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Electronics => PCB/EDA/CAD => KiCad => Topic started by: tehmeme on November 04, 2013, 04:38:06 pm

Title: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 04, 2013, 04:38:06 pm
After listening to the AmpHour podcast featuring Mr Himpe, he briefly mentions his dissatisfaction with KiCad and OSS in general but also mentions that KiCad is unable to generate gerbers correctly. (I hope I haven't put words in his mouth)

I have done a brief search for any such specific issues but was unable to come up with anything in the later versions.

I'm currently working on a slightly more involved project than usual and decided to try KiCad.
(I usually work with Eagle light )

So far the UI, nomenclature, work flow quirkiness were easy to get over by reading the manuals, FAQs & howtos and customising it to my needs.

Gerber generation will be one of the final stages of my design and do not really want to be stonewalled at that stage, so could someone with more experience using KiCad please enlighten me to what the gerber issues are?

Should I continue with KiCad or move onto another tool before I spend too much effort on this?
The alternative would be to purchase an Eagle license since my design exceeds it's free license limitations.

Thanks in advance,
Teh
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: djsb on November 04, 2013, 08:16:54 pm
There aren't any issues with gerber output that I'm aware of. I regularly use Kicad and have been doing so for over 5 years.
I've sent the generated gerbers from Kicad to an outside board house and also used it on LPKF's CircuitCAM.

David.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: PChi on November 04, 2013, 09:56:18 pm
KiCad generated good Gerber files for me but I did find that the viewer didn't work properly for me. I used GCPrevue (free and I had used it before) to view the Gerber files and had PCB Pool manufacture a couple of double sided designs which worked OK.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 05, 2013, 12:13:35 am
Thanks for the responses.

I think I might stay with KiCad hopefully any issues I face will be standard issues I can deal with.
cheers
Teh
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: c4757p on November 05, 2013, 12:16:45 am
I remember him saying that slots don't output correctly. I believe he is correct - they never look right in Gerber viewers for me. Usually, I exclude them and specify the slot separately on a mechanical layer.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 05, 2013, 12:31:31 am
Quote from: c4757p on November 05, 2013, 12:16:45 am
I remember him saying that slots don't output correctly. I believe he is correct - they never look right in Gerber viewers for me. Usually, I exclude them and specify the slot separately on a mechanical layer.

Thanks c4757p, I'll keep that in mind. That's very useful to know.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: HackedFridgeMagnet on November 05, 2013, 12:49:31 am
I had a quick go at putting slots on a module, it seemed to render ok in 3d viewer and gerber viewer.

Any further info on this? I am using a pcbnew version marked 28th of Sept 2013.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: c4757p on November 05, 2013, 01:11:29 am
I just tried a slot in a very recent testing version (Oct. 29). This is what it outputs for a 1x3mm slot (excerpt with relevant commands) - I think it may be fixed. Anyone who knows more about Excellon format want to comment?

Code: [Select]
G90
G05
T1C1.000
X144.018Y-83.836G85X144.018Y-85.836

G85 (buried in the last line, if you missed it) is the "slot" command. There are a couple other ways that can do it as well - I believe what KiCad used to do is to specify that the drill bit be dragged down the length of the slot (quite bad for the type of bit used).

From the way old versions used to work (not just the slots), I got the impression that the KiCad people thought Excellon was just a funny vector graphics format...
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: free_electron on November 05, 2013, 01:18:19 am
slot data should be exported in a separate file to begin with .

Anyway. Kicad evolves. My comments are based on Kicad 2 years ago (when i played with it last time)

i don't have time nor the desire to test that stuff. My current tools works perfectly fine thank you very much.
i have no desire to be the guinea pig for all that stuff, nor do i want to spend time double checking and second-guessing everything.
My current tool is 1 click of the button and any board house knows how to process the output.

Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: c4757p on November 05, 2013, 01:20:57 am
Quote from: free_electron on November 05, 2013, 01:18:19 am
slot data should be exported in a separate file to begin with .

I remember you saying this before. I've never heard it anywhere else, though. I asked ITEAD how they preferred slots and was told to put them on a mechanical layer - probably because they take a lot of boards from novices who mess them up. How standard is that?
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: HackedFridgeMagnet on November 05, 2013, 01:26:02 am
In the test I just did, I did get a 2nd excellon file. (.drl) for kicad.

I have no idea of what it should look like but here it is.


Code: [Select]
M48
;DRILL file {Pcbnew (2013-09-28 BZR 4356)-product} date 5/11/2013 11:45:09 AM
;FORMAT={-:-/ absolute / inch / decimal}
FMAT,2
INCH,TZ
T1C0.055
%
G90
G05
M72
T1
X2.4791Y-3.8775G85X2.6209Y-3.8775
G05
T0
M30
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 05, 2013, 01:52:33 am
Quote from: free_electron on November 05, 2013, 01:18:19 am
...
Anyway. Kicad evolves. My comments are based on Kicad 2 years ago (when i played with it last time)

i don't have time nor the desire to test that stuff. My current tools works perfectly fine thank you very much.
i have no desire to be the guinea pig for all that stuff, nor do i want to spend time double checking and second-guessing everything.
My current tool is 1 click of the button and any board house knows how to process the output.

The question was born from wanting to gain insight of any problems i may face and not in any way intended to question your experience with KiCad. Thanks for clarifying. :)

I also agree with you about having the best tool for the job as per that project's parameters and constraints.

I don't want to be wasting my time either, nor do I want to try every tool out there.
The last time I worked as an EE professionaly I also used the tool best suited for the job and had the budget for it. Alas, I am now a hobbyist and as previously stated, if KiCad doesn't pan out I am willing to shell out for a paid lic.

Of course I would prefer not to spend any more money on something I am no longer doing professionaly if I could spend a little more time to work around it.

Sorry about the couple of people on the other thread that have missed the point and taken your words out of context.

cheers
Teh
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: alm on November 05, 2013, 06:30:45 am
One thing to keep in mind is that Vincent was likely not comparing the output to other hobbyist tools like Eagle, but to a professional tool like Altium. So don't automatically assume that Eagle will fix whatever flaws Kicad might have.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: miceuz on November 05, 2013, 07:47:23 am
Quote from: tehmeme on November 04, 2013, 04:38:06 pm
After listening to the AmpHour podcast featuring Mr Himpe, he briefly mentions his dissatisfaction with KiCad and OSS in general but also mentions that KiCad is unable to generate gerbers correctly. (I hope I haven't put words in his mouth)

I've recently put three boards made with kicad thru seeed -- all of them came out without any problems. BTW, I'm using trunk build of kicad. If you just download and install it, you'll probable get some ancient "stable" version they released like 3 years ago - maybe that one had some problems?
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 05, 2013, 05:24:09 pm
Thanks all for the re-assurance. I've already completed the schematic a few days ago at least I can now be confident in proceeding with pcbnew.


Quote from: alm on November 05, 2013, 06:30:45 am
One thing to keep in mind is that Vincent was likely not comparing the output to other hobbyist tools like Eagle, but to a professional tool like Altium. So don't automatically assume that Eagle will fix whatever flaws Kicad might have.

That's a good point, I mention eagle because I have had no major problems getting PCBs made using it. (granted they were nothing too complicated, just a few vanilla boards.)

The gerber format is fairly standard and is the linchpin of my communication with the pcb fabricator. Therefore whether using altium, eagle, kicad (or protel 99/se  & Proteus back when this was my job) the gerber output should be reliable and the same across the board (pun intended).  edit: I am aware that all tools have their own unique set of quirks and bugs that either get fixed or I can live with, and if I can't then I use an alternative.

I'm pleased that whatever the issues were, they were dealt with.
After starting this thread i started to look deeper into the proposed future developments and contributors to kicad, if they are implemented correctly kicad will reach maturity fairly soon, and the quirks will be replaced by new ones.  >:D

I look forward to it.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: HackedFridgeMagnet on November 05, 2013, 10:27:36 pm
I use Kicad and think it is a great program.

One thing I would suggest though is to use source control on all your project files and all your library files. They are all text and I find this very useful in differencing any changes I make, whether they be intended or unintended.
I use SVN with the Tortoise addons for this source control but there are others such as GIT.
Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: HackedFridgeMagnet on November 05, 2013, 10:44:09 pm
BTW I just got some boards back with slots in them that were manufactured correctly.
But these were done on a hardware layer as c4757p mentioned.

I think the bug must have been when the slots were part of a module placed onto the board.
Currently there is a check box to add the pad to a mechanical layer and it seems to work and gives the extra excellon file.
So as far as I can tell the bug is fixed as of Sept 2013, and probably well before.
If anyone could link a logged Kicad bug in, I would be interested to see it.




Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: tehmeme on November 06, 2013, 12:25:16 am
Quote from: HackedFridgeMagnet on November 05, 2013, 10:27:36 pm
...
One thing I would suggest though is to use source control on all your project files and all your library files. They are all text and I find this very useful in differencing any changes I make, whether they be intended or unintended.
I use SVN with the Tortoise addons for this source control but there are others such as GIT.

Thanks for the suggestions, I'll have a look at it when i get some time.



Title: Re: What exactly is wrong with KiCad's gerber output?
Post by: Dago on November 09, 2013, 10:46:50 pm
I have never had any problems with KiCADs Gerber output files. I've sent them to three different factories so far without any difficulties.