Homebrew PCBs

Steve wrote:
> --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote:
> 
>>Steve wrote:
>>
>>>--- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@> wrote:
>>>
>>>
>>>>Any idiot can see that relying on the vacuum pump to clean the
>>>>nozzles is useless if the first nozzle to run freely prevents the
>>
>> >>other nozzles from being cleaned!
>>
>>>Let's keep it civil.
>>>
>>>A peristaltic pump with a hose hundreds of times larger diameter than
>>>the nozzles... I don't think it's quite that clear cut, if it were
>>>then the vacuum pump cleaner would be completely useless.
>>
>>The surface tension is a constant of the fluid. The force required to
>>form a droplet is independant of nozzle diameter. Therefore, the Pascals
>>required to form the same surface deflection is proportional to 1/area
>>or 1/diameter^2. Increasing the peristaltic pump hose diameter will make
>>no difference whatsoever. The vacuum pump is only for taking away the
>>fluid and forcing it into that fat dunny-roll inside the printer.
> 
> 
> I'm not sure it is forming a droplet. It is possible to push or pull
> ink through the nozzles without relying on the formation of droplets.

I know. But the force needs to exceed the surface tension before you'll
get any kind of flow out of the nozzle.

> In any case, putting cleaning fluid in the park pad and letting it sit
> for hours or a day seems to be a much more efficient way to unclog
> badly clogged nozzles. 

When i tried Nifti as a refill, i set it for 20 cleanout cycles. When i
came back, it was working, so it could have been unblocked in much fewer
cycles. A drop of the ink in some Nifti shows it's an excellent solvent
for it (epson black ink).