Inventor 2021 Solid Sweep has a mind of it's own??

[CamperUnhappy]

I was messing around with trying to design a router template to print on my 3D printer and wanted to simulate a router bit path around a profile.  When I went to go sweep the cutter body around a very simple slot profile, inventor just seems to dream up it's own weird path to follow.

I thought it might be because it was a closed loop, so I converted one line to sketch geometry, but that had no effect.  I then thought it might have something to do with using the cutter tangent instead of constrained to a point on the center of the cutter.....but the same result.

[CamperUnhappy]

Here is the part file in case anyone wants to check it out.

[imajar]

I've seen that behavior before, even outside of solid sweep.  And I reproduced the issue in Inventor 2020 by the way.

My workaround is to place the circle at a discrete point in the path.  If no point exists, then I split a line and make a point, that is what has worked for me in the past (and it worked for this as well).

[johnsonshiue]

Hi! I believe it has something to do with the start of the path. When the tool is not located at the start, the transformation can look odd. Use Direct Edit -> Body -> Move or edit the sketch to relocate the body closer to a point on the path (the intersection between the straight line and the arc). After that, it will look more predictable.

Many thanks!

[CamperUnhappy]

@johnsonshiue  I did some more testing on this and it doesn't seem to have anything to do with where the sketch is, but rather if there is a node on the path that intersects the swept body.

The help file says "Place the toolbody at the start of the sweep path."  If the path is a circle.....or a closed loop like my slot that seems like an edge case that wasn't considered?

Here's a screencast demonstrating the behaviour

e2ad16cb-b031-415b-88fc-a514414b71e4,640,620

[CamperUnhappy]

The forum is being a jerk and not letting me post my screencast.  let me try again....

nope.  not working.  "Your post has been changed because invalid HTML was found in the message body. The invalid HTML has been removed. Please review the message and submit the message when you are satisfied."

the forums ARE what generated the HTML code to even embed the screencast.

I give up.

[imajar]

I have found that going back and editing the post after posting it will usually get the screencast link to work.  Otherwise, just paste the generic URL to the screencast here.

[CamperUnhappy]

@imajar  I tried editing the post, I tried editing the HTML code, I tried posting the embed code that's generated from the screencast portion of my dashboard.  Seriously so frustrating.  I must have wasted 15 minutes trying to post one simple reply.

Here's the screencast URL  https://autode.sk/2EhedGw 

[imajar]

I hear you - I've been there!

Nice screencast, thats a really good visual showing what I described in my first post.

[johnsonshiue]

Hi Richard,

If I understood how Solid Sweep worked, I believed the start of the path is determined by the closest vertex on the path to the toolbody. For a full circle, the start is usually at where the +X axis intersects the circle (when the center is at origin).

The behavior is indeed slightly different than Profile Sweep.  Profile Sweep relocates the profile plane to the start point, while the Solid Sweep keeps the toolbody intact.

Many thanks!