Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [Homebrew_PCBs] Pump for sray etching

From: mpdickens <md30022@...>
Date: 2003-11-23

--- Adam Seychell <adam_seychell@...> wrote:

> What was the voltage and current during
> your test ?

I set the pump up in a configuration I was told was
the most common in an RV (At least, most RV's here in
the US):

12 Volts
5.5 AMPS (The pump is rated up to 7.0 amps)

Question:

What are the dimensions and specifications of the
nozzles that you are using. I've settled on using
quanitity-6 180 degree fan nozzles (Three for the
front of a pcb and three for the back of a pcb.
Further, I think I'm going to use quantity-2,
windshield wiper motors to rotate the nozzles back and
forth. This will afford me multiple speeds of 180
degree back and forth rotation without having to do a
stepper motor. Also, I've found a portable plastic
sink that I'm going to use as the enclosure that
houses the spray machine. I going to build a door that
fits on the top of the sink that will have a lexan
window for viewing. The drain in the bottom of the
sink will be connected to a gasoline can (Firmly
attached, but quickly and easily removable). The
etchant will be pumped from the gasoline can into the
enclosure and then allowed to drain back into a
gasoline can (For easy maintenace). So, basically,
during the etching process, the etchant will circulate
between the gasoline can and the enclosure via the
pump. Modularizing the etchant allows for a couple of
features/benefits:

1.) I can filter the etchant as it etches (Less wear
on the pump) so that viscosity stays realively
constant.

2.) Regenerating etchant and/or changing out etchant
is easy.

3.) I can easily wash the pump out with h20 following
use without diluting/contaiminating the etchant.

4.) I can wash the board in the machine prior to
removal.

5.) breaking down the etching machine is easy: The
etchant is self contained and easily storable.


Best regards


Marvin Dickens

=====
Registered Linux User No. 80253
If you use linux, get counted at:
http://www.linuxcounter.org

__________________________________
Do you Yahoo!?
Free Pop-Up Blocker - Get it now
http://companion.yahoo.com/