New trace deletes existing trace on other side


Strange issue here. I’d like to increase the current that can be transported on a short trace from one through-hole pad to another by drawing a trace on both sides of the PCB between these two points. I’ve done that before (maybe with KiCad 5) but when I do it now, adding a trace on the same path as the previous, it always deletes the trace from the other side! I can only have that trace on one side not both now.

Why does KiCad do that and how can I stop it? I want traces on both sides, not a single side. As both ends already exist on both sides, it doesn’t cost me anything to have these two traces. There are no crossing traces or anything, this is a free area. I could draw either without a problem, but it will delete the other that I’ve just drawn before.

I’ve verified this by hiding each layer and see what’s left. But usually the active layer is always rendered on top so you could already see.

KiCad 6.0.7 on Windows 10

The cause of problem: Both Tracks are on the same Net (either a defined Net or, both on no-net)

Solution: Put one on a Net (double-click for panel). Other ways to access the panel, too…

Image shows both connected (look at 3D view’s ~transparency to see other trace - )

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There’s an option (Route > Interactive router settings) which allows to enable/disable “Remove redundant tracks”. Unchecking it should do the trick.


Thank you, the router option helped. I must have used this in previous KiCad versions and it somehow got lost.

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I have used the disable remove redundant tracks option, but it can be dangerous, so I like the net-tie suggestion above.

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I think all Electronic’s Geeks should have Ground-Loop problems. Then, we discover, through problem solving, the importance of paying attention to what and how we hook-up circuits

Sure, if just blinking LED’s, you wouldn’t notice ground-loop effect…

I don’t know but, perhaps, common-sense and that is why the default is to Not permit redundant traces, thus forcing designer to intentionally do it (as in forcing them on separate Nets…).

Go ahead and Google “electronic circuit ground loops”, knowing and learning about them won’t hurt…

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Okay, I googled that and most of what I found described audio effects. I’ve heard that effect before when connecting a TV with a stereo amp across the room many years ago when we still had analogue audio lines. A decoupling transformer helped back then.

My PCB now has a pulsed (PWM) LED power line of up to 2 A (24 V), not an audio signal. And my trace is a few millimetres long, 1 mm wide (standard 35 µm thickness) and runs exactly on the same path on both sides. The connectors are through-hole parts, so the connection is already accessible on both sides. From my limited experience I wouldn’t expect any issues here. But just in case, would placing vias along that double-sided trace be of any use here?

And since the problem seems to be mostly about ground loops: Isn’t a ground plane with a hole (making space for other traces) also a ground loop? I mean, the current could flow left and right of that hole, which is two paths.

We (me) have no idea about your design - it could be anything from blinking led to 240V cube of Tofu. Difficult to comment re the problem…

You may not be making an Audio gizmo - but, it isn’t Audio that causes the problem, the audio noise is an audible indicator of a problem (in audio, it’s often a ground problem)

Though I and others are often interested in solving design problems, this forum is more about Kicad and using it, versus how to wire-up a circuit.

Not helpful, I know. But, you could have helped us to ‘help you’ by being clearer about your design.

And, though I cited Ground-Loops, the issue of redundant traces, power and signal loops can be similar. Again, it depends on the design…

Here’s a good, quick read (and may answer your question about GND-Plane and Hole)…

There are handfuls of Sites dedicated to design and problem solving designs (and, getting advice on your design. Best describe your design/etc so you get help…

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I believe the reason why KiCad deletes redundant traces by default is simply to make editing easier. Like if you have a track that goes in an unnecessarily roundabout way, you simply draw the shorter/better route and KiCad will automatically delete the old path without you having to manually select and delete it.

Redundant ground traces are most often not a problem, if you have multiple ground planes and stitching vias and so on, you have redundancy pretty much by inevitably.

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