parametric inputs for clothoid loop

[kevcarro]

I am trying to make a clothoid loop curve for a roller coaster model except I cant seem to find the proper !MATHMATICAL! inputs to make it happen in the equation curve tool

[TheCADWhisperer]

What version of Inventor are you using?

Can you use a 3D intersection rather than equation curve?

[kevcarro]

Version 2020

A  3d intersection isnt as clean

I think the issue I had before was that I wasnt entering the function in the form of an integral but I dont know how to submit it as such

[johnsonshiue]

Hi! Please share your attempt here. There should be a workflow in Inventor to do that.

Many thanks!

[kevcarro]

Yeah there is..... its called telling me how to input an integral in the equation curve tool.

[TheCADWhisperer]

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@kevcarro wrote:

A  3d intersection isnt as clean

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What is your manufacturing/assembly tolerance for the finished design?

[kevcarro]

Here is the unclean version now how about you guys just tell me how do I properly go about implementing the fresnel integrals into the equation curve tool since apparently it wont let me just copy/paste the ∫ symbol into it 

[johnsonshiue]

Hi! Could you zip up the file and attach it here?

Many thanks!

[kevcarro]

Hi! could you tell me why you arent divulging the cleaner faster method of just using the equation tool?

Many thanks!

[johnsonshiue]

Hi! I believe there are equations available to tackle this curve. Google it and you may find some suitable equations. In 3D Equation Curve, make sure you set coordinate system to Cylindrical. It will make life much easier. I don't think using the spline is the right approach in your case.

Many thanks!

[kevcarro]

OMG YOU'RE NOT EVEN PAYING ATTENTION TO MY LAST POSTS

I ALREADY TOLD AND SHOWED YOU THE EQUATION THAT I NEED TO USE BUT THE EQUATION IS IN INTEGRAL FORM AND THE EQUATION CURVE TOOL WONT SEEM TO LET ME USE THE ∫ SYMBOL 

HOW DO I INPUT INTEGRALS GAWD **** IT!!!!!!!

[karthur1 · Accepted solution]

You can't enter an Integral as an equation in Inventor.  Integrals are not used to plot functions.  You can enter the clothoid function in Inventor.  There are a few different ways to approach this, but the easiest I found is to use a 3D equation curve.  For the x-coordinate, it will be a function of Cos (t) and the y-Coord will be a function of sin (t).  I am not sure of some of the constants you are working with, but this is what I came up with for a sample curve.

The function that I used for this is:

[kevcarro]

Thank you for getting the closest answer but is there one to make a perfect clothoid?

https://www.physicsclassroom.com/Class/circles/u6l2b2.gif

[karthur1 · Accepted solution]

"Perfect" would be left for interpretation.  Here is a webpage that will plot a parametric equation. With this you can quickly see the shape and tell if it is where you want it to be.  You can always scale it and get it where it needs to be in Inventor.

[kevcarro]

Seriously how are you a software engineer when it seems quite apparent that you fail at reading comprehension?