Change parameters fuction not working unless I only move in tiny increments

[engineeringNZDU2]

I am trying to design a seal in fusion. Drew a sketch of the shape (about 20 lines) I fully defined the entire thing and made every single dimension parametric based off 1 parameter for the Y dimensions and another parameter for the X dimensions. The idea is I can change 2 of the parameters and it will change the sketch to the size I want it at. When I tried to do this it worked if I only changed the parameters by .01in or less. the second I wanted to make a change larger then that it would turn red. I started at .305in as y parameter, I can switch it to .315 or .295 but if I try to jump any further then that it will turn red and fail. I can go .315, then .325, then .335, and so on but then it will take me forever to get to any considerable difference. 

I confirmed it was fully defined as I have the red lock symbol on my sketch. I don't think it is my computer not able to compute something too big it because I have the same issue with a different computer as well as when I check how hard my CPU was running as I attempted the change there was no considerable difference. What am I doing wrong here and how can I fix it?

[laughingcreek]

Without seeing the model it would be really hard to say.  there are so many ways of constraining a sketch that could cause problems like this.

[engineeringNZDU2]

@laughingcreek I have all the points of the lines dimensioned with an X dimension and a Y dimension based of one point on the sketch. then each of them have a parameter. if there is a way for me to send you my file I can

[laughingcreek]

export as an .f3d file and attach at bottom of post

[engineeringNZDU2]

thank you, I am attaching the file.

It might be a confusing drawing so I will do my best to explain it. I have 5 parameters, the first one only references to one dimension and works just fine. the second and 3rd ones are the ones I want to change but don't work well. the 4th and 5th parameter are for the sake of a ratio to scale my sketch properly. 

[laughingcreek]

out of curiosity, where did you get these measurements?

[engineeringNZDU2]

@laughingcreek I measured them with an optical comparator

[laughingcreek · Accepted solution]

I think the short answers is all those dims are overwhelming the sketch solver.  the values do seem to change, but the sketcher can't work out where to place things without being in conflict with other constraints.

some interesting observations.  if instead of controlling groovewidth and  cross separately, you multiply by a common ratio, you can change in larger increments (50%), but to large and the sketcher still fails.-

also if you get rid of all the arcs (replacing with straight lines so you don't lose dims), you can make changes to groovewidth and cross as large as you want and the sketcher will solve it fine no matter how big the jumps are.

makes sense that changing just the x or y scaling would cause issues with solving the arcs.

I also don't think fusion operates well at this scale.  some of your dims are have a differance of as little as .0002.  Was the part your measuring made with a process that would have tolerances out to 6 decimal places?  if you take the same measurements at different points along the circumference how much variance do you get.

if you've just got to define things in this way (instead of for instance defining radiuses and angles, etc), then instead of trying to scale the sketch, make a surface patch from the sketch and scale the surface.  see attached.

[engineeringNZDU2]

@laughingcreek I cant really change the size or the radiuses due to the fact this is all measured units and I cant modify it to get rid of arcs. however the scale feature I think will be able to work. I will need to mess around with the point I'm scaling it from and how the diameter works. thank you for the help, I really appreciate it.