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  1. Ryan6338

    ASME Y14.5 vs ISO 1101 in Australia / internationally

    Daniel, if you're interested in learning ISO GPS I'd recommend reading "Technical Drawing for Product Design by Stefano Tornincasa". It contains - in my opinion - a great functional overview of the ISO system and also covers how it differs from ASME. It explains design intent and use cases...
  2. Ryan6338

    Reference Point System

    Garland, This is an excerpt from ISO 5458 5.4.3 Rule C: indication of a single indication pattern specification: I believe perpendicularity with a CZ modifier could be used to create an internal position constraint on a pattern on holes. I believe the reason you don't see it used that way is...
  3. Ryan6338

    Reference Point System

    Garland23, this comes back to my point that position is less ambiguous because it's better defined. My initial thoughts were the same as yours - that is can't be applied to perpendicularity. But I re-read ISO 5458 to respond to the question and saw that CZ applies an internal constraint that...
  4. Ryan6338

    Reference Point System

    Auxcron, it depends on the function as to whether your application of tolerances is correct/optimal, but what you've done is valid. I believe the use of perpendicularity would have the same effect as position since the CZ modifier internally creates a location constraint for the pattern. That...
  5. Ryan6338

    How to identify/demarcation 2 set of Multiple Identical Features

    Hole tables are a common way to achieve this. Most CAD software should be able to do it automatically. ISO 129 provides the following example of "Tabulated repeated features": Ryan.
  6. Ryan6338

    Machining burrs - any standard?

    "part to be free from machining burrs" is not a defined term. ISO has a standard for defining edges, ISO 13715. The edge break symbol looks like this and defines a tolerance zone for edges. . Ambiguous drawings get ambiguous results. Ryan.
  7. Ryan6338

    ISO - Flatness CZ of Offset Features

    There's a few problems here. Firstly for a combined flatness tolerance zone, the nominal surfaces must be coplanar (See ISO 5458 section 1). Even if they used an applicable constraint such as position, the control is attached to the extension line of the bottom face and as such only applies to...
  8. Ryan6338

    ISO GPS - Line profile for a spine of a bent rod?

    In response to Burunduk's enquiry on where this type of control is defined - The example in Figure B.14 is a combination of a compound feature per ISO 1101 section 9.1.4 and the application of Rule C of ISO 1660 as posted above. The tolerance limits are a tube formed by an infinite series of...
  9. Ryan6338

    Identify a Drawing Symbol

    The symbol is defined in ISO 13715. Technically the drawing should call out the standard explicitly. Ryan.
  10. Ryan6338

    Wrong position for cylinder

    There's no problem with using datum A as a the primary datum on the 45.25 hole. Datum A will constrain perpendicularity of the hole to the datum plane. Datum B will then constrain one translational degree of freedom of the hole. Ryan.
  11. Ryan6338

    Datum Reference

    UF can always be used instead of CT, but not the other way around. There's plenty of these refinements in the ISO standards and I think their value is questionable.
  12. Ryan6338

    Tolerancing 'flush'

    Profile of a surface is allowed and means the same thing as using flatness. I personally prefer to use flatness because it reduces ambiguity by explicitly defining the surfaces as nominally flat & coplanar. Ryan.
  13. Ryan6338

    What is the current price of the full ISO GPS set?

    For what it's worth, I'd strongly recommend Technical Drawing for Product Design by Stefano Tornincasa as a handbook on ISO GPS tolerancing. It functionally covers both ASME and ISO concepts quite well with a bias towards going more in-depth on ISO. Ryan.
  14. Ryan6338

    Defining Datum as Section of Surface

    The method Burunduk mentions is not directly applicable in ISO. ISO 5459 requires the datum symbol to be attached to the dimension line of a feature of size under Rule 1 of the standard. To restrict the datum to the first 150mm you could use the dashed line with a datum target. The dashed line...
  15. Ryan6338

    Dimensioning a Ruler

    Position tolerance is probably the most clear and easiest option. Make the spacing between each mark a TED of 1mm. The linewidth can remain a limit tolerance. Attach a position tolerance to the midplane of the line width and I'd suggest using the front or back face as your primary datum, the top...
  16. Ryan6338

    What is the current price of the full ISO GPS set?

    Not sure how evs gets away with selling them so cheap (evs.ee/en is in english). A great book on ISO GPS is "Technical Drawing for Product Design by Stefano Tornincasa". It covers pretty much all of the standards I mentioned to a functional level and also how the standards differ from ASME. Ryan.
  17. Ryan6338

    What is the current price of the full ISO GPS set?

    These are the ones I've got listed as essentials. Prices are in USD based off the CHF price listed on ISO's website. ISO 1101 - Geometrical tolerancing - Tolerances of form, orientation, location and run-out - $250 ISO 2692 - Geometrical tolerancing - MMR, LMR and RPR - $225 ISO 5458 -...
  18. Ryan6338

    Is this a pattern rule or simultaneous rule

    Sendithard, See the attached snipped from sections 5.1 & 5.3 of ISO 5458:2018. Basic dimensions do not impose any tolerance inherently. Under Rule A from section 5.3, not defining SZ, CZ or CZR is invalid when using a position specification and there are unlocked degrees of freedom. From 5.1...
  19. Ryan6338

    Is this a pattern rule or simultaneous rule

    If this were interpreted under ISO, simultaneity is not default - a CZ modifier would be needed in the FCF to specify this. Ryan.
  20. Ryan6338

    angular tolerance in ISO 2768-1 for sheet metal process

    The rules of ISO 2768-1 are somewhat ambiguous. There's a whole standard on angular features of size - ISO 14405-3. From the section you've highlighted it seems like ISO 2768-1 is applying two-line angular size. Annex A of the standard provides more info this specific case. Unless they've...
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