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part rotation help

charliex

Hello,

 

I'm writing pick and place software, and I just realised something as i work through a test board. I have a board where theres a 1206 led and a 1260 resistor, the rotation of the led is 270o and the resistor is 90o but they're - | orientation on the board, which at first made me scratch my head.

 

So i realised the parts must have been created where one was origin of | and the other was --  on checking thats indeed the problem.

 

So how do board places deal with this (or typical PNP software )? I realise an answer is always use the same orientation for parts, but i looked over a few libraries and they're all  various origins. Do they manually edit the rotations?

 

 

thanks

  • charliex schrieb:

     

    I'm writing pick and place software, and I just realised something as

    i work through a test board. I have a board where theres a 1206 led

    and a 1260 resistor, the rotation of the led is 270o and the resistor

    is 90o but they're - | orientation on the board, which at first made

    me scratch my head.

     

    So i realised the parts must have been created where one was origin

    of | and the other was --  on checking thats indeed the problem.

     

    So how do board places deal with this (or typical PNP software )? I

    realise an answer is always use the same orientation for parts, but i

    looked over a few libraries and they're all  various origins. Do they

    manually edit the rotations?

     

    Basically, all you need is the (relative!) rotational angle between the

    parts orientation in the EAGLE library (where the rotation in the design

    files references to) and the orientation in the feeder of the machine

    (where the rotation in the P&P program refers to).

     

    The way we deal with that: When generating P&P programs, we always use

    our "EAGLE library orientation" as the base. Then we simply declare the

    feeder orientations as related to those in EAGLE. Examples: Resistors in

    our EAGLE lib are "--", as well as in the feeder, so the feeder

    orientation is defined as 0 degrees. Diodes in our libs are defined as

    "|>|", while in the feeders they are "|<|", so we simply enter them as

    being 180 degrees in the feeder. ICs in vibration feeders are declared

    as 270° (pin 1 first) since in our libs they always have pin 1 left.

     

    If we get P&P coordinates by external parties, we need to have a look at

    their orientations (for every package type) to find out how they are in

    their libraries. After that, the process is exactly the same.

     

    HTH,

    Tilmann

     

     

  • in reply to Former Member

    I might be missing something so bear with me. How do you know the relative rotation between the library and the board ?

    C:\

    Fullscreen contentimage_174616.html Download 
    <html><head><title>Jive SBS</title></head>
<body><font face="arial,helvetica,sans-serif">
<b>Error</b><br><font size="-1">
An general error occurred while processing your request.
</font></font></body></html>

     

    So here are my two parts, say 1206 resistors as created in the library editor, one is created as north/south, one is created as east/west . I use each of these symbols on my board and i want them both to be east-west, the first one i rotate 90o, the second one i don't. so one has a 90 degree rotation in eagle, one doesn't. To the best of my knowledge, eagle doesn't know what orientation i've created that part in, so how can i know its not rotated

     

    thanks

    charlie

  • in reply to charliex

    charliex schrieb:

     

    I might be missing something so bear with me. How do you know the

    relative rotation between the library and the board ?

    C:\ Image:test.png

     

    There is no image in your post, just the above text.

     

    However, the relative rotation between library and board simply is the

    "angle" property of the part. You can view that information with the

    INFO command, and it is also contained in the files generated by "export

    partlist" or all those P&P ULPs.

     

    So here are my two parts, say 1206 resistors as created in the

    library editor, one is created as north/south, one is created as

    east/west.

     

    If you have two identically named packages with different orientation in

    your libraries, you indeed have a problem. Correct your libraries.

     

    I use each of these symbols on my board and i want them

    both to be east-west, the first one i rotate 90o, the second one i

    don't. so one has a 90 degree rotation in eagle, one doesn't. To the

    best of my knowledge, eagle doesn't know what orientation i've

    created that part in, so how can i know its not rotated

     

    Your libraries need some minimum of consistence...

     

    Advice: create one single library that serves as a package database. If

    you change something, change it here, and UPDATE all other libraries

    accordingly. Use one single orientation scheme for all packages, i.e.

    SMD discretes always horizontally, SOIC/QFP/QFN always with pin 1 in the

    lower left corner etc.

    That way, you save yourself a lot of time and avoid many problems...

     

    Tilmann

     

  • in reply to Former Member

    > There is no image in your post, just the above text.

     

    That's odd, must be the the multi interfaces for the forum/nntp http://imgur.com/WJvEO

     

     

    I understand how to extract the angle, thats not the problem. I'm writing PNP software for a machine that people send pre made files too, so i'm not in control of the source. This must happen for commercial stuffing houses too, where the orientation is different. I checked a few different libraries to see if there are different rotations, and it seems quite common.

     

    I was hoping someone had some insight into that process, or if it was all just a manual process where they check and updated the files in the PNP software, or supplied centroid/rotation files.

  • in reply to charliex

    charliex wrote:

    >> There is no image in your post, just the above text.

     

    That's odd, must be the the multi interfaces for the forum/nntp

    http://imgur.com/WJvEO

     

     

    There are two methods  to include images when using  Element14 and only the

    true attachment makes it to nntp. The inline images dont get passed. We are

    promised a fix.

    --

    Viewed / responded via the newsgroup at

    news.cadsoft.de

     

     

     

  • in reply to charliex

    charliex schrieb:

     

    I understand how to extract the angle, thats not the problem. I'm

    writing PNP software for a machine that people send pre made files

    too, so i'm not in control of the source. This must happen for

    commercial stuffing houses too, where the orientation is different. I

    checked a few different libraries to see if there are different

    rotations, and it seems quite common.

     

    I was hoping someone had some insight into that process, or if it was

    all just a manual process where they check and updated the files in

    the PNP software, or supplied centroid/rotation files.

     

    Of course it might also be possible to determine the maximum extensions

    of the package (definition from the library) in x/y direction from its

    pads within a ULP, and then assume some rotation. However I fear that

    would easily become somewhat complex, and there is no chance to detect

    the orientation of diodes or tantals this way.

     

    The easier (and safer) way definitely is knowing your libraries. If you

    just get board files, you can still find out the original angle by

    looking at the placement angle and your visual image. If you only get

    x/y/angle data, you can still compare that to a paper printout showing

    the parts and their orientation on board, and extract the "reference

    angle" from that.

     

    I assume that stuffing houses do the same. When we get data for board

    production and SMD assembly, we always also get some documents (PDF or

    paper) showing the desired orientations, which we can use as reference

    and check our PNP program against. Sometimes, we also get a sample.

     

    I don't think you can (reliably) automate this process.

     

    Tilmann

     

  • in reply to charliex

    charliex wrote:

    >> There is no image in your post, just the above text.

     

    That's odd, must be the the multi interfaces for the forum/nntp

    http://imgur.com/WJvEO

     

    >

    I understand how to extract the angle, thats not the problem. I'm

    writing PNP software for a machine that people send pre made files

    too, so i'm not in control of the source. This must happen for

    commercial stuffing houses too, where the orientation is different. I

    checked a few different libraries to see if there are different

    rotations, and it seems quite common.

     

    I was hoping someone had some insight into that process, or if it was

    all just a manual process where they check and updated the files in

    the PNP software, or supplied centroid/rotation files.

     

     

    This doc may help

    http://frontdoor.biz/PCBportal/ResolvingComponentPolarityProblems.pdf

     

    --

    Viewed / responded via the newsgroup at

    news.cadsoft.de

     

     

     

  • in reply to Former Member

    thanks. i guess all the stuffing houses just do it manually. internally we'll just have our own verified parts library and rotate the part to match the tape its fed on.