When you start a 3D printing project with PLA, dialing in the right settings is crucial. While parameters like infill density and wall thickness are adjusted per model, the ideal hotend temperature often becomes a set-it-and-forget-it preset. But what if these presets aren’t truly optimal for PLA? Are you simply relying on manufacturer suggestions or default slicer profiles without exploring the true potential of your PLA filament?
Many 3D printing enthusiasts operate under the general understanding that a standard Pla Printing Temperature hovers around 215°C. The common wisdom suggests that increasing this temperature leads to stronger parts with improved layer adhesion, effectively “welding” layers together. Conversely, lowering the temperature is believed to yield cleaner, crisper prints with less stringing and blobbing. However, this oversimplified view neglects the complexities of material behavior at varying temperatures.
For weeks, we dedicated a workhorse 3D printer to rigorously testing PLA printing temperatures. Our goal? To determine the sweet spot for hotend temperature that balances print aesthetics and part strength. We explored temperatures both within and outside the commonly recommended range for PLA, and what we discovered challenges the simple “hotter is stronger” mantra. It turns out, finding the perfect PLA printing temperature is a nuanced balancing act.
The Temperature Trade-Off: Strength vs. Aesthetics in PLA Printing
The prevailing theory suggests that higher PLA printing temperatures inherently lead to stronger parts due to enhanced layer adhesion. However, this perspective overlooks potential downsides. Excessive heat can induce thermal degradation in PLA. While PLA is more stable than materials like ABS (which notoriously emits harmful fumes due to component boil-off at high temperatures), it’s not immune to heat-related issues.
Furthermore, printing too hot can lead to material bubbling and inconsistent extrusion. This inconsistency translates to gaps and imperfections within the printed part, potentially weakening the structure. These factors need to be carefully weighed against any perceived gains in layer adhesion at higher temperatures.
On the other end of the spectrum, printing PLA at excessively low temperatures also presents challenges. When PLA filament is not sufficiently molten, the extruder struggles to push it through the nozzle and accurately deposit it. This can result in under-extrusion, skipped steps from the extruder motor, and ultimately, weaker parts.
To truly understand the impact of PLA printing temperature, we needed empirical evidence. We designed a series of tests to evaluate both the aesthetic qualities and the mechanical strength of PLA parts printed at different temperatures.
PLA aesthetic test prints at varying temperatures
Setting Up the PLA Temperature Experiment
Our testing methodology involved printing two sets of PLA parts for each temperature we evaluated: one set focused on visual aesthetics and another designed for strength testing. We utilized a Prusa MK3S 3D printer equipped with a 0.6mm Revo nozzle – chosen for its versatility and reliable performance. Slicing was performed using PrusaSlicer 2.5 beta 3, leveraging the Arachne engine and standard 0.2mm layer height profiles. The only variable we adjusted was the hotend temperature, keeping all other settings consistent across the temperature range. First layer temperature was kept at the default to ensure good bed adhesion and part release.
For aesthetic evaluations, we printed a comprehensive test plate containing a 3D Benchy, the TomTest (designed to assess bridging, fine details, text, curling, and overhangs), a scaled-down Salty McCreedy model, and the intricate Prusa SL1 test object. This diverse set of models allowed us to comprehensively assess visual print quality across various features. To minimize temperature fluctuations during printing and isolate temperature effects, each aesthetic test part was printed sequentially.
PLA aesthetic test plate with various models
For strength testing, we employed industry-standard bend strength and impact strength test parts. These were printed in two orientations and replicated to ensure data reliability. We opted for “normal” print settings – 2 perimeters and 15% infill – to reflect real-world 3D printing scenarios, rather than idealized, 100% infill test samples that don’t accurately represent typical 3D printed part characteristics.
PLA strength test parts: bend and impact
Printer setup for PLA temperature testing
PLA Print Aesthetics Across Temperatures: Gloss, Stringing, and Detail
Let’s first examine the visual results. Across the PLA temperature range tested (from lower to higher temperatures), a clear trend emerged in surface finish. Lower temperatures resulted in a matte surface, while higher temperatures progressively increased glossiness.
Sequential printing of aesthetic test parts
Stringing, a common 3D printing artifact, also became more pronounced at higher PLA temperatures. In extreme cases, excessive stringing made completing the aesthetic test plate at the highest temperatures challenging. Interestingly, top surface smoothness in PLA tended to decrease at higher temperatures, becoming somewhat bumpy. However, finer details, such as small features on the Prusa SL1 test model, showed marginal improvement at higher temperatures. Overhang performance remained consistent across the temperature range, indicating temperature had minimal impact on this aspect of print quality in our tests.
PLA aesthetic test parts printed at different temperatures, showing gloss and stringing variations
Close-up of PLA Benchy at different temperatures
TomTest model printed in PLA at varying temperatures
Prusa SL1 test object in PLA, showcasing fine detail reproduction across temperatures
From an aesthetic standpoint, our findings suggest that default PLA printing temperatures generally strike a good balance. While a matte surface finish might be desirable for some applications and achievable by printing colder, we didn’t observe significant improvements in overall print crispness by deviating from the recommended temperature range.
PLA Strength Testing: Bend and Impact Resistance
Moving beyond aesthetics, we delved into the mechanical strength of PLA parts printed at different temperatures. We conducted bend tests using a custom jig and luggage scale to measure the force required to break each sample. Impact tests were performed using a pendulum impact tester to quantify the energy absorbed by the parts before fracture. A higher energy absorption indicates greater toughness.
Bend test setup for PLA samples
Impact test setup for PLA samples
An initial observation during strength testing was that parts printed at lower PLA temperatures tended to be dimensionally larger, sometimes even getting stuck in the test jigs. The reason for this dimensional deviation at lower temperatures remains unclear but warrants further investigation.
Bend Test Results: Consistent Strength Around Default Temperatures
The bend test results for PLA revealed that material strength remained relatively consistent across a wide range of temperatures. There was a slight dip in strength at the very highest temperature tested (275°C) and a more significant strength reduction at the lowest temperature (195°C). This lower temperature weakness likely stems from reduced layer adhesion when printing too cold, hindering the layers from properly bonding.
PLA bend test in progress
However, counterintuitively, layer adhesion (or at least strength in the Z-direction) also appeared to decrease at higher PLA temperatures in our bend tests. This unexpected drop-off could be attributed to several factors: increased stringing at higher temperatures potentially reducing material volume in the test parts, less consistent extrusion control at elevated temperatures leading to minor under-extrusion, or subtle surface imperfections that develop at higher temperatures. Regardless of the precise cause, the bend test data suggests that deviating significantly above the default PLA printing temperature doesn’t enhance, and may even reduce, part strength.
Impact Test Results: More Complex and Less Definitive
Impact strength results proved more challenging to interpret and exhibited greater variability. While we observed a trend suggesting potentially increased impact strength at both very low and very high PLA temperatures, the data was noisy. The apparent increase at high temperatures might be linked to slight material foaming, which could lead to more gradual fracture under impact. However, further, more extensive testing would be needed to definitively confirm these trends and reduce data variability.
PLA impact test in action
Conclusion: Default PLA Temperature is Optimal for Most Prints
Our comprehensive testing indicates that the commonly recommended default PLA printing temperature of approximately 215°C is indeed well-justified. It delivers a strong balance of print quality and part strength for standard PLA filaments and printing speeds. The notion that “printing hotter equals stronger parts” doesn’t hold true for PLA under typical conditions.
While printing colder PLA can yield a matte surface finish, it doesn’t demonstrably improve overall print aesthetics beyond this. Furthermore, significantly reducing PLA printing temperature can compromise layer adhesion and part strength. Conversely, pushing PLA temperatures excessively high can introduce aesthetic issues like increased stringing and surface roughness, and may even slightly reduce part strength in bending.
It’s important to acknowledge that these findings are based on testing with a specific printer (Prusa MK3S with Revo hotend) and Prusament PLA filament. Temperature readings can vary slightly between different 3D printer brands and even individual machines due to thermistor tolerances and calibration. A temperature offset of ±10°C between printers is not uncommon, particularly in budget-friendly models.
Therefore, while our results provide a strong guideline, it’s always advisable to perform temperature calibration prints specific to your printer and PLA filament to fine-tune your settings for truly optimal results. Experimentation within a reasonable range around the default temperature is key to unlocking the best performance from your 3D printing setup.
Ultimately, understanding the nuances of PLA printing temperature empowers you to make informed decisions and achieve consistently high-quality, strong 3D prints.
Relevant products:
- Genuine E3D Nozzles & Obxidian or on Amazon
- Prusament
- Prusa MK3 (S+)
Models shown:
