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

----- Original Message -----
From: Derward Myrick
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, August 22, 2012 9:38 AM
Subject: Re: [Homebrew_PCBs] Re: Magnetic drive pumps for spray etchers


I made an etcher by using a windshield wiper motor from a car and
used it to rock a glass dish(large) I print several on a panel and do all
at once. I have made as many as 20 At a time. I used a 13 volt AC
transformer to drive it. It will work with one board just as well.
I use muriatic acid because I can see the board as it etches.
The 20 boards(on a panel took about 5 minutes to etch with etchant
at room temp.

Derward KD5WWI

----- Original Message -----
From: jcarlosmor
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, August 22, 2012 1:04 AM
Subject: [Homebrew_PCBs] Re: Magnetic drive pumps for spray etchers




Hello Jan,

Very interesting. However, I think that the users in this forum that are interested (including me) in building a spray etching system are more concerned about a real off-the-shelf pump, rather than to experiment with any other methods. The investment in time and money in the construction of a spray etch system may seem confuse for some users, specially if they tend to use the iron-toner method, and only make a few PCBs per month. Some times you need to produce 200, or 400 PCBs per month, and it is a total hassle to work with bubble systems, even if you have 10 or 20 tanks working at the same time. For getting the most advantages of the spray etch system you must use photoresist, and apply the concept of panelizing boards, to load the machine for example with 12x12 inches panels evey time. It makes no sense to build a spray machine for etching 10x10 cms per board.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, Jan Kok <jan.kok.5y@...> wrote:
>
> Something fun to think about or play around with:
>
> FeCl (and probably other etchants as well) is quite conductive.
>
> Now, conductive materials like to stay fixed with respect to magnetic
> fields. See https://www.youtube.com/watch?v=f43fXde2S78 for a
> demonstration. The penny is dragged along by a strong magnet.
>
> See where I'm going with this? A spinning magnet (where the poles
> sweep around) should be able to drag conductive liquids through a tube
> that is wrapped around the spinning magnet.
>
> In fact you don't even need a spinning magnet. You can create a
> rotating magnetic field with electromagnets (for example, remove the
> rotor from a three-phase motor - but use lower voltage when the rotor
> is removed or you'll burn up the windings and/or blow a fuse). You can
> pump conductive liquids with no moving parts at all!
>
> As a bonus, induced current in the liquid would cause heating, so you
> might get your etchant heated as it is being pumped!
>
> Enjoy!
> - Jan
>





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