I have a rather poor quality but full size print of a printed circuit board I wish to duplicate. It's on cheap thin paper with printing on the other side. My scanner gives the best results when using grey rather than B&W. But of course shows the print on the other side. And the edges of the tracks are pretty ragged.
Of course I could just use this as a guide and draw an entire new one - but wondered if it was possible to clean up the track edges and produce only B&W in software?
Of course. However that's just reducing the colour depth, not straightening the edges. An edge detection filter can be useful for that,although it will change the proportions a little. Best of all (complicated, but allows editing afterwards) is to import the bitmap into an SVG editor like Inkscape and then convert it all to line segments.
yes, but you will still have to touch it up.
quick trace over job is far better.
Andy Dingley wibbled on Friday 09 April 2010 10:52
If you were going to do that, might as well download Eagle PCB softaware (it's free for limited sized boards) and copy the design. It's got a fairly small learning curve and does a nice job.
Put a sheet of black paper on the other side when scanning. That will hide the printing. Unless your scanner has a black lid like mine!
Inkscape can trace a greyscale image into vector format.
This has worked for me, a non-glossy black like sugar paper being best.
To get a better scan, cover the page with a sheet of black paper.
This will help to eliminate, or at least reduce any "print-through" from the printing on the back of the scanned page.
Put the print on the scanner and place a piece of black paper/ card over the top of it and see how it comes out. Something like photoshop can improve the contrast of the scan.
Dave
Depends how straight you want your edges. Scan at a high resolution,
Your program to do the B&W conversion really needs the abilty to adjust at what level in the grey scale the transistion from black to white occurs with a WYSIWYG preview of the result.
scanning in colour may be even better.
then maybe a bit of blur, to thicken the lines, then adjust levels, delete most of the light grey then another blur, then adjust levels, delete the lighter lines ?
Photoshop bible is the book i learnt most of my tricks from.
Look at
AWEM
I've got my own PCB drawing software based around a development of Acorn Draw. For the things I do it's fine. I don't really do enough to make it worthwhile learning a dedicated PCB prog. And Draw gets used for other things.
Last time I made PCBs, I found the density of the laser printing toner onto acetate sheets too poor for etching. Perhaps inkjets fare better.
I ended up filling it in by hand using a marker pen, and using a stanley blade to scratch off unwanted spots etc from the acetate.
( However, I was copying an original board by *photocopying* the copper side and then hand-reworking the transparency! FWIW, it was a NAIM 250 power amp which I cloned for a tri-amp setup! )
Funny you should say that. My original inkjet - a Epson Stylus - gave denser blacks than my current Canon i865 - which uses two black tanks. But it's slightly denser than my el cheapo B&W Samsung laser. However, tracing paper gives better results using the laser.
I've got some of that iron on stuff to try next.
The trick is to use tracing paper instead of acetate - use heavy stuff >=90gsm to avoid crinkling in the fuser. See my page
Nice to hear from the horses mouth as it were - I'd already come across your site.
I used to get decent transparencies with my old inkjet - but not with this one. Although there is a difference - it's being printed via a PC rather than direct from the RISC OS machine the artwork originated on, because there aren't suitable RISC OS drivers for modern printers. I'm going to try printing direct from the PC after transferring the files via PDF. But will try tracing paper - have ordered up your recommendation from Viking.
I've already tried printing direct from the PC to the cheap laser onto an acetate and that's rubbish, holding it up to the light. Is it likely to be better going to tracing paper?
Any guidelines for exposure times between transparency to tracing paper? My UV box gives the best results at 8 minutes with transparencies.
Depends on what controls your laser has for the amount of toner deposited, fuser temperature and transfer voltage. My HP Colour Laserjet CP1515n has at least 5 settings for each accessable via it's web interface.
How much did a clone NAP 250 cost to build?
It's a cheap mono Samsung - ML-2240.
There is an adjustment for paper types - dunno what that actually does, and normal lighter darker.
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