How is MMC virtual condition calculated?
Virtual Condition = Tolerance boundary that is constant for all sizes and generated by the cumulative effects of size and geometric tolerance at MMC. For an external feature of size with MMC specified, Virtual Condition = MMC + Geometric tolerance, or as-manufactured size + allowed geometric tolerance at that size.
How do you determine virtual condition?
The calculations for the Virtual Condition are shown below:
- Virtual Condition (internal feature) = MMC (smallest size) – Geometric Tolerance.
- Virtual Condition (external feature) = MMC (largest size) + Geometric Tolerance.
- Inner Boundary @ RFS = Smallest Feature Size – Geometric Tolerance.
What is the MMC virtual condition size of one of the holes?
For the shaft in Figure VC1. 1, the diameter of the virtual condition is the diameter of the MMC shaft plus the diameter of the position tolerance zone. For an internal feature of size, such as a hole, the virtual condition is equal to the size at MMC minus the size of the tolerance zone.
How do you calculate MMC and LMC?
Bonus tolerance explained: As the size of the pin departs from MMC toward LMC, a bonus tolerance is added equal to the amount of that departure. Bonus tolerance equals the difference between the actual feature size and the MMC of the feature. In this case, Bonus Tolerance = MMC-LMC=25-15=10.
What is MMC virtual condition Mcq?
What is MMC Virtual Condition? a) The collective effect of the MMC limit of size of a feature of size, and any applicable geometric tolerance.
What is MMC tolerance?
Definition: Maximum Material Condition or for short, MMC, is a feature of size symbol that describes the condition of a feature or part where the maximum amount of material (volume/size) exists within its dimensional tolerance.
What is MMC of hole?
In GD, maximum material condition (MMC) refers to a feature-of-size that contains the greatest amount of material, yet remains within its tolerance zone. Some examples of MMC include: Largest pin diameter. Smallest hole size.
How is MMC bonus tolerance calculated?
Bonus tolerance equals the difference between the actual feature size and the MMC of the feature. In this case, Bonus Tolerance = MMC-LMC=25-15=10.
What is the MMC of a hole?
The chapter reviews maximum material condition (MMC). The chapter illustrates that for a shaft, MMC would be when the diameter is everywhere at its maximum size, while for a hole, MMC is when its diameter is everywhere at its minimum size.
What is the MMC of a shaft?
Maximum Material Condition (MMC) – This is the maximum limit of an external feature; for example, a shaft manufactured to its high limits would contain the maximum amount of material.
Why MMC conditions are used?
Maximum material condition (MMC) is used to indicate tolerance for mating parts such as a shaft and its housing. Least material condition (LMC) is used to indicate the strength of holes near edges as well as the thickness of pipes.
What is virtual condition in MMC?
Virtual condition is the theoretical extreme boundary condition of a feature of size generated by the collective effects of MMC and any applicable geometric tolerances. Consider above example for better understanding of virtual condition. Here MMC is Ø20.4 and a straightness tolerance 0.1 is specified at MMC.
Is there a minimum from which to base a virtual condition?
Only if an item is required to be perfectly straight or flat at MMC is there a non-zero minimum from which to base a virtual condition.
How to calculate virtual condition (VC)?
In summary, the way to calculate virtual condition (VC) for a shaft and hole is: SHAFT VC = MMC diameter + Position Tolerance Zone Diameter HOLE VC = MMC diameter – Position Tolerance Zone Diameter Virtual condition is extremely useful in the design of functional gauges.
What is the difference between virtual condition and rule 1 boundary?
The virtual condition and rule #1 boundary are two completely separate boundaries that impose different requirements. One requirement can be in force while the other is not. The rule #1 boundary results from actual local size and form limitation imposed by the size dimension and tolerance.