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How to Inspect a Used CNC Machine Before You Buy: A Practical Checklist

January 2, 2026

Buying a used CNC machine can be one of the smartest investments a shop makes — or one of the most expensive mistakes.


The difference comes down to inspection, testing, and transparency.


At Protech Machine Tool Sales, we inspect used Mori Seiki and DMG MORI machines every day. Here’s a practical checklist every buyer should understand before making a purchase.

1. Power-On Matters More Than Paint


A clean machine doesn’t mean a healthy machine.

Always insist on:

  • A full power-on
  • Warm-up cycle completion
  • No active alarms or bypassed safety systems


If a seller won’t power up the machine, walk away.


2. Spindle Health Is Everything


The spindle is the heart of any CNC machine — and the most expensive component to repair.


Check for:

  • Smooth acceleration and deceleration
  • No abnormal noise at high RPM
  • Stable temperature during warm-up
  • Acceptable runout


A proper test cut tells you more than hours listed on paper.


3. Axis Movement and Backlash


Jog each axis through full travel and watch for:

  • Hesitation or vibration
  • Inconsistent movement
  • Audible grinding or knocking


Backlash should be minimal and repeatable. Mori Seiki machines are known for excellent axis integrity — but wear still matters.


4. Turret, Toolchanger, and Automation


On lathes:

  • Confirm turret indexing accuracy
  • Test live tooling spindles
  • Check sub-spindle handoff timing


On mills:

  • Cycle the ATC repeatedly
  • Verify pocket mapping
  • Inspect drawbar force if possible


Automation issues are often overlooked — and costly.


5. Control and Electrical Health


Whether it’s Fanuc, MAPPS, or CELOS-based:

  • The control should boot cleanly
  • Inputs and outputs should respond correctly
  • No evidence of bypassed faults or temporary fixes


Older Mori Seiki and DMG MORI machines excel here because of their stable, serviceable control platforms.


Why Buying from Protech Eliminates Guesswork


When you buy from Protech Machine Tool Sales, you don’t have to rely on guesswork or auction descriptions.

We provide:


  • Powered-on inspections
  • Mechanical evaluations
  • Clear documentation
  • Honest assessments


Our goal is simple: sell machines we’re confident will perform.


A used CNC machine should be an asset, not a risk.


If you want proven reliability, transparent inspections, and machines that are ready to work, Protech Machine Tool Sales is here to help.


Contact us or browse our inventory today to find your next Mori Seiki or DMG MORI — inspected, tested, and ready to cut.

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