Sheet Metal Thickness Resetting?

[mslosar]

I have an assembly based on a master part. It has maybe 15 parts in it. 3 of these parts are unistrut tracks with a sheet metal thickness of .1345".  The assembly is configured through an ilogic form. There's no real ilogic in it, all pieces pull parameters from a master ipt file which is largely a blank part containing all the parameters. 

After updating to 2019 in march, we've run into an oddity. It seems when we toggle a parameter on the form, something is forcing the unistrut pieces sheet metal value to be set to .25". There is no parameter in the file that is .25. Moreover, the value is hard coded. This thickness is being set in the sheet metal rule itself, and not being overridden.  I can't see a reason why an update of a positioning parameter would cause the sheet metal rule to change values.

There are other objects in the assembly that are .25" thick, but they are not directly connected to these parts. Any connection seems fairly loose, except that when i re-corrected the unistrut thicknesses in the main rule, it changed the default value of thickness of these parts to .1345. The sheet metal rule is saved in the ipt isn't it? I'd have to go to Tools/Save in the styles panel to save it to the master to get to update to other files, or so i thought.

Again, this only seems to have occurred after updating to 2019 which we did in march. I made this assembly 18ish months ago and no one reported this issue in at least 100 uses prior.

I would post it, but it's a proprietary assembly and i rather like my job 🙂

Just wondering if anyone has seen anything similar?

[swalton · Accepted solution]

Are you using the Derive function to create your sheetmetal parts?  Are you inadvertently linking the sheetmetal styles from the source part to the target part? 

I don't remember when the Link Sheet Metal Styles checkbox was added to the Derive command, but that might be causing your issue.  See the discussion in Posts 12-17 in this thread: https://forums.autodesk.com/t5/inventor-forum/mirror-an-assembly/td-p/8776515

[mslosar]

That looks to be the culprit. Thank you.

Very odd, though. I checked 2017 which we were on the previous 2 years, and the setting is there as well. However, as I said, the assembly functioned just fine in 2017. Only after the bump to 2019 did it start causing an issue.

You would think if that was solely the case it should have acted it from day 1. Perhaps the implementation changed in the interim? I don't know.

[johnsonshiue]

Hi! Have you applied 2019.4 update? I recalled we had an issue in 2019.0, which had been resolved on later updates. Please install 2019.4 update and report back. If it is still not working, please share an example here or send it to me directly (johnson.shiue@autodesk.com).

Many thanks!

[mslosar]

The 2019.4 update was installed a couple days after it was released.

[johnsonshiue]

Hi Mike,

Please share an example here or send it to me directly (johnson.shiue@autodesk.com). I would like to understand the behavior better.

Many thanks!