making a few pcb's for the phabbtone 3.5 eq, any one interested?

[erikb1971]

What for me is still a bit unclear is what exactly to print... just the brd picture?

[phatt]

I take it you are on Eagle?

Under *View*  find  *Display/Hide layers*  Un-click *tplace*

You should then have tracks and pads left on the screen.

Then print it out.

Depending what system you use you may have to mirror the printing.
Have fun ,, Phil.

[erikb1971]

so that would be something like this:

inverted though,...

[J M Fahey]

Excellent tutorial:

http://youtu.be/YJB5PWx9fdA

I would only add:
1) DO use gloves and goggles, this stuff is incredibly nasty.
2) NEVER do this close to any important stuff you care about.
This guy is CRAZY , acid vapors will EAT the insides of all his expensive lab equipment.
How do I know? ... Uh !!! 
3) It´s not very clear, but since he closed the exposure box lid until he finished mixing his chemicals, he has been exposing the PCB/film sandwich. Almost 4 minutes as he said.
You´ll have to find your own time.

I suggest you sandwich your PCB+film between 2 sheets of glass (or 1 glass + 1 anything else) and use a 250W or 500W quartz halogen lamp at about 40 to 60 cm (18 to 24 inches) away.

Personally I silkscreen PCBs, but it´s worth only for 20 or more PCBs
http://youtu.be/8-WGaAmpfOU

Printing each one takes seconds, but cleaning the paint perfectly (or you lose your screen) , making the screens, etc. can take hours.

[erikb1971]

Been a really long time.. but I am back on this subject... I made my first pcb and it looks like this:

It looks to me that I have to build it slightly larger, since there seem to be some connecting problem area's...  especially in the crowded top of the board. No problems though. I am going to start on that now.. but as usual.. comments very welcome!
Cheers

Erik

[Roly]

Cool!   

Tip: when doing the artwork, mark the intended length of at least the longest side on the artwork just outside the edge.  Also, beware photocopiers because they sometimes slightly change the length in one direction only.  As we are stuck with the QWERTY keyboard, so we are stuck with PCB's in inch-by-tenth - don't try to get creative with this.

PCB artworks should have some identification within the board area and should include the name/function of the board, the date for version control, and the name of the creator; e.g. "Phabbtone 121014 erikb1971".

"Oh, I'll remember what that is!" - no, you won't.

Hydrochloric acid (aka Muriatic Acid, "pool acid") as an etchant is just nuts, particularly when he is worried about Ferric Chloride which is relatively harmless.  I read that even vinegar from your local supermarket will work {Distilled white vinegar, Hydrogen peroxide, salt}.

http://hackedgadgets.com/2011/04/11/hydrogen-peroxide-distilled-white-vinegar-and-salt-as-a-pcb-etching-solution/

The comments following this Instructable give some clues to the hidden traps with HCL etchant;

http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/

[erikb1971]

I made the board with photosensitive pcb and a light unit.. works pretty easy.. problem is.. I have not worked on this project for months.. and I have no clue anymore! S I am going back to the last approved schematic, and start all over from there!

[Roly]

I made the board with photosensitive pcb and a light unit.. works pretty easy.. problem is.. I have not worked on this project for months.. and I have no clue anymore! S I am going back to the last approved schematic, and start all over from there!

Oh dear!     QED.  Even one-off home builds need good documentation.

[erikb1971]

and I guess any build needs a thorough understanding of what you are doing.. something which i thoroughly lack.. part of the fun so far!

[J M Fahey]

Cool , but let me comment a couple details:
1) separate parts a little more, some pads and tracks are dangerously close.
2) in the ICs, do not use round pads but oblong/rounded rectangular "IC Pads"
just look at any commercial PCB and you'll se the advantages.
3) add a drill guide hole (say, 28 mils) to every pad center or you will go crazy trying to center thin flexible 1mm drills.
4) *some* labelling is important.
Besides PCB identification as correctly suggested by Roly, try to add (at least a letter) ID to key points, such as "In", "Gnd" , "T/M/B/V" indicating treble mid bass volume, etc.
A + sign on electrolytics positives , an orientation dot for the ICs , etc.