Overhangs refer to parts of a model that are not built upon a previously printed layer. Overhangs can cause many quality issues if you aren't handling them correctly when you're slicing your model. So what we're going to do is take a look at supports and overhangs and how we can pretty much configure our slicer to print decent supports without ruining the quality of our print. So the first thing I'm going to do is show you guys what I mean exactly by the overhangs. Let's just take a second and draw a little picture, you'll have to forgive my artwork. Let's just assume that our layer goes down rectangularly, it would probably be more rounded than anything. But this is our extruded layer, you can imagine it's extruding this way. Now say for some models we want to print and we want to print out on an angle. So there would be an angle to our overhang. And for example if we were to print about half out here, we would get an overhang angle of about 45-degrees.

So essentially the print is moving out about 45-degrees. We can also do further than that, going from about here to here, now we're getting out to a much more dangerous angle of about say 15-degrees. You can imagine that this degrees of deviation from a straight up and down model is a pretty important value when it comes to overhangs because essentially there'll be a point in degrees that our printer can handle and a point after that point it can't handle it, it will start actually not being able to extrude plastic, it won't be able to support itself, this part will start drooping down and we'll get a ruined printed model. So what we're going to do is take a look at our slicer settings for supports, we're going to take a look at a printing test that you can do at home that gets you a very good estimate of what your printer can handle at certain layer heights. So let's jump over into Cura and take a look at that.

Alright guys so here we are in Cura and I've just loaded up our support overhang test. So like we said before, overhangs are these parts here, so you can imagine on a layered level we can have a look at it and see how it's growing out from the bottom of the print. So at this point it's just there and then see how the print grows out at higher layers and the growth of these layers is actually a lot larger as that angle from the z-axis becomes smaller. So here we've got a 45 degree angle from the x-axis, we can measure these in one of two ways from the z-axis being how far it is from straight up and down or we can measure it out from flat. So we'll measure this one from flat as it's got the labels on the model, it won't be as confusing that way. Now supports are essentially what we can print to support these overhangs. So when these parts start getting too hard for our printer to print, we can enable some supports to come and build themselves up off the build platform into our print.

So to do that, we can do that from the quick print menu really easily by ticking this box and that just uses some default settings or if you're like me and you like to just have a little bit more of a say in what's going on, you can actually select them from the full settings menu. So you can do a touching build plate support or an everywhere support. Touching build plate will only build supports up from parts that are overhanging over the build plate. So from here to here. Now I can't really describe it in this model easily but a everywhere, essentially having an everywhere support on would also print supports off your model to another model on top. So if this model was a bit more advanced and had more overhangs up here, you could print supports from this point of your model upwards. The idea behind supports too is that they are removable so there's a few things that we can tweak with supports that will make them easier to remove than normal. So go ahead and click on the three points of ellipsis there and jump into the expert config options for your supports.

And we'll just go through and check them all out. So we've got grids or lines. What does that mean? Let's take a look. Now I believe Cura renders these as a light blue colour. So we can see that those light blue ones are the supports. Sort of like the brims and things that we've seen in the past. So I've currently got grids set to print my supports as grids. And you can see that in every layer it's alternating between like a left to right or an up and down support layer. So that's what a grid looks like. And a line looks like this. Starts off as a mesh and then it just builds up with straight lines. Now what I find is lines are extremely easy to remove, especially when we can change the density of our lines. The prints that I've printed with grid supports have been an absolute nightmare to remove grids from. So I really don't recommend that you go for grids. Lines are usually more than enough to do what you need to do. So that was lines and grids. And we'll just drop past the overhang angle for support at the moment. And we'll have a look at fill and mount.

So this is the percentage of infill in the support structure. So you can imagine if I turn this down to 5, first we'll take a look at what it looks like now. So you can see there's 4 or 5 lines in these gaps here. We'll turn this down to say 5, 5% and have a look at what that means. So now you can see that that has drastically reduced the amount of support that I need on that model. Let's get him out of the way. There we go. So it's quite a small amount of filament is being used comparatively. So this is a good way to save yourself a bit of filament if you've got your printer dialled in correctly. So usually I use about 10 to 15%. That would be my ideal amount of support material. So 10 to 15. Obviously this print is a test, so you wouldn't be printing this one with supports at all. But it's a good way to show you how they all play in. Next we've got distance in the X and Y axes. So this is the actual distance if we take a look at maybe a top down. Top down. So the X and Y axes distance means that it will give a distance of 1.5 millimetres in the X and Y axes, which are those axes there.

So that means that your print isn't going to be touching and your supports aren't going to be super difficult to remove in that direction. Whereas in the Z direction, we have quite a small one. This is 0.15 millimetres. So in the Z dimension, so we can get a good view of that. So that means that once our print... Good. A good view of that. Yep, that's it over there. So see right here where the shell of our print is actually above a support layer from the support layer before, that's going to give a 0.15 millimetre separation between that extruded layer of plastic and the support material. So you can actually experiment with this, but 1.5 is what LulzBot recommends in Cura. Essentially if it's quite difficult to remove a support, you would increase that value. Usually the 1.5 millimetres in the X and Y is perfect for your purposes. And once you finish your print, you can just grab some pliers or some, you know, a scalpel if you like, and just slice away your supports or pull them away or use your fingers and grab them off. Depending on how well you've got that tuned, they'll be quite easy to get off. Finally, let's take a look at this value here.

Now this is the important one and this is the one that we've got this print out for. So this is the overhang angle for support and you can define what value you want to be supported. So if you had that set at zero, this value is actually measured from the Z axis down. So having a value of zero means that anything past zero degrees, so anything out here or out here, all of these things will be printed with supports from touching build plate because that's what we've got selected. But usually 45-degrees is the right amount. So usually a print can manage any overhangs of about 45-degrees past the 45 degree mark. So once we get out to say 50, 60, 70-degrees, all the way down to 90, that's when you have a lot of difficulty because you're not printing onto anything. That's when you need to have supports there to help your printer out. What you can do though, fortunately, is at lower layer heights. So remember our image here. Now we had this, for example, would say 0.25 and let's say at 0.25 millimetres, you might only be able to get 45-degrees safely. But what you can do is if you drop this value down, say to 0.15, you might be able to find out that your print can easily handle say up to 60-degrees of overhang.

So up around this range here. So that's pretty cool. And to find out those values, luckily, there are some people out there that have put together some pretty simple tests that have got those values here. So I've got two tests here that I've printed, one that I printed with support so you can see sort of how it should look, which this one here had supports. And then this one here, which was printed without supports, but it still turned out quite well. So let's have a look at the values that we saw. So these were printed like this, and you can see that they've got the values from the top down, 15-degrees being 15-degrees from the base or from the X, the bed up. So that's 15-degrees, 20-degrees, all the way down to 45. And like we can expect, 45-degrees printed absolutely fine without supports on both of them. Even though supports were enabled, it didn't need it because of that setting, 45-degrees was absolutely fine. You can see that the quality of that 45 degree angle is absolutely okay. So this was the one that was printed without supports. And if you put those side by side, there's not much of a quality difference there.

Now what we did notice was, as we got past 40-degrees, which would be the equivalent of 50-degrees in this one, because we're going from a Z-axis out. So this would be equivalent to 50, 55, 60, 65, 70, 75. As we got to 35 and 40-degrees, we started seeing our print with the unsupported overhangs. These ones are supported. The unsupported overhangs started to fail, so that's when we started losing a bit of quality in those overhangs. And you can see in these layers, they got much worse very quickly, and it started having a lot of difficulty having that plastic printed. This was actually printed with a 1.2 millimetre nozzle as well. So they look a bit big, and it looks like it's been extruding spaghetti. That is why, but it's still fine for our purposes. Whereas our supported one printed really well up until about 25-degrees. After 25-degrees, we still had those issues starting to occur, which you can see, even the marks from the support material, it was quite hard to take off. So what I would do if I were doing this on my LulzBot Mini, for example, I would set up my LulzBot Mini, I'd find a good layer height that I was happy with the finish of, and then I would print one of these models that we've got up on the screen without supports.

Now I'd print it at a decent speed, not too fast, but not too slow. It's only going to take 20 minutes as is, so I'd probably leave it how it is. And I would see where in my print it started failing. So at what bracket did my print start to fail? Say for example, my 30 looked fine, my 25 had some artifacts, I'd set 30, or I'd actually set 60 as the overhang support angle here. So I'd go 60 rather than 40, and by doing that, my print won't actually bother printing supports until it's at, as you can see, at that level there. So at 30, which was 60, which was exactly what I wanted. So that pretty much describes overhangs, I hope it has been educational as it was fun for me, and hopefully you guys now understand a bit better how you can dial in your printer for some good supports, structures to be printed without going overkill and using up all your filament. Thank you for watching guys.