I wanted to place a mount hole at an exact location, and therefore pressed E to edit its position.’
I got this:
When I click the pad itself, I can edit and move it where I want and the popup window’s title is “Pad properties” which I can understand.
When I click the blue circle, it has its own popup window which is called footprint properties. In the case of a mounting gole, isn’t the pad the same as the footprint?
What is this blue circle used for? Its layer is called cmts.user. What is this supposed to be? Comments?
Why don’t other footprintes have a cmts.user layer? And beside this why should it move separately from
the pad itself, why doesn’t it share a unique location?
NB: I have noticed something which is probably related: it’s possible to move a single pad from a footprint, as shown below. So I suppose that what I observe with the pad is the same “feature”. Why would one want to move a single pad from a footprint? I think it would even lead to some errors, by moving a pad accidentally. If the 2 pads are far away from each other, for example for a large throughhole capacitor, then there is a chance of moving a pad,
not enough to be detected from the eye, but enough to prevent the capacitor to be correctly mounted.
You didn’t give version information; I’m talking about 5.1.
Footprints have “locking” property. Locking pads means that you can’t move pads with Move command (M shortcut), but you still can move them by giving new x,y coordinates. Footprints in the standard library should have locked pads. If not, it may be a bug.
Wheter you ever need to move pads freely depends on your workflows. Some users might for example not have a library for each slightly modified footprint, yet want to do slight adjustements for example for space restriction reasons. But basically you don’t need movable pads if you create a new footprint for each variation.
Selecting a footprint which has only one pad seems to be a bit difficult. But it’s always necessary to distinguish between signle pad footprint and the pad, because there are different properties which may need to be adjusted. The problem is the selection logic - click on a pad always selects pad over the footprint. So, if there’s nothing in the footprint outside the pad, you need to use Alt+click (which doesn’t work properly on my Windows installation).
I have never needed it, but I can imagine that someone designing single layer board and placing on it some wire connections could decide to not design the new footprint for every connection distance needed but just move the pads of his one footprint where they are needed.
There is a better option available then using a footprint here.
I would suggest to define the second copper layer as the “wire connection” layer and use vias with traces.
This way you ensure that you do not need to cross your wire connections and you also have it documented where you need to add a wire (if you want to allow crossings then use more than one jumper layer).
With a footprint like you suggest you would somehow need to document which of the pads needs to be connected to which endpoint and you will also need to have every such jumper in the schematic (more work with questionable benefits).
A “legitimate” usecase is if you want to be flexible with where to place the second pad of a THT resistor (or similar part). This can help avoid needing jumpers or multiple runs of selecting the footprint with the correct pin spacing. Comes with the downside that silk no longer documents how to place the resistor and the footprint name no longer documents how you need to bend the leads of your part.
The concept of “locking” have been problematic. It’s possible that in the future there’s something different in KiCad and moving pads independently isn’t possible if the relative pad locations are locked. As it is now, it’s impossible to move a pad by accident - unless you think in a hurry that the pad properties dialog is the footprint properties dialog.
I suppose the blue ring in the mounting hole footprints marks the possible diameter of the head of the screw. Why it’s in the comments layer, I don’t know. Maybe for historical reasons.
I looked into some KiCad’s MountingHole footprints and they have locked pads as expected. As I said, moving them by accident shouldn’t be a problem. The only problem may be selecting either the footprint or the pad. When you have used KiCad for some time you know which one you want, I don’t think the difference between the pad and the footprint is any problem. Only how to select one of those two may be.
In one my project made in 2013 I have added that way two wires at third layer (to have no even one break in my bottom GND layer). But I done it by “Place - pad” function and not “Place - via”.
I don’t know if in KiCad I can place pads (to solder wires) instead of placing vias (covered by soldermask).
The typical application for such solder bridges does not have soldermask (home etching with single layer-> very large number of required bridges.)
If you have only a small number of bridges in a process that has soldermask then of course one would use tht jumper wire footprints. Or alternatively 0 ohm 1206 or larger resistors as this is more easily incorporated in the normal process while still allowing bridging over other traces.
I wonder how popular it still is. About 10…5 years ago I saw (here in Poland) discussions what is better - thermo-transfer or photo-transfer (they bought photo-sensitive film covered PCBs).
But since few years if anyone ask such question then the conclusion is to order in China.
