Which black ink damages the Epson ink switch valve?

[W. Fisher]

Which is guilty? The Photo Black (PK) or the Matte Black (MK) ink that damages the shuttle valve in the Epson printers.

I'm guessing it is the MK (Matte Black) maybe being a thicker ink doing the damage to that valve that switches between the two. If so, I'm thinking of maybe switching it out to a PK tank and tossing out the MK given I can make my own profiles.

W.F.

 

[stratman]

How do you know it is not a poorly designed part(s)?

 

[W. Fisher]

How do you know it is not a poorly designed part(s)?

That's already a given knowing how many have had issues with that valve and the idiotic design behind their PK/MK switching system. I often think Epson designed it to waste ink with subsequent sales of more ink to feed it.

So far, the issues I've seen with that shuttle valve and its design result in:

1. Missing nozzle checks.
2. Ink dribbles and leaks.
3. Contamination of lighter-colored yellow ink from excessive leaking.
4. Wasting of ink for the switching.
5. Rapid filling of the maintenance tank.
6. Sludging of old and dried ink (MK?) around capping station and wiper.
7. Crud buildup beneath the print head's retaining frame.

Epson really should have addressed it long ago, imho, but seems it passes on to later generations as if it is a good idea.

W.F.

 

[Ink stained Fingers]

I rather would think it's the solvent itself , and not so much this or that pigment type, causing some longer term impact onto the plastic parts

 

[W. Fisher]

I rather would think it's the solvent itself , and not so much this or that pigment type, causing some longer term impact onto the plastic parts

hmmm... Maybe solvent related too. Dunno.

Anyone take one of those PK/MK valves apart to see what goes wrong with them? Plugged up with ink crud, or maybe etched by some solvent?

W.F.

 

[The Hat]

I’ve always found the debate on the Epson switch valve interesting but at the same time very dumb, so many guys have had issues with that stupid design, and some have even cut the wire to the switch so it couldn’t be switched accidently, but that meant you were restricted to just one black.

But I’ve never head of anyone removing the switch valve altogether and replacing it with a manual T type joiner which would allow the use of both inks without suffering the hassle of constant clogging and the self-imposed one black fits all...

 

[W. Fisher]

I’ve always found the debate on the Epson switch valve interesting but at the same time very dumb, so many guys have had issues with that stupid design, and some have even cut the wire to the switch so it couldn’t be switched accidentally, but that meant you were restricted to just one black.

But I’ve never head of anyone removing the switch valve altogether and replacing it with a manual T type joiner which would allow the use of both inks without suffering the hassle of constant clogging and the self-imposed one black fits all...

Interesting idea!

I have a PK/MK 3880 valve (A new spare.) and it has four ports on one side and two on the other. I don't know what Epson is doing with that many lines (Six?) in and out of the thing. It's a bizarre looking thing, and Epson wrapped it with some protective tape over the two valve circular parts (I'd think they'd be sealed anyway?), and the ports are separately covered too which seems normal for dirt.

Maybe one could take the shuttle part of the valve out of the two round end pieces that it slides between, and seal it all up to make it feed both blacks. But the sheer number of lines going in and out of it might miss it up too. It's a weird setup.

Looking at the drawing above, it looks like the selection lever pin pushes in on the shuttle valve. Whatever rubber (?) is used to cover and seal the sliding valve may get punctured or the seal broken causing the issue. If punctured I could see the reason for the leaking part, and maybe air and misfiring nozzles too.


Cripes! Now my yellow is missing nozzles when just checked. Other 3880 is still okay, but the Cone yellow pigment one is now clogged. That's a new one as it's usually the blacks and magenta with occasional cyan not firing, but yellow?!!?

W.F.

 

[martin0reg]

My personal speculation about the issue - and how to avoid it -is different and I posted it some time ago at dpreview.
https://www.dpreview.com/forums/thread/3485399?page=2#forum-post-58494351

Here are the main thoughts (excuse for quoting myself)

---------------------------------------
While I'm using my 3880 not very much, what would be the best way to keep this switch valve working:

- avoid switching at all
Possible downside: the channel not in use may clog, the MK even more than PK, and if you once would switch, dried particles may hinder the switching
- do a switch say once a month and print some sheets with the other ink, particular if you are mostly printing with only one sort of paper and ink
- switch the paper and ink just as you like.
Possible downside: the switching valve could be overstrained, if you change the paper and ink very often

I'm just speculating..
..perhaps epson knows the answer, but they won't tell us..

---------------------------------------------

"---While there is no "5 years expiration date" of the printer, the service manual lists some counters which in fact cause maintenance requests... among others:

"...The number of drives of the ink selector has reached the upper limit ... Replace the ink selector (INK,SYSTEM,ASSY.) with a new one, and clear the counter using the Adjustment Program..." and elsewhere it reads:

"6.1.1 Product Life Information
The information of the parts whose product life is controlled is shown below.
Ink Selector: Selection lever switching operations: 7,800 cycles....

...error codes:
1431 Ink selector drive timeover
The number of drives of the Ink Selector has reached the specified
limit....Replace the Ink Selector (INK, SYSTEM, ASSY.) and reset the
counter using the Adjustment Program.
1432 Ink selector error
Changing the ink path by the Ink Selector cannot be completed during a predetermined time period due to a malfunction of the Ink Selector (its sensor or motor)..."

Many users report about the malfunction, but I've never read about an error message before. And I think in most cases the damage is caused by a defective or worn out sealing within the valve rather than by a defective of the selector itself, i.e. its mechanic parts.. Just speculating..but the longevity of sealing material may be less than of motors or gears.. (I admit I like to speculate)..."

------------------------------------------------

My conclusion:
- Do a nozzle check (no cleaning) then some prints, another nozzle check (cleaning if necessary)
at least once a month.
- AND in addition do two black ink switches, from MK to PK and back again.

Because long time of no switching may do more harm to the ink selector than keeping it moving

Regarding the first quastion of the thread, I think MK could "dry harder" than PK, therefor I try to finish the procedure with MK online.

 

[The Hat]

Looking at the drawings it would be simple to bypass the Epson mechanism with two T tube Joiners and clamps to manually control the ink flow yourself, even when switching paper types, you’d still have the choice of which ink to use..

Never have a clogged valve again..


click to enlarge..

 

[W. Fisher]

I'm thinking the easiest solution would be to dump the MK ink and fill that tank with distilled water and maybe a little alcohol. No way would it clog up the valve, unless some residual MK in the line got loose. I don't know about leaving the red-colored Piezoflush in the MK tank as it might contaminate the PK black should an accidental MK/PK switch occur.

Stoopid Epson valve!

W.F.