Epson R3880 Ink Flow

[Ian Barber]

At the end of the ink tube is what I understand to be the dampers.

Can anyone explain what the function of this device is.

I have noticed that after the printer has been stood for some time, maybe 2 hours, I am seeing a blob of ink hanging from under the print head and I don't think this is normal.

I am wondering if ink should only pass through these ports when the printer is actually in use and in the case of the ink blob hanging under the printhead whether there is a leak in this unit

 

[Ink stained Fingers]

what happens before the printer starts printing ? Does the printhead make some moves to wipe the bottomplate clean ? Otherwise you would see those blobs on the paper immediately. If I understand Epson's explanations correctly there are two functions for the dampers - they have a fine wire mesh filter in the ink channels, that's the last barrier for the ink before it goes into the ink channels and nozzles in the printhead. And it happens that this filter clogs with ink residue, and typical cleaning cycles won't clear such clogs. It looks like a printhead problem, with the ink flow, but it might be the dampers, and not the printhead. With large format printers there may even be a service cycle to replace the dampers after x liters of ink or xx meters of paper printed. Then it acts as a pressure buffer, the damper contains some ink and air, and you have different pressures in the ink tubes depending of the head movement direction - the ink either flows with or against the movement of the printhead, and that creates minute pressure changes, and the damper does what the name implies. And you have air pressure changes creating minute changes in the ink system, as well causing such drops, but only after a longer time, that's like level changes in a mercury barometer, and one open end are the nozzles

 

[Ian Barber]

Thanks for the explanation, very interesting and informative

 

[Ian Barber]

Just to follow up on this...

In the nozzle check chart below, does anyone know what CUR InkCount - Pre Ink Count and C-P values mean

 

[Ink stained Fingers]

you get the values of the current total ink consumption after a print, and the previous value before a print, and the delta of C-P in milliliters I think. That allows you to calculate a price for a print based on the actual ink consumption for that printjob.

 

[Ian Barber]

you get the values of the current total ink consumption after a print, and the previous value before a print, and the delta of C-P in milliliters I think. That allows you to calculate a price for a print based on the actual ink consumption for that printjob.

Thanks for the explanation