Line Perpendicular to changing curve
Line Perpendicular to changing curve
(OP)
Hello all, this may have been asked before but I couldn't find the thread if so.
I have a closed 2D contour, call it a jellybean, I want to get a line to be instantaneously perpendicular to this curve at any given point. This is a very simple task with a circular contour, but when my radius changes (fully continuously (the derivative exists!)) the segment follows the old radius and doesn't follow the contour.
An analogy: if I were watching a car race and wanted to see my favorite car in profile for the entire race, following all the twists and turns. 'offset curve' will give you the position, what gives you the orientation (in sketch mode)?
I have a closed 2D contour, call it a jellybean, I want to get a line to be instantaneously perpendicular to this curve at any given point. This is a very simple task with a circular contour, but when my radius changes (fully continuously (the derivative exists!)) the segment follows the old radius and doesn't follow the contour.
An analogy: if I were watching a car race and wanted to see my favorite car in profile for the entire race, following all the twists and turns. 'offset curve' will give you the position, what gives you the orientation (in sketch mode)?






RE: Line Perpendicular to changing curve
Flores
SW06 SP4.1
RE: Line Perpendicular to changing curve
Is this a closed contour made up of several sketch entities? If so, you might try a fit spline. In SW06 you can only get a coincident sketch relation to work between one entity and one other. A cam mate can follow multiple segments, but that probably won't help you.
The fit spline will approximate all the sketch entities (lines and arcs usually) with a single spline, and then you can make a sketch line in the sketch plane that is perpendicular to the spline at any point as you drag it around.
Depending on what you are really trying to do, you may find it more useful to create a ruled surface. If you're trying to set up a sweep, the ruled surface will do what you want much more easily.
RE: Line Perpendicular to changing curve
Hmm, I just got it to work on an ellipse and spline - maybe there's a problem with my contour...
RE: Line Perpendicular to changing curve
When I do this, I draw a line roughly perpendicular to the spline, with one endpoint constrained coincident with the spline. Then select the line (not endpoint) and spline, and the perpendicular constraint is available.
Another workaround is to draw a construction line tangent to the spline with an endpoint coincident to the spline, then draw 2nd line perpendicular to the tangent.
RE: Line Perpendicular to changing curve
Thanks all.
RE: Line Perpendicular to changing curve
Otherwise, I also use TheTick's method mentioned above.
Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all. And awe trumps reason.
RE: Line Perpendicular to changing curve
nodal
RE: Line Perpendicular to changing curve
RE: Line Perpendicular to changing curve
Draw a circle and constrain tangent to the spline. Draw a line from the circle center to where the spline and circle touch. Constrain one line endpoints to circle center, constrain other endpoint coincident to circle and also coincident to spline.