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Sitting at your computer, you probably don’t think much about the mouse you’re using unless you have a problem with it. That’s largely because industrial designers and mechanical engineers spend a lot of time and hard work ensuring that the mouse is easy to use and comfortable over long periods of time.
One of the most critical aspects of a mouse design is shaping the intricate contours of its surface so that it is pleasing to the eye and, even more important, conducive to extended use.
This is a much more difficult task than it seems, and something Microsoft Surfacing Group Manager Dave Beardsley knows all about. It’s one thing to conceive of, sketch, and perhaps model in clay a modernistic creation that perfectly fits the contours of most any hand. It’s another thing to convert that concept into a mathematically precise and manufacturable design.
“Our job is to bridge the gap between industrial design and mechanical engineering,” Beardsley says.
A difficult job to finish. In the past, Beardsley’s team often found it easy to design 98 percent of a mouse, only to spend enormous amounts of time and energy tweaking the last two percent.
“We were able to visualize exactly what we wanted, but faced a great challenge in controlling the surfaces with a curve network that could quickly become insanely complex,” Beardsley says.
“A complex surface in Pro/ENGINEER is built on a curve network foundation,” Beardsley says. “In the past when we needed to change the surface, we had to go back and edit the curves. When we edited the curve, we could never tell exactly what effect it was going to have on the surface. So we often had to go back time and again to perfect that surface.”
The task is particularly difficult when working with complex surfaces such as a highly curvaceous blend between two larger surfaces.
“Often some or all of the curves are locked down to adjacent geometry,” says Peter Newbury, principal of QFD Consultants, Inc., a firm that performs many surface modeling projects for Microsoft on a contract basis. “If the resulting surface doesn’t look exactly right, you might end up throwing some more curves at it to try and clean it up. But this is just like adding fuel to a fire. As fast as you fix one area, you break another.”
Problem solved. With the release of Pro/ENGINEER Wildfire 4.0, Beardsley and Newbury have one less thing to worry about. Now they are using the Surface Edit tool inside the Style feature of Pro/ENGINEER Interactive Surface Design Extension (ISDX) to directly pull and push on a surface using a control mesh. With the ability to edit a surface multiple times at different mesh resolutions, Pro/ENGINEER captures each edit during the normal model regeneration.
“The Pro/ENGINEER Interactive Surface Design Extension Surface Edit tool has enabled us to save an enormous amount of time in designing keyboards and mice,” Beardsley says.
Thumbs up. Newbury faced a challenge recently in designing the thumb groove for a new Microsoft mouse. You might never notice the groove, which improves ergonomics by giving a secure area to grip the mouse—but it had a complicated teardrop profile which was difficult to define with a four-sided boundary patch.
Newbury used a process called overbuilding—in which one surface is constructed to extend past its final profile, which is defined by its intersection with another surface.
“Compare it to a boat hull in water,” Newbury says. “The boat hull is broadly defined, as is the water, but the intersection creates a teardrop shape.”
“The groove felt very nice but we had trouble making the intersection with the body of the mouse as crisp as the industrial designer wanted,” Newbury says. “You have to maintain the curvature in order to make it ergonomically correct. Using the old methods it would have taken a day of trying different curve networks before getting it right. With the Surface Edit feature, we simply pushed and pulled on the surface until it matched both the ergonomic specifications and designer’s requirements—and in only 30 minutes. Behind the scenes, the Pro/ENGINEER Interactive Surface Design Extension Surface Edit tool performed the necessary math to control what we had created.”
On the right side. Newbury has also used the Surface Edit tool in the design of a side-button for another mouse. The side button is located directly on the parting line above the thumb area of the mouse where there is little room to blend surfaces together. As he modeled a side-button that was both aesthetic and functional, Newbury essentially painted himself into a corner.
“The back corner of the side-button ended up being a three-sided degenerate patch—a notoriously difficult surface to make perfectly smooth,” Newbury says.
He solved the problem in minutes by adding an approximate four-sided patch in the critical area and “tapping” it into final shape with the Surface Edit tool.
“I just dialed in the surface to match it up with the partline,” Newbury says. “The Surface Edit tool let me do the job in just a few minutes instead of spending hours reconstructing the entire area.”
“All in all, the Surface Edit tool helps us get products to market faster and at a lower cost,” Beardsley concludes. “We have already saved a lot of time, and will save more once we install the tool for all of our internal users and contractors.”
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