Material Changeover

Once you have pumped resin through an MDM, you must continue to use that resin type in the MDM. This is because the hose that routes resin through to the resin tray will always have residual resin inside. If you attempt to use a different resin in that MDM, the resin type in the tubes will mix with the resin type in the cartridge, rendering the new resin an ineffective mixture.

It is possible to change the material used in an MDM by switching out all components with residual resin inside. The following procedure describes how to do this.

Order Replacement Equipment

Before performing this procedure, you must order the Material Changeover Kit from 3D Systems or your authorized Reseller. The changeover kit is five parts connected together:

mco-tubing-kit.jpg
A Cartridge Coupler - This coupler connects to the resin-cartridge valve at the bottom of the cartridge chute. It stops/starts resin flow into the first set of tubing.
B Pump-Delivery Tube - Delivers resin from the cartridge to the resin pump.
C Resin Pump Head - Interfaces with the resin-pump motor to drive resin flow through the tubing system.
D Resin-Tray Delivery Tube - Delivers resin from the resin pump to the resin tray in the upper build chamber
E Tube Cap - Use this cap to close off the Resin-Tray Delivery Tube.

Material Changeover Procedure

CAUTION: RESIN SPILLS POSSIBLE. WEAR 100% NITRILE GLOVES AND EYE PROTECTION THROUGHOUT THIS PROCEDURE.

 

  1. Premix the resin cartridge for the material you are switching to, according to the section Premix Resin Cartridge Before Installation
 
  1. On the Controller Status screen, expand the Printer on which you wish to change the resin. On the Resin Card, tap the change mat btn.jpg button. This will disable the unit so that it will not receive any print jobs.

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  1. You will see the following screens on the Controller (a) and Printer (b):
    1. mco-bottle-ready-to-be-ejected.jpg Tap the X or Close button to clear this message and free up the Controller for other Modular users.
    2. local-gui-eject-cartridge.jpg
  1. Open the lower-print-chamber door and pull the MDM toward you. There are hard stops built into the slides to keep the MDM from coming completely out.
  2. Fully tighten the white cap on the top of the cartridge.
  1. Press the Eject button to eject the cartridge. Remove the resin cartridge and place the rubber cap over the cartridge valve (Fig. 6.1 below). Store the cartridge (see Step 16). Please see the section Resin Handling and Safety for cartridge-storage guidelines. If you are not storing the cartridge for later use, dispose of the cartridge according to all government regulations. Once you have ejected the cartridge, notice that the screen on the Printer changes to the one below (Fig. 6.2).
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Fig. 6.1
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Fig. 6.2

 

  1. You must untension the resin tray you are switching out before opening the upper chamber door. The tension arms will not release after this door is open. To untension the resin tray, open the lower-chamber door and push the tension toggle button.
    push-tension-button.jpg

  1. Wearing 100% Nitrile gloves, open the upper-chamber door, remove the resin tray, and determine if you will be able to use the same resin tray for the new resin you are switching to, according to the section Resin Tray Material Cross-Usage. If you will be using the same resin tray for the new resin, be sure to follow the instructions in the section Clean Resin Trays. Alternatively, you could use a brand-new resin tray for your new resin. If you are using a new resin tray, label the old tray with the resin name and store the tray in its garage.

  1. Use a T20 screwdriver to remove the bottom two M4 screws (in red, below) on the MDM front panel. Loosen the top two M4 screws (in green, below) a full turn. The panel should now slide up and off.

mdm-screws.jpg

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  1. Place paper towels on the floor in front of the printer, just under the pulled-out MDM. The drip trays in the MDM and printer floor will catch resin drips inside the machine.
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  1. In the upper build chamber, place provided cap on fill nozzle (1, below) and disconnect the tube from its holder (2, below). This will help to avoid resin spills and to preserve the tube for future use. From the front of the machine, reach under the chassis and pull the resin tube down into the lower build chamber.

    NOTE: You should place the red cap on the tubing anytime you remove it from its holder.

remove-resin-tube.jpg

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  1. In the MDM, pull the ring out and to the right to release the MCO Door. Open the MCO Door.
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  1. Remove cartridge coupler from MDM. Wipe out inside of coupler with a dry, lint-free paper towel.
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  1. Remove two thumb screws to disconnect the Resin Pump Head from the Resin-Pump Motor. Remove the Resin Pump Head.

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  1. In the bottom-left of the MDM, unclamp the resin-delivery tube, and carefully pull the tube out through the hole. Pull the rest of the tubing completely out of the MDM.

 

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  1. Roll the tubing into a coil and place it in the provided UV-protective plastic bag. Label the bag with the resin type, date of MCO, and resin lot number (seen on cartridge). Place the tubing, along with its matching resin cartridge, in storage (see Step 6). If you will not reuse this material tubing in the future, discard it according to all government regulations.

NOTE: The used MCO tubing is only good for one month after removal from a printer. After this, you must use a new MCO kit for that resin.

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  1. Obtain the new tubing from your Material Changeover Kit. Place your new cartridge's tubing label on the tube in a position where it will not interfere with the tube fitting into any machine fixture. The image at the right demonstrates a good place to install this label.
mco-tubing-kit-no-letters.jpg
  1. In the bottom-left corner of the MDM, feed the Resin-Delivery Tube through the hole. Once the tube is mostly through, open the clamp, and then secure the tube by pushing in on the clip until you hear a click.

replace-resin-tube-new.jpg

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  1. With the upper-build-chamber door open, feed the Resin-Delivery Tube from the lower chamber up through the hole to the left of the elevator. With your other hand, grab the tube so that it does not fall back through the hole. Ensure that the red cap stays on the tubing throughout this process.
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  1. Place the Resin-Delivery Tube's cap in the fixture as shown at the right. Feed the tube through the delivery fixture, ensuring that the tube does not pinch anywhere. Ensure that the tube does not protrude too far out from the fixture holding it in place. If the tube is too far out, the print platform will hit it on its way up/down.

CAUTION: Failure to remove the red cap will result in the cap being forced off when resin pumps into the resin tray. The cap will fall into the tray and, if not noticed, will cause resin-tray breakage and build failure.

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  1. Back in the MDM, install the Resin Pump Head on the Resin-Pump Motor. Secure it in place with the thumb screws you removed in Step 14. Tighten screws by hand until they are snug, plus one more revolution.
reinstall-peri-pump.jpg
  1. Install Cartridge Coupler with the gray button facing toward the back of the machine. Ensure that the resin tubing below the coupler is firmly within the clamps shown below. These clamps are part of a sensor that detects resin presence in the tubing to assist the machine in certain functions.

resin-presence-sensor.jpg

 

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  1. Close the MCO Door and secure in place by pulling the ring out and to the left.

CAUTION: Failure to perform this step before installing a resin cartridge could damage the cartridge-chip reader.

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  1. Your cartridge must be premixed before being installed in a Printer. Ensure you have done so, as per the section Premix Resin Before Cartridge Installation. Remove the red, rubber cap from the cartridge valve. Carrying the cartridge by its handle, slide the cartridge down the chute in the orientation shown at the right. The Cartridge Key should be on the left (see below). Ensure the cartridge is fully seated by pushing down on it until you hear it click into place.

CAUTION: Ensure that you are installing a cartridge with resin inside. The printer will show an error if an empty cartridge is installed. The minimum requirement for an MCO is >5% of the resin remaining in the cartridge.

  1. Remove the cap from the top of the cartridge and take the following steps to ventilate the cartridge:

    1. Grab the foil seal by the pull-tab on top.

    2. Pull on the tab from the edge of the seal, as seen at the right. Peel the seal off slowly, going down the same axis as the pull tab. Pulling straight up on the tab (below, left), or pulling along the axis perpendicular to the pull tab, can make this task more difficult and can even break the tab.

  1. Recap the cartridge and tighten the cap finger-tight. Then loosen the cap by a quarter turn to allow for ventilation.

CAUTION: DO NOT FORGET TO DO THIS STEP. THE SUCTION OF THE RESIN PUMP WILL CAUSE THE CARTRIDGE TO COLLAPSE IF IT IS NOT VENTILATED, WHICHCAN SPILL RESIN INSIDE THE MACHINE AND CAUSE MACHINE ERRORS. THIS SITUATION WOULD REQUIRE YOU TO CEASE PRINTING AND TO HAVE A 3D SYSTEMS SERVICE CALL TO COMPLETELY CLEAN THE MACHINE.

  1. Push the MDM back until it hits its rear limit.
  1. Reinstall the MDM front plate, sliding the plate over the top two screws to guide it into place. Use a T20 screwdriver to tighten the top two screws (in green, below) and reinstall the bottom two screws (in red, below). If you did not do so in Step 20, ensure that the red cap has been removed from the resin-delivery tube above the resin tray, and close the orange printer door.

mdm-screws.jpg

 

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  1. Carefully lower your new or cleaned resin tray into place, concave side up, as seen at the right. It should fit snugly in the holder on the chassis.

NOTE: If you did not do so in Step 20, ensure that the red cap has been removed from the resin-delivery tube above the resin tray.

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Resin tray shown upside-down for reference

  1. Close the upper-build chamber door and re-tension the resin tray by pressing the tension toggle button.

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  1. On the Printer touch screen, press and hold the finish-mco-btn.jpg button to tell the unit you have finished performing the material-changeover procedure. This will re-enable the Printer.
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  1. The printer can now fill the resin tray according to the section Fill Resin Tray From Empty.
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You have successfully switched resins on a Printer! If you experience any issues with your new resin, please contact 3D Systems Service.