Constraints with User Parameters

[Anonymous]

Hi,

I'm having some issues with using User Parameters to drive dimensions when using constraints. 

In the video below you'll see the issue I am having, when I enter a value manually the sketch scales correctly but if I use a user parameter to drive the sketch the constraints seem to go to pot and I end up with a very unusable result.

Any help with this would be greatly appreciated.

Thank you.

[Sergio.D.Suárez]

Note that the sketch of your file is not completely defined, so it deforms when you change the parameter.
On the other hand, if it is possible in my opinion it is preferable that the roundings are carried out as operations after the sketches, ie after an extrusion for example, because they tend to give problems when varying the parameters and try to update when the sketch is complex or It has too many rounds.
Share your file here if it seems like this, we try together to verify these observation points.

[Sergio.D.Suárez · Accepted solution]

Below I leave an example so you can observe

[jtylerbc]

Whether or not you implement @Sergio.D.Suárez 's suggestion to make the fillets a feature rather than draw them in the sketch, I would suggest getting more of your geometric constraints in place before adding dimensions.  I'm not sure why you're seeing a difference in behavior between a numerical value and a parameter.  But if I were modeling that part, I wouldn't be adding that dimension (or any others) until the overall shape was already locked down by Tangent, Symmetry, and other applicable geometric constraints.

Define the shape first, then the size.  That will give you the most stable, predictable performance in the sketch.