Shuttle matrix printers are designed to be long lasting, heavy duty printers that can go for years of use between maintenance or failure. I have seen printers with print counts in the millions of pages. Although these machines are incredibly long lasting and well built, service and maintenance can add many more years of life to the devices. One of the most common issues with these machines is ink buildup in the print mechanism. This causes the frets (the part that actually presses ink to the page) to either stick or stop short of the page, causing voids in the print or poor print quality. With a few basic tools, (and occasionally an alignment tool, as noted below) breaking down and cleaning the shuttle mechanism is a simple procedure which will extend the usable life of the printer.
If you have any questions or concerns, please feel free to call Midrange Repair & Parts for technical support at 708-597-4222.
How to Clean a Shuttle Frame Assembly Step by Step
• Phillips screwdriver
• 5/32 Allen wrench
• 3/32 Allen wrench
• T10 Torx driver
• 5/16 wrench
• 0.011 feeler gauge (at least 6 inches long)
• Rubbing alcohol
• Natural or plastic bristle brush (not wire)
• Paper towels
• Rubber gloves(optional)
• Alignment tool(only required for P5220dual, P7000 flat & cartridge models, and P8 Model 15 & 20)
- Turn off the printer and unplug the power cable.
- Open the printer lid.
- Open the platen all the way using the platen lever.
- Remove the ribbon from the ribbon hubs and set it aside.
- Using a Phillips screw driver unscrew the two captive screws holding down the shuttle cover.
- Remove the shuttle cover and set it aside.
- Unplug the four cables that connect to the shuttle frame assembly and tuck them out of the way.
- Using a 5/32 Allen wrench unscrew the center captive screw, and the left and right side Allen screws, which hold down the shuttle clamps.
- Place the left and right side 5/32 Allen screws, along with their washers, and the platen clamps aside.
- Unlock and slide the tractors all the way out to the sides. Lift the shuttle out of the printer casting, being sure not to damage the ribbon shield on the tractor assemblies.
- Set the shuttle, frets up, on the work surface which you will be cleaning it on.
- Depending on the model of printer the ribbon shield and hammer bank cover will come in one of two styles. Style A: One piece which snaps on and is held in place by magnets, or Style B: two piece which is held on with T10 screws. Remove the ribbon mask and hammer bank cover.
- Clean the ribbon shield and hammer bank cover using rubbing alcohol. Be sure to not bend the ribbon shield by applying too much force between the plates when cleaning the one-piece (Style A) assembly.
- Once the ribbon mask and hammer bank cover are clean, lay them aside on a clean surface.
- Remove the frets from the shuttle frame assembly. Depending on the model of shuttle, there will be 3 or 4 screws per fret. Also depending on the model, each fret will have between 4 and 20 hammer tips. Be aware that some shuttles require an alignment tool, and all the frets should NOT be removed at once. If this is the case for the machine you are working on, make sure to leave at least 2 frets fully installed at all times.
- After removing all the frets, set them aside temporarily, and using a dry paper towel, wipe down the face of the shuttle frame, removing any inky buildup or debris. After you have gone over the hammer face with a dry cloth, wipe it down again with a paper towel which has been dampened with rubbing alcohol. The towel should not be too wet with alcohol as this may damage the hammer face coating. Once you have finished cleaning the hammer face of the shuttle, it can be set aside
- Using a plastic or natural bristle brush, without any solvent, give each fret a quick once over, to remove any large debris or heavy ink buildup.
- After you have brushed off all the frets, lay them all tips up and give them a light coat of rubbing alcohol. This will soften the remaining buildup on the tips of the hammer frets.
- Using a natural or plastic bristle brush, go over the frets again, one at a time, scrubbing until there is little to no debris left on the frets. Additional alcohol can be used to keep the frets from drying out. Once all the frets have been scrubbed, wet them down with alcohol again.
- Take a paper towel folded over a couple of times and wet it down with alcohol. Wipe down the base and back of the hammer frets first, and then wipe the tips off. Keep doing this until the fret comes away without leaving any ink behind on the towel. Be sure to apply a little pressure to ensure the tips are getting good contact with the towel.
- Once you have cleaned the last of the ink off the fret be sure to set it aside on a clean dry surface to air dry.
- After cleaning all the frets and the hammer frame assembly, clean up the work area to remove any inky waste like dirty paper towels or used paper which was placed on top of a work area, to prevent getting the parts dirty again.
- Before replacing each fret onto the hammer frame assembly, first wipe down the frame assembly, then each individual fret with a clean paper towel to make sure no debris gets under any of the parts, as this can cause print quality issues.
- If you are working on a unit that requires an alignment tool, skip to step 27. There are two guide pins on the hammer frame assembly that align each fret, and two notches on each fret to go over the pins, be sure to get these lined up when placing the frets back on the hammer frame. This alignment does not have to be perfect. At this point we are just getting the parts ready for reinstallation.
- Thread in, but do not tighten down, all the T10 Torx screws that hold the frets into place for all the frets.
- Using your “off hand” thumb, press the frets down against the guide pins, while tightening the screws which hold down the frets, using your “dominant hand”. The screws should be tightened in order, from right to left, as the frame assembly would sit in the machine.
- Place all the frets on the hammer face that have been removed, and thread in but do not tighten the screws. Use the alignment tool to align the frets, and then tighten down the screws.
- Once all the frets have been tightened down, place the hammer bank cover back on the hammer frame assembly, being sure to align the guide holes on the hammer bank cover with the pins on the hammer frame assembly. Look at all the hammer tips through the holes in the hammer bank cover. They should all be near the center of the holes in the hammer bank cover. If the fret is misaligned, the hammer tips will not be centered in the holes of the hammer bank cover. If this is the case, remove the hammer bank cover and the misaligned fret, then reinstall following steps 24-25. Recheck and realign, as necessary, until all the frets are properly installed.
- After being sure all the frets are aligned, reinstall the hammer bank cover and ribbon mask. If this is a one-piece (Style A) hammer bank cover, it is held in place with magnets. If it is a two-piece hammer bank cover (Style B) it will be held down with Torx T10 screws. Also, if you have a two piece (style B) cover, reinstall the ribbon mask.
- Reinstall the hammer frame assembly. Make sure the platen is in the fully closed position, then drop the hammer frame assembly back into place on the casting of the printer. Align the captive 5/32 Allen screw and thread it down but do not tighten it. Replace the two side 5/32 Allen screws along with the washer and shuttle clamps on both sides of the shuttle as well. Being sure not to tighten them down. Pull the hammer frame assembly towards the front left corner of the machine with your left hand and tighten down the center and right-hand screw of the shuttle, before letting the shuttle go. Tighten down the final screw to finish clamping down the shuttle. Be sure to install the 4 cables that go to the shuttle.
- Perform a platen gap adjustment. No paper or ribbon should be loaded. Make sure the platen lever is closed all the way to the “A” position. Loosen the platen motor to keep from damaging the platen open belt. For this you will need a 5/16 wrench. Using a 0.011 feeler gauge, check for proper gapping at the left end of the hammer frame assembly by placing the feeler gauge in between the hammer bank cover and the ribbon mask. There should be slight tension on the gauge as you slide it up and down. If there is too much or not enough tension, it can be adjusted by turning the 3/32 Allen screw at the end of the platen. Clockwise to tighten the gap, counterclockwise to loosen the gap. Once the left end has been gapped properly, adjust the right side of the shuttle the same way. Then recheck the left side to make sure it hasn’t shifted. Once this is done, be sure to tighten the platen belt motor back down, being sure that the platen belt is tensioned.
- Write down the hammer phasing number, which is on the hammer frame assembly, somewhere you can keep it handy.
- Replace the shuttle cover.
- Get the machine ready to test: Load paper and ribbon and plug in the power cord.
- Run the following tests to assure print quality: “Burn In” under the printer mechanism test menu, to assure you do not have any light or dragging frets, “Underlines” from operator print tests to assure proper fret alignment. “Ripple Print” from operator print tests to assure proper phasing.
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