topic Sheet metal bend angle or measure tool inaccuracy in Fusion Support Forum

Sheet metal bend angle or measure tool inaccuracy

JulianGroeli — Tue, 18 Aug 2020 18:02:54 GMT

I'd like to add a 92 degree bent flange to a simple sheet metal part. The bend line is not perpendicular to the part, but off at a strange angle. Creating the flange works as expected, but when I go to measure it afterwards I can't tell if the geometry is accurate.

Measuring the faces doesn't reliably produce the same measurement. Sometimes the inner angle measures 88.0001 deg, sometimes 88.0, sometimes 87.9999, in back to back measurement attempts with no changes to the model. A similar issue happens when checking the perpendicularity of the edge of the sheet. Sometimes it measures 90.0003, sometimes 90.0006 degrees.

This can introduce issues that are hard to find and resolve, especially if they occur early in the model history. See attached file where I've re-created the issue.

Is this an issue with the geometry, or an issue with the measure tool?

Re: Sheet metal bend angle or measure tool inaccuracy

TheCADWhisperer — Tue, 18 Aug 2020 20:08:23 GMT

Q1. How will you measure this angle in the real world?

If you want that angle as 6.2°, why is it not dimensioned as 6.2°?

If you take an infinitely thin split anywhere perpendicular to the axis, you will measure consistent angle. (see Attached)

Re: Sheet metal bend angle or measure tool inaccuracy

JulianGroeli — Tue, 18 Aug 2020 19:55:42 GMT

Point taken, 6.2 deg would make more sense for real world fabrication.
Unfortunately this doesn't resolve the bug. I'm still getting measurements
of 87.9999 when measuring the flange.

Re: Sheet metal bend angle or measure tool inaccuracy

TheCADWhisperer — Tue, 18 Aug 2020 19:59:05 GMT

@JulianGroeli wrote:
Unfortunately this doesn't resolve the bug. I'm still getting measurements
of 87.9999 when measuring the flange.

Show me screen capture of the "issue" using the file that I Attached above.

Re: Sheet metal bend angle or measure tool inaccuracy

JulianGroeli — Tue, 18 Aug 2020 20:25:33 GMT

See attached. It looks like the measure tool is having a hard time measuring the angle between the faces vs between the edges.

EDIT: What's odd is that this doesn't happen every time you measure. Sometimes it's on the first try, other times it's after 3 attempts, measuring the same faces.

Re: Sheet metal bend angle or measure tool inaccuracy

TheCADWhisperer — Tue, 18 Aug 2020 20:26:28 GMT

The line edge is precise as it can be.

Re: Sheet metal bend angle or measure tool inaccuracy

JulianGroeli — Tue, 18 Aug 2020 20:34:16 GMT

Correct, the edges of the split face are reliably measuring in at 88.00 deg.

Thanks for your help confirming that, it's good to know the geometry is as intended.

It seems like the issue in the measure tool when measuring face to face. That should also be 88.00 every time.