Make diagonal cut


Sorry if this is posted wrong…

I am trying to learn Sketchup, and so far so good.

Im trying to do a diagonal cut, and tried with the help of this post

But I can’t get it to work…
This is what I have done

  1. Put a rectangle on
  2. Selected the side and the rectangle
  3. Then I "intersect with selection
  4. Select the pieces I want to delete
  5. I just deleted the side…

Hope someone can help



It would be easier to spot the problem with the model. But here are some things toi look for:

  • Make sure the recatangle passes all the way through and past the side so it’s a complete, clean cut.
  • Make sure that both faces of the sides and the rectangle are all in the same context (not separated by, say, one piece being inside a group or component)
  • Since you’re using Intersect with Selected, select everything with a triple-click.

The following is probably a better, easier way to construct this:



Cant get it to work :smile:

Tried to attache the model

Rygeovn.skp (302.7 KB)


I believe that your problem is you have nested components that are not used consistently for what you want to do. Specifically, the left side is an instance of Side #1, which has an instance of Venstre Side nested in it, and Venstre Side has two instances of Braet#1 and three instances of Lige Braet nested in it. Here’s the issue: the back, an instance of Side, nests Bagside, which nests instances of these same components - Braet#1 and Lige Braet. But you want to cut the left side differently (at a diagonal) than the back side (beveled straight across). Because they internally use the same Components, this is not possible. Anything you do to Venstre Side will immediately be duplicated in Bagside!

To mend things, I’d recommend:

  • open Side and its nested Bagside then make the nested Braet#1 and LigeBraet there unique. This will disentangle them from Side#1 and Side#2.
  • unless you anticipate that the left and right sides will need to differ, consider deleting Side#2 and replacing it with a copy of Side#1 flipped about the green axis. This will give it mirror symmetry from Side#1, which is what you want unless they need to differ.


Well, as i said im new :wink:

I will give it a shot tomorrow, and write back


Ack, it’s worse still! You can’t use Braet#1 for both the front and back boards if you want to cut them at different heights! Likewise, you can’t use instances of Lige Braet for the middle three boards! Because they end up cut at different places, they all need to be unique components or groups!

The idea of flipping a copy for Side #2 will still work, but the stuff nested inside has to use distinct objects for each board. Every instance of a component is identical to all others!

On another level, be aware that intersect with always places Edges in whatever edit context is open at the time. So, for example, if you just select the sloping plane and invoke intersect-with model, the Edges will be in the model, not within any of the nested components or groups. There are two ways you can get them there. Probably the best is to Edit->Copy the sloped plane, open the nested components down to the innermost, do Edit->Paste in Place, then select the pasted copy and do intersect with context. That will put new Edges in that component and you can clean up without affecting anything else. You have to repeat this for each of the nested components, but that’s pretty much inevitable since each of them needs to be edited. The alternative is to do the intersect with model and copy then paste-in-place the edges inside each nested component. This is messier because the copy contains the intersections with everything - a lot more to clean up each time.


Here’s what I got by following the process I described. Feel free to ask questions if you can’t figure out how to get from there to here!

Rygeovn.skp (262.3 KB)

By the way, I agree with the process Gully suggested if you are starting from scratch. I did this the hard way to repair the model you had as a learning exercise for you.


I just think I will start from scratch :smile:

So when I copy paste some components I have to made them unique? And then there is no problem?

When I make the sides, they are made from “planks”, do I then just make each plank a unique components? So I can´t make the whole side one components?


Make each unique plank and board a separate component. A component is a template to stamp out endless copies of the original (which may be mirror images).

If you have two or more identical items, or two items that are mirror image opposites, or an item that is used repeatedly as identical and mirror image copies, all those together count as one unique component. Each duplicate or opposite is simply another instance of the component. An instance is either a copy of a previous instance or a new instance pulled from the Component browser.

So first make one each of all the unique pieces and make them components with descriptive names. Then assemble as many of each as are necessary to make a completed whatever the heck this is.

Save yourself a lot of extra work: always cut out the profile of a board before you Push/Pull it to thickness. If you’ve got a bunch of boards all the same thickness, Push/Pull the first to exact thickness and then double-click the rest to copy the thickness.