Newbie Trim Issue

[timothy_crouse]

Could someone explain to me why the projected circle sketch cannot be trimmed?

I am attempting to create the object in the attached PDF.

Thanks in Advance

-Tim C.

[timothy_crouse]

If anyone has a moment a review  / suggestions for technique improvements would be helpful.

I took a guess at the cut-out radius center points as I did not see all the info needed to specifically place on the object

Thanks in Advance

Tim C.

[Gabriel_Watson · Accepted solution]

First things first, to your question: your circle is a projected geometry, and those lines are un-trimmable, just like associative pattern ones would too (similar thread here: https://forums.autodesk.com/t5/inventor-forum/trim-doesn-t/m-p/5101840/highlight/true#M512526 )

If you press F8 to see the sketch constraints, or simply hover over the circle and select it, you can select the "Projected Geometry" one (see below) and delete it. After that your trim should be able to cut the sketch circle/arc lines:

     

Now, as far as techniques go, there are many tips. But one basic idea is the BORN technique just recently brought up:

https://blogs.rand.com/files/the-born-technique.pdf

And a similar part shown in a recent thread has some great example of how to use a "section" plane to make a flange/bracket with the least amount of work (see the reply linked below):

https://forums.autodesk.com/t5/inventor-forum/how-should-i-start/m-p/10905900/highlight/true#M852786

[SBix26]

Using the BORN technique and only one sketch, along with simplifying to the least work possible, here is a look at my model tree and sketch for this part.  See if you can reproduce the part from this information.

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Sam B

Inventor Pro 2022.2.1 | Windows 10 Home 21H2

[timothy_crouse]

Thank You for the info, I am re-working the model as recommended by SBix26, I have a question about work plane/sketches:
If you rotate the view from perpendicular to the work plane how do you reset the work plane view?

DISREGARD

I discovered the "Look At" command on the navigation tool bar

[timothy_crouse]

Challenge Accepted, Here you go . . . 

Comments Welcome

After I realized the 16X radius(s) are placed tangent to the large circle and Rib it all came together.

One could make a point for not using the BORN on such a simple piece BUT having all the extrusions origin being in the center made it come together nicely too.

Thanks in Advance

-Tim C.

[SBix26 · Accepted solution]

Looks like a winner!  Three observations:

1. The drawing shows that the cutouts do not go all the way through the part; there is a 30mm thick web in there:
   
2. If you create the holes in the ends as extrusions instead of using the Holes tool, you have less data about the holes to use on a drawing made from this model.  Normal best practice is to create holes with the Hole tool.
3. It's generally much easier to create fillets using the Fillet tool as a separate feature, rather than including them in sketches, and to create them as late in the modeling process as possible.  Not only easier to create but much easier to continue work on the model without them in the way.

With all of that said, here (attached) is my first attempt at this part (Inventor 2020 format). 

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Sam B

Inventor Pro 2022.2.1 | Windows 10 Home 21H2

[timothy_crouse]

Can you explain how you created the fillets against the circle?

Thanks

-Tim

[SBix26]

Using the Fillet tool, select the two corners, set the radius to 10mm, click OK.  Very simple.

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Sam B

Inventor Pro 2022.2.1 | Windows 10 Home 21H2

[timothy_crouse]

Hmm, sorry it's not clicking on my end.

I set the end of the part above the fillet you created

I initiated the Fillet command from the 3D Model Tab

I set the dim to 10mm

But no matter what I select I cannot get the fillet to wrap as you have it.

You mention selecting corners, which corners are you referring to (sorry I just am not seeing it)?

-Tim C.

[timothy_crouse]

Hmm, I got it.

I had to mess with the 3D view to get in there.

Good tip.

Thank You!

[timothy_crouse]

This stuff gets addicting 🙂

Everything is such a puzzle 🙂

[JDMather]

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@timothy_crouse wrote:

Comments Welcome

One could make a point for not using the BORN on such a simple piece…

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I cannot think of a logical reason for NOT using the BORN Technique, especially for such a simple piece.