Transcript:
In this cat for newbie’s tutorial. I’ll show you how to make a Mobius Strip in fusion 360 Let’s get started as going guys. Angus, here from makers Muse Reza, over on Patreon got in touch and asked this. Hello, Angus. I’ve been trying to design a Mobius Strip with three twists on fusion 360 so far. It has been a challenge. I wonder if you can make a tutorial. But what is a Mobius Strip? Anyway, well here. I have a piece of paper this strip of paper. Imagine it has no thickness. Its 0 thickness is a single surface. If I just fold it around itself like this, you end up with a loop with two surfaces and two edges, However, a Mobius Strip takes on those ends and rotates it around 180 degrees, and now you end up with a single surface and a single edge, so no matter where you start if you go around and trace the shape you end up back where you started and I remember back when I started University. The first CAD class I had. I was a bit cheeky, and I asked my tutor. How do you 3d model a Mobius Strip? Well, it turns out you can in fusion 360 but it doesn’t really like it. So let’s dive into the software so far out fusion 360 and start with a blank workspace and to model our Mobius Strip. We’re going to use the sweep command. I’ve talked about the sweep command in a previous code for newbies tutorial here, but this command. Lets you take a profile and sweep it along a path. So what we’re going to do is take an edge and sweep it along a circle to produce our Mobius Strip, So we’re gonna start with that circle, which is our path, so I’m going to draw a sketch on our top plane, Create sketch top plane here and hit C for circle and draw it out. I was gonna make it 100 100 there. You go millimeters in diameter. Stop sketch! Now we have our path. We to draw our profile and I’m going to do that on our XZ plane here. Which is the front plane? Click and go, there hit Alpha line and draw a line now positioning. This line is important. I’ve just drawn it here. It actually needs to intersect with our path really to be done properly so to do that. I’m just going to hit pee While highlighting the path and P does a project which actually will project that circle, but from the side view into our current sketch, we’re not going to use this for actually drawing any geometry, just using it to actually locate our line, so click the line again and hold down shift, select that point, right, click and midpoint. I have another tutorial on relations, But midpoint means that this line will be forever locked to the midpoint intersection of that circle, and we just need to give it a length, so just hit D and then select the line and that’s going to make here. Let’s go over 25 that looks good and we’re done, but before I go, I like to make geometry. I’m not using into construction geometry, so it doesn’t get confusing for what the suite needs to do, so I’m going to select that projected line and just hit X It becomes dashed, and you see those dashed lines That means it’s a construction line and it’s not going to be part of our final geometry, and that’s the basis for our Mobius Strip, But to draw it as I said, imagine. This has zero thickness. We can’t do that. In the model workspace, we need to jump over to the patch workspace in fusion 360 so select over here on the left hand side model and then go to patch patches our surfaces, they have no thickness, so it works very similar to the model workspace. You go and drop down from the create menu and we have a patch sweep so here. We have the window for patch sweep. We can select our profile, which is the line and a path, which is the circle there. We go so just like we did before with the paper. That’s just a normal loop, But we want to make it a Mobius Strip, so you want to rotate one of those ends 180 degrees and to do that, we use the twist angle, so we select the twist angle box and make it 180 degrees, and there you go. We’ve now drawn A Mobius Strip in Fusion 360 however. I did mention that CAD programs don’t like this sort of thing and you can see. That fusion has solved this with this really weird artifact. So when you have these surfaces in in CAD software, they have facing direction because this is going to be a single surface. Now when it joins up because you can trace all around the whole shape, it doesn’t know what to do when it intersects when it ends and it’s doing this really weird artifact, And in fact, if you export this as an STL file and open it in something. Mac, like mesh mixer. This is what you end up with, So it’s taken that profile and swept it around and it has produced a Mobius Strip. But you notice that this this lines these lines here? That’s the the other side of our triangles in the mesh hit W to show the triangles. STL files have a facing direction from those triangles. Tilden called a normal and this is what they face. They face out to this gold side and the other side is the reverse side of those triangles and when it interfaces doesn’t know what to do there. So how can we get around this? We’ll, just like the real world. This paper has a very minut amount of thickness, so if we jump back to fusion 360 and go back to our line here instead of being a zero thickness. I’m gonna make that a construction line now. I’m gonna give it a very small amount of thickness, so go back to model because we’re going to now be drawing a solid, even though it’s very thin, so sketch rectangle Center rectangle, hang out, draw it out using the original line as a guide, so just going to add a midpoint. You could just draw it from scratch again, but just going to make sure that middle middle part of the rectangle is on that on that circle intersection. I’m gonna make it like 0.05 so 0.05 millimeters incredibly thin? But there is still something there. Stop sketch and now! I’m gonna do another sweep for this time. It’s going to be a edge remodel, sweep, so create sweep again, select our profile and select our path and then twist angle will be 180 and there you go so now we have a Mobius Strip, which doesn’t have that weird artifact. However, it doesn’t seem to ever want to join it perfectly and seamlessly. It always seems leave that seam that even though this is a single body as you can as you can see indicated on the side there, and if we export that out into mesh mix that we end up with this, so this is our Mobius Strip with the 0.05 millimeter thickness, so it’s not a true single surface. It does have thickness now, but that outside surface will still trace around the object and end up to the same place You started and you can see that seam there. It doesn’t have the same uniform triangles, but really, if you went to use this for something else or rendered it. You wouldn’t notice that that’s just a anomaly. That kind of annoys me as a designer. I wish I could see it and visualize it completely seamless. Of course. If you wanted to make your Mobius Strip rotate more than 180 degrees you can in residential request. He wanted it to go around three times, so if we did a twist angle, for example, three times so every 180 and 360 then 540 so five four zero. There we go, so it’s rotated around three times and then terminated again like before once again we had that little seam there, but it is a solid object with a small amount of thickness, but if that allows us to draw it in the first place. I’m okay with that. I usually design for 3d printing, not just for pure theoretical zero thickness surfaces. If you find Mobius strips beautiful, then you definitely need to go check out dissing offs Web page, so dissing offers an amazing 3d artist, and he has taken the concept of a Mobius strip and pushed it very very far with mathematical art and these are 3d printable files you can download and print bear in mind. They would be extremely challenging to print on an FDM 3d printer, but his work is incredible and definitely deserves a shout out when talking about the humble Mobius Strip. So thanks for watching guys hope you found this video useful on designing a Mobius Strip in Fusion 360 again, this is part of the CAD for newbie’s tutorial series here on makers Muse. There’s a whole list of them. Go check out the playlist And I look forward to you again Very shortly catch later. Guy’s, bye!