Epson ET-8550 DTF Conversion Part 3: Printhead Maintenance Assembly Installation and Ink Setup

When converting an Epson ET-8550 into a Direct Film (DTF) printer, a critical aspect is maintaining the printhead and ensuring a smooth ink flow, especially when dealing with white ink, which is notorious for clogging. This guide will walk you through critical steps in this conversion process, including removing the star wheel, installing the printhead maintenance system (PMS), and connecting the printer to the ink tank. We also provide insights into how these components work together to keep your DTF printer running smoothly. Check out our video below to see the whole process in action.

Removing the Star Wheel

The first step in this conversion process is to remove the star wheel, sometimes called the "pizza wheel." This diminutive component, located near the printhead, helps manage the media flow under the printhead, but it can interfere with DTF printing. The star wheel is held in place by two screws—one on the left and one on the right.

To remove the star wheel, begin by unscrewing the left-side screw and sliding the printhead carriage to the right to access the second screw. Once both screws are removed, the star wheel will be loose, but it's still held in place by tension springs. Carefully detach these springs, paying close attention to their position, so you can later reassemble the printer if needed.

Tip: When removing the star wheel, ensure the drag chain (which holds the ink tubes in place) is securely installed. Misalignment of the drag chain can cause the tubes to become stuck, interrupting your print flow.

Installing the Printhead Maintenance System (PMS)

Once the star wheel is out, the next step is installing the printhead maintenance system (PMS). This is a crucial part of the conversion, as it helps manage the pressure and flow of ink, ensuring that the printhead remains unclogged and functional.

The PMS unit consists of two tanks and four outputs. The left two outputs manage the white ink, while the right tank handles maintenance fluids, such as cleaning solutions or distilled water. When installing the PMS, position it carefully so the tubes connect correctly to the ink tanks and the printhead.

During the installation, separate the ink tubes based on their function. The four colored inks (cyan, magenta, yellow, and black) go underneath the PMS assembly, while the white ink and maintenance fluid tubes go on top. Make sure the tubes are securely connected using elbow connectors, which help stabilize the ink flow to the dampers.

How the Printhead Maintenance System Works

The primary function of the PMS is to manage the circulation of white ink and maintenance fluids. White ink is one of the most challenging elements of DTF printing because it tends to settle and clog the printhead if not appropriately managed. The PMS includes a secondary tank system that circulates the white ink, preventing clogs and ensuring smooth printing.

The PMS also manages daily printhead cleaning, a crucial task for anyone using white ink in a DTF setup. It does this using a "maintenance line" that flushes cleaning fluid (or water) through the printhead regularly. This maintenance line is connected to the right tank on the PMS, which holds distilled water or other cleaning solutions.

Once installed, the PMS allows the printer to alternate between printing and maintenance modes. This keeps the printhead free from clogs and ensures the white ink remains fluid and usable.

Connecting the White Dampers

After installing the PMS, the next step is to connect the white dampers. These dampers help regulate the flow of white ink, which is crucial for achieving smooth, opaque prints in DTF printing.

This system has two white dampers connected to one of the two white ink nipples on the PMS. The white ink flow is "sandwiched" between the four color lines, ensuring that all colors, including white, are properly distributed during printing.

When connecting the white dampers, ensure the C3 tube (used for white ink) is securely attached to the connectors. The first white damper connects to the leftmost nipple on the PMS, while the second damper connects to the second nipple. These connections are critical for maintaining consistent ink flow, especially during long print runs.

Installing the Maintenance Lines

The maintenance lines are connected to the remaining two nipples on the PMS and are used for daily cleaning and maintenance. These lines are not used during normal printing operations but are essential for keeping the printhead in top condition.

To install these lines, cut the tubing to the same length as the white ink tubes. Connect them to the PMS using elbows or straight connectors, then position them behind the white dampers. These lines will be filled with distilled water or a cleaning solution, allowing you to flush the system whenever necessary.

Although the maintenance lines won't be used for printing, properly installing them ensures that your printhead stays clean and operational, reducing downtime and increasing the life of your DTF printer.

Connecting to the Ink Tanks

The final step of this conversion is connecting the PMS to the external ink tanks. These tanks hold the six colors used in DTF printing: cyan, magenta, yellow, black, and two white inks. In addition, the PMS is connected to a seventh tube, which manages the maintenance fluid.

To connect the tanks, attach the four colored ink tubes to the central connectors on the PMS and the two white ink tubes to the outermost connectors. The maintenance tube connects to the seventh connector on the PMS, allowing the maintenance fluid to flow through the system when needed.

Tip: Always use high-quality inks, such as those from BCH Technologies, to ensure consistent performance and avoid clogging issues. BCH Technologies offers a range of inks designed explicitly for DTF printing, including white ink that stays fluid and resists clogging.

Once all the connections are in place, fill the tanks with the appropriate inks. The white ink tanks should be regularly agitated to prevent settling. In contrast, the maintenance tank should be filled with distilled water or another cleaning solution to keep the printhead in good condition. After completing this process, your Epson ET-8550 is fully converted to a DTF printer. This setup, particularly with integrating the printhead maintenance system, ensures that the printer will run smoothly and efficiently, even during long print jobs. By managing the white ink circulation and keeping the printhead clean, you can significantly reduce the likelihood of clogging and downtime.

If you'd like to see the process in action, check out the video below, where we walk you through each step in detail.