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Why is GibbsCAM "CAD" Different from other programs?

Why is GibbsCAM ‘CAD’ different?

by Bill Gibbs
President, Gibbs and Associates

If you’ve ever used a design CAD software package to design or draw, or create geometry with, the first thing you’ll notice about GibbsCAM is that its geometry CAD tools are different. This leads to a number of different possible first impressions, including that different is “bad”. Especially when it’s different from what you’ve already learned how to use.

Personally, I’m a big believer in the importance and the value of interface consistency, leading to Gibbs’ big investment in Windows compatibility and our Microsoft “Designed for XP” certification. “Different” is not good just for difference sake. But there are reasons why GibbsCAM CAD is different, starting with the fact that it is not intended for the same task or the same user as design CAD software is.

Modern part manufacturing typically goes through several important steps:

  1. Design CAD - The creation of a new design, performed by a design engineer, using a design CAD software (SolidWorks®, Solid Edge®, Autodesk®, Pro/ENGINEER®, CATIA®, Unigraphics®, etc.). This software needs to support the designer’s creativity with a variety of freeform CAD capabilities.

  2. Manufacturing CAD - Here a manufacturing expert (Manufacturing Engineer, NC Programmer, Machinist) receives a design from someone else, in another department or another company. He may need to redraw it, import CAD files, repair and correct the design for manufacturing, and create process models, tooling or fixtures from the part design. One key point is that he is usually not the person doing the original design. Another is that the part design exists before the manufacturing expert starts his work.

  3. CAM (creating the NC program) - Once the manufacturing expert has the part models or geometry ready to machine, he can proceed with planning and creating the actual tools, toolpaths and G-code needed to make a good part.

GibbsCAM is an integrated solution excelling at steps #2 and #3 above. Everything the manufacturing expert needs to complete the job begun by the design engineer. Our user focus and our task focus are very different from the user and the tasks of a design CAD software. In the infrequent case where the designer and the manufacturer are the same person, he may chose to use GibbsCAM CAD just because he likes it, or he may chose to use a design CAD for designing, linking his files to GibbsCAM for manufacturing CAD and CAM. It is not correct to say that GibbsCAM CAD is more or less than any specific design CAD software, as GibbsCAM CAD is aimed at a different user and a different task, and therefore “is” different.

Geometry creation specifics –

Redrawing - When GibbsCAM was first released in 1993, a lot of CAD work was still sent to the machine shop by blueprint, requiring the manufacturing guy to redraw it. So GibbsCAM set out to provide tools allowing a shape to be redrawn faster and easier than design CAD systems could. GibbsCAM CAD tools achieve this, allowing redrawing to be done in a fraction of regular CAD time. Geometry expert pushes this advantage further by providing parametric capabilities for family of parts creation and interactive shape editing.

Just the finished part - You don’t need to recreate an engineering drawing to make a program. GibbsCAM focuses on creating finished shapes to machine, not recreating an engineering drawing. This is a lot less work. GibbsCAM doesn’t require additional geometry created for entry and exit tool moves. Just the finished part.

Chaining - Any CAM system using design CAD as the front end has a chaining step. Chaining attempts to automatically connect one feature with the next, into a machinable shape. This process stops when more than 2 features intersect on the screen, and asks the user, “which way?” This can be a cumbersome process with complex drawings. It gets worse when the chaining function finds a small gap, common with imported geometry. In these cases you get to go back to CAD, fix it, go back to chaining, find the next one, go back to CAD etc., etc. GibbsCAM eliminates the chaining step by allowing the user to create linked/connected geometry. In effect, when you are finished drawing a shape, you are assured that it is already chained and ready for machining. The only chaining function in GibbsCAM is automatically applied to importing geometry from IGES, etc.

Fast & Easy? - There is one big difference between the best way to draw in GibbsCAM and the best way to draw in a design CAD system. GibbsCAM doesn’t have a design CAD style “trim” function. Instead it uses “connectors” to link one feature with the next, graphically trimming automatically when a feature has 2 connectors. A machinist can think of drawing a shape as being like taking a tool around a part in G-code, a sequence of lines and circles.

A design CAD user frequently approaches drawing a part quite differently; creating a large number of untrimmed lines and circles then going back through them “trimming”. Unfortunately, you can do almost the same thing with GibbsCAM CAD. I say “unfortunately” because it is a poor way to use GibbsCAM CAD, leading to the user’s impression that GibbsCAM CAD is different, complicated, and inefficient. Used this way, GibbsCAM CAD can be inefficient and confusing and its connectors can work worse than design CAD trimming. GibbsCAM CAD is always focused on drawing a shape to be machined. All you need to do is to define the lines and circles in some order around a shape. Go CW or CCW, it doesn’t matter. Where you start and your direction has no effect on later machining. You’re just drawing a finished part shape. When you start defining your geometry elements in shape order, a wonderful thing happens. There are rarely more than 2 untrimmed elements on the screen at a time. Connecting and trimming are automatic. You can draw a shape in fewer user actions and eliminate chaining all at the same time. A win-win situation, worth learning a different approach to drawing. Or more specifically, redrawing.Geometry Expert is another powerful shape creation tool in GibbsCAM CAD, based on the same idea of entering features in order around a shape. Parametric associativity and auto-connection speed up the process dramatically.

Beyond geometry creation - GibbsCAM CAD doesn’t stop with 2D and 3D geometry creation. It offers 4 axis geometry creation for wrapping shapes around cylinders, very handy with types of rotary milling. It has a complete integrated solid modeler, with surface capabilities, based on Parasolid, the same UGS kernel inside Unigraphics, SolidWorks, Solid Edge and others. GibbsCAM is committed to providing the absolute best manufacturing focused CAD and CAM capabilities to our customers.

Conclusion

GibbsCAM provides a uniquely focused CAD capability for the task of manufacturing CAD, and a manufacturing user. It is different from design CAD software by intent and for increased productivity. Most GibbsCAM users learn to appreciate the advantages of the GibbsCAM CAD interface and its capabilities. But since the customer is always “right”, GibbsCAM also offers design CAD software links for the integrated use of the customer’s favorite CAD system and GibbsCAM on the same computer. The choice is yours.


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