EEVblog Electronics Community Forum
Electronics => PCB/EDA/CAD => KiCad => Topic started by: phil from seattle on October 29, 2020, 08:20:40 pm
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As I get deeper into KiCAD...
In PCBNew, I am struck by the way they present it as a drawing. I don't see the point of that. Do people actually print it out as paper document? Seems rather odd. But, I ignore it.
What I'm having trouble with is the fact that the origin is in the upper left hand corner of the document frame (actually slightly outside). I can (and do) set a "user origin" by carefully positioning the cursor over the grid origin (that I put in the upper left hand corner of my PCB) and hitting the space bar. So then the dx, dy numbers are relative to that point. Just don't hit the space bar ever again or I have to reset the user origin. Seems oddly user unfriendly.
Is there a way to reset the origin (the one that X and Y at the bottom ceneter of PCBNew are relative to)?
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The space bar method is used for making relative measurements, and you are intended to set the origin at will for such measurements.
What is it you are trying to measure? There is a dimension tool in the RHS toolbar.
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Kicad 6 will have settable origin vectors.
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I use it in general to understand where things are or will go. I use properties to set exact location of things. So I wind up having to use a spread sheet to get precise location relative to the document origin, not the board. For example, I have a daughter card format that I use in a number of different designs. It needs to be aligned to the board's mounting holes (for external alignment). I want to ensure the daughter card's mounting holes are precise relative to the connector. It would be great if I could just set the origin to a corner of the board and work from there.
I'll take a look at V6's stuff when I get some time.
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Yep, that's what I did in a recent project where I try KiCAD 5.99. I use the drill/place origin set to the bottom-left corner of the PCB as origin. Seems to work fine.
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AFAIK, In most of CAM programs as well on CNC machines (refer to CAMBAM) the origin of the work is at the lower left corner of the stock, e.g at table level however the "altitude" is configurable to deal with your CAD software.
This is my simple view of the question: Kicad outputs being electronic documents for manufacturing and not for machining, the origin is at the surface of the corresponding layer, e.g; without "altitude".
In Pcbnew, the origin(s) can be set with two buttons:
Grid origin, [attachimg=1] that is recommended to be set with a big (e.g. 2.54mm or 2.5mm) scale because it's easier to do and to point to the exact point, it defines the positioning of the drawing grid. Useful for recentering the grid when a fine pitch has been used for some reason or a part is defined in metric units while the grid is in inches. I recommend to do this first because all the following operations will snap to this grid.
Machining Origin = "auxiliary axis origin": [attachimg=2] is the origin of the machining operations. This origin, when correctly set then properly configurated in the plot parameters allows to restrict the plot to the active area, referenced where this origin is set. If your layout plot is unreferenced, the result will include a huge useless area referenced to the top left cormer.
Try to first, accurately set the (drawing) grid to the point where you want the layout coordinates to be referenced to (last right button).
Second, set the auxiliary axis origin by clicking on the button above, then place your cursor at the place you want to set it, it will snap to the grid: ONE click only (otherwise the second click will move the point); escape.
Now to properly configure the plot origin, click on the plot button, configure the plot and drill operations as this is mentioned here: [attachimg=3] and here for the drilling operations: [attachimg=4].
All done! Now when you'll plot the tracks and generate the excellon files for drilling, all the machining operations will start at the origin (auxiliary axis) you've set and you'll no longer have a small layout included in a wide blank area.
PS Sorry, I can't manage to insert the pictures in their right place.
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As I get deeper into KiCAD...
In PCBNew, I am struck by the way they present it as a drawing. I don't see the point of that. Do people actually print it out as paper document? Seems rather odd. But, I ignore it.
What I'm having trouble with is the fact that the origin is in the upper left hand corner of the document frame (actually slightly outside). I can (and do) set a "user origin" by carefully positioning the cursor over the grid origin (that I put in the upper left hand corner of my PCB) and hitting the space bar. So then the dx, dy numbers are relative to that point. Just don't hit the space bar ever again or I have to reset the user origin. Seems oddly user unfriendly.
Is there a way to reset the origin (the one that X and Y at the bottom ceneter of PCBNew are relative to)?
turn off the frame and draw where you want the pcb?
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Thanks, that is helpful. I ran into the issues with gerber, BoM and place file generation just last night so your post is quite timely. Still working though how to get a place file without lots of editing. It's frustrating when the bits and pieces of UI are spread all over the place. At least I was able to get everything working so I can submit a job to a PCB house.
But then, every other CAD package has it's share of arcane and obscure interfaces. I don't think Intuitive and CAD are possible together.
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turn off the frame and draw where you want the pcb?
In KiCad the "Page Layout" is a separate file.
You can choose which file to use as layout with:
Pcbnew / File / Page Settings
If you do not have an "empty" page layout file, you can start the "Page Layout Editor" (Most right icon from the KiCad Project Manager), then load any existing file, delete it's contents and save the new file under a different name.