Homebrew_PCBs

----- Original Message -----
From: "Jan Kok" <kok@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, April 22, 2003 7:57 PM
Subject: [Homebrew_PCBs] Stirring or pumping etchant

The older ARRL Handbooks had an agitation system involving an eccentric
mounted on a slow electric motor shaft. The tray was positioned so that the
eccentric rocked it continuously. A heat lamp was mounted above the tray to
keep the etchant hot.

I just agitate a plastic food container holding the etchant and PCB
manually, with it surrounded by a larger container half-filled with very hot
water. I wear rubber gloves to protect my hands. It takes 5 to 10 minutes to
etch a typical board, using FeCl3.

Leon
--
Leon Heller, G1HSM
leon_heller@...
http://www.geocities.com/leon_heller

>Some ideas I haven't tried:
>
>Use a stainless steel stirrer such as is used for making milk shakes.
>
>Make some stirrer vanes out of suitable plastic, drive them with small DC
>motors (so you can adjust speed by adjusting the voltage).
>
>Make a centrifugal pump out of plastic. It doesn't have to be terribly
>efficient, just needs to direct a stream of etchant across the board to be
>etched.
>
>Use an oscillating room fan, or a windshield wiper mechanism to move the
>board around in the etchant solution.
>
>Chemical supply houses have a combination hotplate/stirrer. The stirrer
>works by having a rotating magnet underneath the beaker, and inside the
>beaker you put another magnet that is coated with some inert material. You
>might be able to use a "cow magnet" as the coated magnet. These are fed to
>cows to attract iron nails and stuff in the cow's digestive system and get
>them out of the system. (That's no bull :-) I just called a veterinary
>supply company and they sell a 2-inch coated cow magnet for $2.65.)
>
>You might not even need the cow magnet. Since the etchant is conductive, it
>will try to stay stationary with respect to any magnetic field. So, if you
>rotate a strong magnet adjacent to the tank, the solution may rotate in the
>same direction. This is the principle that makes induction motors work.
>
>Use a peristaltic pump, such as from scrapped medical equipment.
>
>Cheers,
>- Jan
>
>
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>

>Hi Group
>
>This is my first time post here, so please forgive me in case this is
>already known. However, there is a small german company selling very
>low priced spray etchers which are not that bad. There is a model that
>etches one side, and also one that etches two sides at once. However,
>the single sided model can also be used for double sided PCB's by
>simply turning the PCB once one side is etched. The signle sided one
>goes for ~117 Euro (about the same in USD), the double sided one goes
>for ~178 Euro. I have the single sided one and I'm pretty satisfied
>with the results. The advantage of this etcher is that the device is
>"always" ready, there is no mess with etchant since it's a closed box
>and etching goes fairly quick also (3 minutes per side). The principle
>is simple. There is a rotating tube that delves on the bottom of the
>box into the etchant. Since the tube is having fine holes, the etchant
>is forced out of these holes due to the rotational speed of the tube,
>this results in a fine spray of etchant going over the PCB. Even
>though the device is simple I would find it hard to build the same
>device on my own for the same price. Let me stress that I'm not at all
>related to this firm. I'm simply a happy user of one of their
>products.
>
>Here's the link, search for "Sprühätzer".
>
>http://www.radixgmbh.de
>
>A word of warning though. The guy running this site aparently is
>having a problem with the foreign politics of the US governement. Let
>me stress that because of this I really thought twice to publish this
>link here but then the etcher is simply too good to be ignored.
>
>Markus
>
>>Some ideas I haven't tried:
>>
>>Use a stainless steel stirrer such as is used for making milk shakes.
>>
>>Make some stirrer vanes out of suitable plastic, drive them with small DC
>>motors (so you can adjust speed by adjusting the voltage).
>>
>>Make a centrifugal pump out of plastic. It doesn't have to be terribly
>>efficient, just needs to direct a stream of etchant across the board to be
>>etched.
>>
>>Use an oscillating room fan, or a windshield wiper mechanism to move the
>>board around in the etchant solution.
>>
>>Chemical supply houses have a combination hotplate/stirrer. The stirrer
>>works by having a rotating magnet underneath the beaker, and inside the
>>beaker you put another magnet that is coated with some inert material. You
>>might be able to use a "cow magnet" as the coated magnet. These are fed to
>>cows to attract iron nails and stuff in the cow's digestive system and get
>>them out of the system. (That's no bull :-) I just called a veterinary
>>supply company and they sell a 2-inch coated cow magnet for $2.65.)
>>
>>You might not even need the cow magnet. Since the etchant is conductive, it
>>will try to stay stationary with respect to any magnetic field. So, if you
>>rotate a strong magnet adjacent to the tank, the solution may rotate in the
>>same direction. This is the principle that makes induction motors work.
>>
>>Use a peristaltic pump, such as from scrapped medical equipment.
>>
>>Cheers,
>>- Jan
>>
>>
>>
>>
>>Be sure to visit the group home and check for new Bookmarks and files:
>>http://groups.yahoo.com/group/Homebrew_PCBs
>>
>>To unsubscribe from this group, send an email to:
>>Homebrew_PCBs-unsubscribe@yahoogroups.com
>>
>>
>>
>>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

>hi
>
>this link is great!
>as i'm from austria it won't be a problem buying.
>but i'm also wondering if you may describe the function of the spray tubes more exactly.
>it would be very fine if you may describe how the end of the rotating tube is looking, if its simply
>open or if there are some propeller blades or so in.

>the estimated rotating speed, number of holes, size of holes, arrangement, etc, etc... would all be very
>fine.

>I really believe this design is genious, shows that not only the americans and englishmen can invent
>genious things.

>it keeps the whole motor assy out, no shafts, no hoses.. simply very interesting.
>
>i also believe it would not be a very difficult thing to make this myself (it is not so cheap at all i
>think)

>i also think of using maybe two tubes on one side, to get it more smooth and build it single sided only.

>so thanks markus, i believe this is a great page.
>but i also think this guy really doesn't want to sell to us or gb.

>but they can built this themselves i think...
>i really don't want to comment his attitude to selling to us and really hope none of the us guys here
>can read the german statement on the linked page because i really want nobody to think all people think
>so. i also don't like what's going on in some countries (you know what i mean) on but i think we are
>here to discuss homebrew pcbs and not politics.

>regards
>st
>
>
>
>
>23.04.2003 11:17:36, Markus Zingg <m.zingg@...> wrote:
>
>>Hi Group
>>
>>This is my first time post here, so please forgive me in case this is
>>already known. However, there is a small german company selling very
>>low priced spray etchers which are not that bad. There is a model that
>>etches one side, and also one that etches two sides at once. However,
>>the single sided model can also be used for double sided PCB's by
>>simply turning the PCB once one side is etched. The signle sided one
>>goes for ~117 Euro (about the same in USD), the double sided one goes
>>for ~178 Euro. I have the single sided one and I'm pretty satisfied
>>with the results. The advantage of this etcher is that the device is
>>"always" ready, there is no mess with etchant since it's a closed box
>>and etching goes fairly quick also (3 minutes per side). The principle
>>is simple. There is a rotating tube that delves on the bottom of the
>>box into the etchant. Since the tube is having fine holes, the etchant
>>is forced out of these holes due to the rotational speed of the tube,
>>this results in a fine spray of etchant going over the PCB. Even
>>though the device is simple I would find it hard to build the same
>>device on my own for the same price. Let me stress that I'm not at all
>>related to this firm. I'm simply a happy user of one of their
>>products.
>>
>>Here's the link, search for "Sprühätzer".
>>
>>http://www.radixgmbh.de
>>
>>A word of warning though. The guy running this site aparently is
>>having a problem with the foreign politics of the US governement. Let
>>me stress that because of this I really thought twice to publish this
>>link here but then the etcher is simply too good to be ignored.
>>
>>Markus

>Hi Stefan
>
>>hi
>>
>>this link is great!
>>as i'm from austria it won't be a problem buying.
>>but i'm also wondering if you may describe the function of the spray tubes more exactly.
>>it would be very fine if you may describe how the end of the rotating tube is looking, if its simply
>>open or if there are some propeller blades or so in.
>
>The tube is closed with a plate at the end where it's delved into the
>Fe3Cl, but the plate is having three holes. The diameter of the holes
>is aproximately 4 to 5 milimiters (sorry folks, I'm not that good with
>inches).
>
>>the estimated rotating speed, number of holes, size of holes, arrangement, etc, etc... would all be

>>fine.
>
>The speed is fairly high. I haven't measured it, and I hope you
>understand that I don't intend to measure it (how anyways?). The
>electro motor is directly linked to the tube, or in other words, the
>tube is directly mounted to the motors shaft. This may explains why
>the whole thing needs 5Amps when running.
>
>>I really believe this design is genious, shows that not only the americans and englishmen can invent
>>genious things.
>
>Yes, the principle is ok. It was however invented (and patented) by a
>company called Bungard. So, Radix actually copied the principle which
>is fine since the original patent is no longer valid. Bugnard is still
>selling such devices (at a much higher price though) which are said to
>operate better. It's as always - you get what you pay for.
>
>>it keeps the whole motor assy out, no shafts, no hoses.. simply very interesting.
>>
>>i also believe it would not be a very difficult thing to make this myself (it is not so cheap at all i
>>think)
>
>As always, the details may become difficult. I do agree that it's
>doable, but I'm sure you spend more money until you are there. Well,
>definately magnitudes more money if you charge your time also.
>
>>i also think of using maybe two tubes on one side, to get it more smooth and build it single sided

>
>The two sided model does exaclty this. Note though that they are
>sorting out motors to get pairs that turn at the same speed.
>Personally I probably would rather use one motor and either toth
>wheels for two tubes or even better belts.
>
>>so thanks markus, i believe this is a great page.
>>but i also think this guy really doesn't want to sell to us or gb.
>
>From what I know he will be happy to sell such etchers to everybody.
>
>>but they can built this themselves i think...
>>i really don't want to comment his attitude to selling to us and really hope none of the us guys here
>>can read the german statement on the linked page because i really want nobody to think all people

>>so. i also don't like what's going on in some countries (you know what i mean) on but i think we are
>>here to discuss homebrew pcbs and not politics.
>
>My statemet was (and stiill is) not intended to start a poliltical
>discussion. That's not the right spot here. My statemet was there to
>clearly state that I do NOT share this opinion.
>
>Markus
>
>>regards
>>st
>>
>>
>>
>>
>>23.04.2003 11:17:36, Markus Zingg <m.zingg@...> wrote:
>>
>>>Hi Group
>>>
>>>This is my first time post here, so please forgive me in case this is
>>>already known. However, there is a small german company selling very
>>>low priced spray etchers which are not that bad. There is a model that
>>>etches one side, and also one that etches two sides at once. However,
>>>the single sided model can also be used for double sided PCB's by
>>>simply turning the PCB once one side is etched. The signle sided one
>>>goes for ~117 Euro (about the same in USD), the double sided one goes
>>>for ~178 Euro. I have the single sided one and I'm pretty satisfied
>>>with the results. The advantage of this etcher is that the device is
>>>"always" ready, there is no mess with etchant since it's a closed box
>>>and etching goes fairly quick also (3 minutes per side). The principle
>>>is simple. There is a rotating tube that delves on the bottom of the
>>>box into the etchant. Since the tube is having fine holes, the etchant
>>>is forced out of these holes due to the rotational speed of the tube,
>>>this results in a fine spray of etchant going over the PCB. Even
>>>though the device is simple I would find it hard to build the same
>>>device on my own for the same price. Let me stress that I'm not at all
>>>related to this firm. I'm simply a happy user of one of their
>>>products.
>>>
>>>Here's the link, search for "Sprühätzer".
>>>
>>>http://www.radixgmbh.de
>>>
>>>A word of warning though. The guy running this site aparently is
>>>having a problem with the foreign politics of the US governement. Let
>>>me stress that because of this I really thought twice to publish this
>>>link here but then the etcher is simply too good to be ignored.
>>>
>>>Markus
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

> 23.04.2003 17:27:08, Markus Zingg <m.zingg@...> wrote:
> hi
>
> the three holes, are they straight through or are they at an angle drilled?
> (and please stay with the mm, the guys out there really should accept that the metric system is a great
> thing and inches, feet, yard, etc.. is very complicated and difficult to calculate with. i also believe
> they have a better feeling of a millimeter than we have of 5/8 inch or so...)

>
> a questions for the professionals here:
> which glue resists HCL (CuCl2) etching? (does silicone or acrylic mass resist?)
> and would it be enough oxygen regenerating the etchant when leaving the sprayer on some time?

> That's an interesting mechanism of pumping fluids. After
> Markus mentioned Bungard and patents I had a quick search
> The bungard site is http://www.bungard.com/seiten/home.htm
>

>>From looking at this graphic on their website: (bottom one)
>http://www.bungard.com/material/left_4.gif
>
>It appears that the ethchant is drawn up into the tube
>by vacuum pressure.

>The squirrel cage fan on top
>would suck out the air when the tube spins.
>I can't imagine how the etchant is prevented from
>spraying out of the top though....

> I guess there must be
>some sort of barrier that lets air through, but
>prevents fluid from doing so.

>Or, it is possible
>that the fan is also housed within the splash tank.

>Anyone know of a source for all plastic or stainless
>steel squirrel cage fans?

>In the patent drawing posted, it appears that the boards revolve,
>also, and that there are centrifugal pumps on the bottom of the shafts
>that pull etchant down and then force it out via the holes in the tube
>in the center.
>
>
>
>
>Steve Greenfield
>
>
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

----- Original Message -----
From: "Markus Zingg" <m.zingg@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, April 23, 2003 2:17 AM
Subject: Re: [Homebrew_PCBs] Stirring or pumping etchant


> Hi Group
>
> This is my first time post here, so please forgive me in case this is
> already known. However, there is a small german company selling very
> low priced spray etchers which are not that bad. There is a model that
> etches one side, and also one that etches two sides at once. However,
> the single sided model can also be used for double sided PCB's by
> simply turning the PCB once one side is etched. The signle sided one
> goes for ~117 Euro (about the same in USD), the double sided one goes
> for ~178 Euro. I have the single sided one and I'm pretty satisfied
> with the results. The advantage of this etcher is that the device is
> "always" ready, there is no mess with etchant since it's a closed box
> and etching goes fairly quick also (3 minutes per side). The principle
> is simple. There is a rotating tube that delves on the bottom of the
> box into the etchant. Since the tube is having fine holes, the etchant
> is forced out of these holes due to the rotational speed of the tube,
> this results in a fine spray of etchant going over the PCB. Even
> though the device is simple I would find it hard to build the same
> device on my own for the same price. Let me stress that I'm not at all
> related to this firm. I'm simply a happy user of one of their
> products.
>
> Here's the link, search for "Sprühätzer".
>
> http://www.radixgmbh.de
>
> A word of warning though. The guy running this site aparently is
> having a problem with the foreign politics of the US governement. Let
> me stress that because of this I really thought twice to publish this
> link here but then the etcher is simply too good to be ignored.
>
> Markus
>
> >Some ideas I haven't tried:
> >
> >Use a stainless steel stirrer such as is used for making milk shakes.
> >
> >Make some stirrer vanes out of suitable plastic, drive them with small DC
> >motors (so you can adjust speed by adjusting the voltage).
> >
> >Make a centrifugal pump out of plastic. It doesn't have to be terribly
> >efficient, just needs to direct a stream of etchant across the board to
be
> >etched.
> >
> >Use an oscillating room fan, or a windshield wiper mechanism to move the
> >board around in the etchant solution.
> >
> >Chemical supply houses have a combination hotplate/stirrer. The stirrer
> >works by having a rotating magnet underneath the beaker, and inside the
> >beaker you put another magnet that is coated with some inert material.
You
> >might be able to use a "cow magnet" as the coated magnet. These are fed
to
> >cows to attract iron nails and stuff in the cow's digestive system and
get
> >them out of the system. (That's no bull :-) I just called a veterinary
> >supply company and they sell a 2-inch coated cow magnet for $2.65.)
> >
> >You might not even need the cow magnet. Since the etchant is conductive,
it
> >will try to stay stationary with respect to any magnetic field. So, if
you
> >rotate a strong magnet adjacent to the tank, the solution may rotate in
the
> >same direction. This is the principle that makes induction motors work.
> >
> >Use a peristaltic pump, such as from scrapped medical equipment.
> >
> >Cheers,
> >- Jan
> >
> >
> >
> >
> >Be sure to visit the group home and check for new Bookmarks and files:
> >http://groups.yahoo.com/group/Homebrew_PCBs
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>