I've used SU to design sewing machine parts and toys, and they all 3-d printed just fine. You'll need one of the plugins that write STL files, and then you're good to go.

One trick: if it's a small part and there's fine detail, design it at 1000x scale, then shrink it down before you generate the STL file. SU doesn't like fine details.

@sdmitch said:

No but I have sent it to you by PM.

Got it. It's awesome. Thanks! It's exactly what I had in mind. I'm going to put this to good use.

@falk said:

@sdmitch said:

Is this what you were looking for.

Yes, exactly. It even healed the faces. Checking out SDM tools now.

I found lots of cool plugins at http://sdmitch.blogspot.com/, but I couldn't find this one. Is it published yet?

@dave r said:

... So the pommels on these columns as well as the tops of the reeds were done essentially the same way.

As were the stopped chamfers on the stretchers for this hayrake table.

And the stopped flutes on this newel post...

.. and the cope joints on the rails of this door.

And you can't do any of those with a section plane.

OK, now you're just showing off

I've never done anything as nice as those images, but yeah, I've been using this technique for years. I was just looking for something faster for straight cuts.

@sdmitch said:

Is this what you were looking for.

Yes, exactly. It even healed the faces. Checking out SDM tools now.

OK, that was pretty impressive. It's pretty much how I've been doing it; you're just better at it than I am. You should post this under "tutorials"

Oh, I also see how using a cutting rectangle instead of a section plane also automagically healed the faces. Very nice.

@dave r said:

Understood. I'll put my tutorial on hold then.

Don't do that. It will probably help me and it will definitely help other people.

OK, just as an experiment, I tried my example using this technique. With a horizontal section plane, it took me 45 seconds to split my model in two. With a section plane at 45 degrees, it took 90 seconds. I'm sure with practice I could bring those times down.

I use SU for woodworking mainly. My design process is to design the object I want to build, then slice it into boards I could cut on a table saw. This involves a lot of slicing, so if I could automate the process that would be a win. I'm definitely going to put a little bit of time into tinkering with Zorro2.

@box said:

You are missing the simple step of right click on the section plane and Create Group from Slice.
This gives you the intersection that can then be easily exploded in place cutting your model. Then using a selection fence you can easily separate the two halves.

Yes, I've considered that technique, and plan to try it next time I need to slice something. And I agree that it's simple enough to do a mass-delete provided that the cutting plane was aligned with an axis, or the model can be reasonably rotated so that the cutting plane is vertical or horizontal on the screen, but in my experience, there's always a little bit of clean-up to be done.

Look, I get that this isn't hard, I'm just saying it isn't easy, and I was hoping that there would be a plugin because I do this so frequently.

For now, I've downloaded the Zorro2 plugin and am looking at the source code. I think this will be easy to modify to add the feature I want, and will get back to the forum when I've completed it.

The cutting-plane workflow (without a plugin) looks something like this:

• Place the geometry to be cut into a group.
• Create a rectangle that defines the cutting plane. This is several steps -- many more than defining a section plane.
• If unwanted geometry intersects the group, hide it
• Open the group.
• Select all faces.
• Select "intersect faces with model"
• Get out the erase tool and start removing the unwanted geometry.
• Heal the cut faces as needed by redrawing edges
• Delete the cutting rectangle

See http://sketchucation.com/forums/viewtopic.php?f=15%26amp;t=43266

The labor nearly doubles if you want to keep both halves.

I call this slow and tedious compared to the workflow I would rather have:

• Place the geometry to be cut into a group
• Place a section plane
• Select the group
• Select "Slice along section plane" plugin.
  Now I have two groups.

I know how to cut along a plane by creating it, positioning it, intersecting the object with it, and then deleting the unwanted geometry. This is a slow and tedious process and I was looking for a faster way.

The Zorro plugin does most of what I want, but I'm still trying to find an even better way. Do you know one?

Hmmm; I could have sworn I got it to slice the geometry at the section plane without deleting the back half of the geometry, but now I can't make it happen. Well, no matter.

Excellent, thanks. I found a great tutorial video on the subject: https://www.youtube.com/watch?v=wYrsgfWst8Q

Hi all; is there a plugin that will split an object (maybe a group) along a cutting plane? This picture shows pretty clearly what I have in mind.

I looked into "slicer", but it's more elaborate than I need, and requires SU pro.

![Before and after of "slice" function.](/uploads/imported_attachments/qnFp_split-demo.png "Before and after of "slice" function.")

I've replicated the problem in SU8 and SU2014 both. I think it's simply a bug in the ruby API. I suspect that nobody actually tries to create faces from edges.

The disturbing thing is, if I just create a square made out of edges, and retrace some of the edges by hand, I only get a face created if I retrace the last two edges. The first two don't work. It's as if the edges were corrupted somehow.

Anyway, I'm just going to go ahead and create faces from points. I can make a hole in the face using the technique you mentioned: create a face inside another face, then erase the inner face. It worked fine, so I'll just go with that.

Well, pretty much no joy on any of the suggestions here. Oddly enough, I found that manually retracing an edge only produced a face for certain edges. It's almost as if I was creating corrupt edges somehow.

I dumped the edges array, and it's definitely an array of four edges, all with endpoints exactly where they should be and all definitely co-planar.

I'm a little perplexed; this is almost the simplest possible test case for generating a face from edges. I can't imagine why it would fail. I'm also going to try creating the edges from Point3d objects and see if that makes a difference.

FWIW, I looked through all the plugins I've downloaded for SU and none of them generate faces from edges, they all do it from points.

@dan rathbun said:

Also use this to be sure your acting within the current active editing context:
entities = Sketchup.active_model.active_entities

Thanks; I don't think that's the issue: the code I posted above is literally the entire ruby program and I'm executing it in an empty model.

I'll definitely try the suggestions you made above and see what happens.

Well, I'm trying to write a plugin now. Haven't figured out how to create a face with a hole in it.

Hi all; can anybody explain what I'm doing wrong here? The documentation indicates that I can create a face from an array of edges, but it fails.

Now my real question is: how do I create a face with a hole in it.

[pre:3oekbghz]require 'sketchup.rb'

def foo_panel
entities = Sketchup.active_model.entities

Create a face from points

face = entities.add_face [[0,0,10], [20,0,10], [20,0,30], [0,0,30]]
puts face

Create an array of edges from points

edges = entities.add_edges [[30,0,10], [50,0,10], [50,0,30],
[30,0,30], [30,0,10]]
puts edges.length

Create a face from that array of edges -- why does this fail?

face = entities.add_face(edges)
puts face
end[/pre:3oekbghz]

@cotty said:

@falk said:

but can this be done without breaking the frame into separate parts?

I think it can't.

Yeah, that's what I figured. I already did a door that way, and since that's how windows are actually constructed maybe I'll just go ahead. Or maybe I'll take a crack at making a plugin.

Thanks anyway.