How to precisely place the footprint reference anchor?

I created a footprint in metric using a metric grid. The pads for the connections are imperial, though. The validator complains:

Violating F7.2
  For through-hole components, footprint anchor is set on pad 1
  Pad '1' not located at origin
  - Set origin to location of Pad '1'

As the part is metric, Pad 1 is not located on the grid and with “Place footprint reference anchor” I cannot hit Pad 1. I could not find a way to precisely place the reference anchor. Usually one can hit “e” and alter the “Position X” and “Position Y” value for precision placement. But that won’t work for the reference anchor.

How to place the reference anchor on Pad 1?

Version: 5.1.9+dfsg1-1, release build

If you can’t bring the anchor to the pad, then you can bring the pad to the anchor.

  1. First select your pad number 1, and edit it’s properties, and note it’s coordinates.
  2. Drag a box around your whole footprint to select it all.
  3. Right Mouse button, and “Move Exactly” and then enter the coordinates you noted down in step 1). (But reverse their sign).
  4. Edit the pad properties of pad nr 1. again, and verify Position X/Y are set to zero.

Apparently you’ve found a bug in KiCad. While placing the anchor point I also could not manage to snap to a THT pad, even though I verified that Footprint Editor / Preferences / Preferences / Footprint Editor / Editing Options / Magnetic Pads is turned on.

After that I did a Footprint Editor / Place / Line and then the circle does appear in the mouse cursor to indicate a snap point has been found, but the snap distance seems very small.

That seems more like a workaround for a task as common as setting the reference anchor. Is that really the way it’s supposed to be done? Seems convoluted and quite non-intuitive.

I’ll give it a try and use it until I know a better solution. Thanks for the suggestion and the quick reply.

Yes, I noticed that, too.

I fully agree that it’s a workaround for a bug.

Just did a little test in KiCad-nightly V5.99 and in that version the snap to a pad center works normally for placing the anchor point.

KiCad has been maturing quite fast in the last few years, especially considering it is an Open Source project with a limited number of developers. For some things you still have to use a workaround, but such things getting ironed out at a quite reasonable rate.

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Hi wxE5,

To accurately place a footprint reference anchor you can make use of the fact that the mouse pointer will precisely display the pad center when you hover over it.

  1. Select “Set grid origin” on the toolbar as shown in the figure below.
    image (7)

  2. Position the mouse pointer at the pad center as discussed earlier and click.

  3. Select the footprint reference anchor to place the anchor. Next, reset the grid back to the default setting.
    footprint reference anchor

That works. It’s weird that the centre snapping works for “Set grid origin” but for “Place footprint reference anchor” it doesn’t. Not quite what I’d expect. Thanks for the answer.

Placing the footprint reference anchor on pads works, thanks to @Amit_Bahl . But what to do if there’s no pad where the reference anchor should go?

Here’s an example, I have two pads one on (0,0) the other on (10.293,0). The reference anchor should be placed in the centre (5.1465,0). How to I place the reference anchor at precisely this spot? No grid setting will hit the centre and there’s no pad to snap to.

Why not follow the same trick as before? Place a new pad at (5.1465 , 0), snap the anchor, delete the pad.

Smart. I didn’t think of that. Thanks for the nudge.

Footprint Editor / View / Grid Settings / Grid Origin / X:

Then type in literally: 10.293/2
KiCad accepts calculations like this in any numerical entry box.

But setting a pad at that location and deleting it afterwards seems just a bit easier then setting the grid origin to that location and then resetting it afterwards.

So what’s left of this post is that you can enter the calculation itself in the pad coordinates.

That works as well. And yes, I think the pad way is quicker, indeed.