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In the given pictures I have two planes 1 and 7 on which is each a point. On the points should each start an arc 3 and 5. The endpoints of the arcs should be connected with line 4. The arcs 3 and 5 should be tangent to the line 4 and also they should be tangent to a normal on the planes (5 tangent to 6 and 3 tangent to 2 where 6 is normal to 7 and 2 is normal to 1).
To give the situation a bit more context I want to build a pipe between the two planes and the planes are the connection areas of the pipes.
I think geometrically this should be possible with all the given constraints. I tried to put that down with a 3d sketch as shown in the picture but I can't add the tangent constraint. I tried it several times with all restrictions when laying down the arcs ("Ortho Mode", "Dynamic Dimension", etc.) deactivated, but at a certain point, I could not add the required conditions. This is the first time that I have used 3d Sketches and what I found quite confusing for example is that I could not add a tangent constraint to an arc but when I wiggled it around a bit it suddenly worked. I think I haven't wrapped my head around the concepts used in 3d sketches yet.
What I also tried is to use bends shown in the picture below:
In this case, I have line 2 which is normal to plane 1 and I have line 7 which is normal to plane 5. I added the bend 6 between line 7 and 4 and the bend 3 between line 2 and 4. The problem here is, that I cannot constrain the end of the bend to lay on the point on the plane and I want the bend/arc to start on the plane.
I don't think I can use splines, as I suppose they work with Polynomial functions and I need proper arcs in my case.
Is there some way to improve one of my approaches to working out or is there another way to do this? Can someone maybe suggest a video or article to better understand the behavior of arcs in 3d sketches I didn't find anything helpful.
Thnks in advanced for any helpful response
Best Regards
Marcel H.
In the given pictures I have two planes 1 and 7 on which is each a point. On the points should each start an arc 3 and 5. The endpoints of the arcs should be connected with line 4. The arcs 3 and 5 should be tangent to the line 4 and also they should be tangent to a normal on the planes (5 tangent to 6 and 3 tangent to 2 where 6 is normal to 7 and 2 is normal to 1).
To give the situation a bit more context I want to build a pipe between the two planes and the planes are the connection areas of the pipes.
I think geometrically this should be possible with all the given constraints. I tried to put that down with a 3d sketch as shown in the picture but I can't add the tangent constraint. I tried it several times with all restrictions when laying down the arcs ("Ortho Mode", "Dynamic Dimension", etc.) deactivated, but at a certain point, I could not add the required conditions. This is the first time that I have used 3d Sketches and what I found quite confusing for example is that I could not add a tangent constraint to an arc but when I wiggled it around a bit it suddenly worked. I think I haven't wrapped my head around the concepts used in 3d sketches yet.
What I also tried is to use bends shown in the picture below:
In this case, I have line 2 which is normal to plane 1 and I have line 7 which is normal to plane 5. I added the bend 6 between line 7 and 4 and the bend 3 between line 2 and 4. The problem here is, that I cannot constrain the end of the bend to lay on the point on the plane and I want the bend/arc to start on the plane.
I don't think I can use splines, as I suppose they work with Polynomial functions and I need proper arcs in my case.
Is there some way to improve one of my approaches to working out or is there another way to do this? Can someone maybe suggest a video or article to better understand the behavior of arcs in 3d sketches I didn't find anything helpful.
Thnks in advanced for any helpful response
Best Regards
Marcel H.
Hi!
Without the model is hard to say something concrete.
Maybe instead of an arc, you need to use a spline tangent in both sides.
Maybe the you need more reference elements
maybe the planes are not parallel...
if you share the model, probably we can find a way.
Suggestion:
have You try the module "Tube and Pipe"?
https://www.youtube.com/watch?v=dwq4gMShmYY
CCarreiras
Hi!
Without the model is hard to say something concrete.
Maybe instead of an arc, you need to use a spline tangent in both sides.
Maybe the you need more reference elements
maybe the planes are not parallel...
if you share the model, probably we can find a way.
Suggestion:
have You try the module "Tube and Pipe"?
https://www.youtube.com/watch?v=dwq4gMShmYY
CCarreiras
Hi Marcel,
The key to create a 3D Sketch successfully in Inventor is to reduce degree of freedom (DOF) by adding logical construction geometry. In this case, the line and the two arcs need to be coplanar. Simply add a workplane by selecting the three points in 3D Sketch1. Then edit 3D Sketch2 and attach the sketch geometry to the plane by adding coincident constraints.
Please take a look at the attached file. One may argue that it is unnecessary. But the issue is that a piece of unconstrained geometry in 3D has 4 more DOFs than the one in 2D. Reducing the DOF can help stabilize the constraints and the geometry.
Many thanks!
*Updated: The file is attached.
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer
Hi Marcel,
The key to create a 3D Sketch successfully in Inventor is to reduce degree of freedom (DOF) by adding logical construction geometry. In this case, the line and the two arcs need to be coplanar. Simply add a workplane by selecting the three points in 3D Sketch1. Then edit 3D Sketch2 and attach the sketch geometry to the plane by adding coincident constraints.
Please take a look at the attached file. One may argue that it is unnecessary. But the issue is that a piece of unconstrained geometry in 3D has 4 more DOFs than the one in 2D. Reducing the DOF can help stabilize the constraints and the geometry.
Many thanks!
*Updated: The file is attached.
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer
Hi Johnson,
thank you for your response. Your suggestion got me one step further I think. I think I didn't follow your instructions 100% because I directly created the planes in the 3d sketch (as you can see in the tree view) which I just noticed was possible.
This view only looks at the upper part but I attached the updated ipt. So I created plane 5 with lines 2 and 4. Line 2 is a normal to 6. This is almost what I want, I only have lay point 3 on Point 1. If I try directly to put the points on top of each other with coincident it tells me that can not be done as the points lay on the same curve, I don't really understand what the issue is, is there another tool to lay two points on top of each other? If I try to lay point 3 on plane 6 no further information is given why it does not work.
Best Regards
Marcel H.
Hi Johnson,
thank you for your response. Your suggestion got me one step further I think. I think I didn't follow your instructions 100% because I directly created the planes in the 3d sketch (as you can see in the tree view) which I just noticed was possible.
This view only looks at the upper part but I attached the updated ipt. So I created plane 5 with lines 2 and 4. Line 2 is a normal to 6. This is almost what I want, I only have lay point 3 on Point 1. If I try directly to put the points on top of each other with coincident it tells me that can not be done as the points lay on the same curve, I don't really understand what the issue is, is there another tool to lay two points on top of each other? If I try to lay point 3 on plane 6 no further information is given why it does not work.
Best Regards
Marcel H.
I think, it can be done easily with an interpolation spline and two colinear handles to the needed axes.
You can edit this by deleting the intermediate third point of the spline, and changing the length of the handles
Walter Holzwarth
I think, it can be done easily with an interpolation spline and two colinear handles to the needed axes.
You can edit this by deleting the intermediate third point of the spline, and changing the length of the handles
Walter Holzwarth
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