How Much Cooling (Fan Speed) Does ABS Need? (Solved!)

Regardless of the type of filament you use, it’s undeniable that getting the temperature of the plastic correct is one of the pillars of 3D printing, where print temperature, bed temperature, cooling fan speed, and even the ambient temperature of the room play significant roles.

On the other hand, while the print and bed temperature variables are often straightforward to configure correctly by following the manufacturer’s recommendation, getting the cooling fan speed right is usually a bit trickier as it’s a parameter that shows variance based on the scenario.

Today, we will be covering the topic of cooling and fan speed, specifically for printing ABS filament as optimally as possible and avoiding issues related to the plastic cooling down way too slowly or way too quickly, such as warping.

So, how much cooling does ABS need for the 3D printing process?

For the most part, ABS is a type of filament that does not require any cooling or requires minimal cooling, as cooling can cause the plastic to solidify too quickly and prevent the layers from adhering, causing the problem known as layer separation or delamination.

Moving on, we will analyze the optimal cooling speeds for printing with ABS in more detail, discuss the effects of cooling on ABS plastic, and take a quick look at the signs that indicate you may be using too much or too little cooling.

How Much Cooling (Fan Speed) Does ABS Need?

As there is no one-size-fits-all answer when it comes to finding the optimal amount of cooling for printing with ABS plastic, a successful configuration mostly comes down to identifying the purpose of your model and applying a suitable fan speed value.

Provided that you are printing ABS in an enclosure that allows you to keep the ambient temperature stable and protect the model from drafts, you can print most models with zero or minimal (10-20%) cooling with success.

On the other hand, as you may predict, there are some exceptions to this rule where more cooling can be required to stabilize the plastic before the upcoming layers start piling on.

The first exceptions to the rule are the nightmare of every 3D printing enthusiast, known as overhangs and bridges, which will require some assistance in the cooling department to hold on to the rest of the model and not start drooping.

The second exceptions are small layers that don’t take too much time to print, which will also require some cooling due to the lack of time to cool down naturally before the upcoming layer.

In the case of these exceptions, we recommend setting the cooling fan speed to a starting point of 20% and incrementally (increments of 5% should do) working your way up until you don’t face any problems.

As always, to find the optimal level of cooling for your purposes, we highly recommend running test prints with distinct fan speed values before entirely committing to the final product.

What Are the Effects of Cooling on Printing with ABS?

Since cooling impacts the temperature of the plastic directly, which essentially determines how the plastic behaves, it’s possible to observe severe changes in factors such as layer adhesion and surface resolution.

The main impact of cooling on printing with ABS will be the strength of adhesion between the model’s layers – since how fast the cooling fan runs effectively decides how quickly a layer cools down and solidifies from its melted state, which is one of the primary deciders for the adhesion strength.

Since ABS is notorious for layer adhesion issues caused by excessive cooling, blasting the cooling fans throughout the print will make it irrefutable that the layers won’t have enough time to bond before solidifying, which causes the issue we know as layer separation.

As layer separation will drastically damage the durability of the model and cause visible defects through the appearance of cracks, it will most likely render your print unusable regardless of the use case. 

On the other hand, another impact to consider is the surface resolution of the model, as the chance of the model deforming due to more layers coming on top of the plastic that’s still in its fully melted state is directly related to the absence of cooling.

While ABS can usually naturally cool down to a state where it’s suitable to add the next layer without issues, you are likely to see such deformations on layers on the smaller side that don’t have enough time to cool down naturally until the next layer comes.

What Are the Signs of Too Much Cooling on ABS?

Configuring the speed of the cooling fans in a way where they cause ABS to cool down way too quickly is problematic for the health of the printing process, causing issues such as:

  • Weak layer adhesion, which can lead to layer separation (delamination)
  • Problems with model durability that make it prone to cracking or breaking
  • Warping on the first few layers of the model
  • Bridges (if applicable) are likely to be very weak and prone to breakage without too much force
  • Overhangs (if applicable) are very likely to be weak and prone to breakage without too much force

What Are the Signs of Too Little Cooling on ABS?

Applying too little cooling while printing with ABS also comes with its own set of problems, which we have listed below:

  • The appearance of stringing and blobbing on the model
  • Deformation of smaller layers that don’t get enough time to cool down correctly
  • Bridges (if applicable) drooping due to not cooling down quickly enough
  • Overhangs (if applicable) drooping due to not cooling down quickly enough

Wrapping Up

While it may be slightly challenging due to the amount of effort and time that goes into it, correctly configuring the cooling while printing with ABS filament is vital for the health of the printing process.

To quickly recap, we can say that ABS is one of the few types of filament that does not require cooling for a successful print, and in fact, the presence of cooling can have adverse effects on the model by causing the layers to solidify before they can form strong bonds.

On the other hand, when printing smaller layers and overhangs, it may be a good idea to apply a small amount of cooling, as such layers may not have enough time to naturally cool down to a level where it becomes suitable to add the next layer on top.

Happy printing!