Technique to duplicate PCB dimensions and screw hole placements?

[nuke]

I'm used to the tedium of schematic entry. Then schematic, "oh, heck, I missed that", followed by run the rules checker, yell at the rules checker for the oodles of warnings, that hide the 3 or 4 I should really pay attention to but didn't. Then doing the board with a rough outline to fit the box it might go in, then the rat's nest, moving things around, work myself in and out of the mazes I created. Waste some money on the first fab, cut some traces and blue-wire some things until it stops smoking.

Usually though, I have the luxury of cutting and drilling the box to fit the board, since I don't do this for a living. Hat's off to the guys who do things like fit 10 gallons of high-speed logic into a 15mmx10mm board for the latest consumer gadget, where the industrial design group have already set down the "thou shalt fit into this small and weird shape...".

In this case, I have a shape with holes and stuff that I have to fit the board to nicely drop into. A case of reverse-engineering the mechanicals.

It doesn't sound like there are any great secret techniques, other than figuring it out the hard way.

[didit]

...Then you can export it and import that into Kicad where you can place and trace all of your circuit parts.

Can a .pdf be imported into KiCad?

I can't recall if it will import pdf files, but I can always export whatever type of file needed for Kicad. It may be a dxf file form that Kicad will accept for this. I haven't made anything PCB in quite a while. I will check, but you can too... Just use the drop down menu and see what type of files it will allow. It is easy enough to convert a pdf to a dxf by exporting from Corel, or your app of choice.
As a note: you can import your board shape with mounts as a layer in Kicad. After you have placed all of your parts, including mount holes (which you have to include in your schematic, grounded or not), you can delete this layer for a cleaner look. I usually export this file with "crosshairs" over the centers of any holes to make placement of the hole components super easy. Then you can import another file that is just the board outline without holes. There may be a better way but this has always been easy enough and produces great results.

Unclear why PDF became the question. Highly recommend using DXF to get KiCAD strapped down. A well framed up photo image and calipers to measure accurately as was suggested a few days ago, working with whatever mechanical CAD tool is available should quickly get the essentials captured. This then can be used to lay the starting rules for a PCB to place under schematic. KiCAD has some limited "mechanical" drawing capability but for something like this a purposeful tool will be the better option. I have not personally done a project as complicated as proposed but have done DXF import to enable clean design of oddball footprints. And I've done a handful of KiCAD projects though sadly none recently.


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[martin manning]

Unclear why PDF became the question...

.pdf docs are common, and standard office software can create them. No special CAD software required.

[didit]

Unclear why PDF became the question...

.pdf docs are common, and standard office software can create them. No special CAD software required.

Yes, sort of. PDF graphic elements are essentially Postscript, so there is geometric info however it is only loosely related to objects represented. At risk of seeming rude or at least a crank, still questioning the question?

Brief search over on KiCAD forum turned up chronicle of two work flows: import a source image as a PNG and scaling that to ~1:1, and then proceeding to place layout in KiCAD; or import DXF generated in one of the many available CAD tools and embedding that as the basis for the layout. Tools mentioned are LibreCAD, FreeCAD, and Fusion360. Note they had DXF export/import as a recommended flow for migrating a basic board form from an existing KiCAD project to a new one.

Best ..

[rangdipkin]

old industrial scorched earth method of PCB cloning; depopulate the board and scan it along with a precision scale in the X and Y axes, import the scanned image into AutoCAD and adjust to real world units using the scale references. Then manually create polylines over the traces from the image. Precision can be down to a few thou if care is taken. Its a huge pain in the ass but comes in handy if the board is obsolete or unobtanium!

[martin manning]

At risk of seeming rude or at least a crank, still questioning the question?

If I wanted to copy an existing pcb importing some kind of graphic image would be helpful, be it .pdf or .png or whatever. I have had some great faceplates made from .pdf’s so naturally I thought if that.

[dorrisant]

I'm pretty sure you could grab a free app, like Inkscape, to convert to or from PDF files to the desired export... In this case, dxf files.

Almost anything I do that involves transferring graphics from one form to the desired form usually requires two or more applications to get the desired end result. No single application is really the end-all, be-all solution to everything.

Like engraving... whatever form imported, from a hand drawn image scanned in or an image downloaded, convert it to a dxf in Corel, then imported into a CAM program, then exported to Mach3 to get the CNC to engrave it. Same here with Kicad. I can generate the shape, holes and silkscreen graphics in Corel by pulling in whatever is needed into Corel and exporting the file form needed, dxf, png or svg. It is one of the biggest obstacles to get over, figuring out (and remembering) that flow. But once you are familiar with this flow and comfortable with the software manipulation, it is very much downhill and easy from there. Some people see it as a mountain, I try to see it as a molehill.

Make yourself a breadcrumb trail of notes to remind you of this flow until you don't need it anymore.

[dorrisant]

At risk of seeming rude or at least a crank, still questioning the question?

If I wanted to copy an existing pcb importing some kind of graphic image would be helpful, be it .pdf or .png or whatever. I have had some great faceplates made from .pdf’s so naturally I thought if that.

pdf files are great, but contain many layers and sometimes hidden geometries that can cause a lot of trouble. This is why Kicad requires a simpler, stripped down file form.

[martin manning]

I'm a Mac guy. I used to keep a Windows OS running with Bootcamp but ditched it. I guess FreeCAD or Inkscape are viable options.

[didit]

Hello --

I'm a Mac guy. I used to keep a Windows OS running with Bootcamp but ditched it. I guess FreeCAD or Inkscape are viable options.

I too run with a Mac mainly. Inkscape was good for basic vector image capture, used recently with good results. Illustrator "muscle memory" made it fairly easy to learn. My work flow end step was G-code but the goals are close kin.

Best ..