Cura is Lulzbot's own edition of Ultimaker and is the backbone of the Lulzbot 3D printing ecosystem. In this tutorial, Aidan walks you through how to use Cura from a beginners perspective and gleans into some of the intermediate functions.
Hey guys, Aidan here from Core Electronics and I’m back again with the LulzBot Mini to take a deeper look at the 3D printing software of choice for your 3D printer - Cura. We’ll be looking at some of the options available in the quick print view and we’ll also delve into some of the options under the hood in Cura. To finish up i’ll show you guys how to set up your printer with 1.75 mm filament which is also entirely possible using the single extruder tool head.
So just jumping into Cura here guys and the first thing that we need to do is load up a model so we can do that in one of 3 ways. We can use this load model button on the top left of your work space, or we can go into the file menu and select load model or we could just double click on the stl on our desktop or wherever it’s saved. So I’ll just double click on that and load it up. Alright, now a few things happen when you load your model into Cura, you’ll notice that you get the render of the model of the bed and the printer control button becomes active. For us thats the Save G Code button today. If you left click on the model you’ll gain access to some of the options that relate to the models size and position on the bed. We can see these here, we have rotate, scale and mirror. Now this model is just an Apple Watch holder that I happened to grab off the universe, the link is in the description below if you want one. Now with orients like this on the print bed when we load it up and if we switch over to the overhang view mode which is in the top right of your workspace - which is this one, we can see with a little bit of rotation, we can see all these red zones. Now these red zones are overhangs and they require supports to print correctly. So what we can do is we can change the orientation of our print to make it a bit easier for our printer to print it. You might find yourself with a model that loads up sideways or upside down just like this one and to successfully print this sort of thing we’re going to need springs, rafts and supports which aren’t always necessary. So we’re going to do a few quick adjustments just to reduce the amount of supports we’re going to need. Now for us today, rotation is going to play a big part in getting our print to print successfully. So in Cura you can just hold right click and move your mouse around to rotate the view, you can also rotate the print model. So if we click on the rotate button you get a couple of options, we’ve got lay flat here which will essentially just drop it and touch it to the bed. So it doesn’t do a whole lot for us right now, but what we can do is select the axis that we want to rotate it on. So for us today we’re going to use that yellow axis here and we’re just going to drag it around by about 90 degrees and then it’ll just drop down to the bed like that. Now you can see the overhangs - there aren’t a lot. So those red parts that are just touching the bed, they’re not too bad and if we needed we can print some supports just to help out print these little overhangs here. So, that’s a good way to do it. You can also click that lay flat button if you do get it on to the print bed and you just want to make sure that it’s flush against it.
I’ll just go over scaling and mirroring - so scaling you’ve got obviously this option here which just maximises the dimensions of your model so you can print as big as you want - which is that. Or you can just reset it and you also have a uniform scale so you can - say if you scale by 1.2 in the x axis it uniformly scales it. Or you can go ahead and turn that off with this lock button down the bottom. For mirroring we can mirror in the x, y or z axis which can come in handy.
Moving over to the left hand menu here we can see the quick print menu - now this is the one that is enabled by default in Cura. You have levels of material so in here you’ve got first run, beginner, intermediate, advanced, expert and all - its always good to use alliance you start to know your filaments. You know that it will be there and obviously in the material box you’ve just got a big list of materials. We’ve got 3 profiles for most of our filaments here so usually we’re printing with abs so I’ll select that and I’ll just show you the 3 different quick print profiles. So a standard profile, a high speed profile and a high detail profile. Now these profiles usually just define the layer heights and the speed at which the print prints.Bear in mind that with 3D printing you’ve usually got to balance time and quality so this is the perfect example of that. If you want a fast print it’s not going to look as good as a high detail print. So that is something to bear in mind when you’re selecting your print profile. Maybe with a rapid prototyping solution you’d go with a high speed solution but if you’re printing say a high quality model that you wanted to have on display something you’d probably opt for the high detail one. Now below that we have two more options - we have print support structures which we were talking about before and print brim - so what I’m going to do is just talk you through those two.
Print support structures like we said before - it’ll enable us to print extra plastic that will be removable at the end of the print that will support these parts that might be a bit tricky for a print an fdm printer to print. Now support structures help to support those overhangs and like I said you can just remove them either with an exactor blade or you can sometimes just pull them out when the print is done.
Brims are extra skirts, so remember the skirts went down in our last video and they went down around the outside just to poach some of the inaccuracies out of the filament. Well a brim is essentially extra skirts that print and connect up to the base of your model and by doing that you increase the surface area that is touching the bed plate. Sometimes when you’re printing things they might have a really tiny surface area touching the plate - this model doesn’t but you’ll see in the future that there will be some like that. What can happen is you can get those parts just falling off the print bed - like the pdi is great but when there is no surface area to hold on to it can be really tricky. So brims can help you out there and at the end of the print you can essentially just pull them straight off.
Now the quick print profiles that we’re just looking at are great for the most part but if you learn some of the more complicated concepts in 3D printing you’re going to start wanting to change some of the other settings. To get to those settings in Cura what we do is just head over to the expert menu here, we click that one and drop down to switch full settings. Now we get this little thing here ‘profile copy’ so I’m on the standard profile. It’s going to copy all those settings across from a standard profile into my full settings which is a good template to work from. So we’ll go ahead and do that. Now we’ve got 4 tabs up the top here - we’ve got basic settings, advanced settings, plug-ins and start and ng code. So you can actually read the G code as you would go though it. We’re just going to focus on some of these basic settings today including infill percent and filament size and flow rate. We’ll get into a few of the other settings in a later video but for right now these are the ones that you’re probably going to want to change and you can experiment with these just to see how it affects your print.
First off we’re going to look at his option here - we’ve got fill density and now with Cura it’s really good, if you mouse over any of these boxes it’ll give you a great description of what this tool tip does. So lets just go over fill density, this controls how densely filled the insides of your print will be. SO for a solid part use 100% or an empty part use 0% - a value of around 20% is usually enough. So by default we’ve got 20% there. Ive got a model that I’ve printed here and what we did here - we printed this side of it at about a 20% infill and it’s super rigid and sturdy. On the other side which was the bottom half of this jaw we actually printed this at 5% and you can really feel it, it’s a bit almost a bit bendy. It’s printed with abs but it’s a bit bendy but still feels quite sturdy but it came up really nicely to. We slowed the flow rate down on that one but we’ll get into that one in a second. But yeah, our tips for this is if you’re going to be printing something that is going to get used a lot in rugged environments then higher percentages are obviously better - the less air the better. It’s going to last longer but sometimes you’re printing something big like this T-Rex head and if you are printing something this big it’s going to use a lot of filament and dropping that infill percentage can actually save you a bit of filament so it’s worth taking a look at. Events experimenting around with some test prints and seeing what the effect of that on your printing is would be worthwhile. Now you’ve got a couple of other settings here which are pretty self explanatory. You’ve got the print speed, this is the general speed that the print happens, you’ve got your top print temperature and your bed temperature . Now moving down to the filament section you’ve got a diameter here which we can set and a flow percentage. This is essentially a ratio that you add when you’re extruding filament. I’m just going to run you guys through this one here - so this is the setting if you were to want to change your filament type over to a 1.75 mm filament, this is all you have to do. So you just go in here and type in 1.75 mm it’ll do a recalculation of the G Code and it’s really as easy as that! You cants load up your 1.75 mm filament and it will work.
Alright, so that is our guide into the Cura environment today - hopefully it would have given you a bit of a deeper understanding of the model orientation from this video. If you are a bit curious about some of the settings that you can see in this video that I didn’t cover and you wanted some more information on those feel free to message us or leave us a comment and I’ll get around to it. If you want to learn more about 3D printing or even just check out some filaments and printers then head over to core electronics.com.au and take a look around. Thanks for watching and have a great day :-)