Internal cut out came out wrong  - Page 1
Forum section: electronics / general

author: CCB
author_rank: Unknown
timestamp: August 17, 2017, 08:56:55 am
content: Hi Everyone,I spent a bit of time learning to use Kicad and I've just had my first PCB arrive back!I was pretty excited until I saw the internal cut out wasn't what I was expecting.I used 2 circles and then a shape to join them togeather. Did I do this wrong? I assumed the mill would cut the circles and then bit between them? I put these on the edge cuts layer the same as the outside of the board.I checked the gerber files with a non kicad viewer (not 3d) and it looked ok.I've manually cut the section out but it makes be wonder for the next board where I went wrong? Any suggestions or how to? Does this need to be merged in to one shape?Thanks,Carl

author: ElectronicCat
author_rank: Regular Contributor
timestamp: August 17, 2017, 09:20:09 am
content: Is that an OSHPark board? If so, check out theinternal cutout guidancepage and generalKiCad help page. At least it looks like an easy fix.

author: Rerouter
author_rank: Super Contributor
timestamp: August 17, 2017, 09:32:15 am
content: While i agree it should have conveyed it, I would have used arcs, In the past i have marked with text on the layer "cutout area",

author: CCB
author_rank: Unknown
timestamp: August 17, 2017, 09:46:24 am
content: Thanks, I got them made by Elecrow. The pricing is great and the apart from the cut out I'm happy with the quality.I think I might try to use a single shape with arcs like you suggest and mark it with 'cut out' text next timeAt least now I know.

author: firewalker
author_rank: Super Contributor
timestamp: August 17, 2017, 09:52:02 am
content: You should check Elecrow page for cututs. The rules above is for OSHpark.Alexander.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: August 17, 2017, 07:20:11 pm
content: Yes, always ask the fabber for how to specify milling.https://www.elecrow.com/wiki/index.php?title=Q%26A_for_PCB_serviceQuoteNot sure if that applies to internal cutouts, but would if they applied that rule might be consistent with what you received. Or maybe they just got confused as to what they are seeing. Gerbers do not convey the information well.Either way, I would draw the cutout as a single contour. You might find it easier to draw a DXF and import it.

author: tycz
author_rank: Regular Contributor
timestamp: August 18, 2017, 03:02:36 am
content: Quote from: CCB on August 17, 2017, 08:56:55 amYou wanted only one shape cut. Instead of drawing the shape you wanted, you drew three different shapes on top of one another. The CAM engineer/operator (who is a human, not a machine) was confused by this. Try to be unambiguous next time.

author: rs20
author_rank: Super Contributor
timestamp: August 18, 2017, 04:11:45 am
content: You specified the shapes incorrectly. You wanted a single shape consisting of 2 arcs and 2 lines, forming a single, simple, closed shape defining the hole. Instead, you sent a whole mess of self-intersecting shapes such that no human or machine can unambiguously figure out which parts of the board should be present or not.Specify your edge layer such that EVERY line and arc actually delineates a border between PCB and air (unlike, for example, the horizontal lines in your picture which delineate absolutely nothing, they are supposed to have air on either side of them), and such that every line/arc is connected to precisely one other line (unlike, for example, the points at the end of your horizontal lines which have FOUR lines/arcs intersecting at a point, what the hell is that supposed to mean?) and you'll have no problems.I mean, I bet you were thinking while you were drawing this at the design stage, "Iassumethey'llgetwhat Imeanby this, right? Right?". Well, now you've learned an important lesson for delivering engineering design artifacts -- never leave any scope for misinterpretation.