Ratnest Artifacts

New KiCad User but have used similar app’s and have 60 yrs of electronics/engineering.

KiCad Info:
Version: (5.1.5-0), release build

Past few years, all my PCB’s are One or Two sided. Recently needed another Layer so, testing out KiCad.

The learning curve was very short and after a few hours, was able to make:
Symbols
Footprints
Tweak/Edit library files
Make Templates
Create Simulations

Then, Quickly duplicated an existing schem & pcb for my hydroponic controller and Exported Gerber’s.

Lastly, having done the above, loaded Gerbers into CopperCam and all is well!

Referring to the PCB layout, there are a few Ratnest lines that show in the layout (See the White Boxes in image). Also, highlighting a Track/Net seems to highlight only some of the Tack and that varies with respect to how I do it… (confusing…).

I’m not clear on ‘Why’ they don’t disappear like on other tracks but, final results are good (see image).

FYI - the Pink Lines are simply Graphic representations of Jumper Wires.
Pay no attention to details such as pad and holes sizes…
My effort was to do a quick, none-detailed test.

Back to the Question:
Why the Ratnest artifacts?
How to properly lay tracks to avoid them? (Have tried several ways to do it but, always remaining artifacts…)

Thanks

KiCad DRC can be quite picky, if the track overlaps a pad but does not hit the exact center, it regards it as unconnected. Normally if you have magnetic snapping on the tracks find the centers exactly. Otherwise if you have a fine grid the track can be off a few mils from the pad center.

Turning on show track outline and zooming a lot can help spot mis-connections, if deleting the segment and redrawing it doesn’t help.

The rats on the switches are a common “feature”, DRC insists you connect all pads to a net. There are various workarounds depending on how much effort you want to spend. If you have a single sided PCB, you could make connections on the unused layer. The “correct” way to do it probably to use a symbol and footprint with all pins explicitly called out, then connect them as desired.

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This doesn’t explain the issues in the upper two boxes on BlackCoffee’s screenshot.

@BlackCoffee: can you share the kicad layout of this board?

Tom

Thank you for response.

Not sure exactly which file to attach the .PRO or .kicad_pcb.

I tried but, apparently, new users are not allowed to attach any files other than screenshots.
Is there a simple workaround? (no, not interested in Cloud/etc).

Thanks

[EDIT] I Redid the tracks at top in Zoomed-in view and was able to properly attach. That problem is solved.

At bottom, I’m thinking it’s related to the Button Switch (as stock part). Two pins on right are internally connected so, only one track is needed. But, the unconnected pin (doesn’t matter which) generates the ratnest-line. Still, it works fine for my CNC need but, would like to understand it.

If a merging track does not hit center of the target track this is considered not connected.
LHS turn on ‘Show tracks in outline mode (K)’.

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Yes, I thought that too. You can just ignore it if you know the pins are internally connected (KiCad doesn’t).

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Please note that this was the case prior to version 5.0.2. This bug has been fixed and tracks will connect to pads as long as the track end point is inside of the pad copper.

Tracks do not connect to the middle of other tracks yet.

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Thanks everyone!

Generally, after setting DRC parameters, and inspecting the Errors, I ignore them as most often I know what I’m doing and what the design is supposed to be (since I design it).

Learning KiCad is not difficult (for me) as it more about learning the software versus learning about electronics - I built my first circuit in the late 1950’s. OMG!

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