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How to have number of part instances driven by a variable?
david_lynch037
Member Posts: 4 ✭
Hi. I have this part that is a wheel with cylinders on the edge of a wheel, such that the cylinders all touch each other. The wheel is 20 inches in diameter, driven by variable #dia. I would like to be able to change the diameter to 40 inches, by changing #dia, and get more cylinders on the wheel, so that they touch. Right now, there are 18 cylinders, but when I change #dia to 40, I would want enough cylinders so that they still touch each other.
Also complicating this is that there are some values of #dia that will be impossible to fill completely with cylinders. I can't have 1/2 a cylinder or gaps between cylinders.
Is this possible? How do I model this without manually iterating over the pattern tool, trying to find the perfect combination of #dia and the number of cylinders to support scaling of the part to various diameters?
Here is the design:
https://cad.onshape.com/documents/7aef99bb7ab5475c70e92f74/w/cc4a7dc99b6308703b4d0870/e/b7d556c02a14e7bba7fa223a?renderMode=0&uiState=66db9a613ffdfa79fcd6ca40
Thanks!
Comments
Hello David. Is the diameter of the cylinder constant? - Scotty
The size of the backing plate will want to float with cylinder count instead of being fixed. Note that the angle is removed from the circular array and replaced with a tangent of end circle back to the start circle.
Change the configuration variable "cyl_count" and all all follow,
https://cad.onshape.com/documents/8b0a762ab2c76b3213359e75/w/b2489ce104522fd5b1c28ecf/e/c1ee7f1242d662d11ed74f89
Thank you @glen_dewsbury. This makes the diameter a measurement rather than a driver. I didn't know you could do that.
It took me a while to find cyl_count up in the Configuration, but now I learned something new about that! This is awesome! Thanks!