This is topic Is there an Open Source analog to Unigraphics? in forum Ask a Geek! at The Geek Culture Forums!.

To visit this topic, use this URL:;f=12;t=002672

Posted by TheMoMan (Member # 1659) on December 10, 2009, 05:25:
____ Is there an Open Source analog to Unigraphics?

____ Okay for fifteen years I held a seat on a huge unigraphics CAD/CAM/CAE network. I used the system to develop tool paths for NC (numerical Control) Machining. I now would like a true 3D modeling program so I do not have to calculate all of the helixes to make a windmill propeller. I know I could just take some sheet metal and twist it to shape, however I want to carve a wooden blade.

____ Okay I found Open Cascade, however I do not find any reference to helix tools. This would be a huge download and why do so if it would not do what I need.
Posted by Richard Wolf VI (Member # 4993) on December 10, 2009, 08:11:
Checking on Wikipedia, there's FreeCAD, based in Open CASCADE, and BRL-CAD. I don't use CAD software myself, so you ought to ask the developers if they can provide the features you're looking for.
Posted by TheMoMan (Member # 1659) on December 10, 2009, 08:38:
____ Thanks for the heads up. But alas it turned out to be a dead end also.

____ Where I worked we would often laugh at the engineers that brought us Auto-Cad files and wanted us to import them to UG, it was easier to start from scratch than to rebuild their drawing. You can not believe what happens when a 3axis mill decideds to put the cutter inside the solid instead of staying on the outside.

____ Mean while back here on the farm I have calculated about 10% of the points I would need to twist up a piece of sheet metal.

____ Right now my blade is an old truck radiator fan and it spins up the generator quite well, this is to spin it up during low winds.
Posted by Mr. Dave (Member # 1977) on December 14, 2009, 15:28:
I'm afraid I don't know enough about CAD apps to know if this is what you're looking for, but have you heard of OpenSCAD? It's an open-source constructive solid geometry app, which sounds like it might be advantageous when designing CAM models.
Posted by TheMoMan (Member # 1659) on December 14, 2009, 16:24:
____ Here is the problem, Think of a very large clock, three foot long minute hand. Now go to nine O'clock and make a point 1/2 inch below the plane of the dial now make a point 1/2 inch above the plane of the dial, there is also a point at three o'clock in/or on the plane of the dial. Draw an arc from the upper point around through the point at three O'clock and continue to the lowest point at Nine O'clock. That is the outer helix now do the same for a clock with a six inch minute hand.

____ I am interested in the area near Three O'clock on both helixes to make the blade.
Posted by The Famous Druid (Member # 1769) on December 15, 2009, 01:57:
MoMan: you're making a wind-powered town hall clock?
How do you stop it running fast on windy days?
Posted by TheMoMan (Member # 1659) on December 15, 2009, 03:02:
____ Thats the plan.

____ To someone that has no idea of what a Helix is, most people can visualize a clock face, I found that when tutoring apprentises that a clock face made the circlular (Trig) functions easier to understand. The problem with a helix is that it is a generated Arc, you can specify it criteria pitch/dia but until it is generated there is no plane of reference.

____ Think screw thread, how would you discribe a screw thread to someone that had never seen one.

© 2018 Geek Culture

Powered by Infopop Corporation
UBB.classicTM 6.4.0