Sheetmetal TC Survey - Flat Pattern vs. Flat State

We also use Flat State and shows it on the drawing only with the outer dimensions length and width. We have a mapkey to create the Flat State so it's almost as quick as the Plat Pattern. We use it for extport to DXF as well.

I just want to emphasize what John posted above.

One real downside of the Flat State implementation is that it creates family table instances that now have to be managed in Windchill. It would be nice if the Flat State was fully contained as a state within the parent object and was not recognized as a family table instance.

Having the Flat State as part of the family table also makes normal use of the family table more difficult. It means that for every instance that you might create of a sheetmetal part, you also have to create a corresponding flat state in the table.

I'd really like to see a better implementation of these "flat states" (something more like an explode state) with the addition of automatic bend sequence "playback" (like CoCreate).

Regards

Magnus

In Reply to John Frankovich:

We use Flat State company wide.

We create fully formed model drawings that include a second sheet with a separate fully ordinate dimensioned flat view. This view is for in house quality checks at this stage of the manufacturing process. In addition a third sheet is also included for a full scale flat view without dimensions, but with key manufacturing id information. This third sheet is used to create a DXF file that is fed to manufacturing for use in any of 5 different NC tooling packages for turrets, lasers, routers, waterjet, etc.

The Flat State, being created in the family table already, makes control of these views pretty easy. In addition, we can create multiple flat states to represent various in between states (partially formed, rolled, rolled and flanged, etc.)

The Flat Pattern is nice in that it is quick and easy (without a mapkey) and remains at the bottom of the model tree as you continue to add features to the model, but we find the Flat State to be more flexible. For one thing, the Flat State is already suppressed and automatically creates a family table instance.

Also, there are times that you need to create the unbent state, but you have features that need to be added to the formed state that will cause the unbend to fail. In these situations, you create the Flat State and suppress these problem features in the same instance.

One real downside of the Flat State implementation is that it creates family table instances that now have to be managed in Windchill. It would be nice if the Flat State was fully contained as a state within the parent object and was not recognized as a family table instance.

Having the Flat State as part of the family table also makes normal use of the family table more difficult. It means that for every instance that you might create of a sheetmetal part, you also have to create a corresponding flat state in the table.

I'd really like to see a better implementation of these "flat states" (something more like an explode state) with the addition of automatic bend sequence "playback" (like CoCreate).

John Frankovich
The GSI Group LLC

My company hasn't had a clear standard to use one or the other, it has been up to the user.

That said, I am attempting to standardize us on the flat pattern. One of the main reasons is that this feature is always automatically moved to the bottom of the model tree. This helps reduce issues with people creating multiple features that do the same thing not realizing the other flattern step was there initially.

Besides the handy functionaly of always moving to the bottom, we have not noticed any difference in performance between the two features. Flat patterns do however have less options and thus are more simple to use.

Hey Joel,

We try to enforce the Flat State command so we get the Family Tabled _flat easily. However there is much confusion from users on this. Unbend vs. Flat Pattern vs. flat state. I would like to see the Flat State command create a Flat Pattern feature instead of an unbend feature. This way it is clear to users that the Flat Pattern feature shows the flattened form of the model and that the Flat State command is simply a way to create the FT version with a feature that stays at the end of the model.

We use the flat version to show on the drawing and send to DXF for in-house MFG. We do not create or dimension a flat for vendor supplied.

We use Ordinate dims on the flat view and dimension overalls and location of one of the cut-out features so they can verify the DXF. We also dimension all the coutout featute sizes (not all the locations)

I will begin by answering your last questions first. My company does not create flat pattern views on our drawings. Our vendors are taking our parts directly and creating their own flat to meet our final, bent-state design.

That being said, we do not have an in-house standard, per se. My personal preference is to stay away from family tables, so I use flat patterns on all of my sheet metal parts. The self-suppressing, self-reordering to last feature is a big plus for using this feature. I use the flat pattern just to insure that the part will flatten, and to check for any overlap/interference on complex cuts/bends.

Regards,

Jim Melton
Physical Design Engr
Fujitsu Network Communications, Inc.

As a company standard, we use the flat state (driven by a mapkey) so that we can include the flat in our drawing with minimal dimensioning (typically linear bounding dimensions for reference only). We also generate a dxf of the flat for fabrication (no dimensions). I don't know how you would create the drawing with a flat pattern if you want to show both formed and flat geometry.

See replies below...

In our recent Sheetmetal Technical Committee meeting we had a discussion on the functionality and usage of Flat Pattern versus Flat State, and which of the two is used more by users.

If you create a flat model with your Sheetmetal parts, which functionality do you utilize, the Flat Pattern or Flat State?

Set up / Flat State.

Why?

Because we get the flat as a stand alone instance for the drawing.

Is this a personal preference or company standard/practice?

Company standard

What do you use these flat models for?
For example:
Just for verification that a model unfolds?Yes.
Send the flat model to a vendor/in house shop? Tes - for CNC programming of turret and laser.
Create a flat model drawing? Yes.

Do you (your company) create Flat Pattern (State) drawings? Yes

If yes, is the drawing partially or fully dimensioned? Yes..
Is this done for every Sheetmetal part, or specific circumstances that drive this? ALL sheetmetal parts.
What dimension scheme do you use for flat drawings, linear or ordinate? Combination of linear and ordinate.

Thank you for your time and feedback

You're welcome.

Joel Nelson
PTC/USER Sheetmetal TC Chair