DFM practice

[pavvpk]

Hello,

I am trying to learn best practices to implement DFM / DFMA process.

Just wondering how some of experienced peers using implementing these?

Can you please shed some light if there are any better tools or software's available to quickly look into these?

thanks,
pavv

 

[hendersdc]

DFM is process dependent, which manufacturing processes are you interested in?

 

[mfgenggear]

here is a white paper , seems for high volume assembly production

https://me.gatech.edu/files/capstone/L071ME4182DFA

 

[IRstuff]

There are some general rules
> You can't improve something you're not measuring in the first place
> Improvement is a double-edged sword; you can improve one thing, say, process equipment longevity and totally kill something else, say, process yield/reliability -- you need to have a thorough understanding of how every process step affects the end product

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[pavvpk]

thank you for your responses.
I would like mainly find out what tools people mostly use to implement DFM.I have seen module available in ERP system and some add in tools for CAD programs.
Is there any better stand alone software / add in tool for CAD program / ERP system module - that would help us to quickly evaluate steps instead of using excel file.

 

[mfgenggear]

Check into a company called kbmax

 

[IRstuff]

Much of DFM for mechanical is buried in best practices for the machinist or for the CNC machining.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[mfgenggear]

while being an old timer I don't agree with some of the DFMA concepts, like any procedure there are rules that should be broken.
it seems like this is an attempt to stream line the design process for manufacturing, not to trash DFMA it has it's value.
small job shops have different machines and skill sets and sometime have different abilities.
where it has it's value is stream line the designs that work, instead of trying to re invent the wheel over an over.
one has to look at the big picture, installations, (major assembly) . sub assemblies, and detail parts which could be make or buy.
there could be a possibility of a million different parts, that are machined parts, sheet metal parts, castings, powdered metal.
wiring harnesses, solenoids, sensors, to many to list.
In the old days and times have changed, there was a department called the model shop. and it use to be run by engineers and very experienced fabricators
from all walks of life. I use to have volumes of notes how I resolved manufacturing and engineering issues. some of my knowledge was from these guys when I was a kid.
they would come up with concepts, and the draw it as they build it. while in theory DFMA appears sound,
there are to many variables, "it seems to me" to cover them all. old saying "I know enough to know what I don't know."
but it is a step in the right direction.

 

[hendersdc]

If you were making injection molded parts and were interested in making them easier/cheaper to manufacture I would direct you to a design guide for injection molded parts. I would do the same for the other manufacturing processes as well, an individual part can't be optimized for all processes at the same time, only the one you intend to use to make it.

There is no add-in tool for CAD that will design your part well for you.

Are you looking for general rules that apply to design? Like combine parts where possible, make things self aligning where possible, make things symmetric or impossible to install backwards where possible, etc.

 

[reo682]

I am just interested to findout if there are any better tools available (add in tools for CAD programs - for both parts as well as assemblies) or other ERP systems.
So far I have been using general optimization techniques for parts and assemblies and also some times used excel worksheet to analyze functionality of different parts. I never had opportunity to do full scale DFM analysis for complicated assemblies such as automobile parts, etc.
I was just wondering, if there are any tools available to help to process DFM / DFMA techniques in industrial type high volume products efficiently between multiple teams, etc.

 

[reo682]

By the way I noticed DFMXpress add in for solidworks and also 3rd party add-in's such as DFMPro. I am not sure how effective these are. It looks like they just analyze some features and report issues. So far I didn't find any CAD tools that help with assembling part of DFM

 

[IRstuff]

So far as I know, only in large-scale, internal, manufacturing processes would such tools really do justice, since then, you can code in idiosyncrasies of different CNCs or mills, etc. Otherwise, only generalities can be applied; was there an edge break called out, or does the hole clearance match the called-out screw tolerances, etc. So, some things can clearly be caught; I think the rest is possibly machine-shop-specific.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Jessica Herron]

Design for Manufacturability

1. Leverage Industry Standard Design Rules. Leveraging existing industry standards (IPC, JEDEC, ASTM, ISO) when possible is a good starting point for a DfM review. ...
2. Conduct a Formal Design Review. ...
3. Use Simulation and Design Software. ...
4. Perform a Materials and Process Audit.

 

[CWB1]

Which DFMA are you referring to? Design For Machine Assembly, Design For Manufacturing & Assembly, or Design For Morons & A$$#@!es?

As mentioned, DFMA tools will vary by process. Some processes like casting or forging are usually best left to commercial software. Others like machine work and general assembly can be handled nicely with common CAD and a bit of effort. If you don't have a library of hand/power/cutting tool and/or spindle models, or kinematic assembly models of common parts like fasteners then that's where I'd start.

Taking this a step further back, I'd recommend reviewing your dept's knowledge of applicable manufacturing processes as well as your documentation and communication processes. Many engineers today have little/no education in quoting, manufacturing planning, tool/fixture design, nor even much knowledge of common specialty tools. Many choose not to leverage their internal manufacturing/financial/other experts early/often enough. Many make beautiful CAD models and prints that are confusing or add needless cost on the shop floor. Take every opportunity to tour and/or talk to suppliers to learn and find/implement best practices so that you're not wasting money needlessly. Seemingly small details like how you organize a CAD model, draft a print, and choose tools can have a huge cost impact, which is why I recommend every junior engineer spend the first few years of their career at a mega-corp - to learn efficient design.