topic Parametric Modeling Help in AutoCAD Forum

Parametric Modeling Help

sage9HN5X — Tue, 09 Aug 2022 15:44:10 GMT

Hi all,

I have a question for you guys. I am trying to create a 2D parametric model roughly based on the image below. Essentially when I enter a value into the 'input' I need it to obviously shrink or grow to that value while maintaining the 45 degree bevel on each end. More challenging though (for me at least) I need the number of circular cutouts to increase or decrease depending on the input, while maintaining roughly a nominal distance between themselves, and also maintaining a different distance to the edge for the first and last cutout.

Any assistance or suggestions would be greatly appreciated!

Thanks in advance!

- Kelly

Re: Parametric Modeling Help

TheCADnoob — Tue, 09 Aug 2022 16:07:33 GMT

What have you got so far? Share your dwg

Re: Parametric Modeling Help

leeminardi — Tue, 09 Aug 2022 17:00:38 GMT

I do not beleive that changing the number of circular cutouts as a function of "Input" can be done with AutoCAD's parametric features. Autolisp could be used but you need to specify a few more rules. For example:

What is the relationship between Input and the distance between holes?
How is the distance from the first hole to the end determined?

Re: Parametric Modeling Help

TheCADnoob — Tue, 09 Aug 2022 20:07:33 GMT

Theoretically there are ways to fudge an array type thing. Guess it depends on the parameter and restrictions needed. If you use the input to drive a distance between the circles origins you can stack the unused circles on top of each other giving the appearance of new circles once a distance is achieved. The downside is that you have to build in all those items and their formulas.

I used this formula to toggle between a distance or not a distance

CEIL(1/(1+POW(E,(X-d5))) - 0.5)*Y -> X is the distance at which the circle should show up in comparison to the main input d5. Y is the distance from the origin of the first circle.

Re: Parametric Modeling Help

sage9HN5X — Wed, 10 Aug 2022 14:55:46 GMT

Hi guys,

Thanks for all the responses!

Here is what I have so far, pretty close to what you have CADnoob. I'm still trying to figure out the circular cutout relationship. The example you have seems like a really viable option! Any chance you could share the DWG so I can take a closer look?

Re: Parametric Modeling Help

TheCADnoob — Thu, 11 Aug 2022 13:58:42 GMT

@sage9HN5X wrote:
Hi guys,
Thanks for all the responses!
Here is what I have so far, pretty close to what you have CADnoob. I'm still trying to figure out the circular cutout relationship. The example you have seems like a really viable option! Any chance you could share the DWG so I can take a closer look?

Unfortunately I did not save that dwg, but the formula is the hard part to figure out. its based on the Sigmoid Function. Basically you set the distance between two circles to either be zero (this would stack the circle directly on top of each other) or to be a specific distance. The formula below will result in zero or a set distance depending on the input distance. You have to set up this formula and circle for all potential circles that would be used.

CEIL(1/(1+POW(E,(X-d5))) - 0.5)*Y

Where X is the distance at which the circle should show up next to the first circle. Its triggered by a comparison to the main input d5 (in my example). in other words if your you input is bigger than X it will make the circle switch from being zero to the distance you set in the Y variable.

Where Y is the distance from the origin of the first circle that you want the next circle to appear.