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Re: gears
(reading back through this, you gotta be a CAD user to really understand what I am talking about here... hopefully, it is clear)
Here is how I handle gears in Unigraphics. Other CAD packages might have these features, I don't know.
I made a parametric gear model about 3-4 years ago, and I just keep using it when needed. It took a few hours to set up, but I have used it countless times since that point.
The file contains 2 solid models, right on top of each other.
One solid is generated from an intricate sketch that outlines the actual gear teeth. This sketch is parametric, so I can change its parameters (# of teeth, thickness, pitch, etc.). When I change these variables, I get a gear with the proper pitch diameter, correct # of teeth, etc. I can also change the bore size with a variable.
The other solid is a simple cylinder that is created from dimensions calculated from the variables in the above solid. It automatically gets the same thickness, pitch diameter, and bore size that the "actual" gear has.
Since these models are solid, I can whittle on them if I need to put in a hex hole or a pocket, depending on my application.
Then, when I am working in my assembly, I import this gear into the assembled model. UG has a "reference set" feature where I can assign one model in a part to a named reference set. In this case, I have "actual" and "block" reference sets. While working in the assembly, if I turn on "actual" for that gear, I see teeth. If I turn on "block", then it shows a cylinder. In the assembly, I use block reference set most of the time, until I want to make fancy pictures.
This is also nice for dimensioning. All of my detail prints are 1-part assemblies of the part getting dimensions (UG calls it master-modeling). So, when detailing the part, I pull in the "actual" reference set and the print shows the gear teeth. There are other reasons for master-modeling, but this is one advantage.
I am spoiled on Unigraphics. I assume that other CAD systems can do these things. Is this true?
Andy B.
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