Homebrew PCBs

Wow - perfect solution to the part that was causing me a lot of aggravation! Great job! It wouldn't surprise me to see a commercial DLP printer in the near future.

Mark


-----Original Message-----
>From: Jim <jhutch17@...>
>Sent: Sep 8, 2010 4:57 PM
>To: Homebrew_PCBs@yahoogroups.com
>Subject: Re: [Homebrew_PCBs] Re: DLP DS Update
>
>  Hello Mark and Samson
>Mark, Its too bad your day job interferes with your hobby!
>In a previous post today, I briefly described how I modified (with 
>Mark's guidance) the E260 printer to directly print an toner image to a 
>PCB or other substrate.
>I will now describe how I fix (harden) the PCB pattern to the copper 
>substrate.
>When the PCB exits the printer with its pattern, the pattern is attached 
>to the PCB by an electrostatic charge. You can BANG the PCB on the table 
>and nothing comes off the PCB. But if you lightly touch the pattern, it 
>will smear. The usual way to harden the pattern is to use heat (up to 
>400 degrees F). Here is a method that uses NO heat.
>The toner consists of finely ground poly-ester resin. Acetone will 
>dissolve this resin. In fact, Acetone solvent is the perfect way to 
>remove the toner after etching.
>To FIX the toner to the PCB, without heat,  in preparation to etch the 
>board, take a table spoon of acetone and put it in a glass dish that can 
>be covered and sealed. Put something in the bottom of the dish to place 
>the PCB on face up. I use stainless steel bolts. Seal the dish with a 
>glass pane or an acetone resistant plastic cover. Leave the PCB in the 
>VAPOR of the acetone for at least 2 minutes. Remove the PCB and allow 
>the acetone vapors to dissipate from the PCB (30 seconds). You can now 
>touch the toner traces without damaging them and the PCB is ready to etch.
>Jim KI6MZ
>
>On 9/8/2010 5:47 AM, Mark Lerman wrote:
>> Hi Samson,
>>
>> Yes, I know that my final design does not fully mesh with the text.
>> I've gotten bogged down at work and have not looked at this stuff for
>> months. In conversation with some other people from this group (speak
>> up if you wish), it seems that the KY can be eliminated by using foil
>> over the leading edge of the pcb to connect the top and bottom
>> layers. I'm hoping to get back to DLP in the next month or two -
>> these are printers that might work even better that the E260.
>>
>> Mark
>>
>> At 08:03 PM 9/7/2010, you wrote:
>>> Hey Mark,
>>>
>>> I just wanted you and everyone else to know--you are AWESOME.
>>> Documentation is key to a lot of these projects, and your steps made
>>> the modifications a BREEZE. I bought the E260 a few months ago, and
>>> finally got around to modifying the printer! I just want everyone to
>>> know that if you're about to pull the trigger, just do it because
>>> the mod is very well documented and easy to do. The only thing I've
>>> got to comment on is that the software steps are off from your
>>> latest schematic and code, but I've figured that out. I'll probably
>>> be publishing code for the PIC12F series in a few days, which I'd
>>> imagine might be useful for some with dev toolchain setup.
>>>
>>> Once you get the process figured out for yourself, it really does
>>> only take<5 minutes per print before etchant. Tape the board,
>>> print, heat for 2 minutes at 400F (I use a griddle), and then a few
>>> passes through the laminator and you're golden. It's SO much easier
>>> than toner transfer, even with transfer paper, and the time savings
>>> is definitely worth it for me. You also don't need any serious MechE
>>> skills to do the mod, but you will have to get a few things off of
>>> McMaster Carr. I'll probably post a few part numbers--I think I
>>> found a cheaper version of that drive shaft which works fine.
>>>
>>> I've got to admit, I might be saying all of this somewhat early. I'm
>>> still optimizing the process at this point, and later I'm planning
>>> on working out the E&M and maybe getting control over however the
>>> printer adjusts the transfer voltage, which varies depending on
>>> substrate and other conditions.
>>>
>>> The prints are very very promising so far. I've been printing very
>>> large black areas, which I know is most difficult for laser
>>> printers, and I am getting pinholes, but much better than what I had
>>> with toner transfer. There's still some open areas, but that seems
>>> to be because I wasn't very careful with the lubricant spreading.
>>> After etching, though, it's very clear that the toner areas are far
>>> more solid than I've gotten with toner transfer--there's virtually
>>> no leakage through the resist.
>>>
>>> I've also tried to print onto metal substrates (specifically
>>> aluminum). It works with a few sheets of paper underneath the
>>> aluminum carrier, but I'm not sure why. Without them, you get very
>>> serious blotching in the image--I intend to work out the E&M
>>> calculations sometime in the near future to figure out what's going
>>> on. Maybe there's a more optimal stack, or I could try to change the
>>> transfer voltage.
>>>
>>> Anyway, I just wanted to say thanks--this method is AWESOME. Let me
>>> know how double sided is going--it does seem that the feeding
>>> configuration doesn't really lend itself to particularly accurate
>>> y-axis feeding, but it'd be awesome if double sided worked.
>>>
>>> Samson
>>>
>>>
>>>
>>> --- In Homebrew_PCBs@yahoogroups.com, Mark Lerman<mlerman@...>  wrote:
>>>> I am now working on producing ds boards. My first test was to see if
>>>> I can print multiple times on one side of a board with good
>>>> registration. If I can do that, I'm certain I can do the rest. I
>>>> added a reflective sensor to locate the actual position in the motion
>>>> (Y) axis. I could have used one of the leftover E260 interrupter type
>>>> sensors, but it was easier for me to use black tape an white labels
>>>> than to drill holes. In the final version, in the spirit of
>>>> recycling, I might use a leftover.  There are some pictures of the
>>>> sensor and new mcu board on my pbase site<http://www.pbase.com/mark10970>.
>>>>
>>>> As I mentioned previously, when the carrier moves through the
>>>> printer, the leading edge first hits the moving transfer roller,
>>>> which pulls it up into the drum/transfer roller interface. This
>>>> causes a variable delay, which messes up the registration. The "fix"
>>>> is to wait till a couple of inches of carrier is completely through
>>>> the interface before starting the actual timing (timing starts when
>>>> pis is pulled low).  I still have some work to do, but I'm pretty
>>>> sure I can get it to work I printed a test with 5 mil traces - it was
>>>> perfect in the Y axis, but about 5 mils off in the x axis. There is a
>>>> picture on my pbase site.
>>>>
>>>> One problem I foresee is how to tell whether the sides are registered
>>>> before etching. You can't see through the board before it is etched,
>>>> and you don't want to etch it without knowing it is correct.
>>>>
>>>> Mark
>>>>
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> Be sure to visit the group home and check for new Links, Files, and Photos:
>>> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>>>
>>>
>>>
>>
>> ------------------------------------
>>
>> Be sure to visit the group home and check for new Links, Files, and Photos:
>> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>>
>>
>>
>>
>>
>
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
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