jpummil
Well-Known Member
- Joined
- Jan 10, 2011
- Messages
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So, i have been using OpenRocket for quite some time, but never found an automated way to generate an electronic file from inside OR that a CNC person could use to cut something like, say, custom fins! As an Ex CAD/CAE person from way back, I was familiar with a number of CAD packages, but wanted to find something that was Open Source like OR is. Enter LibreCAD! It's a free 2D package that runs on Linux as well as Mac and Win. Somewhat reminiscent of the AutoCAD's of old, it does have some different behavior with respect to some of the standard features found in most CAD packages, but you can quickly accustom yourself to these quirks. The best part is that it's native file format is .dxf which is read by practically all CAD/CAM/CAE packages!
As you see, interface is not overwhelmingly cluttered with options.
As OR can't output an electronic file that you can simply read in to a CAD package, I just went to the shape tab of my fin design and input the coordinates of each vertex manually.
Fin tabs are another strange creature in OR. You can SEE them...but they don't show up in the shape tab of the fin. So, just use the fin tabs option under the fin design box and you can see how much you need to offset the fin vertically before manually drawing the tab.
*Note: While the person doing the CAM file for the CNC can move the shape around, it is preferred (and courteous) to specify the lower left corner of your design as cartesian coordinate 0,0. This is why i said to input your fin design, then move the outline up by the depth of your fin tab, then finally add in your fin tab as this way everything ends up where it belongs.
I sent my completed .dxf files to Tim at Wildman and he said that they read in to his software just fine.
*Note: I should also mention that when it comes to generating geometry to have a CNC operator manufacture, it is you the designer who owns the responsibility that the file you send is correct. Unless the manufacturer just sees something that looks really strange or unusual, they will assume that you have double checked the coordinates and that they are correct. In short...measure twice, cut once :wink:
As you see, interface is not overwhelmingly cluttered with options.
As OR can't output an electronic file that you can simply read in to a CAD package, I just went to the shape tab of my fin design and input the coordinates of each vertex manually.
Fin tabs are another strange creature in OR. You can SEE them...but they don't show up in the shape tab of the fin. So, just use the fin tabs option under the fin design box and you can see how much you need to offset the fin vertically before manually drawing the tab.
*Note: While the person doing the CAM file for the CNC can move the shape around, it is preferred (and courteous) to specify the lower left corner of your design as cartesian coordinate 0,0. This is why i said to input your fin design, then move the outline up by the depth of your fin tab, then finally add in your fin tab as this way everything ends up where it belongs.
I sent my completed .dxf files to Tim at Wildman and he said that they read in to his software just fine.
*Note: I should also mention that when it comes to generating geometry to have a CNC operator manufacture, it is you the designer who owns the responsibility that the file you send is correct. Unless the manufacturer just sees something that looks really strange or unusual, they will assume that you have double checked the coordinates and that they are correct. In short...measure twice, cut once :wink:
