February 10, 2015

Posted on February 10, 2015 by Dave Breiner, Synergis Solutions Engineer:
I get a lot of questions from people not familiar with Sheet Metal. They ask how they can create a quick flat pattern from a cone or transition piece. They may not be interested in learning sheet metal, but need a flat pattern for a customer or for manufacturing. They are afraid that the feature will take a lot of time to learn.  However, it doesn’t have to be that way.
I am going to give you the quick, down and dirty in order to complete your flat pattern. I will expand on the Sheet Metal Rules in a future tutorial.  So let’s go.
The foundation of creating sheet metal components is built on the sheet metal rules that define them.
Creation of accurate sheet metal rules can save an enormous amount of preliminary work when designing sheet metal parts. Sheet metal rules can be set in the Sheet Metal Default or the Standards and Styles editor, and can get rather involved depending on your application. However, like I said, here is the quicker version.
For best results, create your part using a Sheet Metal template. You can select your Sheet Metal Rules before or after you create your sketch. The thickness of the part will be determined by the Sheet Metal Rule you create.
Sheet Metal Rules contain the default parameters used by the component to create its features and define its properties. Multiple rules can be created to reflect different thickness, bend radii, and materials.
One simple way to create your Sheet Metal Defaults or Styles is to open a Sheet Metal IPT. (Fig. 1 & Fig. 2)
sm1 sm2
Select the Sheet Metal Defaults command on the right side of the Sheet Metal Tab. (Fig. 3)
Left mouse click on the Pencil to the right of the Default Sheet Metal Rule Fig. 3. This will open the Style and Standard Editor. (Fig. 4)
Select the New button (Fig. 4) at the top of the window then name the New Style (Fig. 5). In this example the name will be the Material and Gauge: “STEEL, 12 GA”. Select OK.
Notice that the New Styles are “Local” to this Sheet Metal.ipt.
Select the Material that is indicated by the name you have given to this style from the Material pull down. (Fig. 6)
Type the thickness to be used.
Click Save to save this style.
Since we are looking for a basic flat pattern, I will address the remainder of the settings in a future tutorial.
Create all the styles you find necessary by selecting New, setting the Material and Thickness and saving each.
The “Active” rule is in Bold. (Fig. 7)
To activate a different Rule, right-click on the desired rule and select Active.
This is how you set the thickness and material of the part.
When all of the new styles have been completed, select Done at bottom right. Select Cancel or OK from the Sheet Metal Defaults window.
If you have not created a sketch, this is a good time to save this ipt as a Template.
From the Inventor Application Window, select Save As > Save Copy As Template. (Fig. 8)
In the Save Copy As Template window shown near right, you can verify that the new template will be saved in the location of the other Autodesk Inventor templates that you have specified in your Application Options, shown at far right. (Fig. 9 & Fig. 10)
Select a folder, in this case, the English folder,and give the new template a unique and descriptive name. (Fig. 11)
When finished naming the template, select Save. The new template is now available from the selected folder when starting a New Sheet Metal .ipt.
Note: Some may frown upon this method of saving new Sheet Metal styles, however I find it much faster than fooling around with Styles Editor. If any changes are needed, Open the “Named” Sheet Metal.ipt that you want to edit. Make all changes desired and Save Copy As Template and over write the file in the template folder.
Create your part as you would a standard part using sketch tools and in this case, the Loft command. When the Loft command is used, the thickness in the selected rule will be applied to the part.
In order to create a flat pattern of the shape above left (Fig. 12), which would be considered a “Closed” shape, you must add a “Rip” or seam as shown below. (Fig. 14) This will allow the shape to unfold into a flat pattern. (Fig. 13)
Please keep in mind if manufacturing is using a press brake, you cannot provide a full flat pattern as shown above, unless manufacturing can alter the template to use the portion needed.
You may want to provide a half template as below. (Fig. 15 & 16)
I hope this has been a help. I will address other Sheet Metal features very soon, so return and keep an eye out. You are welcome to suggest a topic that you would like to learn more about.
Till then!
Dave Breiner
dave_breiner_MG_0352Dave Breiner joined Synergis in 2013 as a Solutions Engineer on our Manufacturing team with an amazing amount of experience. Coming directly from being a CAD Manager with SPX/Ecolaire, Dave is well versed in implementing and using Autodesk software having transitioned the department from 2D to 3D modeling by developing a 3D modeling program, implementing modeling standards, and creating automated models using iLogic programming. Dave began his career with SPX as a preliminary designer of steam condensers before being promoted to Manager of Drafting. Prior to this, Dave was with Bethlehem Steel for over 20 years, performing many tasks including millwright, rigger and fitter. During this time he also completed his degree in Engineering Design.