Curves in an object


Hi Everyone,

I found this stl file and imported it into sketchup, I need to move the holes a bit while expanding the legs a tad bit longer. I started out making my own design from a starting point of a square, I am a bit stuck on how to make the curves now. I was playing with the arc tool but I cant seem to get the contours looking good enough. Can someone please offer some guidance?


This is what I am starting out with.


Looking at your image the shape is made from a circle an arc and two straight edges. So you need to draw those four elements and then copy them for the other corners.
Here is a quick version, it’s not the exact shape you want but using the correct sizes and angles would get your shape using this method. I have used one plugin here, Curvisard By Fredo6 available from sketchucation, But I only used it to speed up the process of making the edges cut through the face. You can trace edges and intersect etc until the faces separate correctly.



How in the world do you guys come up with this stuff. When I look at some of the stuff you guys do I still can’t believe it. You guys make using this program look so easy. I appreciate the clip as I do save them for reference later on. Now I can finally make those spacers for my drones.

Thanks again


Look at your model for any symmetry and/or repetative chunks of geometry.
In this case it even has a center to rotate about to “copy” parts.
Although credits to @Box with, once again, a very informative animation.


Yes, he’s fast, isn’t he? Note that @Box seems to be using a plugin called Curvizard for some of it.


As I mentioned in the post, complete with misspelling.


That you did mention and I am trying to download it now. I already converted the animation to an mp4 file so I can look at it over and over until I get it. What was a few minutes for Box will be a few hours for me. Hey, everything is difficult before it is easy.

Thanks so much for the help. Looks like the guys above are very familiar with your work as Simon mentioned that you are pretty fast, I agree 100%.

All of you folks are just amazing. Just look at me like a kid that walked into a huge toy store for the first time, that is how amazed I am.


I am having a little troube with this part, how are you mirroring the image to the other side? What command are you pressing to copy it to the other side like that? I tried Ctrl but the entire drawing just moves.


Press the Option or Alt key, to cause the Move [Edit: or the Rotate] operation to actually perform a copy (that is, leaving the original geometry unaffected). There should be a helpful message displayed along the bottom of the viewport window while the Move [or Rotate] tool is active that describes such alternative capabilities.


its the rotate + ctrl


Also note that he clicks then drags to set the axis for the rotate. Arrow keys will also work.


After trying off and on for a few hours I was finally able to get to this point.

What is getting me is the key combinations that needs to be pressed. I keep looking at the video over and over but I cannot tell how the rotate tool stays in the same position from the top then to the right. After the right side I guess the right arrow is pressed while moving to the middle to get on the red axis.

Looking at the video makes it look easy enough, but getting the key combinations down is whats difficult. It took me forever to figure out how to copy the left side to the right without flipping it upside down. Now I am stuck on copying both top and bottom lines.


With the ‘Move’ tool active, hit Ctrl once to get the + sign to indicate that you 'll move a copy of your selection.
Same thing applies to the ‘Rotate’ tool, hit Ctrl once to see that + sign at the cursor.

To rotate (a copy of) your selection, press and hold the L-mouse button at the center of rotation, (first clicked location). Now still with the L-mouse button down, drag the cursor to the desired location (some vertex or along an axis or whatever location) to set the axis of rotation. Only then let go of the L-mouse button.
Second click is the starting point of the rotation angle.
Third click is the end of the rotation angle.
In the beginning of @Box’s video both these two clicks are the corners of the rectangle. (avoiding the flipping into the wild)
Previously the axis of rotation was set (dragged) along the green axis
You may want to look at your model from a slightly different angle to better see what you are doing. You don’t need to make that video like Box does. He needs a “stable” view without hopping around.

There are no tricky key combinations involved.

The last rotation of the two curves don’t need that “drag to set the rotation axis”. The protractor is blue ‘on face’. You only need to subcequently find the two midpoints (top edge and right edge) to set the first click in the center.


Thanks for explaining this, no wonder I wasnt getting it. Just got home and about to try it again from the beginning.


Finally got it, only took a whole day but now its easier.


Well done, time well spent, you’ll not forget those techniques any time soon.


Belive me I wont. I have already re-created the model about 4 times because I either made it too small or I took too much material off when i 3D printed.

Thanks again to everyone for the help.


Here’s another option for you to experiment with. This way uses the diagonal from the center of the circle to rotate the edges for the mirror. This can’t be done using the arrow keys because they only work on axis so you can use it for more options.


Thanks Box, I appreciate you taking the time to teach me some of these techinques. In the meanwhile if you folks ever want to learn what NOT to do I can help you out with that.


I love these little instructional demos as I learn new tricks. So questions, is there a way to find or draw a tangent line from the circle to the box? Also, with both demo’s they have the step to intersect faces. Why is that necessary and when should i be doing that when modeling?