From the course: Fusion 360 Product Design: Lighting

Setting the mass properties - Fusion 360 Tutorial

From the course: Fusion 360 Product Design: Lighting

Start my 1-month free trial

Setting the mass properties

“

- [Instructor] Okay, so the next thing we want to do now is probably come in and have a bit more of a look at our model and see from the left side. There's an area here which is of a little bit of concern. And that is that if we have a look at this part, so I find it in the browser, and then base shell parts, it is the base shell and then there's this other fin component here as well, and then there's this other fin component here. So, there's four parts effectively. There's a lower fin piece. This bit is part of the base belly. This part here is part of the head fin assembly at the top here. Then there's the upper fin and then the top fin shell. But there's four pieces that all join together here and if we have a bit of a look at it, and it's a bit thin walled, so for a start, it's going to be pretty tricky to get all four pieces matching up perfectly the way they are, but later on, if we wanted to use a bit of glue there to glue that together, we only got about two mil of material there to run a bit of glue around. And provided we got the right glue, it would probably hold up okay. At the moment, we'd need to probably go in and set the proper materials on here, if we want to get the proper mass out. So, one of the things that I can do now, is we've gone in and set up the materials as far as the appearance goes, but the parts themselves have actual properties on them as well, so at the moment if we were to isolate one of these internal parts and have a bit of a look like the tail in, maybe we'll activate that and right click and say properties, it'll tell us that the physical material is the default material which is usually steel, and obviously, the mass will be quite a lot of steel. It's not too bad buit it's not steel, we know it's not steel, so we should come in and actually set these things up to be appropriate materials as well and then we'll get proper weight values out of it. So, what we want to do with this is if we go back to the assembly and activate that, and then come in and right click on physical material, we can come into a browser which is similar to the appearance browser, but it's material and what we're looking at is plastic and when we print this out it sees here the resin and at the moment we've got black resin and white resin, and I think, you know, any of these, you're probably going to have a similar mass to what the printed material is from the form two, so I'm just going to grab acrylic clear and drag that up in here and pop that in and what we'll see when we do this to these parts is that our weight for the internal assemble will probably go down. So, if I look at the properties of this now, instead of one part being 250 kilos, the whole internal mass now is 321 grams, which is much better. 200 kilos for one part is probably a bit too much. Okay, so if we go in and do the internal parts and set that material up, that's good, we'll switch that off. We'll go to the external parts and have a bit more of a look at that as well. I think we'll activate that and see if we can go into physical material and that'll be the same thing. It's not necessarily clear but it will just be acrylic. Then we'll drag that and drop it on as well. So, I wonder if we just drag it on everything it will turn up. And now let's have a bit of a look at what's happening if we turn this off, and go to the tail, left-hand side and say properties. It's acrylic, so it's inherited that as well and it's only 83 grams, which is good. Okay, so it's still got the original materials on there. Some of them might have changed a little bit, so we can go back to the main body and update the appearances back on these little windows as well. So, I'm going to go back into my appearance. What you can do in here as well is you can say delete all that are unused, so if there's nothing used in here we can get rid of it and the polycarbonate clear that we had on these little windows, we can drop back in there as well. Alright, so that's good. And I think overall, one of the other things that we want to do, as well as making sure the physical materials are assigned properly to all the parts, is actually have a look at where the center mast is as well. Obviously we want this thing to balance well and stand up nicely when it's finally printed and assembled. And even though we don't have the LED light in there, the controller, I think, in the library is set up so it's got the appropriate mass. Once it's finished calculating the center of mass, we can have a bit of a look in here and change it back to autographic. You can see where it is. This center of mass object lives in the analysis folder as well, so if the model tends to get a bit slow on the performance side of things or something like that, you can actually delete it and get rid of it and just generate it again later. And also, if you go in and create a drawing, you can switch this on, you can do dimensions, you can say how far is it from this side to there, and how far is it from this side to there. At the moment, I think it's pretty good that it's right in the middle, so if it was too far this way, then it might be more inclined to fall over this way, and it means that we may have to add more material down the back here as well. So, that covers a few things about the physical material, center of mass and just keeping an eye on the center of mass. It's quite important to use that as a way of understanding where the balance is and making sure the parts are assigned with the right materials and it's something that you do when you're coming along to finish off the model, you want to make sure that it's got the right sort of things going on. Okay, so in the next movie we're going to come in here and use these four pieces to create a new piece that matches the internal surface and make a new piece that will help bridge all these four parts together nicely.

Contents