Sketchup Question

[Rob Hix]

Hey sketchup gurus,

Can someone whip me up a quick tutorial on how to round over a corner with a certain diameter roundover. I have been trying most of the night to get a 1/8" diameter roundover on the edge of a leg and I have been unsuccessful. Seems the problem I am having is actually drawing the arc to do the push/pull.

Thanks in advance,
Rob Hix

[Dave Richards]

Welcome to the Creek.

My first advice would be to not draw the roundover and instead soften the edge by holding the Ctrl key while clicking on the line with the eraser tool. You would get a similar appearance without the additional faces that you would get by actually rounding it over.

If you still want to make the roundover, start with an arc drawn on the end of the leg. If the edge of the leg is straight and perpendicular to the end, use Push/Pull to roundover the edge. If the edge of the leg is not straight, use Follow Me.

Before you do that go to Window>Model Info>Units and set Precision to 1/64". That ought to let you draw that arc with an 1/8" radius.

You might find it easier to work with if you scale the leg up by a factor of 10 or 100, do the editing and scale it back down. If you don't and the edge of the leg isn't straight, you might get some small faces that aren't filled in.

Finally, if you are going to draw the roundover, change the number of arc segments to no more than 6 from the default 12. You just don't need that many segments to create the roundover.

G'luck.

[Dave Richards]

Here's a little addition to my previous post. Attached is a quick drawing showing two methods of creating the roundover appearance. The legs are drawn at 1 1/2" square. On the right I used arcs with a 1/8" radius. I set the number of segments in the arcs to 6. This leg has 84 edges and 30 faces.

The left leg shows the start of a different method. I copied the edge line onto the adjoining faces. I set the lines 1/8" away from the edge. After repeating that all the way around, I softened the corner (Ctrl+Eraser tool) and hid the offset lines (Shift+Eraser tool). I ended up with a leg with only 36 edges and 14 faces.


For a single leg the segment and face counts isn't very important but in a larger, more complex model this can become an issue for your video card very easily.

Here is a more complex model as an example. The file is 1.3Mb. It has 55674 edges and 22041. Although there are many repeated elements (169 component instances) there are only 29 component definitions which helps to keep the edge and segment counts "low". It still loads up the video card's RAM on this computer.


Well, Rob, that's more than you wanted to know but hopefully some others might get some ideas.

[Jamie Buxton]

Dave, your use of the Soften command surprised me. In my experience, Soften doesn't produce that result. It seems that there are two different Soften operations. One is the one you cited -- Ctrl+Eraser tool -- and the other is one which appears on a floating menu when you right-click on a line. They produce different results.


The other odd thing about Ctrl+Eraser tool is that it doesn't change the shape of the object. If you look closely at the profile of your 2x2, it is still square with nice hard edges.

[Dave Richards]

Jamie, you are correct. Soften doesn't change the profile of the leg and you can see that there's still a 90° corner at the top. On the other hand when given limits which is what the two hidden lines provide, it creates the effect of a small radius without the cost of the associated file bloat.

[Greg Hairston]

Hey Rob,
Long time no see. I see you found you way over here. I thought you were an AutoCad guru. Glad to see you convert to the light side

Greg H
US Navy Retired

[Todd Willhoit]

Digging up an old thread...

I'm glad I am not the only one struggling with roundovers! Using 3/4" material, I would like to add a 3/8" roundover to the back side of a 5" diameter hole. I was hopeful that the Follow Me tool would prove useful but so far, no luck. Any suggestions?

[glenn bradley]

I use Fredo's Roundover Plug-in: http://sketchucation.com/forums/view...=20485#p171721

I believe you need to register with Sketchucation to download some plug-ins.

[Dave Richards]

It can be done with Follow Me but Glenn's suggestion of the Round Corner plugin makes it faster and easier. If you want to know how to do it with Follow Me, I can show you. Knowing how to do it with Follow Me might prove useful for other things, later.

Edit: I decided to just do a quickie to show how to do it with Follow Me.


Draw the profile of the roundover--I drew it above and aligned with the edge of the hole. The line down to the edge of the hole is only to show the alignment. Don't draw it in practice.
Use the edge of the hole as the path and run Follow Me.
Delete the unneeded faces and edges.
Move the profile down into place, run Intersect Faces and delete the inside edge of the hole which will leave the round over.

You could draw the profile in place inside the "board" by orbiting the camera inside. By drawing the roundover profile outside the board geometry, you can play around with it without having to worry about damaging the board.

[Todd Willhoit]

I finally had time go get back to this. Dave's image disappeared, so I tried the method from memory. I was able to create the ring but it would not close completely which may have affected the Intersect Faces command. In any case, the I was not able to complete the ring this way. I would still like to work it out, as it appears to be intuitive. I will try again later.

Fredo's RoundCorner works well.

Thanks guys for the help!

[Dave Richards]

Sorry. I don't know what happened to the image. It would help if you could post the SKP file of your example to see what you're getting.

[Todd Willhoit]

Here is the front baffle with the partially-formed radiused ring above. It is interesting to see in the model statistics how many faces and edges are produced with the ring...

Baffle Test.zip

[Dave Richards]

For that small radius you could manage with 6 sides on the arc for the profile. It'll look just fine.

I'm curious about how you set up the profile. You shouldn't have wound up with that gap. I have a pretty good idea but I'd like to hear or see an image of how you did it.

[Todd Willhoit]

Dave,
I change the arc to six sides as you suggested. Looks good.

When making the profile, I have the option to select the top edge, face, or bottom edge of the hole as the path for the Follow Me tool. I found that selecting the face causes a 7.5 degree gap in the profile. If I use one of the edges, I initially see my original profile slice, a 7.5 degree gap, and then a portion of the extruded profile as I follow the path. As I continue, near the point on the path directly below my profile the extrude profile will completely close.

So, it seems that I have found the source of my issue, but I am not clear as to why the edge and face produce different results.

Thanks again for your help!

gap.jpg

[Todd Willhoit]

Interestingly, when I intersected faces, the finished product has a blue profile on a white surface. I couldn't edit the surface color. RoundCorner left a continuous white surface with no lines. Why the difference, and are both equivalent from a modelling perspective?

intersected.jpg