How to inspect profile tolerance of an big assembly?

[hengone]

Hi,

I have an assembly drawing that state "UNLESS OTHERWISE NOTED WITHIN THE 3D MBD CATIA DATASET, A SURFACE PROFILE OF .030 QUALIFIES DATUM A (PRIMARY). A SURFACE PROFILE OF .030 WITH RESPECT TO DATUM A QUALIFIES DATUM B (SECONDARY). A SURFACE PROFILE OF .030 WITH RESPECT TO DATUM A AND B QUALIFIES DATUM C (TERTIARY). THE TOLERANCE OF ALL OTHER PART FEATURES ARE SUBJECT TO A SURFACE PROFILE OF .050 WITH RESPECT TO DATUM A (MMC [IF APPLICABLE]), DATUM B (MMC [IF APPLICABLE]), AND DATUM C (MMC [IF APPLICABLE])." My question is how to inspect profile tolerance of .050 with respect to datum a,b,c for a big assembly. This assembly can not be fit into CMM.

 

[hengone]

correction from the above statement." UNLESS OTHERWISE NOTED WITHIN THE CATIA DATASET, ALL PARTS ARE LOCATED TO A SURFACE PROFILE TOLERANCE .0600 RELATIVE TO PRIMARY DATUM A, SECONDARY DATUM B AT MMC, AND TERTIARY DATUM C AT MMC." How to inspect a profile tolerance for a big assembly.

 

[axym]

hengone,

There is a coordinate metrology device called a laser tracker that is often used for inspecting profile tolerances on big parts. There are service bureaus that will bring in the device (it is quite portable) and do the measurements. There are other laser-based metrology systems as well, but the laser tracker is probably the most common.

Evan Janeshewski

Axymetrix Quality Engineering Inc.

http://www.axymetrix.ca

 

[MechNorth]

There are also contact mobile-arm systems available; you can move the arm to new locations to encompass the entire workpiece. Consider, though, that open-setup may be useable too; profile tolerances don't always require CMMs of any kind.

Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com