GDT:Position Multi-Single Segment FCF
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| Symbol | Position Multi-Single Segment FCF |
|---|---|
| Type | Location |
| Category | Multi-Segment |
| Standard | ASME Y14.5 |
| Author | Admin |
| Datums | Required for planar FOS; segments should not repeat the same datum set |
| Modifiers | Diameter required for cylindrical FOS; tangent and unequal are not allowed; ST where allowed |
| Tolerance zone | Multiple position segments, each defining its own zone |
| Image | |
| Common mistakes | Missing basic dimensions; missing datums for planar FOS; missing diameter for cylindrical FOS; repeating the same datum set |
| Related | F4:Position MSS Validation |
Summary
Position MSS (multi-single segment) feature control frames apply multiple position requirements to the same feature or pattern.
Definition
An MSS FCF contains two or more position segments. Each segment is a separate requirement and can reference different datum frames. Basic dimensions locate the true position for each requirement.
When to use it
Use position MSS when a feature needs to satisfy multiple position requirements, such as different functional datum frames.
Examples
Example: Position MSS on a hole pattern
Two position segments with different datum references controlling the same pattern.
Common mistakes
- Missing basic dimensions that locate the true position.
- Missing datum references for planar features of size.
- Omitting the diameter modifier for cylindrical features of size.
- Repeating the same datum reference set across segments.