Cutting A Non-Plainer V Groove Into An Object

I've been banging my head against the wall trying to get this thing to do what I want. I basically just have a non-regular rectangle type shape and I want to cut a V groove into it which will wrap around 2 sides. The closest I've come is sweeping a triangle on each surface independantly in Rhino, but the ends of the 2 segments never line up right. Maybe I'm just thinking about it the wrong way. Here's the object and the line where I want the cut. This is just a small part of the overall design, so I've attached a GH file with only this element. Any help would be appreciated. Thanks!

Attachments:

V Groove Cut.gh, 13 KB

Replies to This Discussion

Permalink Reply by Chris Tietjen on July 15, 2013 at 3:55pm

Here it is in Rhino. I don't think that it's simple to do in GH. Are you looking for a definition that just handles a closed curve that goes over a sharp edge or are there other aspects not yet described?

In the attached 3dm look at the layers panel to see the boolean subtrahend used create the V-groove.

Attachments:

Irregular V-Groove.3dm, 298 KB

Permalink Reply by eNon on July 15, 2013 at 6:15pm

I can't open that in Rhino 4 unfortunately. Look at the definition in my other reply to Kevin for what I'm looking for.

It's basically what you'd get if you ran a cone shaped CNC bit perpendicular to each of those surfaces along the above guide line.

Permalink Reply by Chris Tietjen on July 15, 2013 at 6:41pm

Here's the file again saved in V4.

Attachments:

Irregular V-GrooveV4.3dm, 279 KB

Permalink Reply by eNon on July 15, 2013 at 6:50pm

yeah, that's what i need, but i don't know how you made that and layed out your guide lines and what-not.

Permalink Reply by Chris Tietjen on July 15, 2013 at 9:49pm

Here's a link to a screencast detailing how I did this.

Permalink Reply by eNon on July 22, 2013 at 5:58am

I really appreciate you taking your time to make this. I didn't use your exact steps, but instead built a basic grasshopper definition to do something using your concept that I hadn't considered. You're correct in your concern that the 1 rail function in Rhino isn't perfect, which is why I've been having this issue since the beginning. I realized though that due to the size of the object, and the size of this feature related to the object, when I ultimately 3D print this it's not going to make a difference which is noticiable enough to fret about perfection to that degree.

Thanks again!

Permalink Reply by Kevin Boutte on July 15, 2013 at 5:45pm

Do you want the triangles perpendicular to the surface with one vertices pointing towards the surface?

Permalink Reply by eNon on July 15, 2013 at 6:12pm

Yes. I basically want V cuts perpendicular to each surface that meet together at the right places. I've tried doing rail sweeps but there's always some type of unwanted twist by the time it gets to the end so it's no longer perpendicular.

I've put something together and it's kind-of working but it's breaking past certain parameters which may make it unusable. It also seems like a monster of a definition for what i want it to do, but that may be due to me just not knowing how to use grasshopper to it's fullest potential. The ends of the 2 parts aren't meeting up completely so it's leaving a piece hanging between them, but that shouldn't be difficult to fix. Other than that, this is doing pretty much what I want, if I could adjust the sliders without it breaking on me.

Attachments: