Body Extrusion Disappears After Increasing Parameter Value

[thespaltydog]

Hey everyone, I'm having an issue with an extruded body disappearing when I update a master width parameter. I built my model with a width of 60 inches. I can resize to anything under that and it behaves fine, but as soon as I go anywhere over 60 inches it breaks and I'm not sure why. Also, when this happens my browser adds two additional bodies (it seems to be those small squares).

I tried converting them all to components as well but I still experience the same issue.

The parameter I'm updating is masterWidth and the parameter that I'm using to extrude is materialThickness2. I've attached a screencast of my issue along with my file.

Thanks for the help. I appreciate it!

[davebYYPCU]

Blue sketch lines will keep you chasing your tail.

Not that much wrong with the file, 70mm wide and all updates without error, but if you click drag any horizontal line, this happens, and I don't think you wanted that.

Duplicate lines and white dots, all indicators of sketching that can be better.

Get the sketch to all black, with no white dots, 

If things break after that show us how.

[jeff_strater · Accepted solution]

what @davebYYPCU says is correct - you should fully constrain your sketches.  In this case the root cause of the design failing is because you are missing a coincident constraint, which causes the first extrude to produce a wrong outcome by picking a different profile:

To fix it, add a coincident constraint as in this screencast:  repair video 

[jeff_strater]

here is the embedded video:

[davebYYPCU]

Jeff, Photos work, avoid video like the plague, but it turned up after posting, go figure

[thespaltydog]

Thank you! This was quite the overlook on my part. I wasn't even thinking that I didn't have black lines, ha. This is one of the first sketches I've done with non-rectangular shapes.

I tried dragging my sketch away from my projected geometry line similar to the screenshot from @davebYYPCU and made the bottom line of my construction rectangle collinear with the projected line. This seemed to do the trick as well.

Do you know of any benefits or disadvantages of this over making the coincident like you had showed? The projection is from another sketch of mine just on a different plane.

Thanks again for your help!

[davebYYPCU]

That projected line should replace all those bottom sketched lines.  

There are no right / wrong ways, just better or not better.

Might help....

[reboot689]

I have a similar issue. though mine is not fixed by fully constraining the sketch. As I tried, with no luck. I am trying to increase an extrusion of a small piece connected to the side of a simple case shape. When I change it from .4mm to .6, it vanishes. if I attempt to constrain the sketch anymore it says its over constrained.
What should I do?

[davebYYPCU]

File Export, and attach to another message.  Nominate which feature is being adjusted.

[reboot689]

sure thing. Its extrusion 2 and 3. I need them both to be able to increase. 

[davebYYPCU]

Nothing wrong with the Extrude, they update as required.

Delete the Move that is causing your problem. Red at time of loading.

Might help...

[reboot689]

Thank you! that seemed to be causing the issue!