MPD 575 Design for XTerm I Fall 2008

Cohort 9

Design for RetoolBrian Armstrong

Kim Calloway1ML1

December 1, 2008

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Design for Retool

• Introduction to DFR

• Heuristics

• Key Principles of DFR

• Procedures for DFR

• Examples

• Conclusion

• References

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Introduction to DFR

What is Design for Retool?• To reequip with tools ~ Webster• To revise and reorganize, especially for the

purpose of updating or improving~ The Free Dictionary

• Utilize existing capital facilities / equipment to produce (manufacture / assemble) new and improved products ~ Kim and Brian

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Introduction to DFR (cont)

Why Design for Retool?

• Easier to make running changes / incremental improvements• Facilitates Make Like Production (MLP) prototype requirements

as process is well defined• It’s often the only option if late changes are required or if late

decisions drive component changes which in turn affect process• Saves money; return on capital investment, less M.E. resource

investment • Reduces engineering risk as process failure modes are well

understood• Shorten development time; faster time to market

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Introduction to DFR (cont)

What are the drawbacks of Design for Retool?• Can limit design flexibility on all new designs for numerous

reasons• Undesirable component characteristics are sometimes carried

forward because they are too costly in terms of process change to correct

• Can impact engineers to become technically lazy with the mindset that components / processes are carry-over; Can promote complacency

• Business risk that competition is using newer / better process methods obtaining edge in performance, quality and cost

• Old equipment and all the associated concerns with its use

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DFR Heuristics

• If it’s not broke then don’t fix it• Minimize the # of machining / assembly planes• Minimize the # of transfers and orientations• The more knowledgeable the component engineer is

with the current process the better the potential for incremental product improvements given the constraints of the current process

• Engineers should know the process the way you know your own house. You have to live in the process to understand what is good, what is bad and what should be changed.

• Knowledge saves time, effort and money

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DFR Heuristics (Cont)

• Sometimes the unforeseen or unthinkable happens; Murphy’s Law applies.

• If your manager says it won’t happen, then it probably will

• Late design changes are more difficult to deal with than up front engineering assumption related changes

• Any change requires giving something else up (Heuristic from the game of Chess)

• CAD is your friend, but your friends will let you down.

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DFR PrinciplesSome basics that CPMT (Component) Engineers need to know:

What are the processes used?

What is the process order?

What are the transfer systems?

How are components located and oriented?

What tools are used?

• CPMT Engineers do not need to know as much as the M.E. Engineers, but a good understanding of the process basics (answers to the questions above) will be invaluable to the development of incremental product improvement

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DFR PrinciplesComponent:

•Carry forward he best design features

•Try to eliminate excessive or negative features

•Minimize machining stock

•Simplify handling and assembly features

•Open tolerances where possible

Process:

•Eliminate unneeded processes

•Minimize repositioning and multiple fixture where possible

•Utilize capability data from existing process to ‘keep’ what works well and improve processes where capability is a concern.

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DFR Principles•Need to live in the “real world”

•Every Engineer would love to optimize their component for maximum performance / functionality. There are obviously many constraints preventing this one of which is utilization of existing or common process (Retooling).

•Need to challenge status quo mind-set of M.E. within the constraints of existing tooling

•Try to find offsets where concessions are granted to M.E. and others.

• Note: sometimes the offsets are to be found on a sub-system or system level. Balance of ‘real estate’, cost, weight or consumption (oil pressure budget, rotating or reciprocating weights).

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Connecting Rod Sample Process Flow

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DFR Procedures• Use TCe with CAD modeling for process systems

where possible• Virtual fly thru and complete system modeling

is rare (nice in a perfect world)• Models are typically available for transfer

pallets and shipping racks• Generally an envelope around the pallet is

defined and physical protrusion past the envelope creates problems

• 3D CAD modeling data generally isn’t available for older machining lines so it’s important that the engineers are intimate with the process

• GPDS VP prototype builds are required to have MLP components

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DFR Procedures (cont)•CAD / TCe is invaluable for component interface and sub-system to system interface

• Example: checking the position of an engine component relative to a vehicle package

• CAD however doesn’t always have the most accurate models of existing processes. This is due to the following:

• Modifications made to tooling after Job 1

• Inaccurate models due to “field fit” process installation

• Wear or damage

• Old equipment without such data (Lincoln underbody press and Lincoln Knock Down (KD) fixtures.

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DFR Procedures (cont)What should CPMT / Systems Engineers do in the absence of CAD process data? How can improvements be made to the components utilizing the existing process / assembly equipment?

•Walk the line and spend some time there; supplier visits when appropriate (APQP and SBLT are tools)

•Make notes of the process sequence and transfer systems

•Take pictures when appropriate

•Review capability data on critical processes

•Understand the limitations of the equipment ~ fixed spindle versus CNC; Robot transfer versus shuttle feed.

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DFR Procedures (cont)How can improvements be made to the components utilizing the existing process / assembly equipment?

•Know your component!!

•Every feature should be understood!

•What are the features required by M.E.? Manufacturing and assembly.

•Don’t just cut the ham in half as many excessive features are unnecessarily carried forward.

•Benchmark competition often.

•Use lessons learned from other programs and solicit technical experts when needed

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Sample 543 Chart for Engine Assembly

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Sample 543 Chart for Engine Assembly

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TCe Global Search

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CAD of Coyote Engine in Shipping Rack

10.9mm CLEARANCE - OIL FILTER TO SHIPPING RACK

2C3E-6A642-BB OIL COOLER

P415

AA5E-6714-AA

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DFR Procedures (cont)Make Like Production

Once improvements are made to a component the new design must be verified. There are many prototype phases in GPDS, including VP and post VP where components must be MLP.

What is MLP? When Prototype and Production has the same –

• Process Sequence• Material Removal Rates (wet/dry)• Same locating Datums• Fixtures• Tooling (durable/perishable)• Inspection/Gauging methods and programs• Assembly methods

using data to drive investment and resource decisions.

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Make Like Production

ME

Suppliers

PDPrototype& PPM

Plant

Retool creates less disruption to the MLP process because Plant and ME are almost fixed The Plant

selection is typically mandated to PD and ME requirements mostly fixed

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MLP (Engine Engineering)• Early prototypes (pre-VP), rapid prototyping, early

concepts, and MLP can be supported in-house at Ford.

• Engine Manufacturing Development Operations (EMDO)– EMDO uses process that simulate production process to produce

engine components– Process Sequence– Material Removal Rates (wet/dry)– Same locating Datums– Fixtures

• Beech Daly Technical Center (BDTC)– Inspection/Gauging methods and programs– Assembly methods

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Examples

• Connecting Rod

• Engine Oil Cooler

• Specialty Vehicle Team (SVT)

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Connecting RodThe Right Way

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Connecting RodThe Right Way

Increased engine speeds and increased engine specific output (HP/L) drives needed design changes to connecting rod.

• Need increase strength while simultaneously reducing rod weight

• Need to use the existing rod machining line

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Connecting RodThe Right Way

Rod Improvements:• Material change from Powdered Metal to Forged Steel

– Allows use of less material for weight reduction and is stronger than PM

• Maintain critical features for current process– Rod shoulders for part transfer– Clamping pads, pin-end radius for locating and rod cap gnorf

• Other functional improvements:– Rolled threads to allow blind holes for weight reduction

• Lower stress concentrations• Eliminate potential for chips in bolt hole

– Elimination of Piston Pin Bushing• Reduces weight further• Reduces part count and cost

– Tapered Pin End for weight reduction (Piston, Crank as well)

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Connecting RodThe Right Way

The changes to the connecting rod necessitated some changes to the process as follows:

• The harder material required changes to boring, drilling, and grinding operations

• Speed and feeds had to be adjusted• Fracture splitting of rod required laser notch

in lieu of the traditional machining broach– The laser equipment was installed where the old

broach equipment was removed– Some UAW push-back due to Health and Safety

concerns

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Connecting RodThe Right Way

Summary:All of the changes to the connecting rod were

containable via retooling the existing manufacturing line. The improvements to the connecting rod help the overall engine system. The result is a lighter, stronger rod that in turn allows for weight reduction of the piston and crank shaft. Reducing the rotating and reciprocating mass in the engine which improves the overall engine efficiency.

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Engine Oil CoolerThe Wrong Way

Background:In the spring of 2008 at FMC Engine

Engineering. Coyote V8 engine program is in the M1D phase of GPDS with S197 as lead customer and P415 as the secondary but higher volume customer.

– Preliminary testing indicates engine oil temps are marginal

– Lubrication CPMT and Systems Engineer are concerned and request to package protect for an engine oil cooler

– Coyote program manager denies the request to package protect for the oil cooler stating “this engine doesn’t need an oil cooler”

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Engine Oil Cooler (Cont)

• Changes in other engine programs results in the Coyote engine becoming the lead trailer tow engine for P415.– Oil temps that were marginal are now out

of specification– Increased vehicle cooling is not feasible– Engine oil cooler needs to be included in

the EAS Coyote package

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P415 Engine Oil Cooler

P415 INLINE OIL COOLER STUDY

OIL COOLER INTERFERES WITH ALTERNATOR

OIL COOLER INTERFERES WITH DRIP SHIELD

16.26mm OIL COOLER CLEARANCE TO FRAME RAIL

11.5MM CLEARANCE COOLER TO BELT (NOT INCLUDING SLAP)

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Engine Oil Cooler (Cont)• The failure to package

protect for an oil cooler has led to sub-standard design clearances and required process changes.– Nut runners for oil pan to front

cover are mounted on fixed slide driving a process sequencing change

– Alternator install clearance is sub-standard requiring an operator assist as well as a protective shield on cooler during assembly

– Oil filter protrusion results in specifying two different filters (a stubby for assembly and regular FL400 for service)

– EPSA cable rerouted– Redesigned OFA to support

additional weight of cooler

Unique cooler shape results in cooler tooling cost of ½ million USD

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Go See!

Oopsie. Found another problem. The engine cannot be picked level with the poorly designed eye hooks. This makes the cooler package condition worse!

We are measuring 15mm clearance to the stanchion. CAD said we had 17mm… Your friends will lie to you.

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Engine Oil Cooler (Cont)Valley Mounted Cooler

If an engine oil cooler was part of the original engineering assumptions, then more time and resources would have been available to design a product that utilizes the current process without all of the sub-standard clearances and process tear-ups.

A valley mounted cooler would package nicely, but would require more time to sort through the block casting and block retooling changes.

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CONCEPT PACKAGE MODEL –80mm WIDTH, 39mm HEIGHT, 340mm LENGTH

CLEAN OIL IN TO COOLER - 15 dia

COOLED OIL TO BLOCK – 15 dia

WATER IN TO COOLER FROM WATERJACKETS 10 dia

WATER FROM COOLER TO BLOCK – 15 dia

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Engine Oil Cooler (Cont)Valley Mounted Cooler

• This package holds more promise than the external OFA mounted cooler previously shown.

• Larger cooler capacity with better heat rejection• Less coolant and oil pressure loss• Package constraints limited to intake, knock sensors

and wire harness• Fewer water / oil terminations reducing risk of leaks• Requires more Retooling effort and higher cost for

the larger cooler

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SVT

2000 SVT Cobra R

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SVT (cont)•SVT programs are often times built with same carry-over process. This includes Powertrain and Final Assembly

•SVT components are typically higher performance but are confined to existing architecture / package’

•Iconic SVT products are additionally bound by legendary ‘DNA’.

•Example: Mustang Boss 302 has always been naturally aspirated, so if more power is needed, forced induction is not an option.

•Catalog parts are sometimes used in these applications. Performance is known, volumes are low to warrant higher piece price without tooling investment.

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SVT (cont)

The next two slides show a catalog racing connecting rod (H-beam Manley). CAD modeling using Power Kit to add motion to verify packaging and fit within the cylinder block.

The shelf rod is fully machined. Verification for retooling (or in this case, compatibility within the current process) would be reduced to assembly processes only (piston and rod sub-assembling, bearing install, piston stuffing and bolt torque).

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FRONT VIEW- (Con Rod #4)0.015mm CLR TO PISTON SQUIRTER TUBE

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Con Rod #4 to Cyl Blk3.45mm clr

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Conclusion

Engineers who are responsible for the design and release of components should understand the whole manufacturing process related to their component and their system. A good analogy would be someone familiar with the house that they live in. Everyone knows what they like, what they don’t like and what they would change if possible about the house that they live in. Similarly, engineers should know the manufacturing process to understand what is currently possible, what is good about the current process and what they would change if they could.