Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "the_des_bois" <thedesbois@...> 
wrote:
>
> I did purchase a set from eBay for my R1800.
> 
> Loaded only one cart with ink. I was not aware that they could "drop a
> bit of ink when first used" at the time. When I printed with it, my
> paper was smeared with ink on the borders. After 3-4 prints I
> concluded that the cart was defective and removed it.
> 
> I have to say I will not try again as I don't like that amount of ink
> leaking in my printer.

If you look at a clear cart for that design you see a spring loaded ball that should seat with 
pressure from the spring and close off all flow through the port when the cart is out.  In 
hydraulics it is known as a simple "spring loaded check ball".  When the cart is installed 
the check ball is lifted and the print head makes a seal with a rubber gasket.  Lifting the 
cart out the spring pressure should re-insert the ball into the seat and flow is cut off.

The seal is completely dependent on the seat and the ball and print head mating surfaces, 
both the seal made with the ball and seat, and the printhead and seat.  I haven't looked 
closely enough to see if the ball and  printhead seats are using the same piece of material 
or not.  I suspect that they are and it is simply a double sided seal.

That said, two things can happen, the rigid part of the seal, the ball or the print head are 
deformed and break the seal or the rubber seal is deformed or displaced and the seal is 
broken.  I suspect the rubber seal.

I found with MIS spongeless carts that that seal was bad on about ten percent of the carts.  
My  solution was to buy extra carts and remove them at the first sign of leakage and 
replace them and write off the cost.  They also tended to exhibit the leak almost 
immediately.

With this style of cart from the internet supplier mentioned in the thread (and they all look 
to be they same whether from Hong Kong or  other domestic suppliers) but are different 
from the MIS carts it might be nice to get a survey from the group as to what percentage 
might be leakers so that we can make a decision as to whether or not they are worth the 
trouble.

On another note Paul Roark has mentioned a few times that he has found that fiddling the 
ball and seat has stopped some leakers.  That would make perfect sense if the rubber seat 
has simply been installed sloppily and the fiddling pops some edge over a lip or 
something similar.  Personally I've got a stash of extra carts and hate fiddling with 'em.  
(it's too close to how I earn my living where this is supposed to be fun;)  but for those 
inclined that is surely worth a try.  As carts get more difficult to find we could all be there 
or back in Epson's pocket and dependent on the inks they want to give us.  I don't doubt 
that Epson has better quality control than knockoffs but we know what that costs.