General help: easier way to repeat edits on another part of my model?

howto
advice

#1

I’ve been using Sketchup Make for a while, but I’m certainly no pro. I was hoping I could get some tips on how to get better.

One problem I have with Sketchup is that I frequently need to repeat the same edits on multiple parts of my model. For example, this tetrahedron I’ve designed:
ABCD_dice.skp (457.3 KB)
I want to chop off the tips of each of the four corners, so that they’re not as pointy.

The first change I made by measuring 5mm down each edge, and drawing lines between those points. I then deleted the resulting “mini tetrahedron”. You can see the lines one one corner and the removed portion from another corner. The remaining two corners are untouched.

Is there a way I can modify all four corners without performing these same steps manually four times? I tried to copy/paste the mini tetrahedron onto another corner, but that didn’t work because all of the other corners are at different angles, and I couldn’t figure out how to rotate the shape to match the other corners.


#2

If I were going to do model this thing, I would first locate the centers of the faces. You could do that with crossing guidelines placed with the Protractor tool. Then I would draw the lines to outline what gets truncated at one corner and Rotate/Copy the edge around to the other two points, repeating on each face. I’d do this prior to inserting the letters.

Also, if you plan to 3D print this model, remember to correct the face orientation so you have the white front faces out.


#3

That didn’t work, because when I rotated the line segment to another corner, it didn’t appear in the same place. Insteading of being 5mm from the tip, it was 2mm. I guess that means that I didn’t find the exact center of the face, but I don’t see how could have gotten that wrong.

Edit: I figured it out. The midpoint of an edge is not the midpoint because the tip is cut off. Ugh.

As for the faces, is there a quick way to select all the wrong faces?


#4

That’s why I suggested finding the centers before drawing the lines.

Your tetrahedron isn’t exactly a tetrahedron so even if you do make the copies, they may not line up correctly. I’d suggest starting over. You can find tetrahedra in the 3D Warehouse that are properly made.

Here are some screen shots I made to show the rotate process.

Find the center of one face. Lay out one edge–at the top in this case.

Rotate/Copy to make the other two for that face.

Select all three and Rotate/Copy to make the three on the other two upright faces. Rotate about the top point.

Select 3 edges from one face and rotate copy them to the bottom with rotation centered on the bottom edge.

All the faces have the required lines.

Erase the unneeded bits and make sure the face orientation is correct on all of them.

When it’s all finished it should look like this:


#5

It took me forever to align the letters properly, so I’m not keen on starting over. But I’m curious as to why you say my shape is not a tetrahedron. Other than the tips cut off, aren’t all four sides identical regular triangles?

Also, is there a way when I rotate/copy to keep rotating and keeping making copies? When I make the first copy, the rotate stops and I have to reselect and re-rotate everything.


#6

The angles of the corners aren’t exactly 60° which they’d need to be for a proper tetrahedron.

Screenshot%20-%2012_20_2018%20%2C%208_32_09%20PM

Before starting the rotation, hit Option to invoke the copy function. After rotating to make the first copy, immediately type x2 and hit Enter.

Placing the letters shouldn’t take that long. You can drag new instances of the components out from the In Model collection. That’s what I did for the last screen shot.