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How to communicate 3d CAD with complex surfacing?

  1. Oct 12, 2015 #1
    Hello everyone

    I am sure the answer to this would be on the internet but I can't seem to find much.

    When we create a complex 3d cad (examples include Aerodynamic Helmet of a cycle biker, computer mouse, exhaust fan blades etc) that includes complex surfacing in cad, how does one communicate the designs to others in the PROFESSIONAL world? Example to mold or tool makers?
    Is it by directly by sending the relevant 3d cad files in iges/step files?
    How does one dimension such complex geometries on 2d drafting (autocad or pdf)?

    Also how does one represent it in company documentations (say for ISO type quality control )
  2. jcsd
  3. Oct 12, 2015 #2


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  4. Oct 13, 2015 #3


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    Step is well recognized by most CAD software, some with good feature recognition capabilities can actually recreate the build path. I had personal issues with IGES.
    Non-geometric surfaces are not usually dimensioned as it makes no sense, and would generally lead to confusion as reference points/geometries are interpret-able.
    In documentation, sometimes you just refer to a CAD file.
  5. Oct 13, 2015 #4


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    As Lok said you might refer to a CAD file.

    Alternatively, you will (I assume) need to inspect the manufactured part. The inspection data will be described on a separate drawing or an inspection sheet. For FDA or ISO compliance, a reference to that inspection drawing/sheet is sufficient.
  6. Oct 13, 2015 #5
    @ Lok: Thanks for the reply.
    What does non-geometric surface mean? Cosmetic features with no engineering importance?

    @Bandit127: Thanks for the reply
    I have heard about this. Try to quanitify certain features such as mating parts, box dimensions, certain ratios etc
    Can you give an example? Some you have worked on (that you are comfortable to share with) ? Or something online. It'll be great
  7. Oct 14, 2015 #6

    Ranger Mike

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    I have sold metrology instruments and equipment since 1980. Your question is typical in my sales world. CAD computer assisted design. The CAD file is typically sent to the CAD ( computer assisted manufacturer) department where the tool path is programmed to actually mill, shape, drill the part. Next, the part is placed on a CMM (coordinate Measurement machine ) and the production part is inspected and compared to the CAD model in real time. I can go into minute detail if you like but this is the general process in the chip cutting world.
  8. Oct 15, 2015 #7
    @Ranger Mike:
    I forgot about CMM. I guess there are laser scanners too.
    Of course it'll be expensive for hobbyist like me.

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