Category: Cura

Supports are tricky. You must create a fine balance. Too much support and your supports are difficult to remove and leave ugly marks. Too little support and everything falls apart. Today, I wanted to go over a few things that I consider when setting a print up that needs supports.

First, you need to decide whether you need supports or not. Cura has a handy feature that shows you the areas of your model that need supports in red. To enable this feature, go to the Preview tab and click on the eye icon on the top right corner. Then, select Show Overhangs from the drop-down menu. You will see the overhangs highlighted in red on your model.

If you see a lot of red areas, you might want to enable supports. To do this, go to the Prepare tab and click on the Support icon on the left sidebar. You will see several options for supports, such as Support Placement, Support Overhang Angle, Support Density, and more. Here are some tips for choosing the right settings:

  • Support Placement: This option lets you choose where to place the supports. You can choose Everywhere, which means the supports will touch both the build plate and the model, or Touching Build Plate, which means the supports will only touch the build plate and not the model.
  • Support Overhang Angle: This option lets you choose the minimum angle for an overhang to be supported. The default value is 50 degrees, which means any overhang that is less than 50 degrees from horizontal will be supported. You can increase or decrease this value depending on your model and your printer’s capabilities. A lower value will create more supports, which can improve print quality but also increase print time and material usage. A higher value will create fewer supports, which can save time and material but also risk print failure or poor quality.
  • Support Density: This option lets you choose how dense the supports are. The default value is 15%, which means 15% of the support area will be filled with material. You can increase or decrease this value depending on your model and your preferences. A higher value will create stronger and sturdier supports, which can help with complex or heavy models, but also increase print time and material usage. A lower value will create weaker and sparser supports, which can save time and material but also risk breaking or collapsing during printing or removal.
  • Support Interface: This option lets you choose whether to add an extra layer between the supports and the model. This layer can improve print quality by reducing marks or scars on the model surface caused by the supports. To enable this option, check the Generate Support Interface box. You will see two sub-options: Support Roof and Support Floor. The roof is the layer that touches the model from above, and the floor is the layer that touches the model from below. You can adjust the thickness and density of these layers according to your needs.

One of the most important parameters to adjust when slicing a 3D model for printing is the layer height or step height. This is the thickness of each layer that the printer will deposit on top of the previous one, and it affects the quality, speed and strength of the print. I would like to discuss some of the things to consider when setting a step height in a 3D printer slicer.

The first thing to consider is the resolution and detail of your model. If you want to preserve fine details and smooth curves, you will need to use a lower layer height, as this will reduce the visible stair-stepping effect that occurs when printing curved surfaces. However, if your model is simple or has large flat areas, you can use a higher layer height, as this will not affect the appearance much.

The second thing to consider is the printing time and cost. The lower the layer height, the more layers you will need to print, and the longer it will take to finish the print. This also means that your printer will be unavailable for longer. No big deal if you are a hobbyist, but if you have a hourly price associated with your printer it can really increase the cost of your prints. On the other hand, the higher the layer height, the fewer layers you will need to print, and the faster it will finish.

The third thing to consider is the strength and durability of your print. The lower the layer height, the better the adhesion between layers, and the stronger your print will be. This is especially important if you are printing functional parts that need to withstand stress or impact. However, if you are printing decorative or non-functional parts, you can use a higher layer height, as this will not affect the strength much.

There is no single optimal layer height for every print. You will need to balance these factors and choose a layer height that suits your needs and preferences. A good rule of thumb is to start with a layer height that is half of your nozzle diameter, and adjust it up or down depending on your model and desired outcome.

Also, consider “magic numbers.” For most hobbyist FDM printers ideal step heights are in increments of 0.04mm.

While printing with silk PLA, I had a couple of difficulties. One of the things that I encountered was with retraction. Without retraction enabled, my prints were a stringy mess. However, with retraction enabled, my extruder would grind a flat spot onto my silk PLA.

My lifesaver, it turns out, was two settings inside of Cura.

The way that Cura applies these two settings can be translated as “do not retract more than two times until at least 10mm of filament has been extruded.”

Adjusting these settings proved to be very helpful and allowed me to finish the prints that I had been having trouble with.

My daughter recently asked me to print something for her in two entirely different types of filaments. To do so would require me to change almost all of the settings partway through the printing process. Here is how I did it with the post processing script plugin for Cura. This plugin allows you to add custom g-code commands at specific layers or heights of your print, which can override the default settings of your slicer.

To use the post processing script plugin, you need to have Cura installed on your computer. You can download it from https://ultimaker.com/software/ultimaker-cura. Once you have Cura open, load your model and slice it as usual. Then, go to the Extensions menu and select Post Processing > Modify G-Code. This will open a new window where you can add, edit, or delete scripts.

To add a new script, click on the Add a script button and choose one from the list. There are many scripts available, such as ChangeAtZ, PauseAtHeight, FilamentChange, etc. For this example, I will use the ChangeAtZ script, which lets you change any parameter at a given layer or height. After selecting the script, you will see a list of options that you can modify. For example, you can choose whether to trigger the script by layer or by height, what parameter to change, and what value to set it to. You can also add a comment to remind yourself what the script does.

For example, let’s say I want to change the temperature from 200°C to 220°C at layer 50 of my print. I would select the ChangeAtZ script and set the following options:

  • Trigger: Layer No.
  • Layer No.: 50
  • Behavior: Keep value
  • Change extruder 1 temp: True
  • Extruder 1 temp: 220
  • Comment: Increase temperature

This will insert a custom g-code command at layer 50 that will set the temperature of extruder 1 to 220°C and keep it until the end of the print. You can add multiple scripts if you want to change more than one parameter or change them multiple times during the print. You can also edit or delete scripts by clicking on the pencil or trash icons next to them.

Once you are done with adding scripts, click on Close and save your g-code file as usual. Then, transfer it to your printer and start printing. You should see your parameter changes take effect at the specified layers or heights of your print.

The post processing script plugin for Cura is a powerful tool that can help you fine-tune your prints and achieve better results. You can use it to experiment with different settings and see how they affect your print quality, speed, or appearance. You can also use it to create some interesting effects, such as changing colors, pausing for inserts, or adding text or logos. The possibilities are endless!

How to recognize when 3D printer temperature is too low?

The temperature of the nozzle is crucial for the quality and strength of the printed object. If the temperature is too high, the filament may burn, clog the nozzle, or ooze excessively. If the temperature is too low, the filament may not melt properly, resulting in poor adhesion, under-extrusion, or warping.

So how can you tell if your 3D printer temperature is too low? Here are some signs to look out for:

  • The filament does not stick to the build plate or to the previous layers. This can cause gaps, holes, or cracks in the printed object.
  • The filament curls up or bends at the tip of the nozzle. This can cause stringing, blobs, or zits on the surface of the printed object.
  • The filament snaps or breaks easily. This can cause jams, clogs, or extruder skipping.
  • The printed object has a rough or matte surface. This can reduce the aesthetic appeal and smoothness of the printed object.

If you notice any of these signs, you may need to increase your 3D printer temperature by a few degrees and try again. You can also use a temperature tower test to find the optimal temperature range for your filament and printer model. A temperature tower is a simple model that prints at different temperatures along its height, allowing you to compare the results and choose the best one.

Different filaments have different melting points and require different temperatures. For example, PLA typically prints well at around 200°C, while ABS needs around 230°C. You should always follow the manufacturer’s recommendations and adjust accordingly based on your printer’s performance and environment.

Infill is the internal structure that supports the outer shell of a 3D printed object. It can affect the strength, weight, and appearance of the print.

There are many types of infill patterns, such as grid, honeycomb, triangle, gyroid, and more. Each one has its own advantages and disadvantages depending on the application and the desired properties of the print.

Grid infill is one of the most common and simple patterns. It consists of horizontal and vertical lines that form squares. Grid infill is easy to print and provides good strength in all directions. However, it can also be heavy and use more material than other patterns.

Honeycomb infill is another popular pattern that mimics the structure of a bee’s honeycomb. It consists of hexagonal cells that are connected by thin walls. Honeycomb infill is lighter and more efficient than grid infill, as it uses less material while providing similar strength. However, it can also be more difficult to print and require more processing power.

Triangle infill is a pattern that uses equilateral triangles as the basic unit. It is similar to honeycomb infill in terms of efficiency and strength, but it has fewer connections between the cells, which can reduce printing time and noise. However, it can also be less stable and prone to deformation.

Gyroid infill is a complex pattern that creates a continuous surface with no gaps or holes. It is based on a mathematical function that produces a wavy shape. Gyroid infill is very strong and flexible in all directions, as it can absorb stress from different angles. However, it can also be very slow to print and require a lot of memory.

A Z seam isn’t really a “problem,” so much as it is just something that happens in 3d printing when you use an FDM printer. It is a line or a seam that is created along the Z-axis, where the printhead stops and moves up to print the next layer. This can cause a slight gap, a blob, or a zit on the surface of your print, especially on smooth and round objects.

There are several ways to fix or hide the Z seam in your 3D prints, depending on your slicer settings and your model geometry. Here are some of the most effective methods:

  • Adjust retraction settings: Retraction is when the extruder pulls back the filament slightly to prevent oozing during non-printing movements. By improving your retraction settings, you can reduce the amount of material that leaks out at the end of each layer, which can minimize the Z seam. You can adjust the retraction distance, speed, and extra prime amount in your slicer to find the optimal values for your printer and filament.
  • Change Z seam alignment settings: Z seam alignment is how your slicer decides where to place the Z seam on your model. You can choose between random, shortest, user-specified, or sharpest corner options. Random alignment will scatter the Z seams all over your model, making them less noticeable but also less consistent. Shortest alignment will place the Z seams at the closest point to the previous layer, reducing print time but also creating a visible line. User-specified alignment will let you choose a specific location for the Z seam, such as the back or the front of your model. Sharpest corner alignment will place the Z seams at the sharpest corners of your model, hiding them in the details.
  • Reduce print speed: Print speed affects how much pressure is built up in the hotend during printing. If you print too fast, you may have more material oozing out at the end of each layer, creating a bigger Z seam. By reducing your print speed, you can lower the pressure and improve the flow control of your extruder, resulting in a smoother surface finish.
  • Enable coasting: Coasting is when your slicer stops extruding a little bit before the end of each perimeter, letting the remaining pressure in the nozzle push out the filament. This can help reduce oozing and stringing, as well as Z seams. However, coasting can also cause under-extrusion or gaps in some cases, so you need to experiment with different coasting distances and volumes to find the right balance.
  • Enable linear advance: Linear advance is a firmware feature that adjusts the extruder pressure based on the print speed and acceleration. It can help improve print quality by compensating for over-extrusion and under-extrusion at different speeds. By enabling linear advance, you can also reduce the Z seam by having more consistent extrusion throughout each layer.

There are several factors that can cause weak infill in 3D prints, such as:

  • Infill density: This is the percentage of material used to fill the interior of a 3D printed object. A higher infill density means more material and stronger infill, while a lower infill density means less material and weaker infill. A general rule of thumb is to use at least 20% infill density for most prints.
  • Infill pattern: This is the shape of the material used to fill the interior of a 3D printed object. There are many types of infill patterns, such as grid, honeycomb, triangular, gyroid, etc. Some infill patterns are stronger than others, depending on how they distribute the material and how they connect with the outer shell of the object. For example, honeycomb and triangular patterns are stronger than grid and lines patterns.
  • Infill speed: This is the speed at which the nozzle moves while printing the infill. A higher infill speed means faster printing time, but it can also cause under-extrusion, which means not enough material is extruded from the nozzle. Under-extrusion can result in weak and stringy infill, as well as poor adhesion between the layers. A lower infill speed means slower printing time, but it can also ensure better extrusion and stronger infill.
  • Infill line width: This is the thickness of the material used to print the infill. A higher infill line width means more material and stronger infill, while a lower infill line width means less material and weaker infill. The optimal infill line width depends on the nozzle size and layer height you are using. A general rule of thumb is to use an infill line width that is equal to or slightly larger than your nozzle size.

How to Fix Weak Infill?

If you have diagnosed that your 3D prints have weak infill, you can try some of these solutions to fix it:

  • Increase your infill density: This is the easiest way to improve your infill strength. You can adjust your infill density in your slicer software before printing. As mentioned earlier, a minimum of 20% infill density is recommended for most prints.
  • Change your infill pattern: This can also make a big difference in your infill strength. You can choose a different infill pattern in your slicer software before printing. As mentioned earlier, some patterns are stronger than others, so you may want to experiment with different options and see what works best for your print.
  • Lower your infill speed: This can help prevent under-extrusion and improve your infill quality. You can adjust your infill speed in your slicer software before printing. A good way to find the optimal speed is to start with a low value and gradually increase it until you see signs of under-extrusion or poor quality.
  • Increase your infill line width: This can also help increase your infill strength by using more material. You can adjust your infill line width in your slicer software before printing. As mentioned earlier, a good way to find the optimal value is to use an online calculator or a test print.

If you are new to 3D printing, you might encounter some problems with your prints that can be frustrating and confusing. One of the most common issues is a clogged nozzle, which can affect the quality and accuracy of your prints. In this blog post, I will explain how to diagnose a clogged nozzle and what symptoms to look for on your 3D printed part.

A clogged nozzle is when the filament gets stuck or blocked inside the nozzle, preventing it from extruding properly. This can happen for various reasons, such as using low-quality filament, printing at the wrong temperature, or having dust or debris in the nozzle.

A clogged nozzle can cause several problems with your prints, such as under-extrusion, stringing, blobs, gaps, or layer shifts. These symptoms can ruin your print and waste your time and filament. It is important to diagnose a clogged nozzle as soon as possible and fix it before it gets worse.

The good news is that diagnosing a clogged nozzle is not very difficult. You just need to pay attention to some signs that indicate that something is wrong with your nozzle. Here are some of the most common symptoms of a clogged nozzle:

  • Under-extrusion: This is when the nozzle does not extrude enough filament to fill the gaps between the layers or the perimeters. This results in thin or missing walls, weak infill, or holes in the print.
  • Stringing: This is when the nozzle oozes filament during travel moves, creating thin strings or hairs between different parts of the print. This can make your print look messy and require post-processing to remove them.
  • Blobs: This is when the nozzle extrudes too much filament at certain points, creating bumps or lumps on the surface of the print. This can affect the smoothness and accuracy of your print and make it look unprofessional.
  • Gaps: This is when the nozzle skips or misses some parts of the print, leaving empty spaces or holes in the model. This can compromise the integrity and functionality of your print and make it look incomplete.
  • Layer shifts: This is when the nozzle moves out of alignment during printing, causing the layers to shift or misalign. This can distort the shape and dimensions of your print and make it unusable.

If you notice any of these symptoms on your 3D printed part, check your nozzle for clogging and either fix or replace the nozzle.

Sometimes, in Cura, you may encounter gaps in your prints that affect the quality and appearance of your parts. I want to explain how to fill in any gaps in Cura using some simple settings and tips. I’m assuming a properly calibrated 3d printer. If you haven’t done that, do that first.

Gaps can occur in different parts of your prints, such as the top and bottom layers, the walls, or the infill. There are different reasons for these gaps, such as under-extrusion, incorrect nozzle size, low flow rate, or wrong layer height. To fix these gaps, you need to adjust some settings in Cura that affect the amount and distribution of material in your prints.

One of the most important settings to check is the line width, which determines how wide each extruded line is. The line width should match your nozzle size or be slightly larger (up to 120% of the nozzle size). If the line width is too small, there will be gaps between the lines. You can find the line width settings under the Quality category in Cura.

Another setting that affects the gaps is the flow rate, which controls how much material is extruded by the printer. The flow rate should be 100% by default, but you can increase it slightly (up to 110%) if you notice under-extrusion or gaps in your prints. However, be careful not to over-extrude, as this can cause other problems such as blobs or stringing. You can find the flow rate setting under the Material category in Cura.

A third setting that can help you fill in the gaps is the top/bottom pattern, which determines how the top and bottom layers are printed. The top/bottom pattern can be either lines, concentric, zigzag, or triangles. The lines pattern is the fastest and most common option, but it can leave gaps between the lines if they are not aligned properly. The concentric pattern can create a smoother surface, but it can also create gaps if the nozzle moves too far from the center. The zigzag pattern can fill in the gaps better than the lines or concentric patterns, but it can also create more travel moves and stringing. The triangles pattern can create a strong and uniform surface, but it can also increase the print time and material usage. You can find the top/bottom pattern setting under the Shell category in Cura.