KiCAD TRACE SNAP Issue

General Electronics
1

While learning and getting a hang of KiCAD for the first time, I came across a rather unusual scenario. In PCBnew traces are not snapping to the pads of any component (whether it is a TH or smd component). I know it will have a very easy fix (that’s what i presume) but for a newbie, I need your help.

Thanks in advance

Piyush Negi

2

Hi Piyush,
Could you post a picture of the problem? Is it the same over the entire board, or is it just near a corner? There is a known but with regards to corners.

J

3

Oh sorry!!
I forgot to upload the reference… duh!!

Well here is a Screenshot to my problem.

Problem|690x388

Well the problem is on the whole board, not only at the corners

Piyush

4

This is an annoyance with KiCad. It won’t snap to a pad unless the pad is centered on a grid node. There are a few workarounds:

  • Set your grid really fine and snapping will work more often.
  • Double-click when the trace is inside the pad. This seems to terminate the trace and then add a small segment that does snap to the pad center.
  • Click when the trace is inside the pad and then hit Esc to terminate.
  • Hit the “End” key under Windows (not sure if there’s a Mac hot key) to end the trace right where you have it at the moment, presumably inside the pad.

Unlike some other CAD tools, KiCad does not logically “attach” traces to pads - there is no “rubber-banding” where you can drag a component and its attached traces come along with it. Traces just lay where you put them, and if there’s enough copper overlap the rules checker deems them connected.

I’ve read that improvements in this area are coming with v6.

2 Likes
5

Heh. I’ve used Kicad for many years and never knew this since I’ll always snap components in place on a grid. I actually had this on a board recently and on Mac, you just draw the trace and then tap ESC to finish off.

1 Like
6

Thanks for the help Julia!!

You know what, I was doing the same thing (get into a pad and hit esc or right-click). I was so frustrated doing this because it was not allowing me to route a proper differential pair.

The fact about the grid size I use 5 mils for the component placement and 1 mil for routing. And I use external libraries for the footprint (downloaded them from ComponentSearchEngine).

How much grid size would you suggest me?

Piyush

7

Thanks a lot Jensa!!

Snap to pad is a very crucial aspect of a design software, without it designing is hard!!

8

When I’m placing components, I use a coarse grid of 0.25 - 1mm, so everything lines up easily.

When routing, if I don’t feel like fighting with pad snap, I’ll set it to 0.01mm, which is the minimum.

It also feels to me that pad snap behavior is slightly different between Mac and Windows, but I’ve never quantified it and it could be my imagination.

9

Thanks Julia!!

I’ll use your information while designing!!!

Happy designing!!

10

Funny, I’m laying out a board right now on MacOS, I have the grid set to 1mm, and everything is snapping perfectly. Go figure.