Coosbaylumber Posted April 22, 2009 Posted April 22, 2009 How do I... How do I construct a sort of compound curve using Autocad? What I got is a circle or arc of about R=6. A node or endpoint about 5-6 units away from the center. I want a curve of R=10 to create an arc to go through the endpoint, and be tangent to the arc too. I can visualize it, but cannot draft it. Now, I realize that there are a few possible solutions, but only one applies. I tried using the 2P function on curves, but instead of being tangent to the curve it comes up at a right angle to it. I can draw a tangent solution within a couple of seconds, but a curve? Due to wrong soultions, I used to have a solution to this that involved drawing a few offset lines, but cannot remember how that was as I used it so seldom. If I got 4-6 solutions, could I then delete or pick the one I preferred? Wm. Quote
ReMark Posted April 22, 2009 Posted April 22, 2009 Is this what you're asking about? SCAN1946_000.pdf Quote
Coosbaylumber Posted April 23, 2009 Author Posted April 23, 2009 Is this what you're asking about? [ATTACH]11571[/ATTACH] Your PDF is difficult to see but.... The endpoint B=PT has coordinates fixed. Cannot be altered. The endpoint A=PC has coordinates fixed. Cannot be altered. R-2 is 10 units. Of any bearing. R-1 is of 6 units. Known bearing. Delta 1 and Delta 2 are unknown. The bearing to center of R-1 is known, the bearing of tangent is known. The bearing to center of R-2 is unknown, the bearing of tangent to circle (arc) R-2 is unknown. This sort of makes the tangent line a broken-back. The bearing of line O2 to PCC is unknown, but lengths along this line known. Wm. Quote
SEANT Posted April 23, 2009 Posted April 23, 2009 One method would be as shown in the attached images. The one step that is not AutoCAD friendly is offsetting a 6 radius circle 10 towards the inside. Requires some math. Quote
Leafrider Posted June 27, 2012 Posted June 27, 2012 I have a similar inquiry but it's a 3-centered compound curve. Why AutoCAD or Civil 3D doesn't provide a valid tool to do this quickly is beyond me. Would be worth the price of "admission" if you know what I mean. Quote
BIGAL Posted June 28, 2012 Posted June 28, 2012 Leafrider C TTR draw 2 outside arcs add 3rd circle C TTR and trim I think this is what you want when fillet does not work Quote
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