Andy's notes are spot-on for printing size. Test prints/plots are crucial with any low-volume process.
For those who might want to try the toner-transfer method (with which I have had success) I would direct you to the homebrew_pcbs Yahoo! group. <http://groups.yahoo.com/group/Homebrew_PCBs/> That is just one of the methods discussed and used successfully. Very active and friendly group. Donald. ----- Original Message ----- From: "Andy Eskelson" <[email protected]> To: [email protected] Sent: Thursday, November 12, 2009 6:29:20 PM GMT -05:00 US/Canada Eastern Subject: Re: [kicad-users] Export actual size PCB in PCBnew You do not use the zoomed image at all. You should use the print and plot menus. The system will then work everything out based on the settings you set in the various requesters. There are a couple of options you can set.. In the print menu there is an Approx scale and an accurate scale. I will guess that the approx was more useful when computers were slower, just for proof prints. The dimensions are nowhere near good enough for use. The accurate scale option is pretty good. One thing that I did find and this may be something due to my distro, is that when using the print option the drill points were never printed. So I ended up with filled in pads, which made drilling a bit harder. I now use the plot option and I just plot as a postscript file, then print that. That works 100%, small drill points and accurate sizes. I have tried the iron-on transfer method, and to be honest it was not very good. I could never get a toner transfer that stuck well enough or was dense enough to act as a resist. I have also tried LaserTran paper, that was much better Print to lasertran iron it onto the board to set it, then place in water and the paper floats off leaving the toner intact. The board then needs to be dried and heater to ensure that the toner is really stuck. I've made half a dozen boards this way, and it was OK-sort of. I did need to solder over the thin tracks to fix any hairline breaks. Lasertran paper is also expensive for what it is. I now use the photo resist method. using the mega-uk seno system. http://www.megauk.com/pcb_chemicals.php Not quite as good as pre-coated boards, but more than good enough for my needs. The long shelf life of the applicators was the main attraction. For a UV box, I just bought a couple of spare tubes, and built my own (I used a old desktop scanner as the box, the tubes just fitted in diagonally.) The tube choke and starters came from a cheap light fitting from the local DIY shed. I still have a couple of example boards and a description up on my website. http://www.g0poy.com/Pages/pcb/senotest.htm Note that this page is not indexed from the main menu, so you have to use the full URL above. It's just a couple of boards, consisting of a series of parallel tracks. One done with tracing paper, the other with transparency sheets. Andy On Thu, 12 Nov 2009 20:18:52 -0000 "hal8000b" <[email protected]> wrote: > Apologies if this has been asked before. > > One way to make PCB's is to print the PCB template with a laser printer > onto acetate. > The acetate is then ironed to to plain copper clad PCB with a hot iron, the > ink transfers to the copper and when set board is ready to etch. > > My problem is, what viewing size gives actual size components? > In PCBnew the 3D viewer can show top view or bottom view (copper) and > then export as JPG or PNG image. > > Pressing F1 or F2 zooms in/out but I dont know which view ratio is actual > size, can anyone help? > After exporting the copper layer I can change it to black using Gimp but its > getting component, pads and track sizes correct. > > Thanks in advance. > >
