Homebrew PCBs

On Tue, 19 Sep 2006 18:50:12 +0200, jam5411 <mardock@...> wrote:

> The settings for "Best Color" and "matte" were used, which puts out
> quite a lot of ink. The areas of the pads in the test had noticeable
> puddles, so less ink seems to be in order. Needs experimentation here.

I see the same, but if i try to use any less ink it does not fully resist.
I have printed a series of strips on the same PCB offset to each other and  
with different printer settings.
Only the matte with photo or best photo (which puts out most ink) would  
resist, the others are riddled with gaps and holes.
With what do you etch? I thought the CuCl is the culprit but it was even  
worse with FeCl.
Volkan somehow seems to get by with much less ink, thus no puddling.
Maybe it's because he uses the right ink in each slot, i'm a bit puzzled  
by this.
Not a problem with simple boards though, but i would like to get it sorted  
esp. since volkan's results show he doesn't seem to have the problem.

> For the jack screw I used two "L" Brackets and a 4/40 with some nuts.
> allows adjustment of the left side to keep the head level across its
> travel.
> Trying to use the existing plastic printer base. Had to raise the head
>  suction assembly up to keep the head moist when not in use. Seems if
> the left protrusions (head  suction assembly) are set above the mount
> instead of under it the height is about correct. There is a plastic
> post on the right side, I drilled and threaded that post bolting the
> suction device on top of a  spacer. seems to work OK.

Yes, i have done almost the same. The pad height seems not very critical  
since it's spring loaded.

> I agree with you
> the design pulls excess ink  on startup so I did away with the pump
> array. Using a syringe to purge the head.

I have found even after weeks of standstill i can get the head 100% firing  
with a minimal amount of ink wasted, far less than the printer uses for a  
simple clean. If i print frequently (say after a day) the nozzles rarely  
clog at all.
The pump is obviously used as a way to ensure a good steady ink  
consumption no matter how much you print. The speed at which the ink  
counters go down is quite amazing too.

> I should have title this "First successfull ... You would get a kick
> of what the first board looked like after the oven, well, cooked it.
> But even then as the substrate bubbled there was success. In other
> words the cured ink was flexible enough to still act as a resist under
> those conditions.

Yes, but the resulting board is ugly as sin. I've also made those....

> Great fun! I should think this method will supplant the TT method I
> have been using, much quicker, more precise with no distortion which
> is a pain for the CNC drilling.

It seems that way. If only i would have sorted the puddling thing already  
it would be nice.

ST