Design for Assembly in KiCad | Hacker News Reader

Design for Assembly in KiCad

rheingoldheavy.com

27 pointsunwind11 comments

This is a great article. Just this year I've become partially involved in hardware design again after some years now doing mostly just software - it's amazing how cheap fab options are these days!

I recently got a few quotes for contract assembly of some small boards, ~100 SMT parts each and the prices ranged from $12 to $200 per board. Hand-assembled, because the quantities weren't sufficient for pick & place.

I didn't see any mention of KiCad's DRC rules, how does this compare with EAGLE? Specifying solder vs paste mask clearances is something I briefly agonized over but it seems Eagle has sane defaults there that worked out okay in the end.

Back when I decided to pick an economical design tool, I had a four layer board to design and the price was right with KiCad, so I never got into using EAGLE. The clearance issue is one that I do have to wrap my brain around each time I do it, just like pin spacing on custom footprints. I put that down to my own personal issues with keeping three digit numbers straight in my head though, rather than any particular problem with KiCad in general. That's why I consider doing the Gerber visual diff so vital, because it's very easy to tell when you've screwed up the solder vs. paste clearance.

Great article. It has been a few years since I last laid out a board in KiCad, the biggest thing I remember is that importing parts and footprints took a lot of work and it wasn't a very straight forward process.

Does anyone have a good workflow for managing and exporting parts so that people can go and download your cad files and libraries to reproduce your board?

Have you checked out the KiCad library on github[1]? That library is installed with the install script that is included with KiCad I believe when you downloaded the bzr repo. The library maintainers seem to work pretty closely with the KiCad developers. I have started using KiCad for personal projects and have been following the KiCad development for about 6 months now and from what I have gathered there has been a lot of changes in the last year. I would definitely suggest giving it another try in the near future. It also seems that the way footprints and 3d models are handled has changed in the last year.

As for specific help for KiCad, they have a very helpful irc channel on freenode, there is a KiCad yahoo users group, and I just found this website with videos: KiCad.info

There hasn't been a stable release in a while but the developers seem to be serious about making a new stable release in the near future.

[1] https://github.com/KiCad/kicad-library

Chris Gammell of The Amp Hour is also getting http://kicad.info off the ground and there are some really great people providing advice in there.

I've gotten burned too many times using the built-in libraries (hidden pins in EESchema not being connected to PWR/GND / incorrect pin spacing in CvPCB) so I throw those together by hand now. In EESchema I would have done it anyway, just to get the pins arranged in a way that makes my drawing look purrrrty, but the drawing/verifying of footprints does get tedious.

My understanding is that some features were removed (or significantly modified) in subsequent releases of KiCad post the version I'm using (BZR 4022), specifically the BOM export, so I haven't bothered installing another version yet. I have a series of designs about to go into production so I'm leery to change up before those boards get committed for assembly.

This is the first time I have seen the KiCad library on github, that would presumably make sharing generated footprints and parts easier. For the board I produced of in 2011, I shared my library on sourceforge as a zip with no clear installation directions. I mostly learned KiCad from David Jones nice tutorial[1].

I'll check out KiCad in a few days to see how easy it is to share a design with someone else, to see with the latest version if library parts can be easily shared. Thanks for the links and helpful suggestions of consulting the IRC channel for support, I wouldn't have considered the IRC channel.

[1] http://www.alternatezone.com/electronics/files/PCBDesignTuto...

That's a brilliant document! Very thorough!

not exactly yet for import/export parts, but I feel the need for better online interactions with parts too. So, I started working on a small project to make this easier last weekend. First prototype: http://pinboardjs.divshot.io/ - what do you think? does this first sketch speak to you?

great introduction, and impressive depth. thanks for sharing! I wonder what you think of e.g. online tools for PCB design like upvertert.com

I like the idea of an online-for-the-masses EDA tool, but I've actually done layout on a laptop in my father's house with no internet connection. There's no way I could cobble together a schematic without being able to look at datasheets, but the PCB layout and routing doesn't necessarily need to be always-connected.

I tried using Upverter either earlier this year or late last year, can't remember when, and I just remember that I struggled with the interface. That's not a smack on Upverter though, just an incompatibility between the tool and the idiot trying to use it :)

Thanks! Good point, the web supports interaction with datasheets and conceptual work, less with the implementation of a PCB. On a sidenote, I was working on a small (open-source) project the last days to support rendering pin layouts of boards, and maybe address problems with datasheet interaction. A first sneak preview is here: http://pinboardjs.divshot.io/ - I need to document it, but it would be great to hear what you think, if it speaks to you, or not at all.

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