Summary

3D scanning is changing the way we build roll cages, making accurate, professional-level fitment more accessible than ever. Whether you're a DIY builder or a professional fabricator, combining 3D scanning with CAD modelling gives you a powerful way to plan, model, and fabricate roll cages with greater precision and efficiency.

When paired with CNC notching, tube bending, and laser-cut sheet metal, 3D scanning takes the guesswork out of fabrication and delivers consistent, high-quality results. If you're building a roll cage for motorsport use or even if you plan to have one fabricated for you, this workflow can save you time, improve fitment, and help ensure compliance with your local safety regulations.

⚠️ NOTE: Before building your roll cage (aka safety structure), always check with your local motorsport governing authority for rules around cage materials, layout, specs, and welding requirements. These can be class-specific, and you should get this information direct from the source, not from a random forum or internet link. 

00:00 Hey team, Conor here from HPA and welcome back to another one of our webinars.
00:04 This week we're going to be looking at using a 3D scan to model a roll cage.
00:10 We're going to look at how this can boost the efficiency, accuracy, quality of our design process and the manufacturing process and simply lead to better results in the end.
00:21 We're going to look at using a few key tools in our CAD software today.
00:25 So, that's going to be mesh section sketches to set up the sheet metal foundations for the roll cage, basically referencing the scan data.
00:36 And then we're going to move on to using the 3D sketch tool, which is really powerful for then using the pipe tool to create the tubing structure.
00:45 We'll also use the pipe tool to do some notching of the tubes as well.
00:50 And then at the end, we'll be able to export the files for the sheet metal parts to be laser cut and the tubes if we wanted to get them CNC notched and bent as well.
01:00 We could do that, or we could just use this design or model as a reference for then fabricating the part, just using it basically as a planning tool.
01:11 We are just going to look at doing a half cage today just to keep things short, but the same idea is basically going to apply to a full cage as well.
01:20 It's just about looking at the modeling techniques that we'd use and referencing that 3D scan.
01:26 A quick disclaimer before we get started, we are not going to be covering the design of roll cages and all the different things that need to be thought about around that.
01:36 This is just, I'm just going to be showing a representative design that I'm basically going to come up with on the spot.
01:43 If you are designing a cage, then it's going to be up to you to do the research with your local authority, motorsport governing body on the materials that you need to use and the design that you need to follow.
01:58 All different racing series are different, it changes for each car and what you're going to be using that car for, and it's different in every part of the world as well.
02:08 And I recommend not getting this information off just some random guy on a forum.
02:14 You can get it for free from your local authorities, so that's the best place to get that information to make sure it's all correct.
02:21 Also when it comes to, if you do a model of design and then you want to get it fabricated, it really needs to be done by a competent welder.
02:31 If that's you, that's great, but this is not a project to be learning TIG welding on, for example.
02:38 And in some parts of the world, there might be rules around who can actually weld up the cage itself, so for example here in New Zealand, when something is being made out of chromoly for example, a roll cage, then it needs to be handled by a certified welder.
02:54 Not anyone can just weld chromoly for a cage.
02:58 So, yeah, just other things to consider.
03:00 So, think of this as more of an idea around the modelling techniques that you can apply when designing your own cage.
03:09 All right, let's just jump onto my computer screen here.
03:15 And what we have here is a 3D scan, and this is in particular of the interior of a Honda logo in this case.
03:24 This is just the 3D scan that we had, that actually Brandon did on a little project he's working on, and I thought it would be suitable for today's webinar.
03:35 So, again, it's not going to really matter what the car is, I'm sure not many of you have these little Honda logos, but the ideas are going to apply to whatever car you're working on.
03:46 So, this has actually been scanned with a Peel 3 scanner, which is a fairly expensive scanner.
03:54 We do also have an Einstar scanner, which is a lot cheaper, around $1000.
04:01 And to be honest, for something like this, where Brandon scanned this with the pl, and then he's reduced the resolution quite significantly to make sure the file size is quite small and easy to work with.
04:14 If we just jump onto here and show the edges of the triangles, we can see that it's pretty coarse and mesh, and if we zoom in on some of the parts, we can see the resolution isn't anything crazy.
04:27 The accuracy of the scan is probably pretty good from that scanner, and there's a few areas missing, but it really works.
04:34 But the key point I'm trying to make here is that the Einstar is probably, even though it's cheaper, significantly cheaper and relatively accessible, it's actually probably better at doing a scan like this, that's quite a large area.
04:49 The Einstar is designed for larger projects like that, and it'll do it a lot more efficiently.
04:56 So, don't think that to do this you need something the equivalent of a pl or anything better.
05:03 In this case, an Einstar, which is kind of our recommended scanner in that more accessible price range at the moment anyway, is quite capable of producing something like this.
05:15 And of course, if you don't want to do it with a 3D scan, you can just do it with measurements as well.
05:22 It's just going to kind of take away from what we're showing today, but again, you're still going to be able to model the roll cage without the use of a 3D scan.
05:31 If you wanted to learn more about how we'd get to this stage, actually getting the scan set up in our workspace and aligned with the coordinate system like this, then the best place to check that out is our course.
05:48 I think I have covered it in a previous webinar, aligning something like an engine block to our workspace, and the same ideas can be applied here as well.
05:58 But it's really critical that we have a good alignment.
06:01 So, in this case, the chassis is horizontal to the workspace and the center line, if you can just see the coordinate system there, is lined up straight down the middle of the car.
06:15 It's obviously not going to be completely perfect, and we are going to see a little bit of that discrepancy in a moment, but it's pretty good.
06:23 And it helps us a lot to have the scan in this stage.
06:28 So, when we come to doing the sketches and so on, we can use constraints like the vertical or horizontal, and we can use a mirroring tool very easily to model half of the cage like we're going to, and then basically mirror the other half, because mostly they're symmetric.
06:45 So, yeah, anyway, with that, let's get started.
06:48 So, what we're going to do first is we're going to look in these areas down here, and we're going to work towards creating the foundations for the main hoop.
06:59 So, the main hoop, if you're not really familiar with roll cages, comes up here over in the B pillar of the car and forms a hoop from the floor up along the roof down the other side.
07:12 So, we're going to create the foundations for that.
07:14 And there's a few different ways that we can do this.
07:16 If we're going to do a weld in cage, which we're typically going to be wanting to do.
07:21 So, we could just have a plate on the ground here that we weld onto the floor pan of the car.
07:30 We can see things aren't really ideal here, because we still have a lot of the wiring and stuff in the vehicle.
07:35 It wasn't kind of fully stripped.
07:37 It would be better if it was completely stripped, so we have a really clean scan of the floor.
07:42 We have to obviously remove all this before we get to this fabrication stage.
07:47 But anyway, we'll work with what we've got.
07:51 We could have a plate on the ground here, and that works really good if we have a nice flat kind of floor pan or a flat area that we are welding to.
08:00 The alternative is to have what's commonly kind of referred to as a rocker box.
08:05 So, basically making a little sheet metal box here, which is going to attach to the sides here and then down to the floor.
08:14 It'll make a bit more sense as we go through and create it.
08:18 And there's a few advantages of that.
08:20 It's kind of better for working with more irregular surfaces, because we can create these nice flat surfaces that we're going to sit our tube onto.
08:31 And then it also gives the ability to basically pull the box out of the way or cut a hole in it in some cases and drop the roll cage down in cases where we've got it all tacked together or partially welded and we need to weld up in those top areas that you won't be able to reach because the roof's in the way.
08:51 So, what we're going to do is start off by creating that rocker box.
08:58 So, let's get started with that.
09:00 What we're going to do first is jump over to this mesh toolbar.
09:04 And I should say we're working in Autodesk Fusion for today.
09:10 But the ideas here are all the same, no matter what software you're working with.
09:15 Fusion has just got some really good tools for working with mesh files.
09:19 So, we're in the mesh toolbar and we're going to use this create mesh section sketch.
09:24 So, select that.
09:25 What we need to do now is select the body, the mesh body that we want to create the section sketch through.
09:33 And then so with that selected, we can select the section plane.
09:39 We could create a new plane here, but I'm actually just going to use this kind of horizontal plane here.
09:46 And we can already see this orange line that's being drawn through here.
09:51 And that is the created a section profile of where this plane intersects the mesh body.
10:01 So, we're going to use that to reference the mesh.
10:04 So, basically what I'm going to do from here is just drag down on this.
10:11 And we're going to get a section just in that corner where we're going to set up our rocker box.
10:22 So, we get that relatively low down there, about that height.
10:31 Can always play around making it a bit smaller later on.
10:34 I might go a little bit lower there.
10:38 Cool.
10:40 So, we're basically that line there is going to be level with the top of our box.
10:45 I'm just going to click ok there.
10:48 And then we can see down in the timeline here, we have the section sketch feature and we also have the, sorry, yeah, we have the mesh section feature and then we have the sketch here as well.
10:59 I'm just going to hide those.
11:04 So, yeah, I'm going to jump into that mesh section sketch now.
11:07 So, just right click on that and hit edit section.
11:10 And just to make things a little bit easier, I'm going to grab the section analysis tool and I'm just going to chop off the roof basically, just section the sketch through this plane for now, just so we can see down into the area we're working.
11:26 So, we're essentially sketching on this plane here.
11:31 And again, it's not great because this wasn't fully stripped and we're missing a bit of that kind of data around this corner here.
11:39 I can only assume if I was doing this, I'd go and check the car itself and see what's actually happening here.
11:46 But I can only assume this kind of straight little step back there.
11:51 So, again, we're going to jump into create here and we're going to fit curves to mesh section.
11:57 And this is a really helpful feature here.
12:00 So, we're going to basically just do a little short section here.
12:08 And that's just fitting a spline to that profile there.
12:13 We'll hit OK.
12:15 Can't really see that if I highlight it in blue, you can see the little spline that's just following that mesh section profile.
12:23 And then I'm going to do the same thing.
12:26 The seats in the way here from go from here.
12:36 And all the way along, probably just past this B pillar here to about here somewhere.
12:46 I'm actually just going to cancel that one and redo that because it was following that wire around there and I just want to avoid that.
12:58 So, we'll go again from here, come around to just inside that wire.
13:09 And then I'm going to do the same thing here and just extend this out a little bit further.
13:20 So, now I just need to basically connect up these to make a bit of a rectangular shape.
13:31 What I'm going to do first is just lock these splines in place because I don't want them moving.
13:43 And then I'm going to connect these up.
13:47 So, we're basically forming a bit of a profile around the outside here.
13:56 This is going to come something like that.
14:00 And then where do I want that to go to? Onto the side about here somewhere.
14:11 Just set that coincident to that spline.
14:16 I just want to take that constraint off there.
14:20 And this is one of the advantages of having the scan aligned with the coordinate system is I can make that horizontal, that one there too, so they just lined up with the coordinate system nicely.
14:34 And then what I'm going to do is just set the dimension of the length of the box here.
14:47 So, I think about 180 should work pretty well.
14:53 And it depends on the design, but we could play around with that a bit.
14:56 I just realized there's one other little part I need to connect to make this a closed loop there.
15:02 Cool.
15:03 Now, that's shaded blue, so I can use that.
15:07 So, I'll finish the sketch and then we're going to jump into our sheet metal toolbar.
15:10 We're going to use the flange tool.
15:14 Basically, you can see I've got a little bit of an issue here just around that.
15:20 But we'll work with it for now.
15:23 We'd actually want this to just be following straight along the wall here.
15:29 And I'll just go OK.
15:31 And what that's done is made a little flange that basically follows the profile along the side of the car then and then has these two nice straight edges that we're going to bend down in just a moment.
15:45 If I just hide the body real quick, we can see that a little bit better.
15:50 Obviously ignore this little part.
15:52 That should be straight through there.
15:53 But I'll push forward rather than going back and fixing that for now.
15:58 I just want to check sheet metal rules, steel, so it's saying 2.5 mil steel.
16:04 We'll just make that 3 mil steel.
16:07 So, I think that's about the equivalent to eighth inch thick steel.
16:12 Cool.
16:13 We'll show that again.
16:17 Little bit tricky with that seat in the way.
16:20 Maybe we'll just edit the section view really quick and just pull that down a bit lower so we can see a bit better.
16:27 Cool.
16:28 So, we use the flange tool again.
16:34 And we're going to select these two edges.
16:37 And we're going to pull those down like that.
16:40 And we're just going to go straight through the scan data for now.
16:44 So, we've gone down through the floor.
16:46 A little thing we got to think about is this part here.
16:50 So, that is the mitre on the corner.
16:52 So, basically I need to just override those rules, go to this two bend corner override here.
17:00 And what I'm going to do is just make that a kind of round area so we can bend this part without it deforming the sheet metal in a way that we don't want or tearing it or creating a weak point, for example.
17:16 Obviously, when that's welded at the end, that all needs to be welded up.
17:20 It's a smaller gap than it looks, we just zoomed in on it there.
17:24 Cool.
17:25 And I'm going to go OK.
17:26 So, now we have this kind of box here, but it is going down through the floor, which isn't very good to us.
17:32 We're going to basically use the mesh section sketch to do this again.
17:37 So, again, select that tool, select the body, and then we're going to select the side of the part as the section plane and go OK.
17:48 Then we're going to come down to our timeline, we're going to edit that sketch.
17:53 I'm just going to hide the body to make it a bit easier to see here.
17:58 And then, oh sorry, fit curves to mesh section.
18:02 So, this is basically what we did before.
18:08 We'll come down here.
18:11 Again,, this little curve here and here are just from wires running on the floor, so we want to ignore those.
18:27 And we just want to trace a profile along here like that.
18:33 And I'm going to connect, hide the body real quick.
18:39 I just like to lock those in place so they don't move around without me knowing.
18:46 I'm just going to use a little arc, sorry, an arc tool here to join up these points.
18:56 So,mething like that.
18:58 And then what we're going to want to do is use this to cut.
19:04 So, this doesn't really matter.
19:06 I just need to make an outline kind of around the part.
19:14 And I'll make that one horizontal.
19:16 Oh, what's happened there? It snapped to vertical rather than horizontal.
19:23 So, pull that up a bit.
19:25 That should be pretty good.
19:26 OK.
19:27 Oh, I don't have a full closed profile, so I can't extrude that.
19:33 So, we're just going to use the line tool to meet across those.
19:36 And we can see it's gone shaded, so it's a closed profile.
19:40 Jump back to the solid modeling toolbar.
19:42 I'm going to use the extrude tool.
19:44 It's automatically selected that profile.
19:46 And then I'm going to extrude to object, just being the inside there.
19:50 And we can see that has cut the profile into the part there.
19:56 So, if we look at the scan again, we can see that nicely follows the line of the floor there.
20:05 So, basically, we'll do it to the other side here as well.
20:10 And then we'd be able to flatten this out or get a laser cut, bend it up, and then it should slot into the floor quite nicely.
20:17 We've used this on a few projects at HPA for mounting pedal boxes and things like that to the chassis floor, and it's been working really, really well.
20:29 So, I would recommend using this technique because we've had some really good results with it.
20:35 Same thing here, edit that mesh section sketch.
20:46 And what we'll do is just fit curves to the profile.
20:52 Go to here.
20:55 This is just a wiring mess in the side here again.
20:59 So, we want to avoid that.
21:04 Come from here to here and then use an arc again.
21:12 Arc, 3-point arc tool from that end to here to do something like that.
21:26 We could spend longer and make this a little bit more accurate.
21:31 Then I just want to cut out the outside there.
21:35 Cut that closed profile, again, solid modeling tool, extrude to object through there, and that's just going to cut that to the profile of the part.
21:46 So, again, ignoring that little cut out there, we now have our block, our rocker box sitting there and that is nicely kind of contoured to the floor of the part.
21:59 So, if we stuck that in there, that's going to work pretty good.
22:04 A little bit more care and stuff, take trimming it out and just making sure it fits.
22:09 And obviously, after we get the part cut and then bend it up, and if it doesn't quite fit in, we can just use a grinder with a flapper disc or something to tidy it up and just get that fit really nice and close.
22:20 So, when we come and weld this to the chassis, we're not filling any crazy big gaps.
22:25 So, yeah, that's basically that.
22:28 And then I'm just going to use the mirror tool to copy that body through the center plane here.
22:36 Another advantage of having the scan aligned with the coordinate system, and I can just mirror it through there and we can see we've got it on the other side.
22:46 I've just done this to save time basically here, but obviously the floor is probably not going to be quite the same on each side.
22:54 And we might want to kind of keep some of the stuff running through here, depending on what it is.
22:59 So, we'd probably do it for both of them.
23:01 But again, we're doing a live webinar here, so I'm just trying to keep things moving along.
23:06 All right, so now we have those two rocker boxes in place.
23:13 Just get the whole scan back, and next we're going to make the main hoop.
23:20 So, if you have any questions come up throughout this process, feel free to ask them in the chat and I'll do my best at the end to answer them.
23:30 Try to keep them related to CAD or 3D scanning or using 3D scans in CAD rather than roll cage design and things like that.
23:40 Again, that's not really what we're trying to focus on here today.
23:44 I'm not a fabricator, so yeah, we're just working in CAD primarily and showing how you can use 3D scans for your designs.
23:54 All right, let's start to model the main hoop and get a little bit of a roll cage structure in here.
24:00 So, how I'm going to do this, again, working off that standard coordinate system, I want to make a plane that kind of lines up with where the main hoop's going to go.
24:09 I'm going to line it up in this case with the B pillar here.
24:13 We could push it back a little bit further as well, but that will be pretty good, because it would be nice to be able to weld it to the chassis here.
24:21 And that's one of the benefits of using a 3D scan is we can get the parts really nice and close because we're not relying on physical measurements so much.
24:33 So, what we're going to do is create a plane at an angle to this one here.
24:40 And the plane's tiny in this case.
24:42 We'll make it a bit bigger shortly, but lint back at about 10 degrees.
24:51 Seems about right, can't really see it there.
24:53 So, I'll just click OK and I'll zoom in a bit and then start to drag that up.
25:06 Make this plane a bit bigger.
25:11 So, that looks like it's kind of running parallel to the B pillar here.
25:15 Happy with that, and then I'm just going to offset that, so basically copy this plane, but back a little bit.
25:24 And I'm going to try to get that lined up in the center of the B pillar there.
25:29 So, we can see that kind of going through that hole, which is probably for the seatbelt or something.
25:35 We'll do that.
25:36 And I'll just hide that first plane there.
25:38 So, now I have this plane running where I want that main hoop to run.
25:42 Cool.
25:43 So, we're going to start off by sketching on that.
25:47 So, hit the sketch tool and just select that plane is all I did there.
25:53 And then I'm going to just section the part again, just so we can see through that front plane, just make it a little bit easier to see what we're doing.
26:05 So, I'm just kind of cutting off the front of the car so I can see inside it.
26:08 Cool.
26:09 So, we're sketching on that plane that's on an angle and we want to make our main hoop come up here around and down onto the other side.
26:19 So, basically I am just going to sketch one side of it up to this kind of plane here, and then I'm going to mirror it over to the other side.
26:27 So, let's get started.
26:29 The first thing I'm going to do is if we come under here and go project include, we can get the intersect tool or command P as I've set it up on my keyboard.
26:39 And I'm just going to intersect where the plane goes through the top of the rocker box there.
26:45 So, I get this nice straight line where those two parts intersect.
26:51 So, next, I'm just going to start sketching out my main hoop.
26:56 So, I'm going to start from that line down the bottom.
27:00 So, our hoop is sitting on the rocker box.
27:03 I'm going to come up vertically here.
27:07 And if I click and hold at the end of where I place my line infusion, I can just draw this arc here.
27:13 So, that's tangent to the line that makes that arc.
27:19 Same thing, straight line, another arc here, and then we'll just come along the roof line.
27:26 And obviously that's not very good.
27:28 So, let's start tidying that up.
27:29 So, I'm going to make these two tangent to each other.
27:32 So, we get a nice smooth transition.
27:33 I need to do that to that one there as well.
27:37 Again, I'm going to use my...
27:42 I need to project the vertical axis there and just make that point there straight above that.
27:56 Any of those points will be fine.
28:02 So, now if we look at the part straight on, we're just going to make sure we have half of it.
28:09 So, one of the first dimensions I can put onto the sketch to start kind of locking it in and fully defining it is the radius of the center line.
28:19 We're actually sketching out the center line of the pipes here, of the tubes.
28:24 So, the radius is going to really depend on the tooling that we're using.
28:29 And there's different rules here, but generally I think it's about three times the tube diameter that you're using should be the minimum center line radius.
28:40 Don't quote me on that one.
28:41 I think for our tool, the bender that we have in the HPA workshop, we have a six inch center line radius.
28:49 So, I'm going to use six here, and I can use six inches like that, and it'll convert that to my metric units that we work in in New Zealand.
28:59 So, that's just a way of setting that radius of that bend.
29:03 But if we were going to get these CNC bent for us as well, we might just want to talk to the manufacturer about the tooling that they have available to bend those.
29:16 And we obviously want our model to match whatever the manufacturer is going to make, so it's all accurate.
29:21 So, I'm just setting the radiuses of those two curves there equal.
29:26 Also just need to make that horizontal along the top.
29:29 We could kind of have this come up and then bend a little bit.
29:32 I've seen that on a few Porsches, but we're just going to come straight along the top there, because ideally it's best to avoid bending the tubes as much as possible, because where they're bent, they are the weakest.
29:45 So, now I'm just going to do some... Oh, I need a vertical constraint on that one there too.
29:55 And I'm going to start using the linear dimension tool to just block things in a little bit.
30:01 Before I do that, what I'm actually going to do is offset the whole thing.
30:07 Actually, cancel that.
30:10 Set my line type to construction, and I'm going to offset the whole profile there by our diameter of our tube divided by two, because we're working off the center line here.
30:23 So, skipping ahead slightly, we're going to use 44.5 diameter tube.
30:27 I'm just going to divide that by two, and I'll just flip that out the other way, because basically what I'm trying to see here is where the edge of the tube would come out to.
30:37 I can't just work off the center line when I'm trying to line it up with the edges of the chassis here.
30:43 So, that'll give me a little bit of a reference of where the center line...
30:46 Ah, where the edge of the tube will be.
30:49 So, that dotted line there.
30:51 Cool.
30:53 Let's start using some dimensions to position everything where we want it.
31:02 Cool.
31:04 So, I can come out... Got something in the scan there.
31:10 That's just the bottom of the seatbelt, not to worry about that.
31:12 So, I can come out quite a lot more here.
31:15 Let's see how 650 looks.
31:18 That's probably a little bit much.
31:20 We'll pull that back slightly to 640.
31:23 Obviously if we weren't...
31:26 I'm going to pull that in a bit, because we can see down the bottom here it's kind of hitting the rocker panel.
31:32 So, we can play around with this a lot more if we had the time, and kind of line it up with the chassis as much as possible.
31:42 I think that'll be pretty good there.
31:46 That's pretty close to the wall.
31:49 And then we're going to set the height of that.
31:56 So, it kind of matches where that is.
31:58 I think 270 looks about all right there.
32:05 I want to do the length of that.
32:11 Let's start back at 380.
32:13 And this just takes a little bit of time to kind of go around and set everything up.
32:18 We'll set up the height of this now off the bottom of the main hoop.
32:27 That can come up significantly higher there.
32:30 So, let's try something like 1150.
32:34 How's that looking? A little bit higher probably.
32:40 1170, 20 mils higher.
32:47 That should be pretty good there for now.
32:53 Again, when we get the tubes in there we can come back and kind of adjust everything.
32:57 And now I'm just going to pull this back a bit.
33:03 So, we can clear this side here and that looks pretty good.
33:06 So, we can see it's gone all white in this case.
33:08 It would go black if I was working on the white background, but my view settings are on the gray background so it's gone white and that just shows that it's fully defined.
33:18 So, nothing can move by mistake there.
33:23 So, all we're going to do here is we don't actually have to do this step just yet, but I'd like to just mirror these lines through that center plane.
33:42 So, select those lines and I'm just going to mirror them through that center plane there and we can see they've come along over here and I'll just finish the sketch.
33:52 We could just do this next step and then mirror the solid body , but we'll do that as it is for now.
33:59 So, what we're going to do now is create, use the create pipe tool and we're going to create a pipe that's just going to follow the entire profile there, up like that and we want to create a new body for that tube.
34:19 It's going to be hollow and again the size of the tube and everything's really depend on what standards you're working to here and what tubing you're using, what material and so on.
34:31 And just for this example we're going to use a common size tube used in New Zealand, 44.5 and 2.6 wall thickness.
34:42 It is possible though, that is very similar to 1.75 inch, 1 and a quarter and 0.095 wall thickness in imperial units.
34:56 I think this is more like 2.4 for that though.
34:58 So, again, this is just an example so we'll hit okay for that and now we have half of that tube there and what we can do at this point is just mirror that body through here.
35:14 We do want to join it to the solid tube that's already existing, but I don't want it to join to those kind of pedestals or rocker boxes down the bottom.
35:25 So, I'm just going to hide those for now and there we have our main chute.
35:32 And by the looks of things, it fits pretty well around the side there again.
35:38 You can always do some more modifications and kind of play with that.
35:42 We're getting a bit of contact this side just because the mesh isn't perfectly centered in the workspace, but pretty good.
35:50 So, we'll just leave that as that for now.
35:52 We can see down the bottom just from how we created the part that we have this little kind of gap here.
35:58 What we can do is use this press pull tool and then drag this down a little bit and we might choose to leave it long just to basically get the parts made and then we can trim it back to the right length after the fact or if we just want it to be accurate in our model for now we can just drag it down through there.
36:22 We can use this split body tool, select the body we want to split, select the splitting tool which is this top face here and just split that there and then I just want to find that body and remove it basically.
36:39 Did that do the other side as well? I think it might have.
36:44 It did , but I didn't do this first.
36:52 Same thing.
36:57 Push pull on this face, drag it down a bit and then split that and then we have that bit underneath and we can just remove that there.
37:10 So, now we have the main hoop done and I'm pretty happy with where that's kind of sitting in the car, but obviously you can play around and adjust that as you like.
37:22 So, we'll move on and we're going to work on the rear braces first and I'm just going to drag the timeline along here a little bit.
37:29 The eagle eyed viewers of you might have noticed that I had a few more parts here.
37:36 There's a whole lot of different ways that you can actually approach the rear arches and how they are going to, sorry, the rear braces and how they're going to mount to the back of the vehicle.
37:45 You typically want to extend them to the strut towers to keep the suspension points as stiff as possible.
37:55 You can build a box structure like we did around the strut tower.
38:00 You could weld a cross brace tube between the two strut towers and have these rear stays going down to that.
38:07 There's all sorts of different ways you can do it.
38:09 Probably a typical way is just getting a piece of sheet metal, bending it to the kind of form of the strut tower or the wheel well here, like I've kind of modelled here basically and just coming down onto that part.
38:24 So, that's essentially what we're going to do.
38:27 I'm just going to see if I can't drag these back to about there.
38:35 Yeah, it looks like I can.
38:38 Cool.
38:39 So, they're just back in our timeline a little bit and we're going to have our rear stay tubes go down to meet those parts so they can be welded together.
38:49 So, what we're going to do is jump back to our sketch here for the main hoop and we're going to start to modify that into a 3D sketch.
39:00 So, in Fusion, we've just jumped in and we're going to edit it.
39:05 We're just going to hide the scan so we can see a little bit better.
39:08 What we're going to do is use this three sketch preference in our sketch palette down here.
39:14 And that basically allows us to move our parts into 3D space or our elements of our sketch into 3D place.
39:22 So, if I select the line tool now here, I'm going to start a line from the center point of this arc.
39:33 So, that little triangle shows the midpoint along that arc.
39:36 So, I'm going to start the line there.
39:38 And then we get this little coordinate system pop up where that point is.
39:41 And that's basically allowing us to choose the active plane that we're now working on.
39:46 So, rather than just working on the plane highlighted at the moment, which is the active plane for the sketch, we're going to jump onto this one here.
39:57 And we're going to be able to just drag this point down here.
40:01 We're actually going to land right on that.
40:06 And then just exit out of the line tool quickly.
40:08 So, this is going to be one of our rear braces or rear stays.
40:15 And we can see that point's already landing on the surface.
40:18 That's done a good job of just referencing that.
40:21 And I'm actually pretty happy with where it's landing there.
40:24 We could use the... we might just be able to drag it in space here.
40:29 We kind of can in this case, just drag it around.
40:33 But I'm just going to leave it where it is.
40:34 That looks pretty good.
40:36 And that's going to be the rear brace.
40:39 So, from here, we'll just finish the sketch.
40:44 We're going to show that sketch again.
40:45 So, in our browser, come back and just show the 3D sketch.
40:49 And then I'm going to jump into the pipe tool again.
40:52 And as you'd imagine, just select that point.
40:56 We don't want it to cut.
40:57 We want a new body in this case.
41:01 And we're using all the same settings as we did for the same tubing as before.
41:06 And we can just create that.
41:08 So, now we have that tube going down there.
41:12 I'll show the sketch.
41:14 You can see a little bit better.
41:16 And that's looking pretty good.
41:18 Cool.
41:19 So, the next step is going to be notching that tube.
41:24 So, if you see the body here, it just goes up inside it to the end of the line that we've drawn.
41:32 And obviously, there's a pretty big interference here.
41:35 But what we can do is now just split this.
41:39 Yeah, basically use the pipe tool to notch the tube to create that notch so it can all be welded together correctly.
41:48 So, what I'm going to do from here is grab the pipe tool again.
41:53 I'm going to show that sketch.
41:56 I'm just going to turn off the chain selection tool, actually, and just select the little bit that's going through that part.
42:04 And you can see if we use a hollow section in this case, it just does this kind of funny cut through the part.
42:12 But I'm going to unselect that hollow thing just so it notches the whole thing.
42:19 And I don't want it to cut the main hoop.
42:23 So, I'm just going to hide the main hoop.
42:24 So, it only cuts body 22 in that case, which is that rear stay.
42:30 So, we can see there that it's nicely notched that part exactly how we'd want it to be.
42:36 And we can turn that on again and hide that sketch.
42:41 And there we have it, the rear stay done and in place.
42:45 And we can kind of do a similar thing down here where we pull this out through there and then split that body with the surface.
43:02 Split this body with the surface there and then find that body, body 22 now, and just remove that.
43:12 And we have that basically notched for the part of the car that it's going to land on as well.
43:18 So, that's looking pretty good.
43:21 And then all we have to do with that one is create, mirror that component through the center plane.
43:30 And we can just quickly create the one on the other side like that and just show the sketch again to see how it's all lining up.
43:38 It's looking pretty good.
43:39 We've got these little kind of differences in the scan side to side just, because it's not quite aligned with the coordinate system.
43:46 It might be a minute or two off and that just means it goes under the surface like that.
43:51 But that's looking pretty good.
43:54 Cool.
43:56 From here, again, there's all sorts of different ways that we can design the rear structure of the half cage in this case.
44:06 And it's really going to depend on what you're doing.
44:08 For example, if we just jump back to our sketch here and hide that, I can really quickly just create a cross brace over the back.
44:21 So, if I go from this point here and I just don't have to worry about the planes, because I'm going to snap up over here to the midpoint there, finish that sketch.
44:36 Again, got everything where I want it there and I can use that to create a new body that's hollow just like our other tubes.
44:55 And then quickly again use the pipe tool and I am just repeating this in these cases.
45:02 So, it kind of reiterates what I'm doing.
45:07 So, you can see it used more than once.
45:11 I'm going to use that to cut through body 25.
45:18 That's just going to notch it again.
45:20 Don't want it to be hollow.
45:23 And then down here, similar thing.
45:28 Use the pipe tool.
45:32 Use that pipe to cut through this part.
45:38 We don't want to cut 15.
45:43 So, we're just trying to cut through body 25, I think it is.
45:51 And that just notches that part.
45:53 And we could do the same thing to tidy up the end of that there.
45:57 So, if we just come and hide the sketch.
46:05 We need to do one more notch here just to remove the bit of interference between those two.
46:13 So, pipe tool.
46:16 Show that sketch again.
46:17 It's not going to do it.
46:21 So, maybe we can use the split tool.
46:24 It's just another way we can do it.
46:26 So, we want to split this body with this one and that extends.
46:32 And then we just got to find the bit that was there and remove that.
46:37 So, now if we hide that and main hoop, we can see that notch there is done in both angles where that part fits onto each of those.
46:53 So, that part there is notched as well.
46:57 And if we wanted to, we could mirror this part through this plane, the center plane here and we just create a new body.
47:08 And then same thing here.
47:09 We just want to split this body with this one here.
47:16 Find those little center sections and remove those.
47:22 So, it hasn't fully split in half in this case.
47:25 Just touching at the ends here, but we could go through and get an axis through two points here between those two points and then just make a plane through those.
47:41 Drag that around a bit and split this body using that plane.
47:51 We got a little bit of an error there, but we'll just push through anyway.
47:55 But you basically want to split that in two.
47:58 So, yeah, there we have a cross brace on the back of the part.
48:03 And again, you can just kind of see how that's done there.
48:06 I'll just hide that plane.
48:09 Cool.
48:10 So, the last part that we need to do for the half cage is going to be a harness bar.
48:16 And again, there's a few different ways we could do this.
48:19 If we'd made our main hoop a little bit further back here, then there'd be plenty of room behind the seat to put the harness bar straight across.
48:28 But in this case, the harness bar is going to need a little bit of a bend in it to push it back as well.
48:33 And I just didn't really mention this at the start of the process, but it's always good if we're designing something like this to have the seat scanned in the place that it needs to be as well.
48:47 So, we can kind of see everything that we need to clear.
48:50 And for the harness bar, where it's important, the angle of the harnesses as well, it's good to have the seat there so we can see what height we need to put the harness bar.
48:59 Obviously, it could all be done after the fact as well, just by getting the seat in the car before we weld in the harness bar, but this is another way of doing it, of course.
49:09 It's nice to have it all planned out in the 3D sketch, in the 3D model rather.
49:15 So, again, let's just hide the scan, and we're going to jump back into that sketch that we've kind of used for everything now.
49:25 And this is a little bit trickier.
49:27 So, just to make it a kind of easy way to plan out the position of the harness bar, what we're going to do here is just create a little sketch that comes along here, and that's just going to come across this way a little bit.
49:53 And we're basically just, this is what I find really useful for 3D sketches, is sometimes just making this kind of wireframe to be able to align everything up properly.
50:06 So, it basically forms, yeah, like a wireframe for the parts that we're trying to construct, and that's going to make a bit more sense in just a moment.
50:20 So, we've got these kind of vertical lines and everything just showing this kind of structure, and we can just control from this, we'll say 100 millimeters.
50:29 That's just how far back the harness bar is going to be behind the seat, and I've just got it coming off the bottom of that kind of bend there at the moment, but we could control that position as well.
50:42 So, now I'm going to sketch a line along this line, finish it about there, and then on this top plane, I'm going to sketch an arc.
50:56 Again, I just clipped hold there, and then that creates a tangent arc there, and I can control the length of this line here, and we'll call that 500.
51:14 See how that looks.
51:15 I just want to... Got a little bit of an issue here.
51:26 There we go.
51:29 So, that's just half of the harness bar drawn in there.
51:33 Don't worry too much with your 3D sketches if you have curves in them that are not showing fully defined.
51:39 It's quite hard to fully dimension or fully define a curve through space.
51:44 In this case, we know it's tangent to these, and it looks flat with that, so that looks pretty good, , but there's nothing really to say that this couldn't rotate out of the position it's in, which is why it's shown in blue.
51:57 But again, don't stress too much on that for 3D sketches with curves in them.
52:04 And now we're just going to change selection on the pipe tool, select that harness bar, create a new body, and then we'll just mirror that body through this plane, and we want to join it, but we want to hide the main hoop there so it doesn't join to the main hoop.
52:34 We keep everything separate, and then what we'll do is just use the pipe tool on that to notch those tubes, and 29, I think, is the harness bar, the last one we created, so we're just notching that.
53:04 Show everything again, and there we have our harness bar, and if we view the seat here, it looks roughly in the right position.
53:14 Basically,, if we just edit the section view and look through the side plane here, we can see that the harness bar is just a little bit lower than the shoulder holes for the harness to go through, and typically, if we draw a line from horizontal here, generally the rule is that we want it to be within 20 degrees of horizontal there, so usually not higher.
53:47 Sometimes they allow about 10 degrees up, but 20 degrees down is pretty good, so if we kind of draw an imaginary line horizontal and then down there, that's looking pretty good for the angle of the harnesses.
54:00 We would be able to check it, but again, I'm just going to keep things kind of moving on here, and that's kind of our half cage done.
54:08 So, what I'm going to do is we can actually just control the opacity of the scan there, and just hide the origin just so we can kind of see what we've done a little bit better, and yeah, that is the half cage design really quickly done.
54:29 We could make some adjustments, obviously, and make it fit a little bit better there, but done in about an hour, I think it's taken.
54:38 So, that's looking pretty good.
54:40 Yeah,, so again, if you've got any questions just related to CAD or 3D scanning ideally, ask them below, and I'll just cover off a few more things here, and then I'll do my best to answer those questions.
54:54 So, from here, after we've finished the design and we're happy with it, we've kind of got a few options of different ways we can go.
55:02 If we want to export everything, get it made using CNC processes, and then just weld it together ourselves or get someone else to weld it together, then the best option here is going to be, we'll start with the sheet metal parts.
55:21 For the sheet metal parts, we want to create a flat pattern, so we do that.
55:25 We just need to select a flat face, make that the top face for this, and we'll just hide that body, and then basically what that's done is just flattened out that part, and the bend lines and everything should be there, but it's just being a bit weird.
55:43 You can kind of see them.
55:46 And we can just export that as a DXF, and we can send that straight to a laser cutter or a waterjet cutter as well, or a plasma cutter, and get those cut for us, and then we can bend them up, put them in the car, and then weld them as the kind of foundations for the bottom of the part.
56:05 So, we do one of those for each side.
56:07 In this case, it was mirrored, so it would just flip over, but typically we do one for each side, and those ones on the back as well, on the strut towers, but that's the process really, export flat pattern as a DXF.
56:22 If we aren't using the paid version of Fusion 360, it's actually, we can't just do it in that process if we're using the free version, so what we'd have to do is jump in here, and there is a modify unfold stationary entity, and it will unfold those, unfold all bends, and then what we can do is sketch on the top face, and we can project everything like that, and we can actually finish that sketch, come down here, find that sketch, and we can just export as a DXF that way.
57:05 So, that's a little kind of workaround trick if you're not working with the paid version of Fusion.
57:13 That's a little way to get around it.
57:16 So, that's those parts, and then when it comes to getting the tubes CNC notched and bent, all we need to do is provide a step file for the manufacturer.
57:29 So, what we'll do is we'll right-click here and go isolate.
57:35 That's not the part I wanted actually.
57:37 We'll just get the main hoop up.
57:39 So, for example, this main hoop has got the little slash cuts on the bottom.
57:45 It doesn't have any notches in this case, , but all the other parts do, and we'll just go file here, export, and then all we need to export from the bottom is a step file.
57:56 So, we'll just export that step file and send it to the CNC notcher or bender and ask them to produce that part for us.
58:06 We can send a technical drawing as well if we wanted to be really sure of the measurements, something for them to check.
58:13 Some of them will be able to provide the material depending on what we're working with, or maybe we need to give them the material as well.
58:22 For our chromoly tubular subframe that we did in our Honda CRX car, that is a worked example in our 3D modeling course, we exported step files like this and we got some chromoly tube and we sent it to a company called Auto Bend here in New Zealand, and they were able to CNC notch and bend that for us and send it all back, and basically with a little bit of finishing, just chamfering the edges slightly, tidying things up that fit together really well.
58:51 So, it's definitely a process that will be used a lot more in the future I guess for those of us that are really more familiar with CAD rather than working with tube benders and things in a more practical setting.
59:07 It's really opening the door and making this a lot more accessible.
59:10 So, we basically get a package arrive with all of our parts notched and bent as we want and we'd have our laser cut lot on parts here as well and we could work with a fabricator or if you're a fabricator yourself, you can then weld that all together in the car and it should fit pretty well.
59:31 The alternative of course if you're a fabricator and you have the skills to be able to bend everything up yourself is to use this basically just as a reference and you should be able to take some measurements off these with the straight sections and the bend start points and so on and transfer that over to bending measurements and go from there.
59:53 So, it basically just becomes a planning tool and yeah, it gives you a good idea of where everything should sit and the measurements that things should be as well.
01:00:04 Depending on what you're working with, how accurate you think your scan is and so on, sometimes we just need to allow for some tolerance in there and just understand that there may be some small variations.
01:00:16 So, yeah, being able to make some little adjustments as we go and weld things in place is usually the best way to go about that.
01:00:26 But that's kind of shown you the process anyway, so I'll just do my best now to answer any questions if we've got any.
01:00:34 So, Richard Clark, "I know this is just an example, but would it be useful to use a direct mesh edit and then use offset planes to pick up on the profile of the shell and then you could work off that profile just thinking then you can define the offset from the shell.
01:00:53 Maybe nice to change offsets later if required was my thought.".
01:00:57 So, yeah, you can create planes directly off the shells that we were saying.
01:01:02 Sorry, I'll just read this one more time.
01:01:04 Would it be useful to use a direct mesh edit and then use the offset plane to pick up on the profile of the shell, then you could work off that profile.
01:01:14 So, yeah, so what you could do, I think what you're saying is when we created that plane there, no, the next one, this one here, we could have used a section sketch through that plane.
01:01:38 And then we could have basically drawn our sketch and just based it straight off measurements to the actual profile itself.
01:01:46 So, we can define the distance more accurately from those tubes to the mesh section or the chassis in that case.
01:01:57 And that would be one way to approach it.
01:01:59 Definitely that would work really well.
01:02:01 And then you could probably get things really nice and tight.
01:02:05 That's for sure one way to do it.
01:02:06 There's always a few different options.
01:02:10 The other way that I might interpret what you're saying, just in case I haven't got it quite right there, is you can, depending on the software you're working with, you can create planes straight off the shell itself.
01:02:25 So, we can do that infusion using this forms toolbar.
01:02:29 And we can just create a plane through three points here.
01:02:32 And we could have just, for example, created a plane on the surface of the floor there.
01:02:38 And we could work off those as well.
01:02:40 So, that's another way to do it if it's not really well aligned with the coordinate system.
01:02:46 I think what you're saying was more in regards to the first answer I had, though.
01:02:52 So, I'll just leave it there for now.
01:02:54 Cool.
01:02:55 Turee 2, I think that's how you pronounce that.
01:03:00 "Is it worth doing a basic stress analysis once you've designed it? Or is that only if you also have the chassis properly modeled in the 3D space?".
01:03:10 No, you can definitely do it without the chassis fully modeled.
01:03:13 It would be really difficult to model the full chassis unless you're working with a tube chassis, for example.
01:03:21 You could definitely jump from here and go into the simulation workspace, do a static stress analysis.
01:03:36 And from here, what would be important would be doing automatic contacts on everything, given that they're all touching each other.
01:03:43 We should just be able to do that.
01:03:45 And it would basically connect them together like they were welded.
01:03:48 Obviously, if you're doing this really accurately, there's going to be some issues where parts are welded together.
01:03:57 The weld is obviously going to be the weak point.
01:03:59 But just assume that it's good.
01:04:02 In that case, this has been playing up on me a little bit lately, but basically fix those all together.
01:04:08 If we go manage contacts, it says that they're all bonded.
01:04:13 And what we could do is you could fix the points that are mounting to the chassis, and you could apply loads to the top of the hoop, like a rollover or something like that.
01:04:24 And then, yeah, for sure, you'd be able to have a look and see how it responds.
01:04:30 What I would say is that the actual answers you get from doing that won't be representative of the real thing, because obviously in an accident, anything could happen.
01:04:39 It would be really hard to understand what that loading case would be.
01:04:43 I would just say that that process would be a good way to compare different designs to one another.
01:04:49 For example, there's all different ways that you can do this.
01:04:53 You could have a main hoop brace and then kind of leave the brace off the back here.
01:05:02 You can have stays that come from here to this point.
01:05:05 There's all different ways you can design cages, and you could basically just see how they would respond or act differently to those different loading situations.
01:05:14 So, yeah, I would just say it's a good way to compare different designs and decide what you want to go with.
01:05:22 You'd also be able to see the stress in it and try to minimize those maximum stresses, but you'd also be able to see the displacement or the deflection in the design and see which is stiffest as well.
01:05:38 That might be a good way to decide on a roll cage design that's going to result in the stiffest chassis, if that's something you're chasing, which it usually is.
01:05:49 Richard Clark "Joining on the bend of the tube versus a straight part? If you cold draw bend a tube, it's going to oval it slightly, so it might cause a slight fit up issue if mandrel bent, wouldn't be a problem.".
01:06:05 So, yeah, I get what you mean.
01:06:08 So, it's going to change the shape of the part where it's bent slightly, and that's going to be an issue.
01:06:14 In this part, we've modelled it and it obviously doesn't oval it at all, because we're working in CAD and it's all perfect and then we've notched it with that circular section perfectly through it , but the real part might not be completely like that.
01:06:31 If it was mandrel bent, then it wouldn't be a problem so yeah, I think you've got a point there as well.
01:06:39 You need to know the processes you're working with and this just comes down to design for manufacturing and getting everything right and just understanding in some cases you're going to end up with a little bit of tolerance there.
01:06:54 But again generally, I'd say you'd be pretty surprised with how the CNC bent ones come out, but there's always going to be the need for a little bit of fettling of the notches I'd say to make it really accurate and really reduce those gaps as much as possible when it comes to the fitter.
01:07:16 Richard Clark again, "Could you add some sort of tab and slot system in it to locate the tube of sending out for CNC laser cutting and so on?".
01:07:29 I think you, yeah you definitely can.
01:07:33 I would be hesitant to do that into the tube itself just because you'd be kind of forming a weak point, but that would be something I would consider doing maybe on the sheet metal parts down the bottom here.
01:07:49 You could do like a tab and slot setup and the laser notcher should be able to do that.
01:07:55 Again, you just have to ask the manufacturer in that case and that would be a good way to kind of self-jig it all together and make sure you got everything in the right place.
01:08:03 So, yeah it's a pretty good idea.
01:08:05 I know that Cagekits out of the US do some stuff where they laser etch into the tube showing the positions and locations where everything's supposed to set up.
01:08:18 So, they're just basically engraving a really thin little line into it and you could probably do something like that as well.
01:08:24 Wouldn't be too hard to model in CAD, it just depends who you're getting to make the tubes, whether they could do that detail or not, but that's just a discussion with them.
01:08:37 That looks like the end of our questions so hopefully that's given you some insight into scan-based design for a roll cage and how it could be used to hopefully make the fabrication process easier and more accurate and more efficient or just give you the ability to plan projects like this out in CAD before you tackle them in real life and avoid some of that back and forth because it's a lot easier to make changes in CAD than to make them in real life once you've bent up and notched the tube.
01:09:12 That's significantly more time consuming and expensive, but yeah if you are interested in picking up any of these skills I'd recommend checking out our 3D modeling or our 3D scanning course as well and that'll allow you the skills to be able to do all of what we've just done here.
01:09:31 So, yeah I'll leave it at that and thanks for coming along today and we'll see you next week.