Hi,
made a pcb with lines:
1/1200" (0.833mil)
2/1200" (1.66mil)
4/1200" (3.33mil)
8/1200" (6.66mil)
16/1200" (13.3mil)
32/1200" (26.6mil)
printed at 600dpi resolution the first 2 are the same, and totally broken
up after transfer and etch.
3.33mil is partially broken up, 6.66 is consistent. didn't try 3 600dpi
dots, but it will be in between.
33mil high text is well readable in copper, 16mil text is bad already, i
think 25mil might be the limit.
i futher did a series of 13mil wide tracks spaced the listed above
distances, the smallest two result in no visible gap, the third just a
hairline. 6.66mil gap seems reliable, but i haven't rubbed the paper well
so it is not etched completely.
Groundplane worked fine.
You can see the results at
<
http://www.trethan.at.tf/pub/img1/>
, the images pcb?.jpg.
There's also some other stuff for PCB making, note that the pivoting drill
press is prepared for mounting the optical projection viewfinder but there
wasn't time to actually implement it. The image will be taken by a lens
right under the pcb and mirrored back to a screen on the big frame you
see. Also i must make springs to balance the press (hold it up when idle)
and a better stop.
The fuser assy is a proof of concept that stayed that way, but it works
just fine.
The etchtank is almost perfect (for me, anyway), only thing i'd change is
rotate it 90 degrees (more high than wide) for various reasons. You can
see the one-hand-no-gloves-no-mess holder/lid.
Anyone wanting the resolution test layout is welcome, but i would make it
different the next time.
seems to me 6.66mil is pretty much all we get, i would like to know if a
1200dpi printer allows better results.
ST