adicont2 wrote:
>"I'm not convinced those slots will be small enough to prevent the
>vapor coming out when the bubbler is on."
>
>Those slots can be sealed whith soft rubber material like surgical
>gloves. I understand that you keep the etchant in tank when you don't
>use it. Am I wright?
>
>
>
Yes, it'll be very easy to do..
>"Anyway, if you make that pendulum, why not attach soft plastic
>brushes that brush the board? might be more uniform, and the wiping
>action surely mixes the etchant well enough."
>
>I'm totaly agree whith this opinion. All my actual boards is made
>whith a bowl and a sponge brush. The quality of etched board is very
>good.
>
>
>
While this can work well by hand, a mechanical means will tend to make
streaks. And a pendulum has a non-linear sweep from top to bottom
anyway. Bubbles have the high advantage of once released they travel
basically linearly upwards.
>"A spray etcher may not be that much more complicated in the end."
>Yes if we solve the pump corosion problem.
>
>
Order of magnitude more of a PITA to get many nozzels to spray evenly,
and sweeping just one or very few in both X and Y will require much more
complexity. Point source for bubbles, and gravity takes care of the
other direction.
>
>"I'm not gonna try that any time soon, since my setup is just too
>simple and too well working to change.
>
>Tell me Stefan, you use a homemade tube or a comercialy one like those
>make it for aquariums, or a long stone?
>
>"duh if a stone is too uneven sitting there then move it"
>
>Is perfect true. Moving the bubbler or the board orizontaly is much
>better. But this don't solve the problem of differences between top
>and bottom of the board.
>
>
>
>
Almost every other aspect of a bubbler and several other methods was
discussed thoroughly a year or two ago.. A simple wedge shape to force
the bubbles back against the board as they try to spread out as they
rise is all that's needed. Easy to linearize the swing, and with the
edge of the board not holding the bubbles in place as well, non-linear a
bit may actually be better.
Construction and maintenance advantages should be way over the other
units. Once engineered, about anyone could go to Walmart and the
hardware store, get the parts, and build it up in an hour or two. While
many things can be made to work, air is simple and reliable. I'd bet
you could assemble 3 or 4 of these or more in the time taken to get
about anything else working evenly, not even thinking about whether the
others will be long term reliable. So simple I may make it just to see
it work, even though I'm moving away from making most of my own boards..
Alan