How do I resize a sketch circle?

[johnwYMVVZ]

I originally projected these circles from the mounting holes on a PC board from which to extrude mounting pins.  I realize now that they should be slightly smaller in diameter.  I can't seem to change the diameter of the circles or even select them to do an offset (which would require changing the extrusion base too).  Changing the diameter would be best - how do I do this?

[HughesTooling]

You will not be able to modify the diameter of a projected circle, if you break the link you'll also lose the link for position so not an option. You should be able to offset them, just make sure the sketch that contains them is active. After offsetting you might want to change the projected curves to construction curves.

Another option that might be easier is offset the hole surface. Just use press pull and select all the hole surfaces and add an offset to the size you want.

Mark

[johnwYMVVZ]

I can't get the offset to use those circles for some reason.

So I tried press pull, but after selecting the first circle it changes to extrude and there is no offset option.

https://www.screencast.com/t/SfS6ntVZ

[HughesTooling]

Press pull will only work on the 3d model not the sketch. For offset were you in sketch edit mode, right click the sketch in the timeline and edit or were you trying to use Offset Face from the Modify menu?

Also please don't attach pictures. There's an option Photos on the editor toolbar to embed them, please use this option.

Mark

[johnwYMVVZ]

I was in edit sketch mode when I tried to offset.

I can't seem to select the mounting holes when using press pull.  The sketch on the ground plane keeps lighting up but the PC board model doesn't flicker.

The photo tool won't accept my screenshots.  It gives me an error message that says enter a complete url.  And I can't paste them into the message directly like I can in gmail.

https://www.screencast.com/t/0h2PlWqBj

[HughesTooling]

You will not be able to modify the PCB as it's an imported linked part. You will need to create the sketch in Fusion, project the edges then offset. Any sketches or models in the linked design are not editable in Fusion, hard to tell what you really want to do. If you're making the mounting plate in Fusion and need smaller holes just project the edges, make them construction geometry then use their centre points as points for the hole tool. 

When adding pictures, after clicking the photo option click on the grey are above where it says Choose File and press Ctrl+V to paste directly from the clipboard.

Mark

[johnwYMVVZ]

I started over since apparently I can't import any board changes into my existing case anway.  Bad design there, but that's a different issue.

So I projected the board outline and 4 mounting holes into a new sketch.  I made the holes construction lines and created new offset circles.  And I did a .5mm offset of the board outline to allow breathing room and I'm now trying to move the top line + 2 side curves to allow space for the wifi antenna before extruding and shelling.  I cannot get these things to move.  What am I doing wrong now?

[HughesTooling · Accepted solution]

They are part of an offset so fully constrained, you can't move just part of an offset. Think I'd just draw a rectangle around the projected edges and dimension the offsets for each side. Keep the corners sharp and use Fillet on the 3d model after extruding.

Mark

[johnwYMVVZ]

I'm glad I tested this first before buying!

Anyway thanks for your help. 

[chrisplyler]

It makes sense.

First, you Projected in the edge of the board. That gave you the purple outline, which means it's a linked projection. Then, you selected that entire purple outline and did an Offset of it 0.5mm.

So you can't just Move the purple stuff, because it's linked. And you can't just Move any of the outer edge because it's defined by that 0.5mm Offset value.

#1. Stop trying to use the Move tool on sketch elements. Instead, set things up properly with dimensions, and when you want to change the position of something, double click and edit the appropriate dimension value.

#2. In order to do that with your top edge and the two fillets, you will need to delete the existing outer edge you created with Offset, and Offset the bottom and three sides as a single Offset. Then use Lines and arcs to draw the upper portion, constrain it appropriately, and dimension that top line away from the purple projected line the desired distance. In this way, you will have one Offset value assigned to the bottom and two sides, but a separate dimensioned value for the top, which can be adjusted/edited separately from the Offset value that the other sides have.

#3. It might be easier just to draw a rectangle around the purple projected one, and then dimensions the four sides from the purple projected sides independently. Then you could change the distance of any side alone, or in combinations, or whatever.

[johnwYMVVZ]

I've been an autocad user since versions were single-digit so I'm having to unlearn in some cases.  "Properly" doesn't mean the same thing even between products from the same company.

In this case specifically, it would make more sense (to me) to have an option to force a constraint, but that shouldn't be the default behavior.  The fillets on my board aren't a clean 3 or 4mm so matching them on the case after creating a rectangular block and filleting the 3d structure is a matter of trial and error.  An offset that created a new line that I could manipulate then extrude would have been much less time consuming and straightforward, given my experience with other autodesk tools.

That being said, I appreciate the advice.  I will continue to learn yet another way to do the same thing 😉

[chrisplyler]

Of course I mean "properly" as in "properly for the software being used." Back when you started learning Autocad, there was a learning curve to it also. Don't get discouraged.

I realize my dimensions aren't right for your case, but observe the methodology in my video below. Notice that:

1. I made the lower three sides in one offset.

2. I made the top side in a separate offset.

3. I filleted the top two corners manually, and drove their radius relative to the board's projected radius.

4. I reestablished the offset dimensions because creating those fillets caused them to be deleted. If you think about this, it makes sense.

5. The entire offset outline turns black, because it has all the constraints/dimensions it needs to be fully defined relative to the board projection.

https://knowledge.autodesk.com/community/screencast/ec702050-cbf8-4378-89d3-4de676db945c

[HughesTooling]

Ok here's how I'd do it, using a reference dimension for the radius is not parametric so could break with edits, using an equal constraint is easier. @johnwYMVVZ  There is some unlearning needed to pick up best practice using a sketch solver. It might take a bit longer to set up to begin with but edits and everything updating automatically make it worth the effort.

Mark

[johnwYMVVZ]

Interesting.  Thanks for taking the time to do that.

[johnwYMVVZ]

Also interesting.  Thank you.

[chrisplyler]

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@HughesTooling wrote:

...using a reference dimension for the radius is not parametric so could break with edits, using an equal constraint is easier.

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Yes. That's better!