3. Objective 1: Roll Geometry Into a Cylinder
The objective of this tutorial is to demonstrate techniques which can be used to roll a flat sheet into a cylinder (tight spiral). Parameters will be used to capture critical variables required to generate a cylinder using a Spiral of Archimedes.
Detailed View
~80”
Beginning Geometry
.01” Thk Flat Sheet w/ repeating tabs along the top/bottom edge

4. Preparation: Configuration Options
In order to work with the very detailed features in our example model, it will be necessary to set several configuration options before we begin.
First, we must set the model accuracy finer than the default accuracy range allows. To accomplish this, reset the lower accuracy boundary by selecting ToolsOptions and setting the accuracy_lower_bound option to as shown below. 4

5. Setting the Accuracy
Set the accuracy of the model to by selecting FilePropertiesAccuracyChange
Enter and select Regenerate Model as shown below.
Close the Properties dialog box to proceed.

6. Setting the Model Display Properties
To insure the tight curves in this tutorial are displayed smoothly on screen, set the Edge Quality to Very High by selecting ViewDisplay SettingsModel Display
From the Edge/Line tab, set the Edge Quality as shown.

7. Beginning Geometry
This tutorial assumes pre-existing geometry with irregular features will be rolled into a cylinder.
Starting from scratch, there are other, less cumbersome techniques for rolling/unrolling a cylinder. However, these techniques usually begin with a spiral curve or cylinder and end with flat geometry. This procedure begins with flat geometry and ends with a spiral cylinder.
Flat Geometry
Rolled Geometry

8. Spiral/Coil Parameter Definitions
coil_outer_dia
coil_inner_dia
coil_gap_thk
coil_sheet_thk
These 4 parameters will be used to create the spiral curve equation in subsequent steps.

9. Spiral Curve Reference Requirements
Curves created from an equation require a single coordinate system as a reference. For this tutorial, the spiral will be created in the X-Y plane (the “Top” plane) and centered on the Z axis.
The CSYS below has been named for convenience.
Placement of this coordinate system feature is important.
Place it along one edge of the solid geometry in the location you want the spiral to begin.
See Next Slide for details.
Solid Geometry Removed for Clarity

10. Important Considerations for Spiral CSYS
The coordinate system for the spiral should fall along a solid geometry edge. Notice that the spiral below falls on the end of the flat geometry with the Z axis aligned to the vertical edge.
Note the location of the CSYS along the rear edge of the solid geometry
+Z Axis Aligned to this Edge
This slide intended only to illustrate CSYS placement. Spiral curves will be created on the next slides!
Spiral Curve Top View Reference Only
Spiral Curve Isometric View Reference Only

11. Overview: Steps for Rolling Solid Geometry
Step 1: Create parameters to define spiral (req’d in Step 3)
Step 2: Create a coordinate system as the starting reference for a spiral curve.
Step 3: Create a Curve From Equation to define the spiral.
Step 4: Extrude a surface from the spiral curve which will be used as a wrapping reference.
Step 5: Wrap a sketched copy of the solid geometry around the reference surface from previous step.
Step 6: Trim away unused portions of the reference surface.
Step 7: Thicken the reference surface to create the solid.
Although the remainder of this tutorial documents the steps required to create the specific geometry shown in the examples, you should apply the lessons learned to your own designs. Experiment with the sample models to gain additional insights into the techniques presented. For example, change the orientation of the reference coordinate system in Step 1 or alter the equations shown in Step 2 to see the effect of these modifications.
Detailed Instructions For Each Step Follow on Next Slides

12. Step 1: Create Parameters to Define Spiral
From the top Pro/ENGINEER menu, select ToolsParameters. Enter the four new parameters and the values shown below.
See Slide #7 to review the parameter definitions.
These parameter values will be changed later.
We’re using them as an initial start point.

13. Step 2: Create a Reference CSYS
Create a coordinate system as the starting reference for a spiral curve. Locate the coordinate system keeping in mind the requirements and considerations on Slides 8 & 9.
+Z Axis
Isometric View CSYS Placement Detail
Top View CSYS Placement Detail

14. Step 3: Create a Spiral Curve From Equation
To create a Curve From Equation, from the top menu select InsertModel DatumCurve or use the Datum Curve icon circled below. Select From Equation and Done from the menu to proceed.
When the Curve dialog box opens, select the coordinate system created in the previous step. Choose Cylindrical as the Csys Type.
The relation editor will automatically open (see next slide).

15. Step 3: Creating a Curve (Cont)
The Relation Editor will automatically open with some default comments. From the editor window, select FileOpen and load the file “spiral_relation.txt” included with the tutorial files. The modified file appears below.
Relation Notes
All lines beginning with “/*” are comments
For a cylindrical equation (used in this example), you must define each of the following three variables:
r – radius
theta – angle of rotation (polar)
z – depth
When Z is equal to zero, the curve will remain flat and coplanar to the reference coordinate system

16. Step 3: Creating a Curve (Cont)
From the editor window, select FileSave to save the relations. Select FileExit to exit the editor and return to the Curve dialog box.
Select OK to complete the curve definition.
A spiral curve will appear centered on the reference coordinate system as shown below.
Top View Spiral Curve Detail

17. Step 4: Extrude a Surface from the Curve
Start the Extrude tool (InsertExtrude). Select the “Top” datum plane as the sketch plane. Once in Sketch Mode, select SketchUse Edge and select the curve.
Select the entire curve with the Use Edge function. This will copy the curve as the sketch for the Extrude feature
Select “Top” as sketch plane
Top View Spiral Curve Detail

18. Step 4: Extrude a Surface (Cont)
Complete the sketch by selecting to return to the Extrude Tool dashboard.
Set the dashboard as shown below turning on the Surface option and setting the depth symmetrical to 5.00 inches. When done, complete the feature by selecting
Set the Surface option here
Use Symmetric depth
Set depth value to 5.00
Extrude Dashboard Options
Extrude Preview

19. Introducing the Wrap Tool
The Wrap Tool provides the ability realistically wrap a sketch around any surface.
For our demonstration model, we’re using the extruded surface from Step 4 as our reference surface.
One limitation of the Wrap Tool is that it cannot be used directly on solid geometry. Therefore, we will generate a sketch which mimics the solid geometry outline and use this copy within the Wrap feature.
The procedure for this technique begins with Step 5 on the next slide.

20. Step 5: Wrap a Sketch Around Surface
Start the Wrap Tool by selecting EditWrap from the top Pro/E menu. Select the References sub-tab from the dashboard as shown below.
Select the spiral surface created in Step 4 as the Destination reference.
Select Define to define the sketch.
Wrap Target will be changed to Sketcher CSYS later
Define sketch
Select spiral surface as Destination reference
Wrap Tool Dashboard

21. Step 5: Wrap a Sketch (Cont)
Orient the sketch such that you have a full view of the solid geometry. For our demonstration model, the orientation is shown below.
Select SketchUse Edge (or use the icon) and pick the Loop radio button as shown.
Select the front surface of the solid geometry. The entire outline of the part should be copied.
Selecting “Loop” insures the sketch will always update to include the entire solid geometry outline
Partial View of Solid Geometry after Loop Selection

22. Step 5: Wrap a Sketch (Cont)
Next, create a Sketched Coordinate System by selecting SketchCoordinate System from the top menu (or by using the icon shown here from the side flyout menu). Snap the new sketched coordinate system to the edge of your sketch at the center datum plane.
Long sketched edge (orange line - hard to see)
Drag the new sketched CSYS toward the midpoint of the long edge
Sketched CSYS should snap to the midpoint of the edge.
In this case, the CSYS will fall on the center datum plane.

23. Step 5: Wrap a Sketch (Cont)
Complete the sketch by selecting to return to the Wrap Tool dashboard.
Change the Wrap Target to Sketcher CSYS. Note that this option will remain greyed out unless a coordinate system was created in the sketch as shown on the previous slide.
Direction Control
Change Wrap Target to Sketcher CSYS
Wrap Tool Dashboard
When done, complete the feature by selecting If the feature fails, flip the direction using the Direction Control.

24. Step 5: Wrap a Sketch (Cont)
The final geometry for Step 5 is shown below.
Surface Geometry Hidden to Show Curves
Curves Shown Wrapped Around Reference Surface

25. Step 6: Trim Portions of Reference Surface
A surface trim allows us to cut away portions of a surface using a curve as the cutting tool. To use this tool, select extruded surface created in Step 4. With the surface highlighted, select EditTrim from the top menu. Select the References sub-tab.
The pre-selected surface should already appear as the Trimmed Quilt reference. Select Details next to the Trimming Object reference to continue.
By pre-selecting the surface before starting the Trim Tool, the reference will appear here automatically
Click here to select a curve to use as a cutting tool
Trim Tool Dashboard

26. Step 6: Trim Reference Surface (Cont)
From the Chain dialog box, select the radio button for Rule-based as shown. Also select Partial Loop as the rule type. In the next slide, we’ll select the top loop of curves as a cutting tool for the surface trim.
Top Portion of Wrapped Curves Shown (Surface Hidden for Clarity)
Our intent in the next slide is to select only the wrapped curves along the top edge of the surface and use them as a cutting tool.
Chain Dialog Box
Spiral Surface with Wrapped Curves

27. Step 6: Trim Reference Surface (Cont)
Looking only at the top portion of the spiral surface, select the inside and outside end curves as boundaries for the partial loop. The two end curves are shown in Red below. The system should select the chain of curves in between (as shown highlighted in orange below).
See next two slides for additional views & tips.
Outside End Curve Shown Selected in Red
Inside End Curve Shown Selected in Red Chain Loop Shown Selected in Orange

28. Step 6: Trim Reference Surface (Cont)
In some circumstances, the system will highlight the chain of edges in the wrong direction. If this happens, select the Flip command shown below.
Sometimes you’ll have to explicitly pick inside the Extent Reference box (shown below) before you can pick the second end curve.
Select the box here (in Green) to reactivate the curve reference collector if you find you cannot pick the second end curve
Click here to flip the direction of the chain

29. Step 6: Trim Reference Surface (Cont)
The top views below are intended as additional visual aids to assist in selecting the partial curve chain. The system should automatically select the Partial Loop chain in Orange.
Outside End Curve Shown Selected in Red
Inside End Curve Shown Selected in Red Chain Loop Shown Selected in Orange

30. Step 6: Trim Reference Surface (Cont)
Once the chain has been selected, close the Chain dialog box. Pay attention to the yellow directional arrow. The arrow points to the portion of the surface to keep after the trim.
If necessary, select the Flip command to change the cut direction. When done, select to complete the feature.
Flip Command
Trim Curve & Surface Selected Yellow Arrow Shows Direction to Keep
Trim Tool Dashboard

31. Step 6: Trim Reference Surface (Cont)
Repeat Step 6 for the lower loop of curves. The final trimmed surface (top & bottom) appears below.
Detailed View of Trimmed Surface
Final Trimmed Surface

32. Step 7: Thicken the Trimmed Surface
Highlight the trimmed surface from Step 6 and select EditThicken from the top menu. Enter the desired depth and direction to thicken. Complete the command to finish the procedure.
Top View (Dark Background) of Final Wrapped Geometry
Top View Isometric of Final Wrapped Geometry

33. Objective 1: Review Notes
To further automate the model, use relations to drive the thickness of the solid flat geometry and the thicken feature in Step 7 from the coil_sheet_thk parameter (defined in Step 1)
Be aware that the extruded surface in Step 4 should extend beyond the limits of the flat geometry. If the extruded surface doesn’t extend beyond the flat geometry, the wrapped curve will fail.
Selecting the top/bottom partial loops can be simplified by using Intent Chains but this is beyond the scope of this document
Inheritance, Copy Geometry, Flexible Features, and Family Tables all provide methods for displaying the model in the flat or rolled state.

34. Objective 1: Review Notes (Cont)
At times during the creation of this tutorial, the relations loaded in Step 3 failed to save properly. If this occurs, open the spiral_relations.txt file and copy/paste the text into the Relations Editor (rather than attempting to import the file). This resolves the problem.
The Curve From Equation may need to be slightly tweaked to account for material thickness. (For example, one material thickness may need to be removed from the outer diameter to keep it within the desired boundaries).
If geometry fails to regenerate at any step, be sure to check the model accuracy, references, direction of features, and critical dimensions.
Failure to keep the sketcher coordinate system directly on the edge of your sketch in Step 5 can cause the feature to fail.