Stefan Trethan wrote:
> On Fri, 15 Apr 2005 18:09:02 -0400, Alan King <alan@...> wrote:
>
>
>> Nope, would take some tests. Just a flat plate in the bottom corner
>>leaning
>>in at an angle should give an idea. Just occurred to me off the top of
>>my head
>>that the bubbles are giving less action from spreading out horizontally
>>and
>>joining together as they rise when I read your last message. A wedge
>>pushing
>>them back towards the board should do a lot for it.
>
>
>
> Well, while it sounds like a good idea, it needn't necessarily really work
> ;-) .
>
LOL heard that!
> I think the bubbles will not stay attached to the board, unless you can
> get that wedge very, very close.
> Which might actually work, like making the gap smaller than bubble
> diameter. the flow of etchant is pretty high from the bubbles so it should
> stay fresh.
>
Well I was thinking make more bubbles. If you have enough bubbles 1/4" or
1/2" shouldn't be a problem, more like a circulating foam..
>
> BUT this needs experimenting, and i can not just make the walls of the new
> tank sloped a guessed angle.
> I think it is easier to make the tank straight and insert plastic plates
> at a later time. It could be like a upside-down funnel shape at the bottom
> of the board, herding all bubbles through a small gap between pcb and the
> bubble-guide.
>
> A possible problem i see with this is that one would need a very precise
> board holder, if the board is not centered precisely it will cause trouble.
>
Yep test plates in a normal tank to figure the angle. May be easier to have
a straight tank and insert type plates anyway..
If you've got 2 bubble tubes one on each side with enough bubbles, and enough
slope forcing the bubbles in, the board should stay fairly centered as long as
about the same amount of bubbles are on each side I think..
Hmm two bubble tubes touching and the board sitting in the groove between
them should do it. Bottom 1/4" or 1/2" may over etch but that's a small price
to pay for simplicity.
Hard to keep the tubes aerating evenly in a fishtank but I think nothing will
grow in etchant. Still may clog over time but I think they're cheap..
Alan