GM 1925

.

GM-1925 Fixture Standards 2013

0

General Motors Corporation Published By Global Purhasin! and Supply Chain

Foreword The GM Fixture Standards for Suppliers of Production Material was developed to establish common GM Supplier PPAP checking fixture standards worldwide. Previously fixture standards existed at the divisional or unit level only. !n "##$ a development team was formed which included representatives from GM Truck Mid%&ux and the Small 'ar Group. Group. !n addition the development process included collaboration with Saturn GM Powertrain Powertrain and GM 'anada Group. !n March ())* the GM Fixture Standards for Suppliers of Production Material GM contained in this March ())* printing are the 1925 manual was revised. The revisions contained result of collaboration from representatives from GM +A,- APP GM +A,- /ixture 0ngineering and GM 1imensional 1imensional 0ngineering. !n March ())2 the GM Fixture Standards for Suppliers of Production Material GM contained in this printing have been reviewed reviewed 1925 manual was revised. The revisions contained and agreed upon by the GM +A,- Supplier uality Gage Group. !n /ebruary ())3 the GM Fixture Standards for Suppliers of Production Material was revised. The revisions contained contained in this printing have been GM 1925 manual was reviewed and agreed upon by the GM +A,- Supplier uality Gage Group. !n +ovember ()"4 the GM Fixture Standards for Suppliers of Production Material manual was revised. revised. The revisions contained contained in this publication are the the GM 1925 manual result of collaboration from representatives representatives from GM Supplier uality and GM+A 1imensional 0ngineering and have been approved by the GM S Global Process Team.


1


Table of Contents Subject

Pae

!.

Preface

)5

!!.

Part Supplier 6esponsibilities

)*

!!!.

1esign 'oncept

)$

!,.

'oncept Approval

)3

,.

1esign 6e7uirements

)#

,!.

8uild 6e7uirements

"4

,!!. 'ertification 6e7uirements

"*

,!!!. Gage 6epeatability and 6eproducibility 6e7uirements

"$

!9. Gage /inal Approval

"2

9.

Maintenance 6e7uirements

"2

9!.

Glossary

"2

GM Gage 1esign Approval 'hecklist Appendix A

"#

GM Gage 8uild Approval 'hecklist GM-1925 Fixture Standards 2013

2

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Appendix 8 GM Gage 'oncept Approval 'hecklist Appendix '

"#

-peration 1escription Sheet :-1S;

"#

-peration 1escription Sheet :-1S; 0xample

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Gage%'hecking /ixture Types < +oun +ames

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This manual supersedes the following documents= 

Truck > 8us 'hecking /ixture%Gage Standards :T>8 4#"; 1ecember "#3#.



M!1%&?9 Part /ixturing 1esign%8uild Standards April "##$.



"#(* /ixture Standards March ())* thru /ebruary ())3


3


GM Fixture Standards !.

Preface ".

!ntroduction

!n accordance with The Automotive !ndustry Action Group :A!AG; The Advanced Product uality Planning :APP; Manual and The Production Part Approval Process :PPAP; part suppliers will obtain fixtures :if and when re7uired; to monitor their product as part of their 7uality plan. Production part suppliers shall utili@e this manual in addition to their own standards and minimum re7uirements when 7uoting designing and building fixtures for General Motors purchased parts. The GM Supplier uality 0ngineer reserves the right with engineering approval to modify the gage standards :including Geometric 1imensioning and Tolerancing and measurement points;. The GM Supplier uality 0ngineer will obtain direction and approval from GM 1imensional 0ngineering prior to the modification of these standards. The GM Supplier uality 0ngineer is also re7uired to procure the appropriate supporting documentation for these modifications :e.g. 0- marked drawings approved by engineering etc.;.

#.

Scope

The GM Fixture Standards summari@e the minimum re7uirements that apply to all GM suppliers PPAP checking fixtures worldwide . All GM suppliers must ensure that their subBsuppliers are also meeting these minimum re7uirements. This manual exists to provide a uniform process for the procurement of PPAP checking fixtures suppliers shall incorporate these standards into their inBprocess and $ or subBassembly gaging. !n addition to these standards the following manuals must be utili@ed where applicable= 

The GM P.0.1.B""5 'hecking /ixture%Gage Standards Manual :tolerances listed in the GM"#(* document supersedes tolerances listed in the P.0.1.B""5;

"sse%bl& Gae 'efinitions GM-1925 Fixture Standards 2013

"


P(ase 1 Gae) Production intent gage with datums and hold downs present. Suitable for use as a holding fixture for scanning or 'MM data generation to support builds through M" P(ase 2 Gae) Production gage < Phase " gage plus all measurement ports check rails etc. to support data needs from M( builds through production and beyond Pull "(ead Gae) A production intent gage brought forward in time to support PP- for !,06 builds

!!.

Part Supplier *esponsibilities

A.

hen fixtures are re7uired the part supplier is directly responsible for all elements of the fixture procurement process. !n addition the part supplier shall document all relevant activity. 1ue to the varying complexity of component parts covered under this document the supplier must contact the procuring unit to determine the appropriate extent of the GM S0Cs involvement.

8.

The Supplier shall ensure that the following apply to all fixtures= ".

They are procured in a timely manner to meet program timing obDectives including GPB"" where applicable.

(.

They must agree with functional part usage.

4.

They must comply with part Geometric 1imensioning and Tolerancing :G1>T; by honoring the datum scheme. 4." +-T0= S?PP&!06 !S 60SP-+S!8&0 /-6 ,06!/E!+G !/ M?&T!P&0 ATTA'F!+G S'F0M0S A60 60?!601 :0x. !TF % !TF-?T /AST0+06S;

*.

They are re7uired to have variable data collection devices for all dimensional critical measurement points :P'Cs;. /or critical measurement points the variable data collection device positioning details :SP' ports; must be hard attached to the fixture. The variable data collection devices must be capable of meeting all A!AG Measurement Systems Analysis :MSA; re7uirements.

$.

They must include the ability to discriminate part variation from nominal.


5


'.

!n accordance with TSB"$#5# Global uality 'ertification Standards the supplier shall establish and maintain documented procedures for measuring e7uipment control. This documentation should include= ". (. 4. 5.

A dimensional inspection report. The use of a 'oordinate Measuring Machine :'MM; is preferred. 1ocumentation of engineering changes. A Gage 6epeatability and 6eproducibility study. A math base ?G compatible fixture design.

The supplier shall maintain the change columns of both the fixture design and the fixture. The change column shall reflect the latest production design level whether the fixture has been affected or not. The supplier is expected to resolve design problems in a timely manner. The design and construction source is responsible for immediate notification that a problem exists. Any revision that changes the original fixture cost must be approved by GM Purchasing. !!!.

'esin Concept

A.

Prior to starting a fixture design a preliminary design concept meeting shall be held. 'ore members expected to participate include the following= the GM Supplier uality 0ngineer the supplierCs 0ngineer and the fixture design%construction source representative GM 1esign 6elease 0ngineer :160; 1imensional Systems 0ngineer :1S0; and Gage Process Specialist. -ther members may include the Matching 0ngineer and the GM manufacturing plant representative if applicable.

8.

The design concept shall consist of an electronic sketch and or a written description of the fixture with sufficient detail in order that the fixture design process can proceed. The design concept should not be as detailed as a complete design but it should include the following information= ".

The part position in relationship to the fixture base. !n body position is standard. Fowever other orientations may be appropriate to maximi@e part%fixture usage with the approval of the GM Supplier uality 0ngineer. #) degree increments are recommended. Fowever it may deviate based on measurement accessibility. 1esign must include ability to all re7uirements including back side re7uirements.


#


(.

A datum strategy which represents the specified Geometric 1imensioning and Tolerancing which may re7uire multiple attaching schemes.

4.

1etails and devices for supporting the part :risers datums targets;.

5. Proposed clamping techni7ues must be identified as defined within the G1>T . :Measuring with or without clips clamping; *.

1etails and devices for inspection of features such as=     

$.

Measurement points /eature lines /unctional holes Fistoric :lessons learned; areas of high process variability /or attribute check details on interior and exterior trim parts the use of scribe lines or tolerance bands :check rails; are an acceptable method for part evaluation.

Acceptable construction materials based on fixture usage and environment to ensure functionality repeatability and reproducibility throughout the length of the part program.

Selection of Build Materials hen selecting build materials for fixture%gage checking surfaces the Supplier should consider= 'ost 1urability re7uirements based on fixture use and conditions 'onstruction methods Shape and area of checking surface on fixtures 0nvironmental conditions eight limitations of applyBtype checking fixtures 6obustness to maintain 1imensional !ntegrity during machining and the life cycle of the program.       

?nless the Supplier uality 0ngineer instructs otherwise the design source will adhere to the following material re7uirements= 




?se steel or aluminum for risers support members and brackets of +%' machined fixtures and checking details this decision should in part be based on the following factors= vehicle volumes material cost structural re7uirements weight ability to machine and corrosion resistance. 8ase setup pad re7uirement s flatness .)"mm per "))mm s7uare maximum. +-T T- 09'001 %B."4mm over all flatness. General Motors Corporation $ Published By Global Purhasin! and Supply Chain

 

2.

!+.

?se lightweight materials for hand apply fixtures All material must have the Supplier uality 0ngineerCs approval

Mating or adDacent part representations or features where applicable duplication of mating part at nominal :e.g. 1upes;.

'.

-perator ergonomics part loading and unloading and accessibility for 'MM inspection and Statistical Process 'ontrol :SP'; Product uality 'haracteristic :P'; data collection should be considered in the 1esign 'oncept.

1.

The 9 E H location:s; on product features where variable data will be collected to monitor critical measurement points shall be reviewed and approved by the GM Supplier uality 0ngineer .

Concept "ppro,al

'oncept Approval :form "#(2B(# re7uest for gage construction and design review; is re7uired. https=%%www.gmsupplypower.com%apps%supplypower%+ASApp%spcds%'1S6etrieva lIidJ"(")5#>togglefolderJ(($*5>docKlangJen>lobJ7uality the part supplier shall obtain 'oncept Approval from the GM Supplier uality 0ngineer the GM 1esign 6elease 0ngineer Gage Specialist and the GM 1imensional System 0ngineer prior to initiating the fixture design process. Any change which may occur during the fixture procurement process that has significant impact on the original concept must be reviewed with the GM Supplier uality 0ngineer.

+.

'esin *e-uire%ents

The checking fixtures used to check the fit form and function of the part to the vehicle will be designed in a cooperative effort among the GM Supplier GM-1925 Fixture Standards 2013

%


uality 0ngineer the supplier the GM 1esign 6elease 0ngineer Gage Specialist and the GM 1imensional System 0ngineer and will be built through the supplier.

A.

The 1esign source shall refer to the concept sketch the G1>T the written description and the measurement points provided :as well as; the customerCs Technical 6eview as the controlling expression of the design. !f any of this information was not supplied in the S-6 or at the Technical 6eview it is the supplierCs responsibility to obtain from the GM 1esign 6elease 0ngineer the information necessary to satisfy all support program deliverables.

8.

/or mechanically attached parts the gage must check= ". In respect to inspection of part warpage, refer to GD&T for part measurement requirement, (includes free state, etc) (.

All Part -f Assembly :P-A; fastener locations with and without /asteners :Approved by the GM Supplier uality and 1esign 6elease 0ngineer;

4.

Profile % contour

5.

Part si@e

*. /ixture must have the capability to measure flushness with% without restraint and with fasteners :if re7uired review G1>T to see how part is to be checked; by installing the part into the fixture. The fixture shall also contain release mechanisms by which to remove the part. +o clamping pressure is permissible on ABsurface:s; during part check with fasteners. All metal clip attachments to be built with dual acting Law Mechanisms :where possible;. /or checking without clips :e.g. doghouse attachments; clamping to be accomplished by hook%swing in clamp to clip attachment.

1ual acting Law Mechanisms


9


Fook%swing in clamp to clip attachment

$. The fixture must be able to measure gap and flush at locations defined within the G1>T. 2. All flush and feeler rails to be designed to be $mm offset. All flush and feeler callouts to be stamped and colored accordingly directly into rails. Start and stop of flush and feeler pin @ones to be clearly identified at checking edge rail. 3. All free state net datums to be retractable %removable. All free state net datums not to include clamps. #. All door trim assemblyCs to follow G1>T re7uirements within the drawing. 6e7uirements shown with%without clips. Door Trim with-without clip requ

GM1925 Supplement for Door Trim 13No.

'.

/or tape applied parts the gage must check=

".

/ree State check of contour conformance to surface

(.

/lush % gap fit of part to fixture surface :less than " mm is default unless otherwise specified by G1>T;

1.

4.

Part si@e

5

Profile % contour

").

&ocation of locating features such as pins slots holes etc.

All drawings should have the following= ".

1etails shall be complete in all views and must be dimensioned to machined surfaces and%or body and%or work lines.


10


0.

(.

1rawings should include a representation of the part shown in its gaging position.

4.

All section views shall be referenced by section and sheet number corresponding to the callBout on the gage design drawing.

5.

The stock list shall include all stock si@es and must identify standard items by supplier name and full catalog number.

*.

All dimensions should be in metric however the stock list may contain items in Standard 0nglish dimensions

$.

Stock items :i.e. angle brackets risers hinge drops slides screws dowels etc.; should consist of standard commercially available materials whenever possible.

1atum Fole &ocator:s;=

".

( way gage pins should not restrict part movement in the none locating direction. Slides are recommended in this application

(.

Recommend datum features of size be Regardless of Feature ize (RF) or !a"imum !aterial #ondition s$all be used to positi%el locate t$e part as speci'ed in t$e GD&T

3.


8odyshop sheet metal drawings affected by FoleBtoBFole=

11


/.

1atums that are positioned directly adDacent to a spotBweld seam weld or parting line shall be brought to the attention of the responsible 1esign GM-1925 Fixture Standards 2013 General Motors Corporation 12 Published By Global Purhasin! and Supply Chain

0ngineer. !f the datum cannot be reBlocated clearance shall be provided on the fixture detail to facilitate Gage 6>6.

G.

All details utili@ed for part inspection including check pin si@es shall be identified on the gage design. !n addition all removable and interchangeable details shall be identified including their associated function. The use of color coding details has proven to be an effective techni7ue in communicating the use of multiple model applications on the same fixture. !nterchangeable details re7uire the following= ". (. 4.

Fardened steel bushings for bulletBnosed locator pins. Permanently attached hand knobs. Storage on the fixture base for interchangeable details

F.

To ensure consistent dimensional checking from construction to certification the design should include documented start points for base alignment on a coordinate measuring device. These points can be tooling balls :preferred; bushings blocks or some other clearly identified @ones on the base.

!.

The gage design shall be such that no detail overhangs the gage base when the detail is in any position e.g. Swing in details :clamps SP' ports flush and feeler rails etc;.

L.

All part information including math data used in the design and re7uired for fixture construction must be identified on the fixture design :including latest revision level and date.;

N.

All changes to the fixture design shall be alphaBnumerically indicated in a change notice block. A brief change description referencing the appropriate 0ngineering ork -rder :0-; or applicable engineering change number should be identified with each change event.

&.

-perator instructions and%or a se7uence of operations on the use of the fixture shall be shown on the completed design :see Appendix ';. The use of multilingual operator instructions must be considered where applicable.

M.

The finished fixture design must be reviewed and approved by the GM Supplier uality 0ngineer the GM 1esign 6elease 0ngineer Gage Specialist and the GM 1imensional System 0ngineer :6ef. Appendix A

+!.

#uild *e-uire%ents

A.

All fixtures shall be built to math data and G1>T


13


8.

All datums inspection details clamps and interchangeable details shall be identified on the fixture in a visible location as shown on the design.

'.

/or variable data collection devices a standard @ero block with bushing is to be mounted to the fixture base.

1.

-perator instructions and%or a se7uence of operations on the use of the fixture shall be securely affixed to the gage.

0.

The use of eyeBbolts for fixtures over 4* pounds is recommended.

/.

All weldments shall be stress relieved.

G.

All loose and interchangeable details such as hand knobs and check pins 1ial !ndicators shall be permanently attached to the fixture. The use of self storing :restrained; tethering devices or recoil type cables is recommended.

F.

The use of shims or shim stock is not an acceptable practice in the construction of GM checking fixtures.

!.

hen templates are utili@ed O stock is an acceptable choice for template construction.

L.

Any steel nonBcheck details susceptible to oxidation should be coated in such a manner as to provide long term protection based on usage environment etc. ipeBon solutions that are removed by normal handling of the details are not recommended.

N.

All check pins shall be manufactured from an acceptable material and hardness to ensure durability and functionality throughout the life of the part program.

&.

/ixture 'onstruction Tolerances ".

All fixture details including fixture bases datums and inspection details shall be accurately manufactured in order to ensure the accuracy re7uired for product inspection.

(.

General tolerance guidelines are as follows=  

   


All datums used to position the part= %B ).)* mm. 1etails used for digital%electronic measuring devices which check part features SP'Cs %B ).)* Part representation= %B)."* Surface contour features :flush checks;= %B )."* mm. Trim line features :feeler checks;= %B )."* mm. Template checks :profile of part;= %B )."* mm. General Motors Corporation 1" Published By Global Purhasin! and Supply Chain



M.

'heck Pin 8ushing location tolerance = %B ).") mm

An identification tag shall be affixed to each fixture supplied by the fixture source with the following information at a minimum and updated as re7uired :see example below;=       

Part +ame:s;. Program 1esignation &ess /inish Part +umber :!f Applicable; Part Math 1ata &evel G1>T 1rawing &evel /inal 'ertificate 1ate QProperty of General Motors

!f the fixture is utili@ed to inspect additional parts or assemblies a separate tag containing the drawing numbers engineering levels and dates may be re7uired supplied by the fixture source. All tagging must be multilingual as re7uired. +. !t is re7uired that the finished fixture build be reviewed and approved by the GM Supplier uality 0ngineer the GM 1esign 6elease 0ngineer Gage Specialist and the GM 1imensional System 0ngineer before shipping.

Pre-Production Part Quality Process (PPQP) Pre Production Operations (PPO)


15


Suppliers shall use a holding fixture that meets criteria specified in 'hecking /ixture Standards and repeatability re7uirements for repeatability :"x");. /ixture 1atums must reflect G1>T callouts. /ree state re7uirements identified in G1>T must be followed :6ef. GM"#(* /ixture Standards;. +!!.

Certification *e-uire%ents

A. The certification must include :at a minimum; the following= datums and functional gage features such as data collection devices feeler checks flush checks nets gage pins pin locations mating part representations construction balls etc. The certification must also include certification to multiple locating schemes :e.g. with % without fasteners; per GM re7uirements.

8.

The construction source shall develop an easily comprehensible 9 E H and vector type 'MM certification report. The check sheet should be sufficiently documented to easily relate the check points back to the part drawing. An example is provided below= All 8ushing checks need to be proDected to the built in indicator offset.

9 Master 9 'heck 'atu% "2 4#)).)))

9 1iff.

E Master

43##.#5( B).)*3

'et 5 /MM Flr. Const. 4#").))) 4#)#.##3 B).))(

E 'heck

E 1iff.

*)).))) B()2.2))

H Master

H 'heck

H 1iff. ,ec.1iff.

Type

*)).)3$ ).)3$

"*#(.*))

"*#(.*))

B).)))

).")44

Surf6d

B()2.3"( B).""(

"$)*.)))

"$)*.)))

B).)))

B)."""#

Surf6d

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hen a fixture is inspected and found to be dimensionally incorrect or when specifications are not met the Tier " supplier is directly responsible to identify the root cause and implement corrective action.

1.

A new fixture certification is re7uired for any fixture shipped outside of the region from which it was manufactured. This is to verify that no shipping damage has been done to the fixture.

0. 4rd party certification audit may be re7uested at the discretion of the GM S0 :!f re7uired it must be re7uested at the preBsourcing phase to ensure comparable 7uotations;.

+!!!.

Gae *epeatabilit& and *eproducibilit& *e-uire%ents


1#


A.

Supplier shall ensure that Gage 6>6 is conducted based on A!AG MSA Manual and must include all critical measurement points for each locating scheme :e.g. with % without fasteners.;.

Guidelines for acceptance of an Average and 6ange Gage 6>6 study re= ". ?nder ")R error

Gage system acceptable

(. ")R to 4)R error

May be acceptable based on the importance of the application gage revision cost etc.

4. -ver 4)R error

Gage system needs improvement. Make every effort to identify the problems and have them corrected.

!f there is any 7uestion regarding whether the percentage of gage error listed in item ( above re7uires improvement contact the GM Supplier uality and 1esign 0ngineer for direction. '.

!0.

0.

A Gage 6>6 study should be performed after any modifications are made to the fixture which might affect the repeatability and reproducibility performance.

Gae Final "ppro,al

A.

Supplier is re7uired to contact the GM Supplier uality 0ngineer for a completed fixture review prior to gage shipment.

8.

Supplier is re7uired to obtain from the GM Supplier uality 0ngineer an approved copy of the GM Global 6e7uest for Gage 'onstruction % 1esign review. Supplier is re7uired to submit % maintain this document with PPAP documentation.

'.

The finished fixture build must be reviewed and approved by the GM Supplier uality and 1esign 0ngineer. :6ef. Appendix 8;.

Maintenance *e-uire%ents

A.

!n accordance with !S-%TSB"$#5# Global uality 'ertification Standards the part supplier must perform regularly scheduled fixture maintenance :based on usage; to retain the measurement capability of the fixture throughout the entire part program.


1$


8.

0!.

The part supplier must continually update fixtures to the latest engineering change level on the identification tag whether the changes affect the fixture or not.

Glossar&

#od& Position= The positioning of the part in the fixture in the identical orientation the part will have in the final assembled vehicle. 'esin Concept= The first level of development in the fixture design process. The purpose of the design concept is to establish and document the re7uirements of the fixture. This will ensure that the fixture design includes all of the re7uirements of the part supplier and GM. 'ocu%entation *e-uired) Standard Product 'haracteristics that are deemed important to part function and Product 0ngineering will re7uire process capability data documentation.

Gae Certification= The dimensional verification that the fixture details :i.e. datums SP' details etc.; have been manufactured to facilitate accurate part measurement Gae 'esin= The final construction drawings that will enable the fixture builder to construct the fixture that is intended for the part supplier... Gae *epeatabilit& and *eproducibilit& Gae **3 G** or G**4 = A measurement system analysis of the fixture. The analysis is described in the A!AG Measurement Systems Analysis Manual.

CMM Certification *eport= 6eport that shows measured precision re7uirements that are used to verify that a gage%fixture conforms to design and dimensional specifications.

peration 'escription S(eet 'S4

GM"#DS"Sheet.xlsx


1%


6xa%ple 'S

Gage_Checking Fixture Types _Noun

Gae$C(ec7in Fixture T&pes 8 oun a%es


19


GM 1925

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