revit mep for mechanical design

... before the decimal point for values less than one inch Some designers routinely place zeros before the decimal point for values less than one inch This practice is incorrect and confusing for ... opportunity for uniform interpretation and cost-effective assembly GD&T was created to insure the proper assembly of mating parts, to improve quality, and to reduce cost GD&T is a design tool Before designers ... controls in the same category For example, datums are not appropriate for any of the form controls Notice that form controls pertain only to individual features In other words, form controls are not...

Ngày tải lên: 23/01/2014, 04:20

... MHBD031-Cogorno-v5.cls April 18, 2006 15:58 Source: Geometric Dimensioning and Tolerancing for Mechanical Design Chapter Position, General Position is a composite tolerance that controls both the ... tolerance, and at least one datum The numerical tolerance for the surface being controlled is specified as a linear dimension because it generates a uniform-shaped tolerance zone A plus or minus angularity ... the limits of size and may not exceed the boundary of perfect form at MMC, Rule #1 There is no boundary of perfect orientation at MMC for angularity The 90◦ angles on the part also have a tolerance...

Ngày tải lên: 05/08/2014, 09:20

... size and its MMC Bonus tolerance for a particular feature is added directly to the geometric tolerance to equal the total tolerance for that feature Shift tolerance for a single feature of size, ... the form requirement of a size feature at LMC is opposite the form requirement at MMC When a tolerance is specified with an LMC modifier, the feature may not exceed the boundary of perfect form ... 3.500 C 1.500 2.500 1.500 3.000 B A 4X Ø 510 -.525 Figure 7-15 Design a gage to inspect for shift tolerance: Problem 1 On a gage designed to control the four-hole pattern in Fig 7-15, what size...

Ngày tải lên: 05/08/2014, 09:20

... than floating fasteners The formula for fixed fasteners is: t1 + t2 = H − F or H = F + t1 + t2 Where t1 is the tolerance for the threaded hole at MMC, t2 is the tolerance for the clearance hole at ... 013 014 Summary The floating fastener formula is: T = H − F or H = F + T The fixed fastener formula is: t1 + t2 = H − F or H = F + t1 + t2 The LMC clearance hole formula is: H @ LMC = (F + F head)/2 ... and F is the fastener diameter at MMC This formula is sometimes expressed in terms of 2T instead of t1 + t2 ; however, 2T implies that the tolerances for the threaded and the clearance holes are...

Ngày tải lên: 05/08/2014, 09:20

... MHBD031-Cogorno-v6.cls April 11, 2006 22:49 Source: Geometric Dimensioning and Tolerancing for Mechanical Design Chapter Position, Coaxiality One of the most common drawing errors is the failure ... sizes for 3/8 (Ø 375) hex head bolts n]w.025m]A]B]C] n]w.015m]A]B]C] n]w.000m]A]B]C] If the clearance holes in problem actually measure Ø 440, calculate the total positional tolerance for each ... in Fig 8-31 for four Ø 250 socket head cap screws The counterbores are Ø 422 ± 010, the depth is 395 ± 010, and the geometric tolerance is 010 at MMC 17 If the geometric tolerance for just the...

Ngày tải lên: 05/08/2014, 09:20

... Concentricity is appropriately used for large, expensive parts that must have a small coaxial tolerance for balance but need not have the same small tolerance for form and surface imperfections Concentricity ... and form Differential measurement excludes size, shape, and form while controlling the median points of the feature The concentricity tolerance is often used to accurately control balance for ... MHBD031-Cogorno-v6.cls April 10, 2006 20:56 Source: Geometric Dimensioning and Tolerancing for Mechanical Design Chapter 11 Runout Runout is a surface control It controls surfaces constructed around...

Ngày tải lên: 05/08/2014, 09:20

... properly orient and locate the surface The application of datums for the profile control is very similar to the application of datums for the position control In Fig 12-3, the profile of a surface ... at maximum material condition (MMC) Material conditions apply for datums if they are features of size Datums are generally not used for the profile of a line when only the cross section is being ... diameter with a plus or minus tolerance If just the form of a cone is to be toleranced, no datums are required Figure 12-10 shows datums controlling both form and orientation of a cone Composite Profile...

Ngày tải lên: 05/08/2014, 09:20