Round pipes present a unique challenge. Using the Extract Isocurve command, small pipe sections are separated out. Once detached, they can be offset inwards or outwards, depending on the detail needed.
- [Instructor] Next up we're going to play 3-D plumber and build some funky piping. The key of this video like many of my other videos, will be to leverage existing geometry whenever possible. Let's zoom out from the example, I've got the path already drawn, so we're going to go ahead and just make our basic pipe command. That's on the Solid menu. Here is Pipe, I'm going to select the curve and this is the usual where you get to select the radius or diameter and most people will just pick one diameter to be the entire length.
However, we're going to mix it up a little bit here. I'm going to start off at 20 and then we're going to end a little bit bigger at the opposite side, I'm going to make that 36, but also I just want to point out, you could put another circle profile anywhere and make it any size. I'm not going to do that, so I'll just right-click to accept. And there we have our varying radius pipe from one end to the other. Now one of the keys to the operations I'm going to show you is we need to be working on a single surface. It looks like my pipe command was defaulting to cap the ends.
We don't need those, in fact this whole process will not work if it's multiple surfaces or poly surfaces joined together. A quick way to get rid of those two end caps is just explode it. It's off here to the left side. These are all now detached and I can just delete the ones I don't want. So you can just pick them or leave them there, actually it won't matter. Let's start off by building a little recess or seam on this end. Now in the past you might have done a curve project.
We're going to try something a little bit better and a lot more accurate. So I'm going to go over to the split and if I use right-click, that will split by isocurve. And this is the reason it needs to be a single piece, not joined together. So I select the surface right-click to accept and it gives me one of the directions of isocurves. As you can see, that is the wrong direction. Since there are only two directions, it's pretty easy just to go over to the toggle option on the command line, and now we're going the other way.
So you do want to pick two different spots here, I'm going to break this out so it doesn't matter exactly where they are, you just want to make sure that this is a separate piece from either side. Now we'll go ahead and give it some, not only thickness, but we want some end walls. So the way we do this is surface offset I just mentioned all surfaces have two directions of isocurves, they also have two sides. And right now this is pointing normal up or out; however, we want to go in.
It's just a simple matter of clicking or going to the toggle to flip directions. So let's just go inside. I'm going to make this a distance of six, so let's go over to the command line here, it's already set to a default-- typically it's one. I'm going to make this six, and then every time you do this, you will have to come back here and select Solid=Yes. So those are the two inputs we need, right-click to accept. And you can see here in this view, we have an offset surface but also those two end caps, which are really handy and that's why I did the solid options.
You can see it inside there. However, we don't need this outside piece any more. The whole idea was to make a seam going in; however, I just used that as kind of a handy piece of construction geometry. So let's go over to the extract. This time I'm not going to explode. I'm going to right-click and extract. And that lets me pick a single piece, or multiples if I keep going, that's now separated and I can hit delete and it leaves everything else alone. I would like to put a chamfer along these edges.
However, that is a solid command, so I do need to have all these joined together. So let's pick the little recess here with the two walls and then the pipe section either side, just by holding down shift and the shortcut for joining is Control-J. You can also find it on the Edit menu or here on the main toolbar with the little puzzle-looking icon. Okay, the join is complete, let's do the chamfer now, Solid, Fillet Edge, and chamfer is kind of hidden away as is some of the other commands here under fillets, since they're all closely related I assume.
Let's chamfer that edge. I'm going to change this distance from the default of one to make it two. And now I can pick multiple edges as I go. I can actually pick a lot more edges and as long as they're fairly clean, I can do this to maybe 50 or even 100 edges at the same time. I just want to point out that you don't have to pick one and then do the chamfer, and then the next and do the chamfer, you can do them multiples at once. So I'm going to right-click here, we get a little bit of a preview, and there is the chamfer done. So that is our recess or joint from the pipe.
Let's go to the opposite end and make more of a coupling or outward-type of detail, so we'll do the same process here. We're going to split the surface by the isocurve, select this end of the pipe, and I'm getting a problem here. Nothing is working. If you remember from earlier, I said it had to be a single surface and these have already been joined because I used that chamfer command. Let's hit Escape to get out of the command and I'll go back one more time and just extract this end of the pipe from the rest of the geometry, and then I can rejoin those at any time, as long as I don't move them away.
Okay, one more time. Right-click to split by isocurve, and I'm going to pick two spots just like I did before, there we go, right-click to accept, that part is now popped outside. We can do Surface Offset, it is defaulting to one of the two directions, I want to go the opposite way, so I'll just click one more time to toggle it, the distance is okay, I am going to stick with six; however, I do want to say Solid=Yes. Again, you have to do that every single time.
Right-click and there is our coupling or joint. Let's also put some fillets on the edge of this guy. So same process, Solid, Fillet edge, Fillet Edge, we'll go ahead and use a value of two for the radius, type that in, and then again we can pick the two edges at the same time, right-click, two, execute, we get a little bit of a preview once or twice, and there's some nice fillets on that little coupling. For the final component, I want to make that hexagon nut shape but I can't see the center curves.
So that's pretty simple to fix, we'll go over to Wireframe view, there's the curve in the center, I'm going to go over to the hexagon shape, which is actually called a polygon and by default it'll probably say a different number, maybe three, so we'll change that to six and don't forget about the Around Curve, we already did that a bunch of times, so I'm going to select that curve in the center, pick a spot, you can track anywhere you want, I'm going do it it right about there, and I'll come out a fair amount, I'm just going to eyeball this, make sure it goes outside.
Now we can switch back to shaded, let's do that now, so there it is outside. We can give it some thickness, with a solid extrude, there's the extrude planar curve, we'll go straight, now by default this will probably just go one direction, so you can toggle on both sides. I like to center stuff because it makes it a little more accurate. So make sure you click on both sides equals yes and just come out a little bit of ways it's not really important. Now this is a typical confusing fillet situation because we have three corners meeting here.
I'll just fillet one of these edges and talk about how I'd wrap it up. So let's go to Solid, fillet Edge, fillet edge that's the rounded one, I want to make this a much bigger radius. Oops, and we hit Control to get it out, and then I can go back and pick the one I want. Okay, so this is the general rule I was talking about where we do big fillets first, small fillets later, because those small fillets typically drive around the bigger fillets, and it's when you have the opposite case, where you end up with the fillets exploding or crashing.
Now I'm in Perspective viewport you might have noticed, and I do that just to do all these double checks, making sure everything looks right, but also I have picked correctly. So I'm going to right-click to accept, and there you go, so it's a much larger radius. I would probably come back one more time and put a smaller fillet along this edge. Something along the order of two or three would work perfectly. Just make sure it's below 15. Now let's talk about the process of what to do when you change your mind. So most people would probably start this from scratch, which is perfectly normal.
I'm going to show you a better way to do this. I'm going to delete some of the geometry here just to get it out of the way. So now you don't have to go back a whole bunch of steps, because, and you may not be aware of this, Rhino remembers all the original geometry every time you do a trim or split. So I'm going to show that to you right now by going over to the trim and right-clicking for the untrim command. So right-click on there, and you just pick the edge that has been trimmed from the original, and boom, the original surface comes back.
Now we're still in the middle of the command so you've got to be careful, you don't want to untrim too much, so you do have to click, right-click to Escape or finish the command. This process of getting curves onto a surface for later splitting or trimming, is by far one of my favorites. Now you can always draw and then project but I recommend using the isocurves that are already there. These isocurves will always be properly aligned and more accurate as long as they occur where you need them.
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- Making a flexible duct
- Building details on round pipes
- Modeling organic objects
- Using the SrfSeam command to move seams out of your way