Ink & Fluid Management
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      How do I change ink types in my CM750 printer?

      Learn how to safely flush and switch fluids using the Clean Ink System routine on the CM750, so you avoid blockages, poor print quality, and system damage.

      Changing ink without flushing first? That’s how you ruin a printer.

      Whenever you're switching between different ink formulations (e.g. MEK to ethanol), colours, or even from OEM to Needham replacement fluids, running the Clean Ink System on your CM750 is essential. Skipping this step risks cross-contamination, blocked nozzles, unstable print streams, and costly repairs.

      This guide gives you everything you need to know about when, why, and how to run the Clean Ink System correctly.

      When you must run the Clean Ink System

      Run the Clean Ink System routine if:

      • You are switching to a different ink formulation or colour

      • You are replacing OEM ink with Needham fluids

      • The printer has been idle for 3+ weeks

      • Ink is expired, contaminated, or unstable

      What the Clean Ink System does

      It fully flushes your ink system using solvent:

      • Clears ink from tanks, pumps, head, umbilical, and most valves

      • Ensures no chemical residue or pigment build-up remains

      • Prepares your printer for clean operation with new fluid

      ⚠️ Note: It skips valves 1, 2, 3, and 9 intentionally—those are reserved for other service routines.

      Step-by-step: How to run the Clean Ink System

      1. Check your solvent

        • Load ~700 mL of the correct solvent for your next ink type.

        • Make sure it’s already installed in the system.

      2. Access the cleaning cycle

        • On your CM750, go to: System > Clean Ink System

      3. Start the process

        • Press Start. It will take about 40 minutes to complete.

        • Do not interrupt the cycle once it begins.

      4. Post-clean steps

        • Remove any excess solvent from the ink tank.

        • Load your new ink.

        • Run a Fill Mixer or startup cycle to prime the system.

      Pro tips from the field

      • Use the correct solvent. Don’t guess—ask your supplier or check the ink datasheet.

      • Label your bottles. Especially when working with multiple chemistries (MEK, Acetone, Ethanol).

      • Switching colours? Run the Clean Ink System twice to avoid ghosting.

      What happens if you skip it

      If you change fluids without cleaning:

      • Your ink stream may destabilise

      • You’ll see charge or deflection faults

      • Your print may look patchy or misaligned

      • Worst case: the nozzle blocks permanently

      If you’ve already changed inks and see these issues—run the Clean Ink System immediately.

      Need advice on which solvent or ink to use?

      Talk to our team