Temperature is, without a doubt, the most vital factor in 3D printing, as the temperature values that the material hits throughout the printing process essentially decide the quality of the print.
While the bed temperature and the nozzle temperature parameters are the first things that come to mind when we think of temperature, another parameter that has an equal amount of significance in deciding the temperature of the plastic is the cooling, also known as fan speed.
In today’s article, we will try to discover the optimal fan speed values for printing with PLA filament, which we believe will be helpful for many 3D printing enthusiasts as there is a lot of discussion in the 3D printing community on this subject in particular.
So, what is the optimal fan speed for printing PLA?
We recommend using a fan speed of 100% while printing with PLA filament for the best print quality possible, as PLA is a type of filament that doesn’t suffer from layer adhesion issues due to insufficient cooling and can even deform during the printing process if left uncooled.
Moving forward, we will conduct a more detailed analysis of the optimal fan speeds for printing PLA filament, discuss the effects of different fan speed values on the printing process, and look at the signs that may indicate that you’re either using a too high or too low fan speed value for printing PLA.
What Is the Optimal Fan Speed for Printing PLA?
As the fan speed parameter is one of the essential points of configuration for the 3D printing process to succeed, configuring the fan speed as optimally as possible is one of the first steps we need to take.
We can consider a fan speed of 100% to be optimal for printing PLA, as PLA requires a decent amount of cooling to solidify and form a high-quality surface before it starts getting droopy and creates an aesthetically low-quality model as a result of the deformation.
Considering that PLA is not prone to warping at all and that PLA layers can bond to each other rather quickly also contributes to the usage of high fan speeds for printing PLA, as these are the primary reasons behind high fan speeds being unsuitable for many other filament types.
On the other hand, there is one case where using a lower fan speed for printing PLA can be highly beneficial, which is the printing of the initial layers.
Even though PLA is not a type of filament that creates issues in the bed adhesion department, going with a low cooling fan speed (0-10%) for the first few layers ensures that the plastic has enough time to form bonds with the build surface, which goes a long way in not facing bed adhesion problems.
Finally, it’s worth mentioning that while printing PLA with cooling fans on 100% is standard practice, going for lower fan speeds will increase your model’s overall durability and strength at the expense of surface quality, and even though PLA is not the best choice for printing functional parts, it’s worth keeping this tradeoff in mind.
What Are the Effects of Different Fan Speeds on Printing PLA?
Having a clear understanding of how different fan speeds impact the printing process is a vital skill to configure the fan speed value as best as possible, which is a significant step towards getting the 3D printing process to yield the final product you envision.
The fan speed parameter provides a tradeoff between surface quality and strength for all types of filaments, and PLA is no exception to this rule, where higher fan speed values provide higher surface quality, and lower fan speed values provide better strength.
On the other hand, while the tradeoff remains the same for all filaments, the difference in effects is caused by the characteristics of the filaments, with distinct fan speed values affecting different filament types in different ways.
In the case of PLA, while going lower than the 100% fan speed will indeed increase the part’s strength just as it does for any other filament, the added strength is not what PLA needs for three reasons:
- PLA is prone to deforming during the printing process and needs all the cooling possible to solidify as quickly as possible for obtaining a high surface quality model.
- PLA doesn’t suffer from layer adhesion issues, meaning that cooling it down too quickly won’t negatively affect the structural integrity of your print.
- PLA is not a suitable material for functional parts due to being inherently weak, making it a better idea to go for a stronger type of plastic instead of increasing part strength by reducing cooling.
With these points in consideration, we can say that, in most cases, the effects of going with lower fan speeds for printing PLA would be adverse, as PLA benefits highly from cooling, doesn’t lose anything due to it, and would see more harm than good from the absence of it.
Signs of Using Too Low Fan Speeds for Printing PLA
Since the usage of too low fan speeds has adverse effects on the printing process, it’s vital to identify such cases as quickly as possible and apply the appropriate fix.
The primary sign you will notice when the cooling fan speed is way too low while printing PLA is the deformation of the print, where your model will look low-quality instead of being sharp and detailed and looking practically identical to the 3D model you see on your computer screen.
If you’re printing a model with overhangs and bridges without using supports, it’s highly likely for these overhangs and bridges to droop heavily and even entirely crumble before they can solidify, as they won’t be able to hold their shape for long enough until they can cool down naturally.
As such signs will be reasonably apparent due to them directly affecting how the model you have printed looks, you should be able to quickly tell that a low fan speed is indeed the problem.
While PLA is one of the more forgiving filaments when it comes to configuring the fan speed value, using a fan speed that is as optimal as possible is still necessary to obtain the best possible final product from the 3D printing process regardless of the filament you use.
Unlike PETG, where high fan speeds cause issues, the optimal fan speed for printing PLA is 100%, as it allows you to achieve the highest surface quality possible by drying the plastic and solidifying it before it can deform, without causing any layer adhesion issues in the process.
On the other hand, just as with many other filaments, keeping the fan speed down or even off for the first few layers while printing with PLA is usually a good idea to ensure that you don’t face issues with bed adhesion, as bed adhesion is often tricky to get right regardless of the filament you use.