A CURA 3D SLICER TUTORIAL TO GET YOUR SLICER SETTINGS RIGHT (Part 3)
Posted: 2020-07-16 1:44
MACHINE SETTINGS: PRINTER TAB
Clicking on Machine Settings for a printer will take you to the configuration window for that printer. Here are the settings under the Printer tab for my Maker Select Plus:
The Printer Settings section has fields for the size of the bed (X and Y axes) and maximum build height (Z-axis). Some of these are the defaults. Others I had to input manually to match my printer. That’s ok though. Even the most rudimentary manual will include the build area and nozzle dimensions.
This section also has options for build plate shape, the origin location, bed heat, and ‘G-code flavor.’
BUILD PLATE SHAPE
For the build plate shape, you can choose rectangular or elliptical. A cartesian printer like my Maker Select Plus will typically have a rectangular build plate, whereas a delta style printer will have an elliptical one. Related to this, the Origin at Center option tells Cura that you want the printer to use the center of the build plate as the home position. This generally only applies to delta style printers. If you would like more information on the different styles of 3D printers, please see our article about the Four FFF Printer Styles.
Select the Heated bed option if you know your printer has a heated build surface. The manual will definitely say if it does, if for no other reason than they need to warn you about the risk of burns.
For the G-code flavor setting, Cura includes nine different options. Let’s stop here for a second and define what we’re talking about.
For those new to 3D printing, g-code is just written instructions for the printer to follow. It’s plain text that spells out every movement and other commands the printer needs to follow to create the model you are slicing. It’s been in use by industrial tooling, such as CNC machines, for decades, and was adapted to 3D printers because many of the concepts are the same. There are many variants of g-code, which is why Cura has an option to specify which one your printer uses, referred to as the ‘flavor.’
For pre-built profiles, the ‘G-code flavor’ option should already be set to the correct type, but if you are adding a custom printer, you will have to find out what one to use. Fortunately, 3D printing has a lot of active online communities, and a quick search should get you the information you need. It mostly comes down to the type of firmware your printer is running.
Mine, for instance, is using a version of Marlin. The topic of different printer firmware and g-code types gets very technical very fast. The important thing to know here is that they don’t all operate the same, so it’s important that you select the best option for your printer.
The Printhead Settings section only applies if you are planning to do what Cura calls ‘one at a time printing,’ where if you have multiple models added to the bed, Cura will write the g-code to finish each object one at a time instead of doing them together one layer at a time. This can reduce some problems, such as filament stringing between objects, but if you plan on printing this way it is very important that you use this section of the settings to tell Cura the distance between the extruder nozzle and the rest of the print head, or it is virtually guaranteed to crash into something while moving between finished models.
START G-CODE AND END G-CODE
The Start G-code and End G-code sections tell Cura what you want the printer to do at the beginning and end of each print. The above settings are the defaults, which do some basic housekeeping tasks, such as homing the extruder at the beginning of a print and turning off the hot end and bed heat at the end. Unless you have done some research, these settings will look like complete gibberish, but as long as your printer is doing the things you need to it to at the beginning and end of prints, do not change them. Incorrect changes to these settings could seriously damage your printer and/or be a potential fire hazard. Editing g-code is a whole different level of 3D printing that is outside the scope of this article, but I plan to cover some basics in another article soon.
MACHINE SETTINGS: EXTRUDER TABS
Since I have the number of extruders set to one in my printer settings, there is only one corresponding extruder tab to go with it: Extruder 1. This tab has a fairly small number of options but contains the absolutely critical Nozzle Size and Compatible Filament Size settings. If these do not match your printer, getting decent print quality is basically impossible.
Currently, my printer has a 0.4mm nozzle on it. This is a standard size that most FFF printers come with, but they can be changed easily to fit your needs. Most common sizes range from 0.2mm up to 1.0mm, with others available if you search around a bit. The size of the nozzle mostly affects the level of detail (resolution) the printer is capable of. For instance, the 0.4mm nozzle on my printer is perfect for day-to-day objects, but if I were going to start printing miniatures for tabletop gaming I would want to switch it to a 0.2mm nozzle to better handle the small details.
The extruder on my printer is designed to use 1.75mm filament, but yours may not be. Currently, there is a good mix of printers that use 2.85mm filament instead. It all depends on the design considerations the printer manufacturer made when they developed it. One size isn’t necessarily better than the other, it’s just important that you know which one your printer uses so you can purchase the right material.
One thing to keep in mind with filament sizes: the diameter of the filament is nominal, meaning it isn’t going to be exactly that diameter for its entire length. Manufacturers will do their best, but there are limits to the precision they are able to achieve on low-cost goods like a plastic filament. Reputable manufacturers will have the tolerance value right on the package, which allows you to adjust your filament profiles to match. I will cover that in the Materials section below.
The Nozzle offset options only need to be changed on a single extruder setup if the nozzle on your printer is not where Cura assumes it is on the print head in reference to the printer home position. Let’s break that down.
When a printer receives the home command, it will move the print head to a predefined position (home). On a cartesian printer, that is usually the lower left corner of the bed. On a delta printer, that is usually the center of the bed. Cura assumes the nozzle is in the middle of the print head, so when the print head is in the home position the nozzle is either exactly in the corner or exactly in the middle of the bed, depending on the printer style. If that is not the case, the nozzle offset values tell Cura exactly how far off of home the nozzle is so it can adjust print commands to ensure it doesn’t accidentally run off the edge of the bed.
On a stock, single extruder printer these values usually do not need to be changed from the default of 0.
COOLING FAN NUMBER
The same can be said for the Cooling Fan Number. Most 3D printers only have one nozzle cooling fan (a.k.a. Filament cooler), which is fan 0. The fan number is essentially the address that the printer sends fan commands to. In this case, it’s like a street with only one house on it, and the addresses start at zero. However, if you had a dual extruder printer, there would be two houses on the street, addresses zero and one.
What you don’t want to do is tell the printer to send commands to an empty lot, so make sure not to change the cooling fan number unless you have a good reason.
Keep in mind, your printer may have more than one fan on it, my Maker Select Plus has two: the hot end cooling fan, and the nozzle cooling fan. On my printer, the hot end fan is always running if the printer is turned on. It’s wired directly to the power supply and cannot be controlled. The nozzle cooling fan (fan 0) is the one that Cura can write instructions for based on the specified cooling fan number.
Here is what it looks like on my Monoprice Maker Select Plus:
EXTRUDER START AND EXTRUDER END G-CODE
Finally, the Extruder Start and Extruder End G-code sections can also generally be left alone. These fields are intended to hold g-code that is specifically for that extruder, an idea that makes more sense on a multi-extruder printer. For instance, on a dual extruder printer, you may want to prime extruder 1 at the beginning, while at the same time retracting extruder 2 so it doesn’t leak while waiting for its turn to print. On a single extruder printer, Cura just writes the beginning and ending instructions into the printer Start G-code and End G-code fields as mentioned a few sections ago.