Creating a parabola in WF2,
Creating a parabola in WF2,
(OP)
Hello gang. I need to create a parabola for rear tail lamp for a van. It is the backup and stop/turn cavities. I am trying to create the parabola without using the technique that PTC recommends. they recmommend a new coordinate system located some where in the tail lamp and then by trail and error, locate the parabola in the correct spot. I am creating a 2d sketch in wf2.0. My goals is to use angles, a par, dimension, ex, .75 or .50; a par value that is equal to a parabola. I know that I have seen this sketch somewhere. Can someone help me out as to how to create this parabola. - thanks texaspete





RE: Creating a parabola in WF2,
A conic parameter of 0.5 will give you a parabola. Higher values give you hyperbolae and lower values give you ellipses.
See pages 38-40 of the document at http://pkatuch.szm.sk/download/sketcher.pdf for more details about the conic parameter.
RE: Creating a parabola in WF2,
PTC has x=D*cos(180*t), y=B-C*cos(360*t), z=0.
I think I have to some variable assigned to "A, B, C, t" before the equation.
I have no clue what to type. I think the equation window is notepad.
thanks to all. texaspete
RE: Creating a parabola in WF2,
/*Parabola by equation
/* For cartesian coordinate system
height = 3
span = 4
x = (span/2) * cos(t*180)
y = (4 * height / span^2) * x^2
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The suggestion to use a conic arc with rho = 0.5 is easier, though.
See the following links for some layout geometry.
htt
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Very simply, though, to create a revolved parabolic surface 1 high x 2 dia:
Reference points will be [1, 0], [0, 1], [0, 2].
Axis of revolution [0, 0], [0, 1].
Conic arc [0, 1] to [1, 0].
Tangent directions; normal to axis and coincident with a line from [1, 0] to [0, 2].
Rho = 0.5.
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