Hey gang, Tim here from Core Electronics and today we're diving back into the 3D printing landscape. I'm going to show you how to print perfect first layers so all your models can be the envy of all your friends.

The first layer results are crucial to the success of 3D printing components and sometimes a single layer print is all that is designed. There's a lot you can do with single layer prints, creating complex interlocked origami structures, stylish lamps or even printing nice tree firm fronts like you can see with what I have brought to the hideout with me today. A sign of success when it comes to first layers is a model with a shiny and flat bottom surface. Furthermore, success is a model that is rigid and dimensionally correct without any excess or peculiarly placed build lines. Now if the initial layer is not firmly set to the build platform it will end up as a failed print with the best results being a warped misshapen product.

There are a number of explanations if you're having issues with the first couple of layers or of single layer prints. One of the first points of call if your bottom layer of your prints is constantly having issues with adhesion is the build platform. It is crucial to have a flat and level build platform which is parallel to the path of the nozzle. If your build platform is incorrectly calibrated it will constantly cause large issues with all prints and particularly so for single layer prints. For Ultimaker 3D printers there's a guide on our website to calibrate that build platform.

So a factor that is very important to single layer prints is initial squish. Both calibrating the height manually and altering settings within Cura, which is a free 3D printing slicing software, can directly impact the initial squish. It's important to find the right balance between too much squish and not enough squish. Too much squish can result in a messy and uneven first layer, while not enough squish can lead to poor adhesion and a failed print. Another factor to consider is the bed surface. Different bed surfaces have different levels of adhesion. Some popular options include glass beds, PEI sheets, and BuildTak surfaces. Experimenting with different bed surfaces can help improve the adhesion of your first layers.

Lastly, make sure to clean your build platform regularly. Dust, oils, and other contaminants can interfere with the adhesion of the first layer. Using isopropyl alcohol or a similar cleaning solution can help remove any residue and ensure a clean surface for printing.

Affect the initial squish. So to clarify, the initial squish is how much the first layer of print is pushed onto the build platform. Higher squish will produce a flatter first layer which has more contact with the build platform but a smaller z-axis height. The printed lines will also blend much better together. If the bottom of the printed part is shiny, it's very pleasing aesthetically and it also is an excellent indication that the model has adhered well to that build plate. If you're looking at these single fronts, you can see exactly how shiny these pieces are. This one adhered very well. This one you can see a little blemish right there. And the initial one that I printed, you can see where it runs into issues at the top. So putting them in order of how I printed them, you can see an improvement between these results.

So looking at the single layer fronts I brought to the table, you can see the three separate results. The print that failed, I used a weaker initial squish as compared to the two successful prints which I used a higher initial squish consecutively. Squish was all altered in settings within Cura.

So if this is your first time hearing about Cura, put simply, it is a software which allows you to turn your computer files of your design into a recipe for a 3D printer to follow. It is available online and is a completely free software used by over a million users worldwide.

So let's jump into Cura. As you can see by the build platform, here are the two fronts and the two settings to refine initial squish are the initial layer height and the initial layer line width. Both of these are hidden settings. So to unlock them, you need to go into the settings up here. You need to click on configure setting visibility. And you can either type in the particular setting or you can scroll down and find it. Once you've unhidden them, you'll be able to find them here under the quality heading inside the custom print settings.

So these are all printed with a normal print profile using an Ultimaker S5 and Tough PLA. So I increased the initial layer height by 0.05. This guy over here. And I increased the layer line width by 10% incrementally for these prints. Single layer prints are a lot of fun, particularly because of the speed it takes to produce them. Each of these models took less than 20 minutes to make.

So now we're talking about speed. Speed absolutely murders good single layer prints. So if you're running into problems, another easy setting to alter is the initial layer print speed and initial layer travel speed. So jumping back into Cura, these two hidden settings can be found under the speed heading in the custom setting print menu. Down here, we've got the print speed initial layer print speed and the initial layer travel speed. So for first layer prints, 20 millimetres per second is an excellent speed for all of these settings. This will minimize the vibrations and give the filament a better chance to extrude out reliably onto the build platform.

Finally, when printing aesthetically pleasing first layers, combing is a feature that often comes up in conversation. Combing is a method used in 3D slicing software to minimize stringing and print nozzles dribbling effects. Stringing is a blemish which looks like a whisker or hair on a model. It occurs when the filament is incorrectly under pressure, causing material to ooze out of the print nozzle. Combing makes any of these dribbles or stringing from the nozzle end up deposited internally. Inside the model, by forcing the printhead to move inside the perimeter of the part instead of traveling across a void. This is great for large parts as the location will not be covered but not so good for single layer models or surface finishes.

This is because on a single layer part you'll be able to see the combing lines in undesirable places. So I'm holding these two models that I brought to the table. One has combing and one doesn't. So you can clearly see the negative effects of combing to the surface finish. This one in this hand doesn't have any combing whereas this one does and you can see distinctly blemishes on the surface. The two settings to help adjust combing with a focus on printing the best possible single layer models are combing mode and maximum comb distance with no retract. These settings can be accessed under the travel heading in the custom print settings.

For an optimal single layer print, set combing mode to not in shell and set the max comb distance with no retract to 10 millimetres. Both of these mean that the combing will never occur in areas that are inside the perimeter and any time the printhead moves more than 10 millimetres when traveling, it will force retraction to occur. This will stop lines being printed on the bottom layer in places you don't want them. Retraction specifically is when the feeder pulls the filament away from the nozzle. And that's it! There's a write-up on this topic at our Core Electronics website which goes significantly deeper into these concepts. If you want more insight, it's definitely worth checking out.

Hope this has been helpful and inspired future 3D printing endeavors in your life. Until next time, stay cozy.