Experimental Dedication of the Results of Slicer Settings on the Mechanical Power of Fused Filament Fabrication Manufactured Specimens

Samuel Hart and Trevor Grey

Mechanical Engineering
Valparaiso College
Valparaiso, Indiana

Dr. Daniel Blood

Assistant Professor of Mechanical Engineering and Bioengineering
Valparaiso College
Valparaiso, Indiana

ABSTRACT:

The patron-level Fused Filament Fabrication (FFF) group has little scientific info obtainable on the mechanical properties of printed elements. Even much less is thought concerning the relationship between slicer settings, reminiscent of hotend temperature, and the ensuing mechanical energy with varied filaments. This paper presents a proposed technique of characterizing the connection between slicer settings for various filament varieties and the ensuing mechanical energy of FFF elements. Moreover, outcomes of testing MatterHackers’ MH Construct PLA, PRO Sequence PLA, PRO Sequence ABS, PRO Sequence PETG, PRO Sequence Nylon, and NylonX filaments are reported. It’s discovered that NylonX has the best energy to weight ratio at 92 lbf/g, MH Construct PLA has the best peak load at 478 lbf, and PRO Sequence Nylon has the best ductility of the filaments examined with 25.6% pressure at failure. PRO Sequence PLA energy depends the least on the path of the utilized drive with an isotropic score of fifty%. Further parameters, reminiscent of half fan velocity, print velocity, and infill share, are examined to find out their impact on tensile energy.

1. INTRODUCTION

1.1 Motivation

The expiration of Stratasys’ Fused Deposition Modeling (FDM) patent in 2009 resulted in a beforehand unimaginable explosion in do-it-yourself (DIY) tech [1]. The open-source group renamed the printing course of Fused Filament Fabrication (FFF) to stop infringement on Stratasys’ FDM trademark. Filament primarily based 3D printing maintains its place as the first printer know-how for shoppers as a result of relative low value of entry, and the worldwide help group. The aggressive FFF printer market adjustments at a staggering tempo from 12 months to 12 months, and new capabilities are allowed by this new tech. Improvements in printer {hardware} and new varieties of filament present customers with an ever-expanding array of choices. Whereas many of those improvements are designed to make printers extra user-friendly, many extra declare to supply the ‘finest’ prints attainable; nonetheless, and not using a scientific comparability of the alternate options it is unattainable to validate these claims. The analysis staff at Valparaiso College (Valpo) acknowledges that there’s a want for unbiased analysis of printer elements and consumables, and the staff has spent two years creating a repeatable technique of analysis.

[1] Crump, S. Scott, “Equipment and Technique for Creating Three-Dimensional Objects,” U.S. Patent 5 121 329, 9 June 9, 1992.

1.2 Figuring out Elements that Have an effect on Printed Elements

A aim for many 3D printing lovers is to supply elements which might be aesthetically pleasing, and have comparatively excessive mechanical energy. Sadly, these two desired traits is probably not attainable with the identical printer/filament/slicer setting combos, and solely the person printing the half can decide if they need operate, kind, or a combination. An extra problem with quantifying aesthetics is the subjective nature of attractiveness. Determine 1 reveals an instance of two prints that come from the identical mannequin and general settings, however with a distinction within the .STL decision leading to ‘easy’ and ‘low-poly’ prints. Because of the subjective nature of aesthetics, the Valparaiso College analysis staff is specializing in quantifying mechanical properties.

Step one in evaluating energy is figuring out failure modes of printed elements. Preliminary tensile testing of FFF specimens reveals three main modes of failure: yielding of the fabric, delamination between Z-layers, and delamination within the X-Y path. Subsequent, course of parameters are recognized that will contribute to failure for every of the three modes. The next conclusions are primarily based on evaluation of the failed specimens, evaluate of slicer settings, and comparability of printer elements.

1.2.1 Failure Resulting from Yielding

Yield energy is outlined because the transition from elastic (recoverable) deformation to plastic (everlasting) deformation [2]. Within the case of an injection molded half, that is largely as a result of materials properties of the polymer, and the inner residual stresses because of the injection course of. FFF printing is much like injection molding on this respect, however adjustments in materials properties and the bodily strategy of producing inside residual stresses are distinctive. Extruded materials properties are largely a operate of the polymer sort, however the materials properties are additionally affected by the extent of polymer degradation. This degradation of the polymers can happen from moisture, ultra-violet (UV) gentle, chemical substances, and most notable for FFF printing, heating. Some degradation probably happens earlier than the person receives the filament as a result of potential use of recycled plastics, and heating of the polymer on the time of filament manufacturing. Additional degradation can happen on the person’s finish from improper filament storage, or overheating throughout extrusion. Consequently, the three gadgets recognized as necessary for materials properties are filament sort (materials, producer, and storage historical past), extruder-hotend-nozzle mixture, and slicer settings (hotend temperature and extrusion fee).

Inner residual stresses are brought on by the uneven cooling of a fabric. Injection molded elements sometimes cool faster on the skin surfaces as in comparison with the within. The polymer turns into extra inflexible and contracts because it cools; consequently, if the skin floor cools too quickly the inner materials could have no strategy to freely contract. Determine 2 reveals an instance of this phenomenon with a visual dip within the injection molded half floor. This ends in a non-zero state of stress within the half earlier than any exterior masses are utilized, and in the end will have an effect on the yield energy. FFF printed elements expertise an identical inconsistency in cooling, however it’s brought on by the delay between extrusion of the layers. New layers are extruded at the next temperature than the cooled earlier layer, and when the brand new layer cools it should trigger a contraction of each layers. Determine 3 demonstrates warping of printed elements that generally happens and not using a heated mattress or managed environmental circumstances. Printing on a heated mattress or controlling ambient temperatures permits every layer to chill to the next ambient temperature, and thus ends in a extra constant cooling of layers and diminished warping. The first gadgets recognized as necessary for inside residual stresses are filament sort (materials), printer ambient circumstances (heated mattress and heated chamber), and slicer settings (hotend temperature and extrusion velocity).

[2] Beer, Ferdinand P., et al., Mechanics of Supplies, McGraw-Hill Training (India) Personal Restricted, 2017.

1.2.2 Failure Resulting from Delamination within the Z-Route

Delamination of Z-layers, as seen in Determine 4, happens when there’s inadequate bonding between printed layers. This can be a results of incorrect extrusion temperature leading to a chilly joint, extreme contraction between layers, or from international contaminants stopping correct physiochemical adhesion. The recognized causes of delamination are primarily as a result of filament (materials, producer, and storage historical past), extruder-hotend-nozzle mixture, printer heating functionality (mattress and chamber), and slicer settings (hotend temperature).

1.2.3 Failure Resulting from Delamination within the X-Y Route

Geometric accuracy of injection molded elements is closely influenced by the standard of the mildew and the cooling of the elements after injection, however FFF print accuracy relies on the flexibility to exactly management the place and quantity of filament extruded. The correct quantity of the fabric should be extruded within the appropriate location for every layer. The fabric is extruded in traces that could be parallel or overlap different extruded traces. The standard of the line-to-line bond is necessary to stop extruded traces from separating below load. Slicing software program sometimes modifies the extruder path to create overlap between outlines and infill to advertise adhesion, but when the extrusion settings are incorrect there could also be inadequate materials extruded to permit correct bonding between the respective extruded traces. The recognized variables affecting delamination within the X-Y path are filament (materials, producer, and storage historical past), extruder-hotend-nozzle mixture, printer movement system accuracy/repeatability, and slicer settings (hotend temperature, define overlap, and extrusion multiplier).

1.3 Testing Parameters for Section One

Desk 1: Failure modes and recognized causes of failure.

Desk 1 reveals a abstract of the earlier part evaluation. The seemingly limitless mixture of the above components makes it impractical to check each attainable variable directly. The Valpo staff acknowledges that many shoppers are financially restricted on {hardware} modifications, and the buyer group will profit extra from a information on free software-based adjustments to their printing course of. The staff additionally recognized the significance of performing early assessments with generally utilized elements in order that outcomes usually tend to apply to a typical person’s setup.

1.4 Testing ‘Dumbbell’ Specimens

The primary specimen geometry examined is the ASTM D412-06a ‘dumbbell’, as seen in Determine 5. This testing customary evaluates tensile properties of each thermoplastic elastomers and vulcanized thermoset rubbers. This customary was initially chosen to permit testing of inflexible filaments like PLA, and versatile filaments like TPU/TPE.

Preliminary assessments with the ‘dumbbell’ specimen reveal that the geometry could also be efficient for testing polymer/elastomer sheets, however it’s not conducive for FFF printed half testing. The geometry’s faults are as follows:

1. The specimen should be clamped on each ends for tensile assessments, and this restricts the person to 100% infill of the ends to stop crushing.
2. Any misalignment of the specimen within the testing equipment ends in non-uniaxial forces that contribute to inconsistent peak specimen masses.
3. Printing the specimens in a vertical orientation ends in a comparatively tall and slender print that’s susceptible to geometric printing errors on the high.
4. The vertical association additionally ends in stacked potential failure factors, and the weakest layer bond controls the breaking energy.
5. The size of the specimen limits variation within the p.c infill, variety of outlines, and variety of high/backside layers.
6. The gap between the highest floor of the printed half and the printer mattress is a number of orders of magnitude completely different for vertical and horizontally printed specimens. The distinction partially heating can have an effect on the bond energy, and this is able to end in non-equivalent comparability of the 2 print orientations.
7. Few horizontally oriented specimens may be printed at one time so it reduces batch specimen print measurement.

These shortcomings display the necessity for a brand new specimen geometry to correctly characterize the FFF course of.

2. EXPERIMENTAL SETUP

2.1 Tensile Specimen Geometry

The inherent variability of FFF 3D printers made it difficult to pick the specimen geometry that ends in probably the most constant tensile testing. The aim is to search out probably the most acceptable specimen geometry the place the outcomes may be extrapolated to a number of hotend and printer combos. Desired properties of the brand new specimen are:

1. The power to print the specimen in numerous orientations with out widespread printer limitations affecting the specimen energy.
2. A geometry that permits for a mess of slicer settings to alter the ensuing printed specimen.
3. Comparatively low specimen quantity to attenuate print time and value.
4. Comparatively small footprint to allow giant batch sizes.
5. Ease of removing from printer mattress to attenuate the impact of specimen dealing with.
6. Potential to attenuate non-uniaxial forces produced from misalignment within the tensile testing equipment.

The brand new specimen design, as proven in Determine 6 and seven, overcomes the challenges found within the first set of assessments in a number of methods. First, the brand new specimen geometry self-aligns when performing tensile testing because of using loading pins as a substitute of clamps. This additionally eliminates the necessity for clamping onto strong sections of the specimen. The brand new loading course of introduces the next stage of repeatability and reduces the cycle time for assessments. The specimen form can be designed with slicer settings in thoughts; particularly, high/backside layers, variety of outlines, and p.c infill. The thicker specimen permits for a wider vary of those settings to be examined on the identical geometry. The print space decreases from 2500 mm2 to 1100 mm2, and the strong physique quantity stays comparatively low at 7000 mm3. Lastly, the form permits for the elements to be printed in numerous configurations with out requiring vital helps, or rising the size to thickness ratio excessively.

2.2 Printing {Hardware} and Filament

The Prusa i3 MK2 printer is used because the testing {hardware} as a result of sub $1000 price ticket, a direct-drive extruder, a heated mattress, real E3D-V6 hotend, and auto-leveling {hardware}. Additionally, there isn’t a enclosure to guard the specimen or printer from the house surroundings. This permits for extra generalization as most finances client printers should not have enclosures. Sooner or later, an enclosure shall be added so the advantages of environmental safety from disturbances, reminiscent of drafts from an AC vent, may be quantified. The printers had been assembled by one particular person on the staff. The one modification made to the printers is exchanging the brass nozzle for a hardened metal nozzle of the identical diameter when printing NylonX. That is completed to stop put on in order that the brass nozzles can be utilized for future specimens.

MatterHackers’ filament is used for the testing because of its widespread use, availability of filament varieties, and their filament particular recommendations for baseline slicer settings. Within the title of transparency it also needs to be famous that MatterHackers donated filament to help this analysis, however all outcomes are absolutely generated by the Valparaiso College staff with out modification.

2.3 Batch Printing Configuration

Ten specimens are printed in every batch to restrict print time whereas sustaining smaller printer compatibility. Further batches are printed after the ‘finest’ extrusion temperature is decided to scale back uncertainty. A complete of thirty specimens are produced for the ‘finest’, ‘finest’+5 ˚C, and ‘finest’-5 ˚C extrusion temperatures respectively. Format of the specimens, as seen in Determine 8, is dictated mechanically by Simplify3D. This eliminates the possibility of inconsistent spacing when creating new print information. Specimens and unused filament are saved inside a Ziploc WeatherShield 26.5 Quart Storage container with a 1.7 lbm silica gel desiccant bead canister till testing or printing. Tensile testing is usually accomplished inside 3 days of printing the specimens.

2.4 Slicer Software program

Simplify3D is used because the slicer software program because of its versatility with setting selections and its reputation amongst shoppers. All baseline parameters are pulled from the MatterHackers on-line information. If a spread is given then the imply worth is used. Testing focuses closely on figuring out the ‘finest’ hotend temperatures for every respective filament. That is outlined because the minimal temperature the place the tensile energy stays comparatively fixed no matter a rise within the extrusion temperature. The bottom worth is reported to attenuate oozing/zits widespread with increased extrusion temperatures. Probably the most acceptable hotend temperature is a hotly debated matter throughout the printing group; nonetheless, numerous variables can have an effect on the ‘finest’ temperature for every filament sort. The hotend temperature is the one parameter different within the first set of assessments. Further assessments are carried out after the ‘finest’ hotend temperature is decided. These assessments concurrently fluctuate completely different parameters to find out tensile energy sensitivity.

All of the prints are carried out utilizing an SD card for g-code switch. Inconsistent switch of the g-code to the printer from a pc can come up because of connection or software program points, and using a SD card eliminates that further variability.

3. TESTING METHODOLOGY

3.1 Verification of Equal Printer Assumption

Two Prusa i3 MK2s are used on this part to expedite testing. It’s essential to validate the null speculation that any distinction within the tensile energy between the 2 printers is as a result of inherent variability within the course of. These assessments used a single roll of black MH Construct Sequence PLA printed at 200 °C and 215 °C respectively. Outcomes for these take a look at are proven in Desk 2. A two-way evaluation of variance is performed on the tensile energy of the specimens after tensile testing. The impact of utilizing two separate printers isn’t statistically vital on the 0.05 significance stage (F ratio = 0.024, p>0.05). The statistically insignificant distinction justifies the transfer to deal with variability launched by the 2 printers as negligible

Desk 2: Tensile take a look at outcomes to find out whether it is acceptable to contemplate the printers as equal.

A collection of the baseline slicer settings for the printed specimens are listed in Desk 3, and detailed screenshots of settings are offered within the appendix. Non-filament particular settings, reminiscent of print velocity, are generated from the Prusa i3 MK2 profile on Prusa’s official web site. Any remaining settings are chosen from previous expertise and data from the Valpo staff.

Desk 3: A collection of the slicer baseline slicer settings used within the first set of assessments.

3.3 Dedication of Minimal Hotend Temperature

Minimal hotend temperature for every sort of filament is decided from evaluation of each the height load and energy to weight ratios. Most temperature assessments begin at 15 °C under the MatterHackers common really helpful hotend temperature; nonetheless, in some circumstances after knowledge is reviewed, it might be decided that the minimal hotend temperature isn’t reached. In these circumstances, hotend temperature is dropped by 5 °C for each batch till both the minimal temperature is discovered, or print failure happens (e.g. delamination within the z-direction throughout printing).

3.4 Tensile Testing Process

After a batch of specimens finishes printing, it’s positioned in a Ziploc WeatherShield 26.5 Quart Storage container with a 1.7 lbm silica gel desiccant bead canister inside for no less than 8 hours. Specimens are examined at room temperature, 70 ± 5 °F. When sufficient specimens are printed, every batch is then weighed with an AWS-100 scale, and the typical recorded. Specimens are loaded right into a MTS QTest 150 tensile machine through the loading pins which begin with a center-to-center distance of roughly 19 mm. A continuing elongation fee of 5 mm/min is utilized when testing begins. This testing velocity relies off the ASTM customary mentioned beforehand. A 33700 lbf (150 kN) MTS load cell is used to measure the utilized load, the displacement relies on the body readings, and the info is collected by a Dell Optiplex 990 PC at 60 Hz.

4. RESULTS

4.1 Hotend Tensile Outcomes

Desk 4: Tensile take a look at outcomes for MatterHackers filament. Values symbolize the typical for specimens printed at or above the minimal really helpful hotend temperature.

A comparability of the experimentally decided tensile properties for every respective filament sort is offered in Desk 4. The desk compares prints of MatterHackers MH Construct PLA, PRO Sequence PLA, PRO Sequence PETG, PRO Sequence ABS, PRO Sequence Nylon, and NylonX. The height load, energy to weight ratio, and pressure at failure are all averages of specimens that meet or exceed the minimal prompt hotend temperature. The models of lbf/g are chosen for the energy to weight ratio because of customers’ familiarity with lbf and the widespread observe of measuring filament/prints in grams.

These numbers should not meant to foretell the energy of a person’s particular printed half. The outcomes are merely used to find out the relative energy of 1 filament to a different. This permits a wider viewers to use the teachings discovered in the direction of their very own prints. The advanced nature of FFF printed elements requires a extra advanced evaluation of stress concentrators, loading path/sort/fee, and the consequences of working temperature/humidity/age/and so on… to find out the mechanical properties of a particular half.

4.1.1 Black MH Construct PLA

MatterHackers Black MH Construct PLA is the primary filament examined. Determine 9 reveals the hotend-temperature energy to weight ratio (S-W) curve for Black MH Construct PLA. The plot reveals that a rise from 185 °C to 200 °C yields a 43% improve within the energy to weight ratio. The graph reveals that after 200 °C the height load stays comparatively fixed; consequently, the really helpful minimal hotend temperature for Black MH Construct PLA is 200 °C.

4.1.2 Black PRO Sequence PLA

Determine 10 reveals the outcomes for MatterHackers Black PRO Sequence PLA. It’s anticipated that PRO Sequence PLA will carry out much like the MH Construct PLA, and above the 200 °C mark the 2 supplies produce comparable outcomes; nonetheless, PRO Sequence PLA didn’t expertise the drop off in energy under 200 °C. The authors advocate printing with no less than 200 °C for this specific printer setup as a result of slight improve within the S-W ratio; nonetheless, it doesn’t seem that there shall be a major discount within the half energy for this testing orientation under 200 °C.

4.1.3 Black PRO Sequence ABS

Black PRO Sequence ABS filament produced the weakest prints with most failing under 400 lbf. Determine 11 reveals the inconsistent S-W ratio pattern for the examined hotend temperatures. One subject with printing the ABS specimens is that warping of the specimens happens for many batches. It’s attainable that the specimens carry out poorly throughout tensile testing because of residual stresses induced by the uneven cooling, and a rise within the ambient temperature would possibly scale back this impact. Further assessments past the preliminary ten specimens should not carried out as a result of challenges in printing ABS with the present setup. The Valpo staff is hesitant to make a suggestion with out further assessments in an elevated temperature printing surroundings, however the specimens printed at 220 °C demonstrated the best peak load and biggest ductility; subsequently, that’s the present prompt minimal hotend temperature.

Future assessments on all filament varieties will reveal what enhancements within the tensile energy are available with an elevated ambient temperature.

4.1.4 Pink PRO Sequence PETG

Pink PRO Sequence PETG outcomes, as proven in Determine 12, reveal a rise within the S-W ratio from 235 °C to 240 °C, after which a comparatively fixed S-W ratio above 240 °C. This leads the Valpo staff to recommend a minimal hotend temperature of 240 °C. It is very important observe that though PRO Sequence PETG has a decrease S-W ratio as in comparison with PLA, it didn’t fail in a brittle method. PRO Sequence PETG specimens sometimes stayed intact, and had roughly double the elongation earlier than failure as in comparison with PLA. This improve within the elongation result in an roughly threefold improve within the toughness as a result of form of the stress-strain curve. The upper extrusion temperature and slight variability of samples leads the Valpo staff to hypothesize that further positive factors in energy could also be discovered with a rise within the ambient print temperature.

4.1.5 Blue PRO Sequence Nylon

Nylon is broadly thought of as a comparatively ductile polymer. MatterHackers Blue PRO Sequence Nylon carried out as anticipated with the best ductility score of all filaments by greater than 100%. PRO Sequence Nylon’s most attention-grabbing attribute is its failure modes. At decrease hotend temperatures PRO Sequence Nylon’s layers delaminate inflicting peak load functionality to drop. The delamination impact disappears after a hotend temperature threshold of 245 °C is obtained, and the failure mode transitions right into a extra anticipated yielding failure. Each PRO Sequence PETG and NylonX expertise the delamination failure, however the Nylon filament requires the next hotend temperature earlier than the failure mode dies out. Determine 13 reveals that the S-W ratio dips at 250 °C and the Valpo staff believes this is because of a single 10 specimen batch that exhibited decrease S-W ratios as in comparison with the opposite batches at 250 °C. The prompt minimal hotend temperature for PRO Sequence Nylon on this specific setup is 245 °C.

4.1.6 NylonX

Maybe probably the most attention-grabbing filament take a look at outcomes are MatterHackers’ NylonX. There may be vital problem bonding the z-layers of NylonX at low hotend temperatures. The staff attributes this to an open print mattress surroundings slightly than an enclosed chamber. The S-W ratio of NylonX is the bottom of all filaments examined on the low temperature finish, nevertheless it achieves the best score after the 260 °C mark. Using a hardened metal nozzle of 0.4 mm allowed the staff to protect the brass nozzles for testing continuity, however the decrease thermal conductivity of the metal limits warmth switch to the filament. To rectify this, the staff printed at increased hotend temperatures than different filaments. Determine 14 reveals that rising the hotend temperature from 255 °C to 260 °C ends in a 55% improve within the S-W ratio. The prompt hotend temperature for NylonX with a hardened metal nozzle is no less than 260 °C.

4.2 Further Assessments

Figuring out minimal hotend temperatures is a crucial side of FFF printing, nevertheless it doesn’t embody the entire components that have an effect on print energy. The Valparaiso College staff realizes that the tensile energy of elements printed within the earlier part are depending on further components reminiscent of half fan cooling, z-layer top, variety of outlines, variety of high/backside layers, infill share, and print velocity. An in-depth evaluation of all these components would require a paper of its personal, however these preliminary outcomes ought to help customers in making extra knowledgeable selections about their slicer settings.

4.2.1 Half Fan Cooling

Desk 5: Tensile outcomes for half fan assessments with Black MH Construct PLA.

The usage of an element fan can improve the capabilities of a printer throughout bridging operations or for areas with steep angles, nevertheless it additionally might have an effect on the flexibility for layers to bond. Testing this impact on the tensile energy first requires figuring out the minimal hotend temperature, after which printing a batch of thirty specimens in Black MH Construct PLA with the half fan off. Desk 5 reveals that printing with the half fan off produces a statistically vital impact on the height load; nonetheless, the rise in energy is just 5%. The fan’s low affect on half energy signifies that the fan can be utilized with a statistically vital, however minimal impact on the energy of PLA elements.

4.2.2 Layer Peak

Decreasing the layer thickness can have a constructive impact on the beauty look of a printed half, however it may possibly additionally improve the general print time. These are comparatively simple outcomes to foretell with trendy slicer outputs, however the impact on mechanical energy with completely different layer thicknesses is unknown.

Specimens from part 4 are printed with 0.3 mm layer heights to lower the general print time. Further assessments are run with 0.1 mm layers to find out if the thinner layers have a statistically vital impact on the tensile energy. One further modification to the baseline g-code is to regulate the variety of high and backside strong layers. That is an try to keep up the general thickness of the strong layers on the highest and backside of every tensile specimen.

Desk 6 reveals the outcomes of the layer top take a look at, and the 0.3 mm and 0.1 mm tensile outcomes are statistically comparable. Further assessments are essential to enhance the statistical certainty that layer top doesn’t have an effect on the tensile energy of specimens, however these preliminary assessments recommend that it doesn’t play a major function.

Desk 6: Tensile outcomes for layer top assessments with Black MH Construct PLA.

4.2.3 Outlines or Prime/Backside Layers

Including materials to printed elements can improve the general energy. The person can add outlines, high/backside strong layers, or improve infill share, however which technique of addition is only in rising energy? The Valpo staff printed specimens with double the variety of outlines, double the strong layers on the highest/backside, and a rise to 70% infill. The worth of 70% infill is chosen as a result of comparable specimen weight in comparison with the opposite two modified specimens.

Evaluation of the ends in Desk 7 demonstrates that a rise within the energy to weight ratio is feasible with outlines and strong layers, however that rising the infill share didn’t have a statistically vital impact. It is very important observe that the kind of loading and print geometry is important to the place materials needs to be added. Compressive masses or advanced geometry might shift the necessary areas. Future assessments with completely different loading configurations might shine gentle on these results.

Desk 7: Tensile energy of specimens with added materials in numerous areas.

4.2.4 Infill

The earlier part evaluations the impact of a rise from 50% infill to 70% infill. Further infill percentages have to be investigated to find out if the rise in energy follows a pattern.

Determine 15 shows p.c infill versus peak load for specimens present process tensile loading. This graph reveals that from 50% to 80% infill the slope for rising energy is comparatively shallow; nonetheless, the slope is roughly 4 occasions higher above 80% infill. That is probably because of elevated bonding between infill traces. These outcomes will have to be repeated for different geometries and masses, reminiscent of pure compression, to definitively state a higher improve within the peak load is noticed for the 80-100% infill vary.

4.2.5 Print Pace

Print velocity is one other issue that sometimes has an impact on the person expertise. The power to print ever quicker is a requirement on the FFF trade, however the impact of this improve in print velocity on half energy is typically neglected.

The Prusa i3 MK2 baseline specimens are all printed at 1800 mm/min with the intent of minimizing geometric errors. The printer is, nonetheless, able to printing quicker. Further velocity take a look at outcomes are proven in Determine 16. Black MH Construct PLA reveals no statistically vital lower in energy when rising the velocity from 1800 to 3600 mm/min, however at 4800 mm/min the S-W ratio decreases by 8%. Black PRO Sequence PLA S-W ratio barely will increase at 3600 mm/min, however much like MH Construct PLA it decreases at 4800 mm/min. Solely the top person can decide if this lower in energy is appropriate, and if there are further beauty results from printing at these increased speeds. The impact of accelerating print velocity will probably change primarily based on the geometric accuracy of printers at increased speeds, and on the flexibility of the hotend-nozzle mixture to switch ample power into the extruded filament.

4.3 Abstract of Check Outcomes

Desk 8: Comparability of MatterHackers filaments.

Desk 8 reveals the relative rankings of peak load, energy to weight ratio, ductility, and isotropic (non-directionality of energy). Analyzing the desk reveals that MH Construct PLA and PRO Sequence PLA are wonderful normal use filaments for the typical person. They’ve excessive peak masses, and exhibit the most effective isotropic score. The principle downside is the comparatively brittle failure as in comparison with PRO Sequence PETG and PRO Sequence Nylon.

PRO Sequence ABS carried out poorly within the tensile assessments with the bottom peak load, S-W ratio, and comparatively low ductility. These outcomes, coupled with the problem of warping specimens, make it exhausting to advocate ABS for this printer setup. The emission of styrene whereas printing ABS additional reduces the attractiveness of this filament sort [3]. The Valpo staff believes that the appearance of newer filament varieties eliminates the necessity for ABS within the client printing market.

PRO Sequence PETG outcomes characterize the fabric as a well-rounded filament. The filament is barely weaker than PLA, however with a ~100% improve within the pressure at failure. It has the second highest ductility score and the second highest isotropic score. There are nonetheless challenges related to printing in PETG, reminiscent of the upper extrusion temperature, however general PETG has the potential to problem PLA as the first filament sort.

PRO Sequence Nylon and NylonX are difficult filaments to print; nonetheless, additionally they include some distinctive advantages. If there’s a want for prints to exhibit excessive deformation with out failure, Nylon is the prompt filament. NylonX however is extra appropriate for weight-dependent functions, like customized drone elements.

[3] P. Azimi, D. Zhao, C. Pouzet, et al., “Emissions of Ultrafine Particles and Risky Natural Compounds from Commercially Accessible Desktop Three-Dimensional Printers with A number of Filaments,” Environmental Science and Know-how, Vol. 50, pp 1260-1268, Jan. 2016.

5. CONCLUSION

The analysis staff at Valparaiso College is working to tell the buyer FFF group on how slicer settings, notably hotend temperature, have an effect on tensile properties of various filament supplies. The outcomes can dispel many conventional myths concerning client FFF printing, and they’ll hopefully help each skilled and novice 3D printer customers in figuring out probably the most relevant filament for his or her mission. FFF printers have many variables that have an effect on half energy exterior of simply the slicer settings; subsequently, it’s not really helpful to make use of this knowledge to estimate the energy of printed elements. As a substitute, the analysis staff suggests you have a look at the relative values to find out how completely different filament varieties will probably carry out by yourself printer. Probably the most acceptable slicer settings for different hotend fashions, filament diameters, nozzle diameters, and so on.… might fluctuate broadly. The Valpo staff hopes the outcomes offered on this report encourage customers to contemplate how all these variables would possibly have an effect on printed elements, and the staff hopes future experiments will solely improve parameter consciousness.

The Valpo staff is at all times in search of methods to help the buyer FFF group. You’ll be able to vote on the following space of analysis by visiting our social media accounts on the following web page!

ABOUT THE ACCELERATED 3D PRINTING LAB AND VALPARAISO UNIVERSITY

The Accelerated 3D Printing Lab is situated within the Faculty of Engineering at Valparaiso College. Engineering at Valpo is an undergraduate solely program that’s persistently ranked within the high 20 undergraduate engineering applications within the nation by U.S. Information & World Report. The Accelerated 3D Printing Lab was established within the Summer season of 2018 to help Valpo’s additive manufacturing analysis. College students examine a wide range of conventional and novel additive manufacturing strategies with the intent of open entry to the analysis.

ABOUT THE AUTHORS

Samuel Hart ’17 and Trevor Grey ’20 examined over 2000 specimens to find how slicer settings have an effect on the tensile energy of elements. The outcomes on this paper wouldn’t be attainable with out their exhausting work and dedication. Dr. Daniel Blood, Assistant Professor of Mechanical Engineering and Bioengineering at Valpo, oversaw the work carried out by Sam and Trevor.

Further because of Kelsey Unser, Rima Miller, Tyler Smar, and William Foy for his or her assist in organising the analysis.

Valparaiso College Faculty of Engineering Web site

Accelerated 3D Printing Lab Fb: @Accelerated3DPrintingLab

Twitter: @printing_lab

SPECIAL THANKS TO DAVE GAYLORD AT MATTERHACKERS

The Valpo staff appreciates MatterHackers’ donation of filament for these assessments, and likewise for Dave’s invaluable enter on testing. All filaments examined on this report can be found at their on-line retailer.

Store 3D Printing:

www.matterhackers.com

MatterHackers Fb:

@MatterHackers

Twitter:

@MatterHackers

APPENDIX – SIMPLIFY3D SETTINGS