This is a really screwy problem. I'll do my best to explain it.
I've got a Parameter that currently has the value of 0.50.
You can see that it references a different parameter. Basically, at this point in the design, I want all of these Upper Edge values to be the same, so each one simply references a prior one. It makes it so I can potentially change just one particular one in the sequence and still have all the subsequent ones in the sequence follow on with the newly changed value for that particular one. [ There IS method to my madness ]
I use that parameter in a sketch as the radius of an arc. Actually it's created as a circle that's tangent to the sides of a rectangle and then the un-necessary part is deleted, leaving just the arc connecting the two rectangle sides. Actually I use the value for the radius on the arc on the opposite side as well.
It all looks fine. And the loft that I do through that sketch, joining it to other sketches looks just fine.
I then go back into the Parameters dialog and I CHANGE the definition of that MainBodyUpperEdgeRadiusF so that it references the height of the rectangle and multiples that by a factor in order to get the new radius value, specific to this sketch and NOT identical to the ones used on the other related sketches. And I do that modification to the Parameter WHILE I still have the sketch up in edit mode.
After the edit the parameter and the sketch looks like this:
The parameter has the newly calculated value and the sketch has updated so that the arc also now has the new value.
SO FAR SO GOOD.
I Finish the sketch, so the edit window goes away, but the sketch is still visible on the screen.
I go back into the parameters dialog and CHANGE the MainBodyUpperEdgeRadiusFactor parameter from 0.5 (the current value) to 0.6 and tab to the next parameter.
That causes the MainBodyEdgeRadiusFactor to change to 0.6 as well as the MainBodyUpperEdgeRadiusF to change accordingly in the parameters dialog. BUT !!!!! in the displayed sketch the arcs whose radius is determined by that parameter DO NOT CHANGE. The displayed arcs turn BLUE, but that's all. There's no error or warning issued.
I was expecting the sketch to be updated so that the arcs are now the newer radius, but they're not.
SO I close the parameters dialog and choose to EDIT the sketch, and it comes up like this:
The displayed values for the arc radii are correct, 1.782, just as they are in the updated Parameters list, calculated from the new equations. BUT the actual displayed arcs remain unchanged!. They still are drawn with the old arc radius values.
I then click on one of the displayed arc values to allow for editing the value . . .
and simply accept what's already there, what happens is it finally regenerates the arcs correctly, to the newly calculated values. Note that the displayed values are still the same as in the prior picture, which were correct there and are correct here. The only difference is that NOW the arcs are the correct size.
SO, WHY was it necessary to go and open up the sketch for editing and "edit" the value for the arc (actually just accepting what's already there, no actual edit) in order for the arcs to get re-generated properly?
I also found that if close out the sketch edit and go back to the Parameters and edit the MainBodyUpperEdgeRadiusFactor parameter which, recall, is used in the equation that calculates the radius values for the sketch, IT DOESN'T CHANGE the sketch. In fact I've got a number of sketches (all part of the same Loft operation) that make reference to that MainBodyUpperEdgeRadiusFactor parameter (so that I can basically adjust them all at the same time), and changing that MainBodyUpperEdgeRadiusFactor parameter in the parameters list has NO EFFECT on all those sketches and consequently no effect on the loft operation that joins them all together into a body. INSTEAD, I have to open up each and every sketch and "edit" the corresponding arc radius value (actually just selecting it and accepting what's already there) in order to get the sketch to regenerate itself and create the correct arc line.
I use User Parameters extensively throughout my designs because it makes it so easy, when used correctly, to make simple changes to Parameters and have the entire design update automatically. But this recent problem is totally weird. I change a Parameter and it does NOT update the sketch or the related bodies.
Is this a glitch in Fusion 360? Do I just happen to be doing something that wasn't anticipated in the design of the program, in particular with user defined parameters?
Am I doing something wrong?
Is there a work-around to this?
