Recently, the big news in the MCAD world has been the acquisition of SDRC by EDS (UGS’ parent company). However, SDRC’s immediate software plans will not be affected, in fact, it is going full steam ahead with a new release of I-DEAS (version 9) in the fall. I had the chance to work with a beta version, building a cell phone cover plate, as seen in Figure 1, a part that I had already modeled in several other MCAD programs.
Upon opening I-DEAS 9 to start this project, it is obvious that the program has undergone some design changes since the last major release. The icons located on the three main toolbars on the right now have more of a Windows look, however, the program’s interface still needs improvement. For instance, the first of these three toolbars, called Modeler Commands, is still somewhat of a jumbled mix of tools for setting up workplanes, sketching, building surfaces and solids, along with a few editing commands tossed in. It took a while to remember where everything was located, something that better organization could improve.
The program begins in the XY view and the idea is to start sketching in 2D and then create 3D parts from this profile, although there are no prompts to indicate this. Having worked with prior versions of the software, I knew to start sketching, so I created a rectangle, eyeballing one so it was approximately equal to the length and width of the phone. When completed, I-DEAS automatically placed dimensions on it, which was helpful. Using the Modify command I was able to edit the length to the exact size required, however, I couldn’t do the same for the width without first closing the dialog box and then selecting the width dimension. Although I didn’t need one in this case, I played with a few equations and found applying them to be simple.
By hitting the F3 key, I-DEAS evokes an easy to control rotate mode just by moving the mouse, while F2 zooms and F1 pans. I used the F3 shortcut to rotate the 2D sketch into an isometric view and then selected the Extrude command. The software prompted me to “Pick a curve or section,” so I clicked on one of the four lines of the rectangle, which highlighted the entire entity in red. I-DEAS then asked if I wanted to add or remove another curve or if I was done, and I was able to complete the selection process with a simple click of the middle mouse button.
This put me in a dynamic drag mode, where I could see a wireframe preview of the extrusion, while the cursor grew a little prompt—indicating the changing depth value as I moved the mouse. A left click would have allowed me to finalize my visual input, but I did a middle click instead which called up the Extrusion options dialog box, as seen in Figure 2. This removed the wireframe preview in favor of a green arrow showing the direction and length of the extrusion, while also allowing me to consider other options such as draft angle, which didn’t show in the preview. Knowing that I would later need vertical walls to sketch other elements on, I left the draft angle at zero and just entered a height of 25. After hitting OK, my initial 3D shape was created.
What was interesting was that now, for the first time, three planes appeared in the center of the work area. Knowing that I would soon need to draw a profile curve lengthwise though the center of the part in order to start constructing the surface that would become the top face, I could have used these planes when creating my initial sketch. This would have ensured that the YZ plane ran directly through the center of the part.
Another aspect of the program I found strange was that Ctrl-Z doesn’t undo in I-DEAS. It’s the Revert File command, meaning the current file will be closed and, if the work hasn’t been saved, it’s gone without a warning. There is a regular Undo command, which is the third choice in the Edit Menu, but it doesn’t work on all functions.
To start, I created an offset plane so it ran through the length of the block (see Figure 3). On this plane I drew the first curve that represented the highest points of the cover plate. I-DEAS makes adding these curves very easy, and there is a readout displaying XY distance, which helps in placing the points. However, when the Modify tool was used to tweak the resulting curve, the program only showed the start and end points, not the in-between points that were used to define the curve. While it’s easy to add new points, this shouldn’t be necessary because access to the original points should be permitted.
Figuring that there had to be a more robust way to edit curves, under the Dimension stack of icons I found the Shape tools. This called up its own toolbar and there were a number of powerful tools that allowed me to edit the curve in numerous ways.
With the middle curve exactly the way I wanted it, I projected it to the side face, without associativity, and then a few clicks later I projected this curve to the other side face on the other side, with associativity. Then, using the Shape tools again, it was a breeze to tweak both these end curves simultaneously.
With the three curves in place, I called upon the Loft tool to create the surface that will eventually cut the block and form the top face. With I-DEAS this was fairly simple—all I had to do was select the first curve and indicate the direction, and then do the same for the other two curves (see Figure 4a). The resulting surface is shown in Figure 4b.
There were several options when creating the surface including making a new part or joining it to the existing part (the block). I chose the latter, because this way the associativity would be maintained. This option added more steps when it came to using the Cut tool to trim away the unwanted top of the block, but eventually the basic shape of the phone started to take form, as seen in Figure 5.
The most challenging fillets were the elliptical ones located at the top corners, because I-DEAS has no tool to create a fillet with unequal lengths. One solution was to go back and edit the original sketch. However, because the loft is based on splines that were created on the face of the original extrusion, the curves would have to be remapped, which can get very tricky. What I had to do instead was delete some of the recently added features, including the loft and cut—after the loft operation was saved out as a separate part. Then I edited the original sketch by drawing conic arcs in the appropriate corners and added dimensions to ensure they were the correct size. Next I reapplied the extrusion, this time adding draft because I didn’t need the vertical side walls to create the loft—I just had to call the loft part back in and perform the cut again, which was a lot easier this time because they were now two separate parts. While this wasn’t the ideal solution, in the end I did finally have the elliptical fillets.
Adding the variable fillet around the entire top edge was very easy, as it was just a matter of following the prompts.
I-DEAS automatically highlights the end points of the selected edges and then all that is needed are desired values (see Figure 6). Adding any points in between these end points would have required splitting the edges. After all the filleting was done, the .75mm shell was added without a problem, a feature that has caused other programs trouble (see Figure 7).
Next I created an ellipse using the Extrude tool to create the first cut out for the cell phone’s buttons. To create the pattern, I selected the hole, which was tricky, but once I had it I-DEAS gave me a good indication of where features of the new array would fall as seen in Figure 8a. I then used the new Feature Copy command to drag a few additional off-pattern cutouts that were located near the middle of the cover plate (see Figure 8b).
I-DEAS would not let me pattern the hole along with its chamfer, so I had to add them after all the holes were created. This wasn’t as painful as it sounds, because I was able to select all the top edges in one shot and then enter the chamfer angle and setback distance. Then I just kept hitting the Enter key to accept these new default values for each hole until they were all completed. Technically, the chamfers contained variable angles, but this would have involved too many extra steps so I had to change the design intent.
Another tricky part of the phone is an indentation that is cut approximately halfway into the top surface in order to hold the LCD window. This has been a big problem for most of the other programs, but I-DEAS’ new Emboss tool allowed me to project a 2D sketch a specified distance into the top surface as seen in Figures 9a and 9b.
Finally, I decided to give the indented area of the circular speaker a try. To build this, I had to use the History Access to roll back the features to right before the shell. Then, using an impressive new Version 8 feature called Variational Surface, I was able to deform the face, using a point I drew as the “influence geometry” and a circle as the boundary (Figure 10). At first the rebuild gave me some errors, but then I went back and tweaked a few settings, which produced the desired results.
While there were times that I-DEAS’ “logic” had me scratching my head, overall it offers many powerful modeling tools, including the new Feature Copy, Emboss, and Variational Surface. However, some other modeling functions are still missing and more Undos are needed to prevent frequent trips to the history tree. In addition, generating simple shaded and wireframe views was slow, even on my dual 1GHz Compaq, something SDRC expects will be improved in the final release.