Parabola

[Daniel_H]

First time I need to use an actual parabola (not those curved lines that sometimes look like parabolas) in inventor for simulation of projectile launching in 2D sketch, but I can't find the tool, not even in the help topics (I hope it exists). Does anybody knows how to make it?

thanks

[Ebolagirl]

Hmm... I'm not quite sure what you're trying to accomplish and I don't have Inventor in front of me right now so I can't mess with it. But it sounds like the splines didn't work for you? Try a the three point circle thing. That may work. It's in the circles section.

[Daniel_H]

Originally Posted by Ebolagirl

Hmm... I'm not quite sure what you're trying to accomplish and I don't have Inventor in front of me right now so I can't mess with it. But it sounds like the splines didn't work for you? Try a the three point circle thing. That may work. It's in the circles section.

I used splines and tried to get as close as I could of a parabola, it worked as I needed (even that I had to calculate some reference points in my notebook), but since inventor has so many tools, I thought it would have at least one easy way to get a parabolic shape curve.
Thank you anyway

[Ebolagirl]

Sorry that's the best I could do for you... I've never had to use a parabola shape either. And hopefully I never will... hehe.

[Ianworld]

I believe splines are actually cubic functions so in theory they should be able to approximate a parabola pretty precisely. That doesn't mean its easy to drag it into a correct shape. Just a note, You can also import a parabola graph/image from somewhere else and draw the spline ontop of it to match the image. Best I can offer as well.

[CmptrGk]

i have an idea.

calculate where you would want the endpoints of the parabola to be. find the distance between them. set the two endpoints of the spline to that distance. then find the distance between the mininimum, going straight up, to where the endpoints would be. then set that distance, and make the minimum of the spline halfway between the two end points. im not sure if this will work, but i think it would be pretty close.

[Daniel_H]

Originally Posted by CmptrGk

i have an idea.

calculate where you would want the endpoints of the parabola to be. find the distance between them. set the two endpoints of the spline to that distance. then find the distance between the mininimum, going straight up, to where the endpoints would be. then set that distance, and make the minimum of the spline halfway between the two end points. im not sure if this will work, but i think it would be pretty close.

exactly what I did, plus I also put the start tangent to a line with the angle of my shot. It looks like a parabola but I'm not sure it is one. Well it works fine for projectiles anyway

[sanddrag]

I'm thinking there should be a way to make a line follow an equation. I'm wondering if you could do some fancy work with parameters to make it happen. If anyone knows, I bet'd be DanielBCR. Maybe he'll stumble upon this thread.

[John Gutmann]

I do not yet have autodesk readily availible to mean right now but can you enter equations into the precise input boxes?

[sanddrag]

Originally Posted by sparksandtabs

I do not yet have autodesk readily availible to mean right now but can you enter equations into the precise input boxes?

I believe the answer to that is yes, but I also believe it would just solve the equation rather than plotting it.

I'm not sure exactly what you are trying to do but perhaps something like Excel would be a better tool of choice?

[Dan Zollman]

I don't know much Inventor, but I do know that parabolas are conic sections...can you make a cone and use the intersection between the cone and a plane?