Tying Lines ends with shapes

Layout
1

I want to connect the trapezoid shown in the attachment, to the inner circle and then (perhaps) remove the inner chord transcepted by the trapezoid to create a solid figure. If you run the design rules check on the PCB you will see that the left line end does not meet the circle and I have incomplete closure on the polygon.
Is there a way to complete the connection?
Thanks
Fritz
(upload://iK3yYNjVoyQhUpCFnaRNZ6TwjHa.zip) (22.9 KB)

2

Upload again or fix the link, it’s not a link ATM…

3

Can you tell me where the upload button went? I only see “link” at the bottom near reply
thanks
Fritz

4

I believe its drag and drop to upload

5

Thanks John. That was what I tried to begin with and it produced the invalid result that eelik mentioned. However when I went to do the reply this time I got a more extensive menu at the top of the post with an upload arrow. Result is below–lets see if it works.
thanks again
Fritz

UV_ring.zip (22.9 KB)

6

You have to replace the inner circle with an arc.
Then you can line up the end points of the arc with the two open line ends.

KiCad’s mechanical CAD capabilities are not the greatest, but this is still quite doable and easy for this PCB as long as you know KiCad’s limitations in mind. The inner and outer circle of your design are also not concentric. Is this by design?

Outer circle:
image

Inner circle:
image

I modified your project a bit. What I did was:

  1. Make note of the (5.75, 5.5) coordinate of the inner circle.
  2. Delete the inner circle.
  3. Replace it with an arc which is “approximately right”.
  4. Drag the start point (left side) of the arc to the end point of a line.
  5. Drag the end point (defines arc angle) to the end point of the other line.

Then it still did not render properly in the 3D viewer.
Zooming in on the upper left corner reveals a discrepancy of about 1mill:

image

  1. Because the end point of the arc can only be defined by the “angle”, I took the endpoint of the line and snapped that to the endpoint of the arc. After that I can view it in the 3D viewer without problem.

image
image753×524 47.5 KB

Writing this down (10 minutes?) took much more time then drawing the arc itself (Maybe 2 minutes?) The main trick is making use of what KiCad can do easily, and find the appropriate workaround for the “weak points” in KiCad. A good origin for a circular PCB is to either put the main center point at (0, 0) and then ignore (or modify) the page layout, or use (127, 127) which is also (5in, 5in) as the origin.

7

Thanks Paul
lots of interesting issues here. Indeed building a complete CAD into KiCad would be daunting and I thank you for the work around.

1-First you are correct regarding my centers-I moved the centers while playing with this-I indeed want concentric circles.

2-based upon your post I think I can assume that there is no tool or way to snap a line to fall onto a circle unless the geometry happens to provide a point on the circle that is also on the grid. Is that correct?

3-I tried an alternative approach here-use only the circle tool ( which I prefer) and simply draw the trapezoid separately and then move it to overlap it well into the copper formed by the circles (see attached). The polygon ends meet as expected but when I try to Cu fill the blank areas I cannot. So this seems more like a question about the fill tool capability.

Thanks again for your post and time-
fritz

UV_ring.zip (23.6 KB)

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  1. OK.
  2. Snapping in KiCad is very limited. Apart from the grid, you just have the control points of graphical objects, which show up as small squares when an object is selected. So it mostly is endpoints and the centers of arcs and circles. There is (at the moment) no snap to the mid points, intersections etc. An additional limitation is that snaps between graphical objects only work within the same layer.
  3. This does not work. The rules for Edge.Cuts are quite strict. The endpoint of a graphical object must be the startpoint of the next. Overlaps are not allowed, so you have to use an arc for the inner part.
9

Thanks Paul-the arcs are no problem.
Fritz

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@fsonnichsen
you may try to have a look to KiCAD StepUp for a mechanical collaboration between ECAD & MCAD

uv-ring-FC
uv-ring-FC1787×1517 273 KB

uv-ring-KC
uv-ring-KC2230×1206 250 KB

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Using an external mechanical CAD program is a good solution for complex PCB outlines (FreeCAD + StepUp works, but any program that can export .DXF works too) But I do consider it overkill for this PCB outline. This one is still easily doable with the drawing capabilities of Pcbnew itself.

12

The OP’s pcb seems it would need to be integrated in a mechanical enclosure/box…
so IMO it would benefit from a MCAD approach, at least with a 2D CAD modeler or even better with a 3D real CAD environment.

13

Thanks all. Paul’s response will work here to make the board. These are mounted into a lens assembly which is drafted with Inventor.
Fritz

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Relating to this—I think there is a Grid:Create Array option in KiCad for circular arrays but I cannot find it. Can someone enlighten me here?

thanks
Fritz

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in v5.1.10 you do right click -> create array:

image

image

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OK-now I see it-
thanks
Fritz

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