SEE STEP 12 FOR NEW RESULTS AND AN ETCHING/PROJECT UPDATE!
Recently one of my focuses has been to find a way to make the PCB (Printed Circuit Board) creation process easier. I like being able to design something based on what I want in a circuit and just making it myself on the random weekend. While the toner transfer method has been my go to in the past it’s just not nearly as consistent as I would like it to be. The specific pressure of the iron and timing both make it a hit or miss approach. I’m not a fan of hit or miss I like to know something is going to work every time I try to do it. This sentiment got me exploring new ideas for PCB creation which is the topic of this project.
About a year and a half ago I found this webpage on modifying an Epson inkjet printer into a printer capable of printing on thicker materials such as copper clad board used by hobbyists such as myself to create custom circuit boards. As you'll notice that webpage is centered around an Epson C84 printer, but Epson printers are all somewhat similar so I decided to try this method on the C86 I had lying around the house.
Since I've been working on my own website (www.ryanpourcillie.com) I've documented everything about the project and thought it would be good to put it multiple places so hopefully numerous people can see it and try something new for themselves. I really tried to go into detail on everything I did in this process and the problems I had to troubleshoot because from looking around online there have been a few people who have done these modifications before, but no one really seems to have given a very good in-depth step by step build guide. Hopefully this Instructable can serve as just that.
So all that being said let's start with the tools and materials you'll need for this project:
Materials:
- Obviously you'll need some form of an Epson inkjet printer probably of the C80 family as those are the ones I have seen modifications to in the past.
- A sheet of aluminum or steel or some metal sheet (about 9 inches by 14.5 inches roughly)
- Approximately 4 feet of 1/4 inch bent (90 degree corner piece) aluminum rail
- Some type of brackets and screws to secure them with (I used 3, you'll see an image of them later on)
- Some 4 - 40 screws (I used 1/2 inch long ones)
- Nuts for said screws (I used about 16)
- A small piece of scrap plywood and some other random scraps of 2x4 or something of the sort
- Epoxy and/or hot glue
- The drivers for whichever printer and operating system you decide to use
- An ink kit from Inksupply.com (more details on this later)
Tools:
- A Dremel tool with grinding wheels to cut through metal
- Various screwdrivers
- Pliers or a socket wrench that fits the nuts or screws you'll be using
- A drill of some sort to attach the brackets
- A hot glue gun
- A heat gun
Once you've gathered all of those things you're ready to begin.
Recently one of my focuses has been to find a way to make the PCB (Printed Circuit Board) creation process easier. I like being able to design something based on what I want in a circuit and just making it myself on the random weekend. While the toner transfer method has been my go to in the past it’s just not nearly as consistent as I would like it to be. The specific pressure of the iron and timing both make it a hit or miss approach. I’m not a fan of hit or miss I like to know something is going to work every time I try to do it. This sentiment got me exploring new ideas for PCB creation which is the topic of this project.
About a year and a half ago I found this webpage on modifying an Epson inkjet printer into a printer capable of printing on thicker materials such as copper clad board used by hobbyists such as myself to create custom circuit boards. As you'll notice that webpage is centered around an Epson C84 printer, but Epson printers are all somewhat similar so I decided to try this method on the C86 I had lying around the house.
Since I've been working on my own website (www.ryanpourcillie.com) I've documented everything about the project and thought it would be good to put it multiple places so hopefully numerous people can see it and try something new for themselves. I really tried to go into detail on everything I did in this process and the problems I had to troubleshoot because from looking around online there have been a few people who have done these modifications before, but no one really seems to have given a very good in-depth step by step build guide. Hopefully this Instructable can serve as just that.
So all that being said let's start with the tools and materials you'll need for this project:
Materials:
- Obviously you'll need some form of an Epson inkjet printer probably of the C80 family as those are the ones I have seen modifications to in the past.
- A sheet of aluminum or steel or some metal sheet (about 9 inches by 14.5 inches roughly)
- Approximately 4 feet of 1/4 inch bent (90 degree corner piece) aluminum rail
- Some type of brackets and screws to secure them with (I used 3, you'll see an image of them later on)
- Some 4 - 40 screws (I used 1/2 inch long ones)
- Nuts for said screws (I used about 16)
- A small piece of scrap plywood and some other random scraps of 2x4 or something of the sort
- Epoxy and/or hot glue
- The drivers for whichever printer and operating system you decide to use
- An ink kit from Inksupply.com (more details on this later)
Tools:
- A Dremel tool with grinding wheels to cut through metal
- Various screwdrivers
- Pliers or a socket wrench that fits the nuts or screws you'll be using
- A drill of some sort to attach the brackets
- A hot glue gun
- A heat gun
Once you've gathered all of those things you're ready to begin.
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Signing UpStep 1: Panel Removal and Breakdown
Step one is a pretty easy one and is somewhat self explanatory. The first thing I did was remove the paper feeder sticking out of the back of the printer and toss that aside. Once that's gone you can just use the tabs in various areas of the printer to pop off the front tray, the side panels, and ultimately the main printer casing. I chose to keep the main casing so that I have something to cover the printer with later for storage purposes.
Once you get all that done you'll end up with the internals of the printer ready for modification.
Once you get all that done you'll end up with the internals of the printer ready for modification.
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but have one question,can i use canon printer.
I have been considering a very similar mod, but not had the time to attempt it yet. What I am considering is replacing the print head with a laser diode; which could then expose a presensitized board. This of course would require some new control boards/software - possibly Arduino based, but should be able to generate very high quality boards. First thoughts were of course just cutting the copper with the laser, but my guess on that would be a very powerful laser given the heat transfer properties of copper. Anyone ever tried either; or anyone want to take the idea that does have some time to work on it - feel free!
i had a question. I am working at a startup and we are making comic publications. We need to print rolls of size 4inch by 150 ft long! and this is on bible (thin paper). The question i had was, we cant afford these fancy large format printers which are able to do this. Neither can we outsource as the cost is too high per unit. We need to print these cheaply and with inexpensive equipment. Any ideas if it is possible to convert a normal printer into something which can print 150 feet long documents.
The print quality is only 300 DPI and black and white.
Would really appreciate some help.
The paper path in most laser printers is a sideways U. That means the paper has to bend around the drum and rollers, a normal PCB won't.
Even if you could get a laser printer with a straight path the PCB is too thick and you would need to modify the actual drum/toner assembly and the fuser assembly. Not easy at all.
Lastly the transfer of toner to paper relies on a static charge given to the paper to attract the toner. I don't think the conductive copper will hold the charge well enough, if at all.
The longer answer is it would depend on the construction of the printer and how easily you could "lift" it. Factor into that the different printhead system and whatever other mechanisms a laser printer might have and it could complicate the build. I don't really have access to a "junk" laser printer so I haven't been able to test this idea out. I'd need to take it apart and look at the specific printer to decide how to go about modifying it.
If you do decide to try it and are successful or find some helpful things out make sure to let me know as I would like to try that in the future.
I've been converting an Epson T21 but for various reasons haven't finished it yet (over 3 years !)
The T21 has the whole printing mechanisim and electronics on a vertical steel plate that is held by 2 screws to the base. I just need spacers under the screws to raise it, no cutting, no brackets. I was lucky on that part.
I really should finish it and put up an instructable.
I've just been designing things in all black and then printing them using a black and white option in the printer settings and that has been working fine.
Additionally the program I use the most with this printer is EAGLE and it has an option on the print screen to only print in black which thus far has worked fine for me.
the idea i had was having the printer rollers actually moving the entire printer along rack and pinion type rails on each side of the build surface, and i wasnt sure if the steppers would be powerful enough, got some heartier steppers around though, but different current ratings to most printer steppers so i'd have to make a breakout board to drive them if i had to use them for it. (which would be fairly straight-forward, i got a cnc lathe/mill and a UV LED PCB developing glass table)
anyway, what my question really is, would you know of how to mess with the printer driver program and/or circuitry to use it as a plotter as well, so it could laser reduce graphene oxide in continuous lines while changing from one axis to another instead of rastering? rastering would be fine for the deposition of the EL polymer but i think the graphene would have a more continuous molecular formation if it was reduced as a continuous trace.
apologies for lack of caps and the grammar, i are retard.
i would very much appreciate a reply if you have any information i might find useful to achieve this objective.
Is is just me, or does the final etched product seem rough around the edges for the copper pads and traces, doesn't look very clean in the pictures?
If this is the case, would a better quality printer be the way to a better etch, or is it simply the "DIY"ness of it all that produces the 'rough' results?
As I got everything fixed and calibrated right though the boards got better. I have pictures of the better board I made in there a few places, but now that I know exactly how long to preheat the boards for and how to set the ink better and have a better etching tank the boards are coming out smooth.
I haven't had a chance to post anything new recently because it's been pretty cold outside and I haven't been able to etch boards yet. The new etching tank is nice, but the bubbling ferric chloride isn't something I like to use inside very much. I'm working on designing a few of my own boards currently and when I get a chance to etch them I plan on posting updated photos.
As for the thinnest etched spaces on the board I have a few areas that are even thinner and I would estimate at about .1 to .2 mm wide roughly. I'd venture to say probably more around the .15mm area.
I know there are a lot of others out there using this setup too and maybe some of them are getting different results, but that's what I can tell you from my experience so far. I'm working on my own board design for another project currently so once I can that board all designed and ready to print I may be able to give you more measurements straight from Eagle.
Two main problems in conversion are,
The paper path is never straight, impossible to make it so without very major modifications.
The copper on the PCB will not hold a static charge as it is conductive.
Though if anyone does do it I would be very interested in seeing it. :)
I would suggest that you put MISPRO yellow in all four cartridges. It can be very difficult to get an inkjet printer to print from only one ink shade. More printheads printing may mean more dots filled in, too.
As for the curing, from all reports the temperature and hold time are very important. Volkan, the gentleman who first discovered this process of printing and heat curing pigmented ink, would heat it to the point where the copper just turns purple and hold it there. Others have experimented and found that holding it at 230C/446F for about 3 minutes does the trick, but that it is a very narrow window of temperature.
I just ordered a "Mini SMD Preheater" 21-10135 from MCM that is a hot air rework station, set the board on top of it and it heats between 100C and 350C, temperature controlled. My intention is to use it for pigment ink cure and SMD reflow soldering. I got it on sale earlier today for $40. A toaster oven with a better thermostat should work, too.
To the gentleman asking about using an HP inkjet printer, as you mentioned the MISPRO pigmented inks probably won't work since just about every desktop HP inkjet printer is a bubblejet and uses dye colors. However, there is the hybrid toner method - print using any ink, as long as it doesn't run, and dust laser toner across the ink. The ink stays tacky for quite a long time on a nonporous surface. Then heat until the toner turns shiny.
You are correct that temperature window is very narrow. I bought that heat gun and it was effective, but so touchy to not overheat the board and to try and keep everything uniformly heated. You'll have to update me on that SMD Preheater. I've been thinking of moving to mostly or all SMD parts too, but just haven't quite committed yet. I like the idea of a dual function tool, hopefully that product works out for you.
Glad to hear more input and advice though for sure. I know you guys have quite a thread going and have more ideas and insight than I could probably imagine right now.
But the quality is not yet there...
Maybe you should try mild solvent inks.
I work with large format printers, that also use Epson Printheads.
Most of them use modified heads. The printhead itself withstands pretty harsch organic solvents, it's the plastic part on top, that needs to be of a different material. (compared to a standard waterbased printhead)
There are certain mild solvent inks, that work with unmodified Epson heads.
Used in "Freejet" nontextile printers for example.
And there are also inks with a completely different chemistry like these:
http://www.sepiax.com/anwendungen-en
What would work pretty sure, are the Roland UV-inks used for example in the LEF-12. But the price tag of those machines might be a bit prohibitive.
But i could make some experiments with different inks.
I have access to machines with many different inks. Many of them flatbed machines. Maybe i make some test boards.
So does this mean that an inkjet printer could directly print etchant onto a copper board ?
Then just a short wait and a quick rinse . . ? Now that would save some acid !
Hold on . . . wouldn't this cause massive unemployment in the acid industry ?
This would etch away the printheads.
I'm just supposing a better ink for masking.
Now I see. But hold the thought. We progress by thinking outside the box. Is there, or could there be a way ? All plastic printheads ? All metal parts plastic coated ? A chemical ink that would react with something else to form an acid only where required ?
As there is already metallic silver paint used for circuit board repair, can a way be found to directly print metal (by some means, in some form) straight onto blank circuit board ?
Possibly by adapting some kind of inkjet printer (or plotter), using fine enough metal particles ?
Perhaps an ink consisting of metal particles in a flux, then set by briefly heating to melting point with a blast of hot air ?
If anyone can find a way, it should be extremely environmentally friendly, and would make all other prototyping systems obsolete overnight.
And this could be the website where it is first seen . . .
(And OK, if it's already been invented, well I always say, great minds think alike . . . ;-)
Off the shelf laminator, dextrin paper, and heat gun.
Just two runs through the laminator while shooting the board with a heat gun does the trick admirably. I've tried all the papers and TBH, photo paper, magazine paper, and even the other professional papers wilt in comparison to dextrin paper (e.g. Pulsar). I went through a 100 pack of the "blue" stuff before trying the slightly more expensive dextrin paper, and I'm kicking myself for not trying it sooner.
isn't it easier to just make yourself a UV exposure box and buy boards coated with resist?
I built one years ago then I switched to a commercial (cheap) model.
I'm the happiest champ.
I'm now etching double-sided smd-only boards and the edges are perfect.
I don't etch in FeCl anymore, now I use a 2 to 1 solution of HCl (10M) and H2O2 (3%).
it has a lot of advantages, among which no stains... but it may burn stuff... ehm...
anyway... never thought I'd be as happy with my etching, and using a (again, cheap) etching tank with air pump and heater, I etch a board in about 2 minutes.
that makes the edges very sharp.
I have more trouble drilling 0.6mm holes and center them correctly than to produce the board :)
anyway keep up the experimentation, I would love to see cheap commercial solutions.
to me laser printing acetate, UV exposure, development, etching is a fulfilling experience every time and I'll keep doing it ;)
http://www.bungard.de/index.php?option=com_content&view=article&id=25&Itemid=76&lang=english
I tried some very expensive ones but I had really lousy results.
I expose with a UV exposure box like this one, just an older model
http://nl.farnell.com/cif/bc10/uv-exposure-unit-cip-1840/dp/1332734
then I etch in Copper Chloride in Aqueous Hydrochloric Acid Solution
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/
I use a cheap bubble etching tank with heater at 24ºC and if I preheat for a couple of minutes, my board is perfect after 2-3 minutes.
most of my thin traces are 0.4064 mm (0.016") and there's no visible damage to the trace edges even with the magnifier I use to solder caps in 0805 package.
I've been using this technique for the past 2 years and there's no way I'm steering away from it. :)
I'm placing a laser printed acetate between the UV light and the copper board.
the black area is the actual trace, everything transparent will not be printed on the copper.
the developer I'm using appears like a salt.
can't remember what it is though, I always used the same.
always use freshly made Sodium Persulfate.
it can still be good for a couple of days, but you'll notice the traces getting less sharp after the second day.
you may think it's the etching solution but it ain't.
it's the damn developer :)
here's the last one I made.
those solder spots you see are hand-made vias.
they don't look too pretty but they do their job.
sometimes I clean them with copper braid but it can also mess up your via (been there).
the only slight defect I have on this is marked in yellow.
inspecting the acetate I couldn't see any issue, so it must have been a hole in the protective sticker.
it's happened already in the past, those guys don't exactly handle these with the care they need.
I have lots of tips on making pcb at home, but right now I only use the right equipment:
- purchased UV etching lamp (although I made my own a few years ago).
- Sodium Persulfate
- HCl+H2O2 as per the instructable I linked above
- heated bubble etching tank (I spend a lot of time calibrating the temperature every time and keep it around 32-38 (just to reduce the possibility of massive quantities of fumes)
most of the times I don't flux the board, especially when using solder paste.
I noticed that there's too much flux around when doing this.
I also apply my solder paste by hand without a screen, using magnifiers and a very, very steady hand.
hope these tips will be useful to you.
have a good day
ubi
I'm very happy with the acetate result.
of course you have to make sure your solution is strong enough to etch quickly, or it will start eating out everything.
one trick that I used in the past when I used Ferric Chloride was to print 2 acetates per side and align them.
I also always put the printed side on the board so the black areas are effectively touching the copper surface and the possibility of UV infiltrating from the sides.
I know, it's OCD at full speed and unnecessary.
yesterday I etched (for a test) 0.01mm traces and they were more than decent.
:)
For me it came down to a matter of wanting to try something new and when I was looking at the UV exposure stuff I didn't want to build an exposure box and deal with the sensitized boards and the developing solution when I had a printer I could modify sitting right on my workbench. It's just another case where everybody has a different preference and that's what building your own electronics is all about really.
1)Este proyecto en particular no tiene desperdicio ya que enseña muchas cosas interesantes pero creo que el producto final (PCB) no es del todo bueno, sobre todo en la terminación y a la hora de sumergirlo en cualquiera de los líquidos elegidos, pueda quedar con faltantes de cobre en lugares críticos de soldadura de componentes.Para mi todavía no hay nada mejor que un circuito impreso por una laser (conseguí una vieja Laserjet M400 por muy pocos $ y su rendimiento es maravilloso!!)
2)Cuando uno piensa que el percloruro férrico es nocivo para el medio ambiente e intenta otros medios, hay que pensar que tan peligrosas son las alternativas.El ácido clorhídrico, el muriático así como el sulfúrico o el nítrico (generalmente utilizados para hacer el "aguafuerte" que utilizan los joyeros y artesanos para distinto tipo de metales) son mucho más peligrosos que el mismísimo percloruro, por lo que muy a mi pesar lo sigo utilizando y aconsejo por todo concepto.(Todavía no se inventó líquido alguno que podamos utilizar y luego poder tirar por la cañería sin tener remordimientos...)
3)Por último: entré en tu sitio web y pude ver por las fotos que tu caja de herramientas está "asquerosamente" ordenada!! Nunca pude tener ese orden en la mía,aunque puedo encontrar cualquier cosa que necesite(siempre y cuando cuente con el tiempo suficiente)
Muchas Gracias por compartir tu proyecto con el resto de nosotros!
(Por favor, traducir pues mi inglés es muy malo)
***translation begins***
Generally I don't use to criticize any project because I consider it to be rude. Om the other hand I like to consider new ideas and this particular one looks fantastic to me because it "opens your mind" about every thing you can modify (recycle) and give a second chance to thing that usually would end up in the thrash.
1)This particular project is wasteless (**stands for "very usefull" or "excellent"), because teaches you interesting things but the final product (PCB) is not all that good, specially the finishing and when submerged in any of the suggested liquids, it can result on missing copper on critic places for soldering. There is nothing better yet than a laser printed circuit (I found a old Laserjet M400 for a few $ and its performace is wonderfull!!)
2)When you think about the ferric chloride is noxious for the enviroment and try other ways, you have to think about how dangerous the alternatives are. The chlorhidric acid, the "muriatic" (**this stands for an aqueous solution of sulfuric acid), the sulfuric or the nitric (generally used to make the "strongwater" used by jewelers and artisans for different metals) are way more dangerous that the ferric chloride, that's why although beeing sorry I keep using it and adviceing the use of it (it haves not been invented any liquid that we can use and throw away thorugh the sewer with no remorse...)
3)For last: I've been on your website and I have seen by pictures that your tooling box is "disgustingly" (**this stands for amazingly, it's an irony ;) ) organized!!! I've never been able to keep mine in that kind of organization, although I can always find what I'm looking for (if I have time enough)
Thank you very much for sharing your project with us all!
(please, translate because my english is too bad)
***End of translation***
The acid doesn't do much, except supply a source af Chlorine when the chemistri\y is refreshed by bubbeling Oxygen (Room Air works). This solution can be used forever, it just gradually grows in volume over time. Any tthoughts on using the inkjet printed board with this chemistry?
Perhaps curing the board/ink in an over set to the appropriate temprature for the the correct length of time would solve the pinhole problem.
We used a heat tunnel, which is basically an over with holes in each end and a conveyer belt.
Either way, figure that might help others understand what you meant.
Good comparison though.
Quiznos Subs ovens are similar too.
What's the best looking card you have made so far?
Are there other inks that could be used?
What if a wax ribbon printer (or other transfer type printers) was used... resolution high enough?
There have been a lot of ink suggestions I've seen and I'm trying to look into the availability of some of them for later if I can't get the results I'm hoping for with this ink.
Perhaps you could have an electronic heater below the moving plate, so you'll warm it just enough while printing and just where you are currently printing? Easier to adjust as well instead of the heat gun.
It's perhaps possible to make a micro-etch before printing, which means you etch it very little so you'll get an even and matte surface to print on.
You could glue a support for one corner on the metal plate, so you always find a correct "zero point". Could be as simple as epoxy a piece of pcb with an internal 90 degree angle (L-shape). Then you don't have to use so much scotch tape.
If you find some other colored inks you could also print solder mask (green or other color) and silk screen print (white).
Great work, I hope we'll see more of this.
i still have to build a 16mm caddy for pcbs and one for tshirts/other stuff.
if someone is interested here some pictures. i basically used the same methods as being described here. the only thing i had to add was a wooden spacer for the 3 pressure wheels to prevent them from falling out if there's no spacer inbetween. since i gonna use a caddy i thought i will leave the middle pressure wheel in place sicne the caddy will have an even surface.
thsi instructable finally got me started with that project - thanks!
regarding inks: what about using 2 component inks? first put one layer of chemical on the copper board, then print the second component on there. the non-printed area won't react so before etching you could remove it. these inks do exist but i couldn't get my hands on them yet (restricted use i guess) any ideas? (there's a 2K epoxy system based on epson printers, specialprint.eu i think)
does anyone know where to get new printheads btw?
just the printhead whcih is fastend with the two screws
I've heard a lot of suggestions about various types of inks in numerous comments both here and on Hack a Day. I think this is a project where you could go about doing it in so many ways that I'm having trouble keeping up with them all. I've got a full page of ideas to try right now for better PCBs and I hope one of them works out as I expect something will.
one thing i forgot to mention:
people when copying this make sure the print head docking station is in place and centered properly => if it doesn't work (or the pump doesnt work) the printheads will be clogged in no tiime.
that's actually the only flaw in that DTG HaD hack we refer to => there was no pump connectted.
on the other hand you could remove the pump and always flush clean the printhead or propably apply some duct tape after usage.
oh and i used M4 hexagon bolts to be able to fasten them really really strong. thinking of adding a few drops epoxy glue on top now.
I do like your thoughts on a printer CNC combo though. Might take a bit of work and planning, but it could be possible if you could intercept the right signals and program them into a driving circuit for the Z axis.
I might add one suggestion with regard to etching times and sharpness. I used to work for a university research lab making proto boards. I had worked previously in large-scale PC production, so when I found the lab's habit was to use 2oz copper, I tried hard to convince them that 1oz was entirely adequate and that it would allow for sharper and narrower traces. I pulled out my trusty copy of Coombs' Printed Circuit Handbook (then--and maybe still--the PCB equivalent to the Bible) to prove the sectional area of even 10 mil sneak-through traces ("dog bones") was good up to 1.0A--far more than any digital (or even most analog) circuits require. Nothing doing, they said.
So, if you have a choice of material, my suggestion is that you choose 1oz clad when possible. I always used catalized persulfate etchant (@ 120°F) and it worked very well with the 1oz material. Yes, about 2 minutes in a spray-type etcher.
The key to the TTF method is the second step of adding the green TRF paper on top of the toner.
Will the TRF stick to your resist ink? If it will, that should greatly improve the quality of the traces.
The other thing TRF does is make the resist VERY tough. I etch using a small sponge and just rub the ferric chloride across the board rather than the "bath" method. I can get through 1 oz copper in about 5 minutes this way, and you can watch the process and apply etching where it is needed. I get great results down to 8 mil traces with hardly ever a void.
As for the etching I've built a new heated and aerated etching tank this week to try and get a more consistent etch, but if I have problems with that the sponge method is something I'm going to try.
Have you tried reprinting it 2 or more times to make the ink thicker?
As for the aluminum or possibly steel I'm just going by what I was told it was could be either I'm not 100% sure.
If you check out some engraving supply sites they sell a thin double sided tape that releases easily for holding down your boards that may make setting up easier.
I've been using the C86/C84/C66/C64 printers for a long while now since they are cheap and easy to resurrect/clean if you know what you need to do.
You did a good choice using the C86 (the flasgship of that series) sicne you can completely take apart the print head (see photo attached) and clean it, no matter how clogged it is. It's not much more efford than the method you used but you'll be able to get all dried ink from inside the head to avoid future clotting.
I really really recommend a strong ultrasonic cleaner. without ultrasonic it will be hard to free completely clogged heads.
then even more important then cleaning the heads:
clean the vacuum pump (!!!!!!!) with 30% of all the C86/C84/C66/C64 printers i got (i have 20) the vacuum pump tube was clogged with a solid mess of dried ink. not cleaning the pump will result in clogged nozzles in no time.
Also regarding the printing process: if you use the printer solely for PCB printing and want more ink applied, put ink in all 4 cadridges. also an interesting but little known fact is that you can change the amount of ink being printed by fiddling around with the driver settings. i think i used the "OHP transparent" setting in windows combined with some other mode. now i use linux and it's easier to set how mcuh ink is being printed out.
just my thoughts.
thanks for writing this instructable, i really know how mcuh work you put into this. it convinced me to finally mod my C86 printers for PCB/t-shirt printing.
You need to redo your math on the metric copper thickness. (I think you mean 35 um (micrometer))
I wondered : can you not put the acid directly on the board ?
maybe the print head can tolerate the acid. the plastic probably can.
that way you would get rid of the masking and instead of pinholes you would have (maybe) just isolated islands of copper. but the actual connections would be
untouched copper, and be 100% no pinholes.
BTW, to help with the undercutting during etching, try using the "Sponge Method" on this page http://www.pcbfx.com/main_site/pages/tech_support/no_etching_tank.html ... It works really well for Toner Transfers etc and hardly undercuts at all and works in less than a few minutes...
Just a thought...
I could probably write quite a bit more about this too if your still curious let me know. The project is definitely something I'm still working on and trying to improve I just thought the information was worth getting out there.
http://www.instructables.com/id/GM-Arts-Overdrive-Pedal-Build/step5/Acid-Rocks/
Continuity is nice but on some circuits jagged edges can cause interference, like signals use spiked edges to radiate out of. Plus it just looks bad.
Thanks for the help.
You might try adhering the resist ink to the copper better by ironing it or putting it through a laminator, wrapped with cheap magazine or catalog paper-- what other folks (like me) print onto when doing toner transfer-- since toner doesn't like sticking to the paper as much as to the copper. (This assumes that your resist ink acts similarly, which I don't know ;) Or, have you sufficiently roughed up the copper, with a light brushing of steel wool? That both helps the resist adhere and speeds up the etching.
I'm going to try a few things this week to see if I can get rid of the pinholes and I will definitely update everyone and the Instructable.
Perhaps curing the board/ink in an over set to the appropriate temprature for the the correct length of time would solve the pinhole problem.
We used a heat tunnel, which is basically an over with holes in each end and a conveyer belt.
Regarding the "right" ink: How important is the ink type? I live in Germany, so shipping from inksupply won't be cheap. I do have a chip resetter, so would generic pigmented ink be sufficient, too?
Also this may help. This is a group in Germany who posted a comment on Hack a Day about their similar project and what ink they used. http://shackspace.de/wiki/doku.php?id=project:beta-layout:pcbprinter