Object dimensions

What is the best way to get exact dimensions for my object. I have an object that’s 30"x24". with the material being 1/2" thick. When I’m through the object will be 12" deep which I can use the push/pull. Is there a way that I can specify the 30x24 or do I just draw and adjust.


Select rectangle tool, click and release to start the rectangle, move in the direction you want then let go of the mouse and type in mid air, 30",24" and hit enter.

Hi Mike,

See this video tutorial…

Injecting accuracy into your model — Aidan Chopra

Watched the video good info. Can I also do this with sheet goods and thickness the same way.


SU doesn’t know from “sheet goods.” It knows edges and faces. You can put those edges and faces together so they look like sheet goods or bricks or Ferraris. The same basic principles for specifying dimensions for objects apply, whatever form you’re creating.

You should read these articles:


Yes see the post by Box:

… then you can select the PushPullTool, click a face and move in the direction to pull, and type the thickness in midair, then hit ENTER key.

Ie, do not try to give the Measurements toolbar (Value Control Box) focus by clicking in it. Just type values and the tool puts them into the box.

I’m now trying to add the 1/2" thickness of the wood. I was hoping I could place a picture in the post. The overall dimension is 30"h x 24"w. The top and bottom will be 24" across, but the sides will be only 29" due to the 1/2" thickness of the top and bottom for a total of 29". The top and bottom will sit on top and bottom.

Or should I make all the panels separate and then group

vanity.skp (77.4 KB)

I just noticed my dimensions are incorrect

Yes an image would help, as your description is confusing.

Drag and drop images from file explorer, etc. Or use the Upload button in the edit post toolbar. (It looks like a harddrive with an up arrow above it. It is the 7th icon from the left.)

You can use the scale tool to change three dimensions at once…

Rather than telling you to start over, I’ll work from where you are. You should make a component for the sides, another for the top and bottom, and another for the back (be sure to check “replace selection with component” or you will have extra edges left over). Delete the other side and top or bottom. Edit the components and pushpull them to the desired thickness. Then move/copy them so that they create a box with the required outside dimensions. Finally, edit the sides to shorten/narrow them so that they fit inside the top and bottom. You can shorten/narrow by any of several means: scale tool on the component, edit and pushpull the required face, or edit and move the required face.

Is there a video of your description. I did start all over. I can’t get the top to go all the way across. What am I doing wrong.

vanity2.skp (79.3 KB)

You still aren’t using components effectively. Starting from scratch, here’s how I would draw that vanity box.


  • I followed the practice of drawing a basic rectangle, immediately making it a component, and then editing and pushpulling it to thickness. It would be equally valid to draw the rectangle, pushpull it to thickness, and then create the component from the result - just be sure to triple click so you get all of it.
  • In the pauses where something then jumps in size, I was typing a required value for capture by the measurements box, which wasn’t visible in the screen capture. You don’t click the measurements box first, just start typing and hit enter when done. For example, to size the bottom I typed 24,12. When I moved a copy up to be the top, I typed 29 1/2 (allowing for the thickness).

Having a quick look at your previous posts, you need to spend a bit of time with the basic Beginner videos.

Now I have a better idea. I still have to learn a little more about component.

Also I will revisit the beginners video and pay more attention

What’s the difference between group and component.


I just googled and I think group would work since I don’t need to keep them for other projects. What is the best way to select the item for a group.

I used the selection tool and ctrl and click on the object to group. I’m not sure if I’m doing this correctly. I select the face and the thickness

I just remembered the right to left and left to right command

I like to thank you for your assistance. I don’t know if I should start another thread for this next part. I’m putting 2 doors on the upper have. There will be a shelf on the upper half behind the doors. What’s the best way to show this


I attached the file. First guideline is the top of the shelf, second guideline is the bottom of the doors, third guideline is the top of a shelf.
vanity3.skp (85.7 KB)

In many ways they are quite similar - in fact they use the same core data structure and use very close to the same amount of memory. They differ primarily on three matters:

  1. Groups are by intent each unique. You can copy a Group multiple times, but if you edit any of them it is instantly cut loose from the others and made unique. Components, on the other hand, are like prototypes for things of which there will be multiple instances that all need to be the same. When you edit an instance of a Component, all of the other instances are instantly changed the same way. This can be a major advantage if you ever need to change the size of your model: you edit one instance and the others are automatically fixed. So, in your model, the two sides need to stay the same length and width, likewise the top and bottom. So they are good candidates for Components even if you don’t initially plan to change the size.

  2. Components can be saved in a separate file and later imported into another model. The only way to duplicate a Group from one model to another is cut-and-paste.

  3. Components have various special options and behaviors such as “glue to”, “cut opening” that Groups do not have.

I started a linked topic for this. As you note, it is really launching onto a new topic for which the original title is losing its relevance.

Thank you for the info. I do see where a component has it’s advantage.