How to 'trace' vintage artwork in a modern CAD program

[falter]

I've been messing about with KiCad trying to learn how it works. I have seen examples of artwork, including labomb's excellent Sol Prototype PCB replica.. but I'm curious how you get things like model text, or curved rather than angular traces there? Can KiCad do that?

 

[dfnr2]

There is a way to get curved traces. It's a little indirect, but the results are nice. You need to install the mitxela curved tracks plugin, by selecting it in the plugin manager and installing.

First, in the PCB routing settings, select any-angle traces. Then using a photo as a template, (or free-handing), route the traces using small segments with angles that approximate the desired final curved tracce. This is not particularly time consuming--you just click periodically to "anchor" the trace and start a new segment in an arbitrary direction. Then, you can drag the "anchor" vertices to even more closely approximate the curve. Once you are close, you run the "curved tracks" plugin. Don't overwrite your original file. Choose the option to write to a new file, so you can still edit the rectilinear tracks in your original file. The result is nice curved traces. The plugin can also add teardrops if desired.

Not sure about "model text." What is it? If you're talking about using your own fonts, you can do that. Most PCBs used standard fonts from a template. You will likely find a close modern font and tell Kicad to use it. You may need to add leters indvidually and then move them around to match spacing.

 

[falter]

Thank you. Re 'model text', I mean like replicating a vintage logo or computer model name that the makers etched in copper on the board. For example the Sol has a stylized "Sol" etched on the bottom right corner of the board. It doesn't conform I think to any modern font.

 

[bzotto]

For the text, certainly. KiCad can place text on a copper layer in any font that's installed in your system (just use the font dropdown in the text tool edit box and choose anything besides "KiCad Font"). Placing "images" (eg a pre-rendered logo mark) on the copper layers can also be done, but it’s sort of a hack so it’s confusing and fiddly and can be a bit different depending on whether your source is vector or bitmap. But if you google around people have step-by-steps for how to do both. (You can see evidence of all of the above on the memory board I put together here.)

 

[daver2]

KiCad can import images, and you can place these on copper or silk layers.

Dave

 

[falter]

KiCad can import images, and you can place these on copper or silk layers.

Dave

I was trying to figure out how to do that.. I think that's the bitmap converter tool, but I couldn't figure out how to load the image onto the layer.

 

[daver2]

I am a bit rusty, but you need to be in the PCB tool and you just select the layers you want to load the bitmap into.

Dave

 

[dfnr2]

Thank you. Re 'model text', I mean like replicating a vintage logo or computer model name that the makers etched in copper on the board. For example the Sol has a stylized "Sol" etched on the bottom right corner of the board. It doesn't conform I think to any modern font.

Got it. You have a couple of options:

1) Find or create a DXF of the logo in a drawing program like Illustrator or Inkscape, then import the DXF to the desired layer You can convert closed shapes to polygon or pour zones. If you use pour zones, then you can place smaller "keepout" zones inside, for example, to clear out the triangle in the letter "A", or the inside of the letters "O" and "Q". I am not sure (without checking) if simple polygons offer the same capability.

This option gives you the most flexibility for scaling the logo, since you can scale the DXF in the graphics program or at the time of Kicad import. Kicad doesn't otherwise support (as far as I know) scaling of graphics once created. For vintage computers, once you get the logo, you're done. But for company logos, you can also make a Kicad footprint library at different sizes. Same for Altium, but Altium has the nice feature of allowing you to resize graphics on the fly.

2) Import a photo into Kicad and then trace out the shapes using the drawing primitives, and convert to zones/keepouts as in option 1. But you'd still maybe be better off creating the DXF in a drawing program and importing, for the reasons above.

3) Find a bitmap and import. This option is the least preferable. It can produce decent results with a high-res bitmap, and if it's properly scaled at the outset, it can be the least work since you don't have to fill shapes with copper. But it's the hardest to scale, and scaled bitmaps generally don't look good.

 

[dfnr2]

I was trying to figure out how to do that.. I think that's the bitmap converter tool, but I couldn't figure out how to load the image onto the layer.

I was referring to displaying the logo as a background to be traced. Kicad 7 has a button (icon of mountains and sun) along the right-hand side toolbar to import a bitmap for viewing/tracing.

In general, it's better to work with vector images like DXF or SVG rather than bitmaps, because they will always scale and rotate better than bitmaps.

To import a bitmap image for placement on the PCB, use the image converter.