BlackOrange Posted October 1, 2014 Share Posted October 1, 2014 Hello I have come across a problem during learning the 3D features of AutoCAD (2009) that I seem to be unable to resolve myself. The starting situation is as follows - Two arcs perpendicular to each other: The point is to sweep one arc along the trajectory of the other one in exactly the same position it has in the beginning (i.e. perpendicular to the xy plane). The learning text I am following suggests that this is governed by the Alignment command. I find that confusing because what the command does for me upon being set to NO is exactly what it says - it leaves the first profile where it is (..before sweep), it says nothing about the behavior of the profile along the way as my text suggests. Anyway what I always end up with looks like this: Question is simple (as I am hope is the answer) - how do I make the swept object stay in the implicit position along the entire path? Thanks for any help, it is greatly appreciated. Quote Link to comment Share on other sites More sharing options...
rkent Posted October 1, 2014 Share Posted October 1, 2014 The arc needs to be set perpendicular to the path arc. Quote Link to comment Share on other sites More sharing options...
BlackOrange Posted October 4, 2014 Author Share Posted October 4, 2014 Thank you for your reply. I am not quite sure what that means though. All the time I am trying to achieve this (sorry for the bad quality): Are you saying this cannot be done? I am pretty sure this is actual screen from ACAD originally. Thanks for any help. Quote Link to comment Share on other sites More sharing options...
nestly Posted October 4, 2014 Share Posted October 4, 2014 Is the Alignment option "Yes" Quote Link to comment Share on other sites More sharing options...
JD Mather Posted October 4, 2014 Share Posted October 4, 2014 I am pretty sure this is actual screen from ACAD originally. Is that a Loft or is it a Sweep? If Sweep, where is the path curve? In the middle or at the end? Which curve is the path and which curve is the profile? Quote Link to comment Share on other sites More sharing options...
BlackOrange Posted October 4, 2014 Author Share Posted October 4, 2014 Guys, thanks for your time. The picture of final drawing is taken from the book I follow and is only shown there as a reference. The exercise is to create this using the Sweep command from the situation shown in the very first picture. I feel quite stupid now, because after watching post from nestly I realised I had it all along, if the alignment is set to yes, what is created is what the book wants me to do. The book is a little confusing at this point and I thought I am supposed to create what I ask next. That clarifies it for me. Lets say then that I still want to create what I asked for in the beginning. Surface defined by the arcs as shown in the first picture but all the four border arcs being still in planes perpendicular to XY plane. Something like this (without the surface which I am trying to create): I assume then that this cannot be done by the Sweep command and I would have to use different one for this? Quote Link to comment Share on other sites More sharing options...
nestly Posted October 4, 2014 Share Posted October 4, 2014 Actually I think JD's suggestion was probably the most correct way to create that object Put a profile at each end, and use LOFT with the Guides option. I think you only need a single guide since it appears to be uniform, but you can use multiple guides if you need to change the amplitude in the center. Quote Link to comment Share on other sites More sharing options...
GP_ Posted October 4, 2014 Share Posted October 4, 2014 My 2 cents Quote Link to comment Share on other sites More sharing options...
nestly Posted October 4, 2014 Share Posted October 4, 2014 @ GP, I like your idea, but I think you need more guides to have a uniform curved surface. Quote Link to comment Share on other sites More sharing options...
nestly Posted October 4, 2014 Share Posted October 4, 2014 Different approach ... SLICE a Sphere Quote Link to comment Share on other sites More sharing options...
GP_ Posted October 4, 2014 Share Posted October 4, 2014 ...I think you need more guides to have a uniform curved surface. True Quote Link to comment Share on other sites More sharing options...
BlackOrange Posted October 4, 2014 Author Share Posted October 4, 2014 Thank you all for your input. My original problem was that I didnt understand at first how Sweep works. It looks quite clear now but it was driving me crazy. All of this helped me a lot. Quote Link to comment Share on other sites More sharing options...
SEANT Posted October 4, 2014 Share Posted October 4, 2014 Different approach ... SLICE a Sphere I was going to make the same suggestion earlier today. I even put together a sample file. Unfortunately, the four arc Loft setup would not create a shape geometrically identical to sphere sliced that way. The four edges of the sliced sphere would have different radii (and arc angle) than a center section. The edges would only match properties if they shared a center with the sphere (i.e., were radial cuts). Quote Link to comment Share on other sites More sharing options...
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