The checks that save real money

  • Backups. Ask for parameters, PLC and tool data on physical media before you pay. This is the single most valuable item you can take away with the machine.
  • Battery status. Absolute encoders and memory on older controls rely on batteries; a flat one during transport can mean re-referencing or worse.
  • Screen and keyboard. CRT replacements and membrane keypads are available for common models, but check availability for that exact one.
  • Data transfer. Some older machines still expect RS-232. Confirm whether a DNC solution or a memory card interface is fitted.
  • Alarm history. Ask to see it. Recurring alarms tell a story the seller may not.
A twenty-year-old control with a complete backup and available spares is a working machine. The same control with no backup is a gamble.

Retrofit: when it makes sense

If the mechanics are sound and the control is the only problem, a retrofit can be worthwhile — but budget honestly. A retrofit is a project with engineering, wiring, commissioning and downtime, and it rarely comes out cheaper than expected. It makes most sense on rigid, heavy machines whose mechanical quality would be expensive to replace.

Unsure about a specific control on a machine you are looking at? Send us the model and the control version — we will tell you what we know about parts and service for it.