How do you link CAD parts to press brake tooling?

[mike miller]

For those of you designing sheet metal parts that are processed inhouse, are you responsible to use the correct radius and K-factor or do you have a programmer that assigns press tooling and recalculates blank sizes? I know how to set up a gage table correctly, but the key is knowing exactly what tooling they will use every time. If they change tools because it's Tuesday, my painstaking gage table goes out the window. Oh, and guess who gets the blame for incorrect parts.

Our current system is based on tribal knowledge, which is horrifying from an admin perspective. The problem is; it's not as simple as always using a specific tool set for 10 gauge material, since we have bottoming tools for most bends, air tools for bends past 90, long planer tooling for really big parts, and gooseneck tools for forming lips and handles. And that is one thickness in one material.


My current plan is to create a spreadsheet that Engineering and Fab both reference which will assign a process number for every combination of tool and material. The problem is, if I start with S1 (for steel 1) and we keep adding processes, eventually we end up with a convoluted mess of outdated numbers mixed in with current numbers.

Can anyone out there preserve my sanity by pointing out what I'm doing wrong?

@bnemec, @jcapriotti, @DennisD, or anyone else who may know....

[Lapuo]

Our blank size on drawing is always just for reference.
Programmer is one who is responsible for that.
Actually , software which is used for bending will calculate it.

[MJuric]

For those of you designing sheet metal parts that are processed inhouse, are you responsible to use the correct radius and K-factor or do you have a programmer that assigns press tooling and recalculates blank sizes? I know how to set up a gage table correctly, but the key is knowing exactly what tooling they will use every time. If they change tools because it's Tuesday, my painstaking gage table goes out the window. Oh, and guess who gets the blame for incorrect parts.

Our current system is based on tribal knowledge, which is horrifying from an admin perspective. The problem is; it's not as simple as always using a specific tool set for 10 gauge material, since we have bottoming tools for most bends, air tools for bends past 90, long planer tooling for really big parts, and gooseneck tools for forming lips and handles. And that is one thickness in one material.


My current plan is to create a spreadsheet that Engineering and Fab both reference which will assign a process number for every combination of tool and material. The problem is, if I start with S1 (for steel 1) and we keep adding processes, eventually we end up with a convoluted mess of outdated numbers mixed in with current numbers.

Can anyone out there preserve my sanity by pointing out what I'm doing wrong?

@bnemec, @jcapriotti, @DennisD, or anyone else who may know....

The less of the manufacturing process I can dictate in Engineering the better. "I want a sheet metal part that looks like this, with these speciation's". Anything more on the engineering print is both taking on manufacturing responsibility that is unnecessary as well as limiting manufacturing in how they make the part.

We have a gage table set up very basically so that we generally choose materials that we buy in bulk. With that are some minimum bend radius and that's about it. The rest is left to manufacturing. This is even more true for sheet metal than other parts because the methods used to bend, weld etc are far greater than methods used to machine a block.

[jcapriotti]

For those of you designing sheet metal parts that are processed inhouse, are you responsible to use the correct radius and K-factor or do you have a programmer that assigns press tooling and recalculates blank sizes? I know how to set up a gage table correctly, but the key is knowing exactly what tooling they will use every time. If they change tools because it's Tuesday, my painstaking gage table goes out the window. Oh, and guess who gets the blame for incorrect parts.

Our current system is based on tribal knowledge, which is horrifying from an admin perspective. The problem is; it's not as simple as always using a specific tool set for 10 gauge material, since we have bottoming tools for most bends, air tools for bends past 90, long planer tooling for really big parts, and gooseneck tools for forming lips and handles. And that is one thickness in one material.


My current plan is to create a spreadsheet that Engineering and Fab both reference which will assign a process number for every combination of tool and material. The problem is, if I start with S1 (for steel 1) and we keep adding processes, eventually we end up with a convoluted mess of outdated numbers mixed in with current numbers.

Can anyone out there preserve my sanity by pointing out what I'm doing wrong?

@bnemec, @jcapriotti, @DennisD, or anyone else who may know....

We have default gauge tables we use depending on which equipment it will be made on. We have press brake gauge/bend tables and another for our Salvagnini panel benders. We have to work with mfg to know which equipment they will use.

Of course the Salvagnini parts work every time as it always bends them the same with the same tooling. For the press brake its like you said, I get called out to the factory because a part is not coming out right and it turns out they are using the wrong die because they just finished a different part and don't want to change the die. We try to make the tolerances as loose as possible to accommodate. An experienced operator can usually make it work by working with the tolerance for each bend. Run the high side on one, low on another, etc.

You aren't doing anything wrong, you just have to do what you're doing and document the process. Getting that tribal knowledge on paper and standardized is a chore and keeping it up to date is worse as the factory can and will make changes to keep parts made and shipped. To keep it standardized and documented, you need management buy end on the factory side. When they want to change a process, they need it documented.....maybe tout is as a step toward ISO 9001 certification.

[jcapriotti]

The less of the manufacturing process I can dictate in Engineering the better. "I want a sheet metal part that looks like this, with these speciation's". Anything more on the engineering print is both taking on manufacturing responsibility that is unnecessary as well as limiting manufacturing in how they make the part.

We have a gage table set up very basically so that we generally choose materials that we buy in bulk. With that are some minimum bend radius and that's about it. The rest is left to manufacturing. This is even more true for sheet metal than other parts because the methods used to bend, weld etc are far greater than methods used to machine a block.

We are headed in this direction. We have taken the flat views off the engineering drawing and put them on a separate manufacturing controlled drawing. We have an internal CAD group that handles both engineering and manufacturing documents so the manufacturing bend information can be added to the model after engineering is done designing the part. Engineering no longer specifies any manufacturing information except to insure that the part is manufacturable.

[mike miller]

While I was at Fabtech I was positively salivating over Bystronic's Bysoft software. You can bring in a solid model (basically a dumb solid), assign tooling, create the bend program, create the flat pattern for the laser based on the tooling and bend program, and nest the part. All in a few clicks.

Of course you have to have their equipment for it to work right, which we don't..... Cincinnati has software that will functionally do the same thing, but it's three separate programs. https://www.e-ci.com/software

[bnemec]

For those of you designing sheet metal parts that are processed inhouse, are you responsible to use the correct radius and K-factor or do you have a programmer that assigns press tooling and recalculates blank sizes? I know how to set up a gage table correctly, but the key is knowing exactly what tooling they will use every time. If they change tools because it's Tuesday, my painstaking gage table goes out the window. Oh, and guess who gets the blame for incorrect parts.

Our current system is based on tribal knowledge, which is horrifying from an admin perspective. The problem is; it's not as simple as always using a specific tool set for 10 gauge material, since we have bottoming tools for most bends, air tools for bends past 90, long planer tooling for really big parts, and gooseneck tools for forming lips and handles. And that is one thickness in one material.


My current plan is to create a spreadsheet that Engineering and Fab both reference which will assign a process number for every combination of tool and material. The problem is, if I start with S1 (for steel 1) and we keep adding processes, eventually we end up with a convoluted mess of outdated numbers mixed in with current numbers.

Can anyone out there preserve my sanity by pointing out what I'm doing wrong?

@bnemec, @jcapriotti, @DennisD, or anyone else who may know....

We just use one k-factor for steel. There are a >few< parts that have custom k factor or bend radius set for the part or maybe for just a feature or two. Example custom home-made break press offset tool or something. Really need to consider what you're making and what's needed. What is the tolerance? I get that leg lengths multiply the error and errors can really accumulate across several bends. Are you making washing machines or rack mount equipment enclosures? Most of what we make the design doesn't require the level of precision. To be fair to press operators, we find the variances in the "run of the mill" material that we get cause more problems and make it difficult to guarantee a predictable k-factor or bend radius in air bending, which is mostly what we do on the break. Example is we were doing testing on parts made from our plain carbon sheet steel vs grade 50 sheet steel. Turns out our plain carbon steel is sometimes harder than grade 50. The break press operators handle this better than the die run presses can. We have found it is more important to make clear on the prints what are the significant features on the part. If that is properly conveyed the break press programmer can make good parts that meet the requirements in spite of material variances. Same for progressive die toolers, if we communicate to them what is important and what can move around it's likely that can better plan for hardness or camber variances.

In our experience there are so many other things to spend time and energy on that will have bigger effect on part quality than trying it pin the k-factor or bend radius onto a gnat's hind end. Sorry to be damper on the topic. But, maybe your product already demands a different level of manufacturing processes and raw materials and getting the k-factor right in the model really is a weak link.

[mattpeneguy]

@DennisD,
Had a method he used to test bend a piece of metal and then set the k-factor based on the test bend to get more accurate bends for that batch of sheet metal because different runs of metal they'd receive had different thicknesses, or at least that's my recollection. It hasn't been moved over to the new forum, but I believe it was this thread https://forum.solidworks.com/thread/204571.
Hopefully he'll be by soon and can weigh in, even though the problems you are having are a little different.

[jcapriotti]

@DennisD,
Had a method he used to test bend a piece of metal and then set the k-factor based on the test bend to get more accurate bends for that batch of sheet metal because different runs of metal they'd receive had different thicknesses, or at least that's my recollection. It hasn't been moved over to the new forum, but I believe it was this thread https://forum.solidworks.com/thread/204571.
Hopefully he'll be by soon and can weigh in, even though the problems you are having are a little different.

I think Mike's problem is similar to ours. We did test bends and established bend allowances based on several test samples for various gauges. Then manufacturing starts making many different parts of various gauges and they don't want to switch dies. So they setup the machine to form some 16ga parts then switch to a 12ga part and don't change to the die we ran the sample from, thus bad parts.

An experienced brake press operator can often make it work by bending the legs at one end of the tolerance such that the last leg still falls within tolerance. Less experienced operators don't know how to do this and we get a call.

[mike miller]

I think Mike's problem is similar to ours. We did test bends and established bend allowances based on several test samples for various gauges. Then manufacturing starts making many different parts of various gauges and they don't want to switch dies. So they setup the machine to form some 16ga parts then switch to a 12ga part and don't change to the die we ran the sample from, thus bad parts.

An experienced brake press operator can often make it work by bending the legs at one end of the tolerance such that the last leg still falls within tolerance. Less experienced operators don't know how to do this and we get a call.

Yes. My point exactly.

Even if it's not technically "our fault", engineers have a tendency to become a catch-all for blame. Do not ask me how I know this.

[jcapriotti]

Yes. My point exactly.

Even if it's not technically "our fault", engineers have a tendency to become a catch-all for blame. Do not ask me how I know this.

Well, one way maybe to fix the problem is use your default numbers but make manufacturing figure out where the problem is and write an ECO to have it fixed.

He who fixes problems for others only has others problems to fix - The Sphinx from Mystery Men

[MJuric]

Yes. My point exactly.

Even if it's not technically "our fault", engineers have a tendency to become a catch-all for blame. Do not ask me how I know this.

This is the problem with directing manufacturing from Engineering. If you have a strict wall of "I don't tell manufacturing what to do" then they can only blame you if you screwed up your job, which is designing the parts.

The second you open the door to "Make this part this way", you've just shifted manufacturing's job to Engineering and not only will you get all the blame for every manufacturing error but Engineers aren't...well shouldn't be, as good at deciding exactly how to make a part as manufacturers.

[jcapriotti]

This is the problem with directing manufacturing from Engineering. If you have a strict wall of "I don't tell manufacturing what to do" then they can only blame you if you screwed up your job, which is designing the parts.

The second you open the door to "Make this part this way", you've just shifted manufacturing's job to Engineering and not only will you get all the blame for every manufacturing error but Engineers aren't...well shouldn't be, as good at deciding exactly how to make a part as manufacturers.

Well, since we have separated the engineering design and manufacturing into two separate drawing files, we now get pushback from mfg about having to open two files to get all information.

[HerrTick]

Ultimately, the tool designer and manufacturing need to own the tool and process design, including making sure flat and any intermediate stages AND final product are correct.

You can refine your design process all you want (and probably should), but in the end, each piece and each tool has its own peculiarities. Accounting for and correcting for that also needs to be part of the process (e.g. deviations and revisions).

[MJuric]

Well, since we have separated the engineering design and manufacturing into two separate drawing files, we now get pushback from mfg about having to open two files to get all information.

Manufacturing drawings should be created by manufacturing. Yep in some cases manufacturing doesn't have the expertise and ability to create those drawings so engineering does....it's still based on a manufacturing function and thus manufacturing responsibility.

I absolutely fight tooth and nail anytime I get the "Well manufacturing needs this dimension on the drawing so it should be on the drawing" request. No it does not need to be on the drawing to properly specify the part, so it does not NEED to be on the drawing. If manufacturing needs it then we will make a special drawing for them....that is THEIR responsibility.

If I send this part out I guarantee I will not get a call saying "I need this dimension to make the part" unless the dimension is actually needed to define the part. All my vendors know better and they make whatever drawings they need to make the part themselves. I don't expect anything from my in house manufacturing than I do of my vendors.

The age of CNC and CAM have made manufacturing lazy. They want to place the model into something and push a button and walk away and take zero responsibility for making a good part. "Management" has also fallen into this trap because having engineers do manufacturing functions generally means more qualified people doing the work. The end result however is manufacturing just continues to get worse and worse at their job and you essentially end up baby proofing everything.

It's a trend that started decades ago with the erosion of education, training and talent in the manufacturing sector because "Everyone needs to go to college". It's not how it's supposed to be as a great product requires highly qualified people at every level of the process not just one "Scape Goat"

....ok sorry...rant over...happy Monday

[DanPihlaja]

...
The age of CNC and CAM have made manufacturing lazy. They want to place the model into something and push a button and walk away and take zero responsibility for making a good part. "Management" has also fallen into this trap because having engineers do manufacturing functions generally means more qualified people doing the work. The end result however is manufacturing just continues to get worse and worse at their job and you essentially end up baby proofing everything.

It's a trend that started decades ago with the erosion of education, training and talent in the manufacturing sector because "Everyone needs to go to college". It's not how it's supposed to be as a great product requires highly qualified people at every level of the process not just one "Scape Goat"

...

Just wanted to say, well said!

[MJuric]

Just wanted to say, well said!

I could go on for days on the complete and utter destruction that we've created in this country with our shift away from having respect for a decent "Blue collar" career to "If it doesn't require a degree it's not a worthy career choice". There was a time when a good machinist was given as much respect as a good engineer. Today however a really terrible engineer is generally more valued and respected than a really good machinist...not that there are many left.

[jcapriotti]

I could go on for days on the complete and utter destruction that we've created in this country with our shift away from having respect for a decent "Blue collar" career to "If it doesn't require a degree it's not a worthy career choice". There was a time when a good machinist was given as much respect as a good engineer. Today however a really terrible engineer is generally more valued and respected than a really good machinist...not that there are many left.

Same has happened to 2 year technical degrees. Not sure who's to blame but now many companies are requiring a 4 year degree minimum for a lot of jobs. I have a 2 year degree in Drafting/Design and wasn't even able to get past the HR screeners to talk with a hiring manager one time. Our own company tried to do this in the past which frustrated one of the managers looking for drafters, he kept receiving resumes for 4 year engineers and other degrees that weren't even engineering related. Our screeners weren't letting the experienced 2 or no degreed drafters through.

In US high schools, there were two career paths, 4 year university and vocational technical, I think there still is but the emphasis has shifted to either 4 year or burger flipper.

[MJuric]

In US high schools, there were two career paths, 4 year university and vocational technical, I think there still is but the emphasis has shifted to either 4 year or burger flipper.

Most of the vocational stuff around us has been shut down. We used to have a HS "Vocational Center" that was attached to my HS. My HS had 4K kids in it and the vocational center was larger than the HS and used for students across the city.

it was shut down toward when I was graduating which was when the "Go to college" push really started to ramp up. We had multiple Auto, Electrical, machining, woodworking, Drafting etc etc etc classes. All of that was replaced with STEM only and "Go to college".

Now we have a serious gap in people prepared to enter the manufacturing sector and a bunch of college drop outs that should have spent time on a table saw in HS rather then failing calculus three times that have 20K+ in student debt and no skills other than "You want fries with that"?

I once rented an apartment to a guy from Beligium where apparently higher education was free. He moved to Canada and was working in the US because every job in the country required a relatively high degree. He said he got to Canada, got a job making more money than he could have in Belgium WIT'H a degree. He also said that in some cases they have people with higher level degrees, Masters/PHD's doing much lower level jobs because everyone has a degree. Now how much of that is true, no idea, it was one person in one conversation. However, that's the path we are taking in the US as well.

Give me a guy that spent HS working on cars and making things to be my mechanical designer over the one with a college degree that spent HS studying to do well on the next math test any day of the week. If I need someone to do the stress calcs on the airplane wing....give me the dude that spent all summer studying for next years math, physics etc.

[jcapriotti]

@MJuric Of all our different global engineering groups, we are the only country to have drafters. I mean, they have people doing that work but they are degreed engineers, they don't have any 2 year degreed drafters. I can't imagine a 4 year degreed engineer wants to do just modeling and drafting.

In small company an engineer may wear many hats and do both, but we have 2 dozen people just doing SolidWorks all day long. If we just hired engineers, we'd either being paying twice as much or pay them half what they could be making.

[MJuric]

@MJuric Of all our different global engineering groups, we are the only country to have drafters. I mean, they have people doing that work but they are degreed engineers, they don't have any 2 year degreed drafters. I can't imagine a 4 year degreed engineer wants to do just modeling and drafting.

In small company an engineer may wear many hats and do both, but we have 2 dozen people just doing SolidWorks all day long. If we just hired engineers, we'd either being paying twice as much or pay them half what they could be making.

Most large companies in the US used to have a two forked path to "Engineering". You had the traditional engineer that went thru college and was hired as an engineer and you had the guy that started as a truck driver and worked thru working in the shop, drafting, mechanical designing and eventually became an "Engineer", checker or project manager.

I have the most experience with Germany but they largely do the same thing but much of the first part "Drafting" and "Working in the shop" are actually part of their university education. Pre-Pandemic we would have anywhere from 5-10 interns from Germany each year. They ranged from senior in HS just accepted to Uni to working on their doctorates thesis. Their college education FAR surpasses ours in engineering and largely because they are not only expected but it is mandatory that they spend time in shops, interning, etc etc. For the most part, at least in my experience, I'd hire a two year university student on the engineering track from Germany over a US four year graduate on the same track.

Most of the US graduates I've seen have a "Senior project" that is almost always something "Fun" that they get some practical experience with but it's generally unguided and no where near enough to be useful.

The German students spend far more time with far more talented teachers, again at least in my experience.

[SPerman]

I am a big fan of Mike Rowe Works and similar initiatives to get people involved in the trades. I talk about it with all of my friends, including the math of where they will be in 4 years ($100k in debt vs. money in the bank and a skill in demand.) They all have the same answer: "I can see the value in that for someone else's kid, but mine is going to college."

[MJuric]

They all have the same answer: "I can see the value in that for someone else's kid, but mine is going to college."

Great, so while your kid goes to college, wracks up 100K in debt and ends up with a "Do you want fries with that?" degree, that plumber that got paid $18 an hour to go thru a four year apprentice ship, ended up with no debt....just charged you $150 an hour to replace that broken pipe.

I have ZERO problem with college but I have a HUGE problem with cognitive dissonance. The same people that are proclaiming "My kids going to college" for no other reason than "That's what my kids are supposed to do" are the same people who's kids are running around playing sports all over the country because "Well this is how they will get a scholarship" because there kid is barely passing every class they are taking.

Some kids can be surgeons and some can be NFL quarter backs but most people are somewhere in between. Half, maybe more, of those people would be better off gaining some skills, going to vocational school, doing an apprenticeship etc rather than going to college. This is even more true being that a huge portion of HS students have NO IDEA what they really want to do. Go out, do some things, work in a hospital at some lower level, working in manufacturing etc etc etc and when something clicks you can always go to college.

It took my kid one day in his CNA class in HS actually working in a retirement center to realize "Yeah, that's not what I want to do."

[jcapriotti]

It's a society issue, I don't even quality for my job anymore since there is a 4 year degree requirement. I'm not alone either and the company has flip/flopped several times because there were still enough older senior management to overrule it.

I worked at a medical company and a 2 year degreed drafter had worked there for 30 years and moved up to an engineer for the last 20 years. He had quit then tried to come back a few years later but new HR policy made him no longer "qualified".

I still have a number of years until retirement and wondering if I should go get the paper. They don't seem to care what the 4 year degree is in, just that you have it.

[mike miller]

Confession time: I've never set foot on a college campus, or even a community college. I would not qualify for many positions because of this. The irony is: there are "degree'd engineers" with far less practical knowledge of general CAD, FEA, and DFM principles than I have (don't ask how I know this). I'm not bragging or anything, just sayin'.......

My experience with this, as well as working in other fields with "educated" people has convinced me that on-the-job training and/or apprenticeship is the way to go. Especially after @jcapriotti's statement that some companies don't even care what the degree is, just that you have one! That's silly.

[MJuric]

Confession time: I've never set foot on a college campus, or even a community college. I would not qualify for many positions because of this. The irony is: there are "degree'd engineers" with far less practical knowledge of general CAD, FEA, and DFM principles than I have (don't ask how I know this). I'm not bragging or anything, just sayin'.......

My experience with this, as well as working in other fields with "educated" people has convinced me that on-the-job training and/or apprenticeship is the way to go. Especially after @jcapriotti's statement that some companies don't even care what the degree is, just that you have one! That's silly.

I spent two years and some taking Engineering classes. At the same time I was working in a shop essentially doing mechanical design. At the point where I was correcting some of the things taught in class like "But that's not how we do it" type of stuff I kind of decided I would be better off just continue working.

Today I regret that decision but not because of the engineering side as much as the Math, Physics and Chemistry side. I could be a better mechanical designer with being better in these areas but I mostly wish I would have gone further in those areas because I tend to do personal projects that would benefit from them

I also would never recommend anyone to plan on the route that I took today because it's harder to even get in the door. If you want to get into Engineering you should probably go to college and get a degree as that's a far more sure thing than being "promoted" to mechanical designer. That however does not mean that everyone should go to college. Just that some career paths need a degree and many today that we say do need a degree really don't.

[jcapriotti]

I agree, I don't think I would recommend a drafting degree today. The college I went to doesn't even offer it anymore although others not too far away still do. We even had a candidate apply not long ago that had a 4 year drafting degree.

My 2 year degree cost like $3000 in the early 90's. They got me a part-time drafting job after my first year while I was finishing my second year. I was essentially debt free when I went to work full time. I remember we hired an engineer that just graduated for a drafting position and he was trying to pay off $40,000 of student debt, that was around 1999-2000. Was his debt really worth 10x mine?

If I were conspiracy minded, I might think the University lobby was involved in some way.

[SPerman]

[goldenfiberlaser]

While I was at Fabtech I was positively salivating over Bystronic's Bysoft software. You can bring in a solid model (basically a dumb solid), assign tooling, create the bend program, create the flat pattern for the laser based on the tooling and bend program, and nest the part. All in a few clicks.

Of course, you have to have their equipment for it to work right, which we don't..... Cincinnati has software that will functionally do the same thing, but it's three separate programs. https://www.e-ci.com/software

Golden Laser metal laser cutting machine supports different CAD, Solidworks format and connect with MESS system easy to realize automatic production. https://www.goldenfiberlaser.com/high-p ... ource.html