With so much information available to someone joining the 3D printing world it can be overwhelming. And a lot of that information can be misguided or come from people whose experiences don’t reflect the results. I have been 3D printing for over three and a half years now and I want to share some of the things I have learned.

Note: This post can apply to all types of 3D printers. Some of the values given may need to be adjusted depending on the optimal increments of your stepper motors. (i.e. 0.175 mm could be 0.1 mm or 0.2 mm.)

I have enjoyed my dive into 3D printing and having a successful print to show to others can be such a joyous experience. Likewise I have been so frustrated and discouraged when my printer has broken down. But there’s good news: I have been able to turn my $200 Monoprice Select Mini into a workhorse printer.

First some caveats: My life can get pretty busy, so I want to be able to start a print and walk away knowing that the printer won’t burn the house down. So my settings are a reflection of that “set it and forget it” ideology. Early on I tried having two different presets for resolution types, 0.175 mm and 0.2625 mm. But the quality difference was so dramatic I decided to only print at 0.175 mm. However long the printer takes, it takes. I have learned to live with the time and enjoy the end result.

Build Plate Adhesion is Line #1

Many people new to 3D printing are probably surprised to hear that the proper leveling of a build plate will solve all kinds of issues. Elephant’s foot? Print warping? Falling prints? Are all caused by an improperly leveled bed and poor build plate adhesion.

Check out my post on build plate adhesion and how I level my printer’s bed here.

How does infill effect print cooling?

TLDR: Layer time, but infill has its role to play too. You may have noticed that some models print fine with low infill percentages. While other models are “weak” with the same infill percentage. Let’s break all this down:

Printing a model at very high infill percentages doesn’t guarantee strength. Having printed a few replacement parts with high infill rates using old PTEG, I found those prints weren’t nearly as strong as a similar low infill print using a fresh PLA. Adding more layers that all flow the same direction may help a model from being crushed, but it won’t help a model that is being stressed at its seams. That same inner strength can be achieved with 20% to 30% infill. More than that is likely overkill.

You COULD print every model hallow and with thicker walls, but small parts would still be weak prone to breaking off. My toddler has had a heavy influence on my perception of how strong prints should be. Vertical layer strength is important when orientating a part for printing. Using an Infill Pattern like Cubic can add vertical  strength to your model. It’s my preferred infill pattern. A little bit of infill, say 10% to 15%, can go a long way to adding strength to your print.

Bonus: 3D prints make great bath toys. If the shell of a Grid infill print becomes cracked, the whole model will slowly fill with water. Unlike Grid infill, models with Cubic infill will not fill with water because of their shifting grid pattern.

Filament Notes: My old PTEG seemed to age a lot faster then my various PLAs. It’s a hot mess even after putting it in a food dehydrator. Also, I recently purchased two PLA “metal” colors and they feel stronger then most PLAs. I would guess it has to do with the additives to get that color of sheen. So far those filaments have been great for printing replacement parts.

Software Cooling – Configuring your Slicer

So we learned both wall thickness and an infill pattern are important to print strength. My most common setup is a Wall Count of 4 with Top/Bottom Layers of 4 as well and 15% infill. This provides a solid shell and some inner material for strength. The one drawback to a low infill percentage is that each layer will be printed quicker. Printing a layer too fast can result in sloppy details. But why slow the entire printer down for a few details?

Minimum Layer Time

Cura has a great setting called Minimum Layer Time. The default value is 5 seconds, but raising it to 8 seconds has provided great results for me. This will slow the print head down to around 10 mm/s so small details get a chance to cool before the next round of filament. You COULD go crazy and turn the Minimum Layer Time way up, but then I would guess you need better cooling hardware.

Check out part 2 of this Print Cooling guide here.

Small Feature Speed

Like Minimum Layer Time, Small Feature Speed will slow down the print head. This helps with cooling and detail accuracy. I use 35% of my print speed, but you might find a different value works best for you. My rationale was that I want to print as fast as possible, yet slow the printer down when the model gets detailed. While in Cura’s Preview section, you can switch the view to Feedrate. There you can see exactly which parts of your model will have the slower feedrate. After that I recommend watching those sections get printed. Did the print head seem to fly by? Or did it slow down enough to accurately print and cool that detail?

Overhang Wall Angle

Great, our printer is slowing down for details. Now we need to make the same adjustment to overhangs and bridges. There are three settings we will need to change. First is Overhang Wall Angle, this is the threshold for detecting an overhang. Because we want to print relatively fast, we are going to be aggressive and set the overhang wall angle to 40 degrees. This will now slow the printer down on overhangs. How slow you ask? Next we need to set Overhang Wall Speed. Like Small Feature Speed, this is the rate at which we want to slow the print head. Again, I went with 35%, but watch your prints and adjust accordingly. And finally we check Enable Bridge Settings. This detects bridges and adjusts the print and fan speed for improved printing.

Support Generation

What if my details and overhangs still suck? Some models may require support in order to get a successful print. But with proper cooling, you can save on filament and print time by only generating support when necessary.

Support Overhang Angle controls the threshold for when to generate support. When set to 79 degrees Cura will only generate support in areas that absolutely need it. At 73 degrees the support provided will help stabilize most problem areas in a model.

Where this falls down, literally, is when portions of a model rest on supports for a long time before being joined to the main body. Like the bottom of a knight’s sword that is printed long before the extending arm. If the settings are too aggressive and the model angles are too steep; the part may fall over or get knocked out of place by the print head. Learn to identify problem areas before sending a model to print.

Closing Thoughts

So we have covered a bunch of different adjustments we can make to Cura to help us create better prints. But it’s only part of the overall solution for better cooling. Check out part 2 of this Print Cooling guide here. Low cost printers might require some hardware upgrades to get great prints.

You can also check out the complete list of my Cura settings here.