Epson DX5 are one of the most difficult print heads to recover. They are easily damaged with the excess pressure, ultrasonic vibrations, and chemistry of the fluids. Print Head Doctor is the only way to clean DX5 print heads safely and effectively.
Epson DX5 heads come with different variations of the manifold. The adapter of Print Head Doctor allows mounting of all kinds of DX5 manifolds. On this video we are working with a Mutoh Valuejet 1614 print head which requires an additional riser block for a proper mount.
We insert a so-called Ultrasonic Dampening Plate in the tank. The purpose for this plate is to reduce the amount of ultrasonic energy delivered to a print head and thus minimize the risk of print head damage.
Our first set-up is Reverse Flushing with Suction Method. All eight ports of a print head are connected to the input filters on the Print Head Doctor's tower. Both output ports must be capped and the Relief Valve must be open. We use the Syphon cycle (F6), which keeps the fluid pump on for 30 minutes, and the ultrasound is turned on at a 50% duty cycle. The first thing we see is that some tubes are sucking in a lot of air, which signals a poor connection between the print head and the tubing of Print Head Doctor. As we tightened both mounting screws a little, all connections were fixed except for one (the 4th port from the left): it kept sucking in air. Then we detached the tubing and tested the 4th port with a syringe filled with the same recovery fluid (1DX). The port appears to have a crack on the side.
Next, we replaced the plastic manifold of the DX5 head with a new one (yes, they are available), re-installed the print head and repeated the Reverse Flushing cycle. This time everything looked good and we allowed the full 30-minute cycled to finish.
After that, we switched the set-up for a normal (forward) flushing and repeated cycle F6. Note that we kept the pressure at all times at 5 psi, as it's the recommended safe pressure for DX5 print head. At such a low pressure it's impossible to assess the condition of the nozzles by lifting the print head, as all you see is the fluid dripping down. 5 psi is definitely not enough to form a curtain of straight streams coming out of the nozzles, and we cannot increase the pressure without damaging the print head. Therefore the only way to check the print head is by trying to print with it on a printer.
If such test reveals incomplete nozzle recovery, but some progress in the nozzle condition, we can give it another Forward Flush cycle with the same fluid. If no progress was spotted, we can try switching to the next recovery fluid and repeating the Forward Flushing cycle again. Reverse Flushing won't be necessary anymore. We should use only 2 cycles: Syphon (with 50% ultrasound) or LPRF Foam-Free (with no ultrasound at all, but safest for a print head).
10 дек 2011
