Three-dimensional Tolerance stack utilizing Cetol:ItsImportance & usage John Deere

Format:

Book

Conference/Event

Author/Creator:

Sarma, Anindita Upasana, author.

Contributor:

K, Yogesh

Conference Name:

International Conference on Advances in Design, Materials, Manufacturing and Surface Engineering for Mobility (2020-09-25 : Chennai, India)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2020

Summary:

Tolerance stack ups are vital to achieve mechanical fit, assembly and performance requirements in any product. Mechanical fit ensures the parts building up the assembly always fit with each other and achieve mechanical performance requirements (can include either performance of a mechanism like actuators, switches et cetera or performance of equipment or machines).Tolerance stack up is a technique which calculates the collective effect of part tolerances considering assembly requirement. The logic behind this method is adding tolerances to find total part tolerance and then comparing it with the performance limits (available gap). This allows us to check whether our assembly would work according to the design needs. This comparison, also known as worst case analysis is normally useful for problems involving less numbers of parts and mostly in 1-D. If the analysis involves part dimensions that are not parallel to the assembly measurement being studied, we must approach other stack-up method since 2D variation such as angles that is not parallel with the 1D direction does not affect the assembly measurement.Apart from Worst Case method (WC), many organizations utilize statistical method for tolerance analysis like RSS method (Root-Sum-Squared). Instead of summing up tolerances (as in WC analysis) statistical analysis sums dimension distributions. Worst-case analysis is used to validate a design whereas statistical analysis can be used to predict the actual variation of an assembly based on the variation of the part dimensions. This approach needs distributions to be normal with all parts at the same quality level, id est +/- 3σ which is a limitation.CETOL 6 Sigma utilize a method called Method of System Moments which disregards this limitation and many critical analyses of 1D,2D or 3D nature can be created with no restriction in distribution type or quality level

Notes:

Vendor supplied data

Publisher Number:

2020-28-0495

Access Restriction:

Restricted for use by site license