BMWiley Posted October 10, 2012 Share Posted October 10, 2012 How is everyone this glorious morning!!! Ok so im in a pickle. Having problems creating a helical truss/ shape. Ive managed to get a simple spline spiral. Which im still not 100 percent happy with. But it will suffice for right now. Now one of my problems is extruding, and offsetting. Im pretty ok at 3d modelling, but when it comes to complex shapes i fall flat on my face. Ive including a dwg that shows a plan view of the structure, as well as my 3d spine. the small circles are the truss cords. Its a 16" flat truss, ran parallel with another to create a spiral ribbon. The plan view is from the designer, ive noticed but maybe its not true... their helix doesnt seem consistent. I know im leaving a lot of info out, please ask all thw questions youd like. Ill be here all day. Using, 64bit ACAD 2011 Nilla Spiral Truss.dwg Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 10, 2012 Share Posted October 10, 2012 What will your truss be supporting? Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 Itself... Its an architainment piece. Imagine a walk way through the center, and scrim stretched between the paralleled truss. The red in the plan view is the open area. Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 10, 2012 Share Posted October 10, 2012 Were you thinking of using a tube shape (square/rectangular) or a cylindrical shape to construct the truss? Could the multiple 3" diameter circles suggest you are going cylindrical? Is there a kink of sorts in your spline or is it an optical illusion? Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 the cords are 3 inch aluminum and the diagonal pipe will be 1 1/2". Here is a image of one of their references. In the process of inquiring if a model exsists, and is available. Quote Link to comment Share on other sites More sharing options...
JD Mather Posted October 10, 2012 Share Posted October 10, 2012 Helix Sweep then a whole bunch of work for the connecting pieces or Helix Curve driven pattern in a modern program like Autodesk Inventor. Hmm, haven't they added a curve driven Array in AutoCAD? Might not be so bad afterall. Measure or Divide if the curve driven Array isn't in there (but I think maybe it is). Quote Link to comment Share on other sites More sharing options...
JD Mather Posted October 10, 2012 Share Posted October 10, 2012 Ive managed to get a simple spline spiral. Which im still not 100 percent .... How did you get that - it doesn't look right to me. Look at end view - it should be circular. Did you use the Helix command? Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 Is there a kink of sorts in your spline or is it an optical illusion? Yes there is a kink, i copied one section multiple times. and havent smoothed it out yet. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 When i tried the helix command the results werent what i was looking for. When laid on top of the designers plan, it didnt match, what makes me think either theirs may not be possible, or its not consistent. Or maybe im just wrong... which isnt a far stretch. What i did to get the kink was i mapped out one revolution with a spline, then copied, and tried doing little modifications to get smooth. But yes, its not exactly perfect, im not 100% percent happy, but i wanted to figure out the process. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 (edited) HelixSweep then a whole bunch of work for the connecting pieces or . Ive managaed to create something a little better with helix... not sure what i did wrong first time around, but on a better track. Thanks. Still stumped but in a better place now. Edited October 10, 2012 by BMWiley Spelling Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 10, 2012 Author Share Posted October 10, 2012 Well I did create this truss finally, I used JD's method of helix and placing all the diagonal peices manually. Still feel there has to be an easier way but thank you for all your help!! Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 10, 2012 Share Posted October 10, 2012 Don't keep us in suspense BMW....post an image! LoL Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 11, 2012 Author Share Posted October 11, 2012 Don't keep us in suspense BMW....post an image! LoL Dont worry thats not my intentions, just will not post an unfinished peice... soon enough my friend, soon enough. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 12, 2012 Author Share Posted October 12, 2012 Well heres update number one, ill keep you all updated on this. Thanks again for all your help!! Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 12, 2012 Share Posted October 12, 2012 Interesting. Looks like that was a lot of fun to do. Or was it? Anyway, thanks for sharing and glad to see you got it figured out. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 12, 2012 Author Share Posted October 12, 2012 Yes it was alot of fun. Tedious, but fun. lol. Now the real fun starts, reverse engineering to figure out how to jig, weld, assemble, and fit this beast through double doors!! Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 12, 2012 Share Posted October 12, 2012 The guys in the fab shop are going to be using your name in ways you never thought of. I think some of the parts might even be named after you in a manner of speaking. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 12, 2012 Author Share Posted October 12, 2012 Haha, you have no idea! Im pretty sure they wont be nice names, ill tell you that. This isnt our first large scale peice, but is definetly the most uniquely built one. Ill update with build pics too when it comes to it, were getting the cords rolled by another shop. So in about 8 weeks or so we build!! Quote Link to comment Share on other sites More sharing options...
ReMark Posted October 12, 2012 Share Posted October 12, 2012 We eagerly await the "roll out". Have them weld some stops on it so the assembly doesn't roll down the hill and cause an accident. Good luck. Quote Link to comment Share on other sites More sharing options...
BMWiley Posted October 12, 2012 Author Share Posted October 12, 2012 Haha!! Plan is to jig it suspended, so that cant happen! But id love to change design so it rotates in place, but thats obviously a dream of mine. Continous orbit will suffice. Quote Link to comment Share on other sites More sharing options...
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