Digital BW, The Print

Carl Schofield wrote:

>I think it is more involved than just flushing out the black line.  Can't remember where I read 
>this but essentially there is some convoluted procedure involving draining all of the inks on 
>one side of the printer to these cartridges and then after changing the black ink moving all of 
>the inks back again.
>
>  
>
Sounds more like my hack on the 10000.  The new wide format printers 
have pressurised carts like the 10000. They are located below the head 
height and so need pressurised carts and electric valves in the ink 
channels to get inks to the heads and keep the lines filled when the 
printer is idle.  When the heads are free of the capping station you can 
apply a vacuum instead of pressure on the chamber around the inkbag and 
suck the ink back to the carts. (On the capping station that would be a 
disaster as filthy ink would get into all ink channels) Change the black 
cart and pressurise the carts again.
Do the new auto nozzle test and the printer is ready. The reason to use 
special carts may be related to a one way valve in the normal carts that 
makes it impossible to refill them c.q. makes it impossible to let the 
ink flow back in the cart (but the last is already impossible in the 
10000 with the electric valves in the inkline, yet it has the same one 
way valves in the carts).

I do the same in the 10000 hack but on the black inkline only with a 
cart that I can set vacuum on with a pump. The one way valves in the 
carts are operated on. The electric valve in the black inkline needs a 
finger to stay open. There's a nice extra effect on taking out ink in 
reverse flow, accumulated dirt at the damper flows back with the ink 
that is in the head, a normal flow doesn't do that. This issue may get 
more important if the new heads are the same as the 10000, integrated 
dampers that are part of the total assembly and can't be 
replaced-cleaned separately. There are solutions already.

Ernst