Scale 3d print model without distortion in all directions

Using sketchup web.

I have a model that I’ve downloaded to 3d print. I need to resize it. I’ve tried many things to lengthen the sides without also changing the size of the cylinder. In the attached image1,
I need to lengthen the distance that is marked. However, I need the cylinder to stay the same diameter of 3/16. The remaining dimensions could change a little and that would be ok. For instance, the bottom length (see image 2) of the model could increase and that would be ok.

Also, many of the models I download for 3d printing have all the “faces” on the surface of the model. I don’t know why this happens. Is it possible to change that so there are fewer or just one face on any given surface.

You would need to separate the handle from the rest of it so you can scale the rest without scaling the handle. The handle is such a simple thing–just a cylinder–I would delete hae handles geometry and remake it after getting the thing to be the right size. What about the holes in the base? Do they need to get resized too? If so, erase them and add them back later.

Probably a better and cleaner method would be to use that one as a rough guide and model the thing frm scratch making sure all of the dimensions are what you want. Scaling the existing geometry vertically will stretch the arc at the top into an parabolic shape. Scaling the width will also distort the shape. You could use Move to adjust the length but I think it would be best to start over.

Which web version? Your profile says you are using SketchUp Pro. You’d have more options with Pro.

If you aren’t using Pro please correct your forum profile.

I’m not sure where you’re seeing that I have sketchup pro. I looked at my profile and have sketchup go. As far as the version of sketchup web, wasn’t aware of there could be different versions. I have the paid version of sketchup web, not the free version.

To “separate” the model, I followed these steps. I don’t see a command to separate anything. So I right click on the model and choose explode. I then removed the cylinder. Resized the remaining part of the model. Not sure how the holes ended up. Those are there for screws. They are counter sunk so the screw will set flush to face. If they resized slightly that is ok.

Then I tried to add the cylinder back to the model. I couldn’t get it on the face of the model where the previous cylinder was. See attachment.

To design this from scratch is the last thing I want to do. I find sketchup and other similar programs so unintuitive to make basic changes that I start with a design. And most other 3d printer users do the same. There are many web sites to download existing 3d models. So that is how I want to start.

Screenshot - 9_4_2023 , 9_37_23 AM

No. There isn’t a specific command for that. It requires editing the component or exploding it as you did.

Before you add the cylinder back you need to clean up the mess left by deleting the original one. There should be no holes in the surface.

You could create a solid compnoent of the bracket and a separate solid component of the pin. If they are placed properly the slicer will treat them as a single object.

Again, I think you would find it better and easier to remodel the thing the way you want it rather than trying to beat that import stl intoshape.

I found the license type on my profile and changed it to Sketchup Go.
Should display correctly now.

You mentioned to “clean up the mess left by deleting the original one. There should be no holes in the surface.”. Don’t know where to even start on doing that.

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Erasing the edges creating the holes would be the start. If the surface of the part is flat erasing those edges around the hole should cause the face to fill.

FWIW, I eyeballed your model and created a representation that is clean. It doesn’t have all the triangulation of your imported .stl file. The pin and the bracket are separate solid objects.

Modeled this way resizing it with the Move tool instead of scaling prevent distortion.

Here it is in the slicer.

I wonder if the pins should be made separately or perhaps be metal instead.

This is a regular issue, people not understanding the basics of Sketchup attempting to modify a model created in another software.
The shape is so simple to create if you know the basics but almost impossible to modify by blindly stumbling about.


Your model allows you to do it in 5 seconds. As you can see in the yellow circle there is a small vertical section of sides. In front ortho (no perspective) view, select both sides with the handle as shown by the red rectangle (just above the horizontal tray) and lift up. That’s all.

Any other transformations like scaling due to curvature will be difficult for you.

A general comment about modifying .stl files: By definition the geometry of .stl files is always triangulated even if the tirangulation isn’t strictly required to generate faces. Before you attempt to modify the imported .stl file you should go through and remove the unneeded edges. In SketchUp for Web that requires manually erasing edges. If the face remains, the edge was unneeded. If the faces on either side of the deleted edge disappear you need to undo the deletion because the is required to support the faces.

This is why I advised you to use the imported object as a guide for modeling it from scratch. You can create good clean geometry more easily than you can fix up the imported .stl geometry.

In SketchUp Pro this is much easier. There is an setting in the Import Options to remove coplanar edges and there are a number of extensions that can be used to clean things up further. Even then it’s often easier to create the geometry correctly than it is to fix or modify the imported object.

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I went ahead and recreated this model. Tried for several hours to do the most basic task on the existing model and got so frustrated with it I gave up. The problem with that is that many models I download would be a massive amount of time to recreate. And the same issues will happen. The training videos I find are of now help for most of the things I need to do.
So I’m stuck with making no changes to it. It is a waste of money to purchase sketchup when it is so difficult to get basic task done. Enough of my ranting.

Noticed that on my model different parts of the model are different colors. I searched the forum, but found no help on why that is happening. Searching for “different colors” doesn’t provide assistance. Must be a property of the model other than color that is different and the color changes to reflect that difference.

Also, I tried to create a round over on the top edges using the arc tool. See image 4.
The proces of drawing a line along two edges and using the arc tool to connect those two points isn’t working. I can create an arc with the concave side to outside. See image 5.
However, creating a arc with the convex side to the outer edge didn’t work. I click on the two edges and then click along the face. The arc isn’t created.
No feedback on why, just the arc wasn’t created.

If you learn to use SketchUp properly you’ll find that it’s less work to recreate the geometry with SketchUp’s tools than it is to manually clean up the .stl file so that you can work with it.

Look at the tutorials as instruction for using the tools. It really doesn’t matter what the models are. The same basic procedures apply to all of them.

The faces in SketchUp have a fronts and backs. The front faces are colored white and the back faces are colored blue. Right click on a blue back face and choose Reverse Faces. Or right click on a correctly oriented front face and choose Orient Faces. Face orientation is critical as far as 3D printing goes. The print media will be against the back faces while the front sides will be toward air.

With the correct modeling workflow reversed faces should be very rare.

Maybe due to the size of the model. When I model for 3D printing I do so treating millimeters as meters. The exported .stl file is unitless so it doesn’t matter that the model is 1000 times larger but it helps to avoid issues with tiny geometry. The example I showed was done that way. The shorter thing was modeled so it would be 1-1/4 inches (31.75 mm) long when printed but it was mmodeled as 31.75 meters long.

As I wrote before, it takes a few seconds of work to transform your model. I specifically triangulated the model to be similar to yours. When moving geometry, use the arrows to lock the direction.

Sturnus, Did not know that the move action could be used in this way. I thought it just moved the entire model at once. I was able to change the height based on your recommendations. Wasn’t exactly what I wanted, but close enough. Still distorted because I couldn’t select the exact low point so that everything moved up. The sides were squared a little. Thanks for your help.

I showed you that in my post from 9 hours ago. You can move a selection of the geometry within the object.

DaveR, Thanks for your help. I didn’t know that the colors mean front/back faces. I have no idea how they got reversed. I reversed them and colors are what I expect. Why the faces on a cylinder can be reversed makes no sense to me.

When I’m finished with the model I always select the download menu and use the stl format.
Is that the best way to use in a slicer. When importing a stl file to SU, is it possible to eliminate some of the triangulation. It is really distracting to me. Should I convert the stl to some other format before importing to SU?

Faces in SketchUp are just faces. They all have fronts and backs. Generally the back faces become exposed during incorrect order of operations. The faces on the cylinder were reversed because you extruded the cylinder from a circle drawn on a reversed face.

Yes. Since the slicer needs the .stl file to slice.

As I wrote before, in the web versions you would need to clean that up manually. The .stl importer in SketchUp Pro can merge coplanar faces which removed unneeded triangulation and there are a variety of extensions that can clean up and simplify the geometry.

I expect that no matter what you use as an intermediate file it will still have the triangulation because that’s the way .stl files are. Somewhere along the way, they have to get cleaned up.

Again, I think you would find the workflow much simpler to create a new model in SketchUp instead of fighting with the geometry in the .stl files.

Many times this is true, but not in the OP case, the STL geometry allowed to obtain the desired effect in a few seconds. It will take more time to recreate it. Especially for an inexperienced user like OP.

You need to practice selection, you need to select the geometry just above the top of the tray with the selection window. As I showed in my first post.

Though it could take longer to a beginner to model it from scratch than to an experienced user, it would be a great practice so you understand better the software and in the future you’ll be able to solve this kind of things and even more complex easily. I also recommend you to try the pro version, there are more tools native and plug-ins that make the work a lot easier. If you use it as a hobby you could try sketchup Make 2017, that was the last free version that was able to install plug-ins, it’s not downloadable from the official sketchup website anymore but a lot of people are still using it and if you take 5 mins on google or even on this forum you can find the installer.

Edit I found a post:

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This is a crossroads of sorts… yes, editing the STL file is not a difficult process. BUT, in order to do so, you need to understand how to use SketchUp well enough to know how to do basic editing… if you had the basic abilities you needed to edit the STL file, then modeling this geometry from scratch would be pretty easy!

SketchUp is a easy to learn 3D modeling software, but you do have to spend time learning it. With this specific model, you have three options:

  1. Learn SketchUp well enough to model from scratch (I recommend checking out

  2. Learn SketchUp well enough to edit your imported STL (same suggestion for learning here)

  3. Ask someone to help you by editing your STL (and learn SketchUp so you have the ability to edit your next file on your own)

As someone who has used and taught SketchUp for a little while, now, I can say that you can do this! You will, however, have to put in some time before you can do it!

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