I’'m trying to switch from the (good old!!!) KiCAD 2013 version to the new KiCAD version. Schematic wise, it looks OK. However, when going to PCB and looking for PTH capacitors (Capacitors_THT), I see all distances are now metrical, not the good old inch unit. Where are the capacitors with distances of 5.08, 7.62 and so on? Don’t thell me they’re gone…
Replace with the nearest metric value. I think capacitors are manufactured with metric pitches.
Not only capacitors are metric, I see switches suffering from the same… 
Why not keeping “backwards compatibility”? Not all components are for sure metric nowadays. Still heaps that are imperial.
Metric or imperial are not intrinsic properties, it’s just a number. I’ll bet most manufacturers make their “imperial” products with metric equipment. It’s a big enough task maintaining the libraries as it is without maintaining multiple measurement systems.
Clearly metric is the global standard, imperial is obsolete.
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Only, that there isn’t a 2.54mm cap footprint; which I think is the question the OP is asking.
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Somebody who’s used to create PCB’s will definitely not struggle about that question/choice. It’s obvious.
My biggest problem is that all my current PCB designs (created with the 2013 version of KiCAD) are all imperial based. I still can use the legacy libs, but the 3D views are screwed…
Exactly, that’s the issue…
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Which capacitor series are you using, and what is the nearest footprint you can find for the capacitors you’re using?
I’m using the mod_capacitors from smisioto (and a lot of other footprints from this mighty library). Those are all 2.54 mm (or a multiple of it).
That means, I’m using e.g. 5.08 mm distances for all my components (resistors, coils, capacitors, transistors,…).
The closest I’ve seen in the “pretty” series is 5mm.
Whatever others might think, I still prefer to layout my PCB’s on a 2.54mm raster, rather than a raster aligned on mm. Especially because all the IC’s in DIL format (and many, many other components) are still on a 2.54 raster.
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In opengl mode you do not need to have everything on raster. Tracks snap to the center of the pads. (Don’t know how this is in legacy canvas)
Worst case you have a short trace somewhere that is used to change between rasters.
I’ve got a board with this issue of imperial to metric.
I was able to flip between the different grids imp/met in OGL and use the interactive router to mesh the two together.
It was not easy.
Someone needs to invent a breadboard for metric SMD devices then I can be happy.
I just place all my components on 0.25mm or 0.05mm grid. (First placement on the 0.25mm grid then i reduce it down to 0.05 if i need to get a trace somewhere where a component currently is.)
It does not matter if the pads of this component are on imperial or metric grid. The traces snap automatically. (This was the core information of the post you quoted.)
While i lay down traces i stay at 0.05mm grid. (This means my vias are all on this grid as long as i do not use the interactive drag function which ignores the grid.)
The only application i can think of where you might need imperial grid is when you have external constrains given in imperial units. (Then it makes sense to design the complete PCB in imperial and have metric footprint pads of grid.)
The footprint editor is a different story.
Is when you are a born American and can not easily visualize metric “things”.
Oh, and where is that Metric Spaced Breadbard?!
For whatever reason, some parts are still cheaper, and more available, in Imperial sized parts.
For what it is worth, providing the holes are sufficiently large, 0.04mm will not make much difference on a 2.5 mm pitch component.
If you are really desperate to have imperial pitch size, use the nearest metric part you can find, set the center at 1.25mm from either pad, then switch to imperial settings, and move the pads to sit 0.1" either side of the centre. Similar reasoning applies to 5.08, 10.16 pitches etc.
Save them to your own library, maybe Capacitors_Imperial? The 3D will not be quite right, but at least the board and devices are guaranteed to fit each other.
In practice it only really becomes an issue with large pitch errors such as 20 pin SIL headers. They do need to be on 0.1" pitch, as the error over 20 pins becomes 0.76mm by pin 20. However most common connectors are given in 2.54 pitch or 2.5, 5.08 or 5 etc in the libraries.
All breadboards I’ve seen have metric spaced holes, 2.54mm apart 
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I meant what physical capacitors do you use?
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I was quite amazed that even the old Mullard C280 “tropical fish” capacitors were actually hard metric.
The tolerance in the lead out dimensions of most radial capacitors is so bad that the difference between 2.5 and 2.54 multiples only becomes an issue at around 20mm
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I also think this does not matter most of the time. Maybe when you have large film capacitors with stiff legs they can be more picky to be properly seated flat against the pcb. The free standing ones are more tolerant, like the ones you mentioned. It’s not given that there’s a metric footprint for all given imperial values in someones datasheet, though. All though, yes, I highly doubt there a datasheet with lead spacing for a capacitor given in inches, or parts of inches.
I have learned to get the digital micrometer out and check fussy parts with short or stiff legs for pitch and lead diameter. Datasheets are often wrong, I suppose manufacturing changes don’t find there way back into the datasheet
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