Problem erasing part of object with intersect faces

I’ve been trying to erase part of a cylinder by intersecting a rectangle box with it. I’ve placed the rectangle overlapping with the cylinder and selected intersect faces with model, but I’m not able to get the overlapped portion erased. I’ve attached a screenshot of what I’m seeing immediately after doing the intersect faces with model. Any help greatly appreciated!

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From your screenshot it almost looks like you have two overlapping cylinders. Can you share the .skp file so we can see what you actually have going on in your model?

And what is it you actually want? The cylinder with a slot in it?

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The most common problem people encounter using Intersect Faces With… is not realizing that the new edges are created in whatever context is active at the time, regardless of which choice you pick. For example, unless you open a component or group for edit, the new edges will go into the model, not the group or component. Hence they won’t cut the faces inside the group or component. Conversely, if a component is open for edit, the new edges will cut only faces in that component, not ones in the model even if you choose “with model”.

This behavior can actually be an advantage. For example in your model, you can group the cylinder and then draw and position the cutter in the model context, where it won’t stick to or otherwise interact with the group’s geometry. Then edit cut the cutter block, open the group for edit and paste in place. Then run intersect faces with while the group is still open.

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I was editing the component (i.e. I triple clicked on it from my model), so shouldn’t I be able to erase the intersection in that view?

I attached a model with just this component here - I’m trying to model a hidden barrel hinge (seen here:

Thanks for your help!

Barrel hinge closed.skp (67.7 KB)

The intersection geometry was created on the surfaces of the ungrouped box and not in the component. You would need to open the component for editing before using Intersect Faces>With Model.

If you want the geometry from the block to create the faces in the notch in the cylinder, you need to put that geometry inside the component before intersecting.

Try the following steps. Note I have a keyboard shortcut set up for Paste in place.

  1. Select the block geometry and reverse the faces.
  2. While the block geometry is selected, cut it to the Clipboard.
  3. Open the cylinder component for editing.
  4. Click Edit>Paste in place.
  5. Select all of the geometry, right click on it and choose Intersect Faces>With Selection.
    6.Erase/delete all the geometry except the cylinder with the slot.
    7.Repeat steps 3 through 6 for the other cylinder.

I know this is about Intersect, but keep the whole picture in mind when doing things like this, the section you want to remove aligns with the facets of the cylinder, so you could just draw 3 edges and use pushpull.


Dave - thank you that worked perfectly! Now I’m trying to wrap my head around why it worked bt I’ll get there… Box, actually that’s what I originally tried to do but I think when I first drew the rectangle to push/pull I wasn’t “on” the component similar to Dave’s explanation.

Here’s the barrel hinge now - any advice on how to finish it and make it look more like the real item?

Thanks again!

You could have a look at the cylinder hinges (aka barrel hinges) I drew and uploaded to the 3D Warehouse. They might serve your purpose.

Wow that saved me a ton of time! :slight_smile: Thanks John!

If they aren’t the right size, you can scale them. The real ones come in a range of sizes usually in multiples of 2mm diameter. I’ve seen them from a small 8mmD up to 24mmD.