Degree Thesis
HALMSTAD
UNIVERSITY
Bachelor's Programme in Mechanical Engineering, 180 credits
Optimization of Granulate 3D Printer
Focus on cooling
Mechanical Engineering, 15 credits
Oskar Geraldsson, Kristoffer Ylander Mikkelsen
Foreword
We would like to thank our supervisors Johan Wretborn and Håkan Pettersson for
the instructions as well as the rich and fresh ideas that have helped us come to the
conclusions of the thesis work. We would also like to thank Fredric Ottermo for the
help with thermal and fluid mechanics calculations.
Abstract
The authors, Oskar Geraldsson and Kristoffer Ylander Mikkelsen, together with AB Svenska Konstruktörsbyrån, have customized and optimized a granulate 3D printer.
The main goal for the authors is to improve the cooling of the liquid ABS plas- tic leaving the nozzle to prevent displacement and dislocation during the printing process. Furthermore the printers current state is poor resulting in further work regarding the overall mechanics of the printer such as the power supply, electrical motors and linear guides.
The authors have studied existing 3D printers and searched through scientific ar-
ticles to get inspiration and knowledge of the mechanical process of the printers as
well as the materials.
Contents
1 Introduction 1
1.1 Scope . . . . 1
1.2 Problems Ranked from Most to Least Important . . . . 1
1.3 Demarcation . . . . 1
2 Background 2 2.1 Environment . . . . 2
2.1.1 ABS vs. PLA . . . . 3
2.2 Previous Thesis Work . . . . 3
3 Theoretical Framework 4 3.1 Fused Deposition Modeling . . . . 4
3.2 Scientific Method . . . . 4
3.2.1 Natural Convection . . . . 4
3.2.2 Fluid Mechanics . . . . 5
3.3 Extrusion with Screw . . . . 5
3.4 Printing with Plastic Granulate . . . . 5
3.4.1 Dampness of Material . . . . 6
3.4.2 Temperature and Cooling . . . . 6
3.5 Software . . . . 7
3.6 Brainstorming . . . . 8
3.7 Prototyping . . . . 8
4 Method 9 4.1 Pre-Study . . . . 9
4.2 Timeline . . . . 9
4.3 Analysis . . . . 9
4.3.1 Cooling System . . . . 9
4.3.2 Heatbed . . . . 10
4.3.3 Z-Axis . . . . 10
4.3.4 Wiring . . . . 10
4.3.5 Software . . . . 10
4.4 Brainstorming . . . . 11
5 Results 12 5.1 Cost Analysis . . . . 12
5.2 Heatbed . . . . 12
5.2.1 Leveling . . . . 12
5.2.2 Heating . . . . 13
5.3 Wiring . . . . 13
5.4 Extrusion . . . . 14
5.5 Cooling . . . . 14
5.5.1 Calculations . . . . 15
5.6 Software . . . . 16
6 Discussion 17 6.1 Critical Analysis . . . . 18
6.1.1 Social Aspects . . . . 18
6.1.2 Economical Aspects . . . . 18
6.1.3 Environmental Aspects . . . . 18
7 Conclusion 19 7.1 Division of Labor . . . . 19
8 References 20 9 Appendix 22 9.1 Level Heatbed (Previous) . . . . 22
9.2 Level Heatbed (Wheel Removed) . . . . 23
9.3 Level Heatbed (Improved) . . . . 24
9.4 Timetable . . . . 25
9.5 Natural Convection Calculations . . . . 26
9.6 Fluid Mechanics Calculation . . . . 27
1 Introduction
1.1 Scope
The purpose of this thesis work is to finalize the 3D printer and make sure that the prints have high repeatability every print while the machine remains fully enclosed and aesthetically pleasing. The goal is to publish the machine and compete with other printers in the same category.
The main objective is to refine the cooling of the melted plastic (ABS in partic- ular) to prevent dislocation while printing without supports.
1.2 Problems Ranked from Most to Least Important
1. Cooling of the liquid ABS plastic leaving the nozzle 2. Add three phase power
3. Make the printer more reliable
4. Make the printer more aesthetically pleasing
1.3 Demarcation
The main focus of this project is to improve the cooling of the ABS plastic in gran- ulate form. Due to several complications regarding the wiring, the heated bed, motors, linear guides as well as software these will also be included in the report.
The conversion from single phase connection to three phase power was not done by
the authors due to disqualifications however is still stated in the report.
2 Background
AB Svenska Konstruktörsbyrån is a Swedish consultant company located in Halm- stad. For several years they have had students from University of Halmstad develop their 3D-printer. On January 2017 two mechatronical engineer students replaced and updated the electronics of the machine to increase the reliability.
This year (2019) they searched for student that could finish the project, with the goal to launch the 3D-printer as a cheaper alternative on the market. The main as- pect that lowers the price is the use of plastic in a form of pellets, granulate, rather than wire. The available machines in this scale costs about 5 million SEK [15] as of writing of this rapport.
ABS plastic is not as commonly used in 3D-printing as PLA plastic, the main reason for this is the requirement of a heatbed for the ABS plastic to not dislocate, shrink or warp. However, ABS has better thermal and mechanical properties and creates a sturdier final product as well as being a lot cheaper than PLA. This is because the injection-molding business uses ABS granulate [8] and because plastic in pellets form is a lot cheaper to make than wire form.
The 3D-printer project is divided into two groups, one group focus on the cool- ing while the other focus on the humidity of the ABS plastic. This report contains the cooling but both groups are responsible for the outcome.
2.1 Environment
3D-printing is a relative new process that enables a person or company to make prototypes much faster and cheaper than conventional methods such as injection- molding. This also makes 3D printing less harmful for the environment since there is no need to make expensive tools. In Sweden the recycling of plastic packaging is common and in 2017, 44% of all plastic packaging was recycled (not including PET-bottles) [10]. This might seems like a lot, but compared to the global plastic waste recycled 2015, 19.5%, its more than double [11].
Plastic isn’t known for being good for the environment considering the energy re-
quired to get rid of it. But on the other hand, using plastic in a 3D printer is quite
effective considering old plastic can be reused and recycled. Another factor that
could play in on the environment is the energy consumption required to heat the
extruder as well as the heatbed. More specifically when heating a large 3D printing
as shown in this thesis work, it required a great amount of energy however if the
availability to harvest electricity from a more natural source was available it would
not be as big of an impact.
2.1.1 ABS vs. PLA
There are pros and cons for using both ABS and PLA. Companies that print out mechanical parts tend to use ABS for its sturdiness and higher melting point while PLA is an easier material to print with and use. PLA is mostly used by smaller machines, it don’t require a heatbed and want a more elegant print with smoother surfaces, also it is biodegradable. ABS is much broader and available in granulate form and that is why ABS was chosen.
2.2 Previous Thesis Work
The printer has been an ongoing project for over four years, and this thesis is based on the fourth group working on it. The 3D-printer has gone through different stages, from building the frame to installing motors and making the machine capable of its purpose. This year there are two groups working simultaneously on the machine however on different specific areas. This requires a form of correlation and good communication for the result to be optimal.
A lot of small problems have been fixed to make the machine operational, this meant
a much broader involvement making the authors work outside of their comfort zone.
3 Theoretical Framework
3.1 Fused Deposition Modeling
Fused Deposition Modeling is a popular manufacturing method for prototypes and is the theory that 3D printing is based on. This method builds on the idea of plas- tic being extruded through a heated nozzle and then in turn is built layer by layer.
Stratasys owned the rights to this method making it known as Fused Filament Fab- rication. [14]
3.2 Scientific Method
Calculating the cooling of the plastic is done with natural convection and fluid me- chanics. Every formula is from the book "Fundamentals of Thermal-Fluid Sci- ences" [3].
3.2.1 Natural Convection
The first formula is for heat dissipation; ˙ Q is the dissipated heat, h is a constant which depends on e.g heat, flow speed, turbulent or laminar flow etc. A is the area and ∆T is the change in temperature.
Q ˙ = hA(T s − T ∞ ) or ˙ Q = hA∆T (1)
This is the formula for the Nusselt number (Nu), which is a ratio of convective to conductive heat transfer.
Nu = hL
k (2)
Rayleigh number (R aL ), is a product of Grashof number and Prandtl number. It describes the relationship between; buoyancy, viscosity, momentum diffusivity and thermal diffusivity within a fluid.
R aL = gβ (T s − T ∞ )L 3
v 2 Pr (3)
β can be re-written as seen below.
β = 1
T avg (4)
The average temperature is self-explanatory.
T avg = T s + T ∞
2 (5)
Differential equation for solving how much time it takes for the melted liquid to reach the point where it hardens.
Q ˙ = -mc ˙ T s = hA(T s - T ∞ ) =>
T ˙ s + mc hA T s = hAT mc ∞ =>
T ˙ s (t) + mc hA T s (t) = mc hA T ∞ =>
T s (t) = (T s,0 − T ∞ )e mc hA + T ∞ (6)
T s,0 is the temperature of the plastic when it leaves the nozzle, T ∞ is the surrounding temperature and
T s (t) is the time, in seconds, it takes from T 2,0 to T ∞ . 3.2.2 Fluid Mechanics
Isotropic process as well the first law of fluid mechanics.
v = r 2k
k − 1 RT 1 (1 − P 2
P 1 ) k−1 k (7)
This will be used to calculate the velocity of the air pressure pushed through a nozzle with 3mm in diameter. This is mainly to get an idea of how much pressure is being forced onto the ABS plastic to cool it.
3.3 Extrusion with Screw
Extruding plastic through a screw is commonly used in the injection-molding busi- ness as briefly stated in [2.1], basically plastic granulate is dropped in a screw which feeds is through heating elements. The heat makes the plastic change from solid pel- lets to liquid form, the further the plastic travels the higher the pressure is due to how the screw is shaped, see figure 1. The hot pressurized liquid can then be pushed into molds, this process is common due to its high repeatability and low scrap rates.
The downsides are expensive tooling costs and the great lead times when changing products, this method was implemented in the 3D-printer [5].
3.4 Printing with Plastic Granulate
Most 3D printers use plastic in wire form that is rolled around a quill, it’s created
by carefully and precisely melting plastic in to a fine wire. This type is great for
delivering precision into the print. Granulate form is made in a similar fashion
except the wire is cut into small flakes. This granulate form does not deliver a fine
quality however it’s a lot cheaper [1]. The main reason for this is that the wiring
method requires a quill that’s quite expensive to manufacture.
Figure 1: Common Extruder [12]
3.4.1 Dampness of Material
The dampness of the material can be a crucial problem in 3D printing, if the material contains a lot of water it requires more energy in order for it to melt. Moist plastic can be noticed by the crackling noise and this causes vaporization to build up in the extruder causing a lot of pressure. Then pressure then causes the print quality to be lowered below the acceptable standard.
3.4.2 Temperature and Cooling
3D printing requires great temperature regulation to easily change the physical state from solid to liquid form. The plastic changes states in the hotend (therefore the name) and when it leaves the nozzle it begins to cool until it hits the heatbed. Fur- thermore it needs to be cooled correctly in order for the plastic to fuse together with the previous layers in order for the build to be smooth and even.
Heatbed Not every material that is available for 3D printing requires a heated bed, but often a heated bed gives the material better adhesion. Temperatures between 45 - 115°C [4],cover almost every 3D-printable material, for ABS the ideal temperature is 85°C for maximal adhesion. The heating elements are silicone heaters which essentially is a wire-loop encased in silicon [9]. When current is pushed through the loop the wires heat up, this is a simple heater and with an added temperature- sensor the heater can be controlled precisely.
Hotend As stated in [3.4.2] the hotend is the part of the machine that changes the
plastics physical state from solid to liquid. With the help from heating strips the
nozzles reaches the target temperature for the specific plastic used however if the
plastic rises it can clog the screw. Generally, a fan is attached to prevent this form
taking place, as seen in figure 2.
Figure 2: Extruder Fan
3.5 Software
The 3D printing software turned out the be a challenge. Several modifications were made to make the software compatible with the motors. This process starts with the settings and geometry that are controlled through a 3D slicing software called Simplify3D. These commands are then uploaded on the Octoprint printing server installed on a Linux platform which then sends commands to the control board which works as the brain of the printer.
G-code is the universal language for 3D printing and the mechanical properties are based on the G-code typed in the terminal of Octoprint. G-code is mainly used in computer-aided manufacturing to control automated machines, like CNC machines or 3d printers.
Simplify3D is a 3D slicing software where STL files are uploaded and the gen- eral tuning settings for the print quality, primary layer heights and G-code scripts can be applied. The software also gives the user a general idea of how each layer will be built as well as the positioning and scale in the Cartesian coordinate system.
Octoprint is an open source 3D print controller application. Octoprint provides
a web interface for controlling the 3D printer through G-code sent to the control
board. Through Octoprint the user can monitor the print job as well as the printer
itself primarily the temperature of the hotend (nozzle) and the heatbed (printing
surface). Octoprint uses a plugin system and these plugins can be installed from
Github and allows various visualization assistants.
3.6 Brainstorming
Brainstorming is a problem solving technique where the members of the group writes down their ideas on pieces of paper and continues until they have no new ideas. It is important that during the brainstorming process no ideas are seen as bad, the goal is to have as many different solutions as possible. Afterwards the ideas are evaluated and the best ideas are further developed.
3.7 Prototyping
The prototyping process is to materialize the solutions and try it out, when dealing with a physical prototype problems that was overlooked at the idea-stage is discov- ered and can be fixed. When prototyping functions is valued more than appearance.
The university’s metal workshop was at the authors disposal and they received help
from Håkan Pettersson, the man responsible for the workshop.
4 Method
The initial objective was to improve the cooling of the ABS plastic during the print.
Primarily the authors did a pre-study to determine the accomplishments of the ear- lier thesis works. This information was studied through the thesis reports that were written about this specific 3D printer.
4.1 Pre-Study
During the pre-study the authors familiarized themselves with the previous thesis, general mechanical functions, thermodynamics, as well as a study of materials.
From this the authors were able the take decisions regarding the improvement of the printer.
4.2 Timeline
A timeline was made to keep the authors on track throughout the project, milestones were placed to keep track of the important stages, see appendix 11.4.
4.3 Analysis
The consistency of the prints was not satisfactory, to determine what the problems were an analysis was conducted covering all areas of the printer.
4.3.1 Cooling System
The existing cooling system was just for visual representation since it did not work, the two centrifugal fans did not cool the melted plastic. During tests there was no visible difference with the fans on or off.
A new air cooling system had to be made, air pressure was an alternative since there was an air compressor in the workshop as well as pneumatic tubes and valves.
The ability to use pressurized air with a custom nozzle and easily regulate the pres- sure will come in handy to find out the optimal pressure required to get a smooth print with good contours.
To get the volume per minute of air released from the nozzle a calculation was
made. This calculation is important to find the optimal air pressure estimated to be
between 1 and 2 bars (+1 bar from atmospheric pressure). To cool air over a larger
surface area with regulated compressed air is the optimal solution.
4.3.2 Heatbed
Heating Due to the lack of power required to heat the bed rapidly a three phase connection was added to replaced the previous single phase connection. This would make the work more effective and not waste too much time heating up the heatbed rather than printing.
Leveling The z-axis probe attached to the motor was also used to gather data in order to level the bed. Being supported on rails attached to the general structure.
4.3.3 Z-Axis
The z-axis carrying the extruder is not in equilibrium, the side with the motor is heavier than the other which causes the z-axis to tilt. This has not been permanently corrected, before each print the z-axis is manually leveled. Shown in the the figure below, a spirit level is placed on the z-axis to represent the change in horizontal height.
Figure 3: Crooked z-axis
4.3.4 Wiring
The power going in to the machine consisted of one 230V 16A line and one 230V 10A line, it was upgraded by an outside contractor to three phase power (three lines with 230V 16A). This will be tested by recording the increase in temperature of the heatbed every 5 minutes.
4.3.5 Software
The software was outdated and not functioning correctly so an update was required,
mainly due to the lack of plugins for the older Octoprint version. These plugins
serve to ease the visualization aid and general ease of use. This is done by research- ing on forums and guides due to lack of knowledge.
4.4 Brainstorming
The authors brainstormed together and came up with many different ideas and and
solutions for their problems. The best ideas were further developed and discussed
with SVKB for approval. After approval the idea was written down, optimized and
tested.
5 Results
5.1 Cost Analysis
The budget had no limit, the authors just had to confirm the orders with SVKB, almost every item was a consumable.
Name Quantity (pc) Price (SEK)
Wire 1 17.9
Vinyl hose 10m x 9mm 1 54.9
Marking labels 1 32.9
Hose clamp 11 - 13mm 4 22.9
Braided cable sock 12mm 1 74.9
Cable ties 1 54.9
Storage box 2 159.8
Storage box lid 2 59.8
Hose clamp 50 - 70mm 2 22.9
PVC pipe 30° 50mm 1 19.9
PVC pipe 45° 32mm 1 54.9
Totalt 575.7
Figure 4: Cost Analysis
5.2 Heatbed
5.2.1 Leveling
With the ABL-script (Automatic Bed Leveling-script) the authors received infor- mation of how even or uneven the bed is. As you can see the heatbed is much more even now than it was in the beginning. Related pictures of data and height maps can be found in the appendix section; Previous[9.1], Wheel Removed[9.2] and Im- proved[9.3].
State Min Max Deviation
Previous -0.6 6.5 7.1
Wheel Removed -0.8 2.6 3.4
Improved -2.9 0.2 3.1
Figure 5: Heatbed Deviation
The deviations is less than half now and as seen in the pictures the high- and low- points are in the same locations almost every time. With even more tinkering the authors are confident that the deviation can be brought down to less than 1.5 - 2mm.
5.2.2 Heating
With the change from single phase to three phase the siliconheaters are warming up much faster. The results are displayed below in figure 5.
Figure 6: Temperature over Time
The optimal temperature is 85°C according to our testing and as you can see it only takes 30 min now instead of never even reaching that temperature before. The heating elements are limited to 9amps each now instead of 3.25amps.
5.3 Wiring
The wiring was done by an external contractor and the results was amazing, from single phase to three phase which meant that the heatbeds could heat up the surface much faster. This also meant that there is only one three phase contact needed in- stead of two single phase contact.
Before:
230V * 16A = 3680W
230V * 10A = 2300W
Total 5980W = 5.98kW
Now:
3 * 230V * 16A = 11040W = 11.04kW.
11.04 / 5.98 = 1.846153846 = 1.846 = 84.6% increase.
5.4 Extrusion
Due to the lack of time and miss communication between the two groups, dry gran- ulate have not yet been tested properly leaving no results regards to the extrusion.
A test to dry the granulate in a standard kitchen oven was done and the results are shown in the figure 7 below, humid material on the left and dry material on the right.
Figure 7: The difference in dry granulate and moist.
5.5 Cooling
The cooling design improves the print quality as seen in Figure 8. Air pressure of
2 Bar was the sweet-spot according to all of the tests. The new cooling system is
shown in Figure 9 below.
Figure 8: Image of the new cooling system from below.
Figure 9: Cooling with Different Pressures.
5.5.1 Calculations
With formula (6) it takes 15 minutes and 23.5 seconds for 31.5 grams of ABS to cool down from 230°C to 110°C, that is roughly two layers of ABS with the dimen- sions 100 x 100 x 3 mm.
Using formula (7) we were able to get the speed to 198.402 m/s. This however
was without taking some external factors into consideration such as the distance to
the compressor. However, with this result we can get an understanding of how much
force is being pressurized on the plastic as we print.
Calculation files can be found in appendix 9.5 and 9.6, calculations was done in Mathematica 12.0.
5.6 Software
The 3D-printer is working better and faster now after updating the software and easier to use since there has been added functions and button so the end-user doesn’t need to write gcode. Rather than the 3D printer measures 9 points with the z probe to bed level before every print, a test file was written to specifically measure the bed leveling. This gave an easier and quicker way to start a new print.
Figure 10: Gcode Script
6 Discussion
At the start of the project we quickly realized that this project would turn out to be a lot more complex than initially planned. Due to this our timetable wasn’t accurate and a lot of other areas turned out to be set backs. Even though other areas were setbacks we decided that this was a crucial part of the 3D printer and required a lot of time and effort in order to work properly. A prime example of this was the amount of time and effort we put into learning and using the software as well as the heatbed leveling.
As mentioned earlier in the report the software was crucial for us to understand in order to command the printer and understand how each setting can effect the print. A further improvement regarding the software would be if we understood and researched more about the slicing software (Simplify3D) more since a lot of G-code commands and be used to ease the process and make the prints smoother and more accurate.
Due to lack of time we decided not to replace parts from previous years since that would most likely create a lot more problems regarding the mechanical movement and operation of the printer. Instead we decided to modify the feeding of the ABS plastic as well as removing the cogwheel for the belt pulley.
Considering the cooling, we were quite pleased with the results. After realizing we had air-pressure available in the workshop, we were able to connect the com- pressed air with our nozzle which gave great cooling over a larger area. It was a great improvement replacing the old plastic nozzle with a new steel nozzle with greater spread of the compressed air covering a substantially larger area.
The level of the heatbed is very important for good quality prints, due to how the heatbed was built it was hard to level it properly. If there was time we would like to have the heatbed rebuilt so it was not connected to the main structure anymore, this would have made it a lot easier to level.
The calculations for the natural convection is not entirely correct since it takes about five minutes to print. This means the print is cooling down alongside it be- ing printed, the calculations is done with the print done and all of it homogeneous 230°C. The problem is that it’s a lot harder to calculate different cooldown zones, but the calculations still gives us a rough estimate.
Due to several factors that can affect the calculations for the airspeed through the nozzle. The air compressor is located in a different room next to the workshop.
The distance the air travels might affect the pressure flowing into the printer. Since
temperature effects the outcome of the velocity of air, we assumed the temperature
in the room was around 22 degrees Celsius but this might vary.
6.1 Critical Analysis
6.1.1 Social Aspects
Considering the social aspects of the 3D printer regards to health would involve the fumes released from the melted plastic and it’s effects on the user. On the other hand products and prototypes could be manufactured locally, with better knowledge and tools to handle the fumes it would benefit the community.
6.1.2 Economical Aspects
Since the SVKB’s goal was to create a cheaper alternative of a big scale 3D printer to compete against other existing ones on the market the budget was not quite de- fined, however building the parts from reusable materials from the workshop was viable. We were able to construct a new cooling system with just about 580 SEK which we consider was the cheapest alternative with the best results. The cost anal- yses is shown in Figure 4 for a more detailed visualization.
6.1.3 Environmental Aspects
As stated in section 2.1, 3D printing a relative new process and is a more environ- mentally friendly alternative to creating a few prototypes rather than mass produc- tion as in plastic moulding.
We quickly realized that the amount of plastic used for printing at such a large
scale required quite a lot of ABS plastic granulate. However due the fact that ABS
plastic granulate is often recycled from various plastic sources this wouldn’t impact
the environment greatly. The plastic granulate however was often imported from
eastern Asian countries such as China and the transport is considered a benefactor
to the global warming from the gases released from airplanes or other modes of
shipping. We were however not able to find any alternative plastic manufacturers
around Sweden.
7 Conclusion
The project have been an adventure through the world of 3D-printing and 3D- printers, the authors have explored areas of these subjects they didn’t even realized played a part in the outcome of the prints. Due to some lack of communication and knowledge in the area the authors have not completed as much as they would like to do. Yet they have learned a lot about the subject and are happy they chose this project.
The problems stated in the scope section of the thesis report have mostly been solved. With the methods used the authors were able to get appropriate results in both the calculation part as well as the physical build. The print quality has been improved a lot but could be improved more, but that would require rebuilding some parts of the machine.
7.1 Division of Labor
We the authors think the division of labor have been fair and that everyone in the
group have done their part. It has been a naturally divide because of our personal
interests, one is a little more interested in programming while the other is more ex-
perienced in the workshop. Even though both of the authors have been responsible
for different parts they have never felt like one is doing more than the other.
8 References
[1] Berggren, Kenneth. Konstruera i Plast. Industrilitteratur, 2008.
[2] Landry, Taylor. “Beat Moisture Before It Kills Your 3D Printing Filament.”
MatterHackers, 28 July 2016, www.matterhackers.com/news/filament-an-water [3] Cengel Yunus A., et al. Fundamentals of Thermal-Fluid Sciences. McGraw-Hill Higher Education, 2012.
[4] “3D Printing Material Properties Table - Compare Top Filaments.” Simplify3D Software, 2019, www.simplify3d.com/support/materials-guide/properties-table [5] Rogers, Tony. “Everything You Need To Know About Injection Mold- ing.” Everything You Need To Know About Injection Molding, 2019, www.creativemechanisms.com/blog/everything-you-need-to-know-about-
injection-molding
[6] “Wire Size & amp; Current Rating .” Current Rating, www.jst.fr/doc/jst/pdf/current_rating.pdf
[7] Björklund, S., Gustafsson, G., Hågeryd, L. Rundqvist, B. (red.) (2015).
Karlebo handbok. (16., omarb. och utvidgade uppl.) Stockholm: Liber.
[8] Leijon, W. (red.) (2014). Karlebo Materiallära. (15. uppl.) Stockholm:
Liber.
[9] "Flexible silicone rubber Fiberglass insulated heaters", Omega, https://assets.omega.com/pdf/process-heaters-and-coolers/flexible-
heaters/SRFR_SRFG.pdf
[10] "Återvinning av förpackningar i Sverige", SCB, https://www.scb.se/hitta- statistik/sverige-i-siffror/miljo/atervinning-av-forpackningar-i-sverige/
[11] "Global plastic waste by disposal", Our world in data, https://ourworldindata.org/faq-on-plasticshow-much-of-global-plastic-is-recycled [12] Stromvall Hans-Erik. Producera i Plast. Sveriges Verkstadsindustrier (VI), 2002.
[13] Klason, Carl, et al. Plaster: Materialval Och Materialdata. Sveriges
Verkstadsindustrier, 2001.
[14] Comprehensive materials processing : 13 volume set / editor-in-chief, M. S. J. Hashmi. [Elektronisk resurs]. Elsevier.
https://www.sciencedirect.com/science/article/pii/B9780080965321010025
[15] Gigantic The Box 3D printer revealed with 2.5 m3 build volume, 1200 mm/sec
3D print speeds, 3ders.com, http://www.3ders.org/articles/20160718-gigantic-the-
box-3d-printer-revealed-with-2-5-m3-build-volume-3d-print-speeds.html
9 Appendix
9.1 Level Heatbed (Previous)
9.2 Level Heatbed (Wheel Removed)
9.3 Level Heatbed (Improved)
9.4 Timetable
Optimering av 3D-skrivare med avseende på kylning
Oskar Geraldsson & Kristoffer Ylander Mikkelsen
Project Start Date Display Week 1
Project Lead
21 22 23 24 25 26 27 28 293031 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
WBS TASK LEAD START END DAYS %
DONE WORK
DAYS M T W T F S S M TWT F S S M T W T F S S M T W T F S S M T W T F S S M T
1 Viktiga datum mån 1-21-19 mån 1-21-19 1
1.1 Projektstart [Name] mån 1-21-19 mån 1-21-19 1 0% 1 1.2 Projektbeskrivning mån 1-21-19 fre 2-01-19 12 0% 10
1.2.1 Inlämning mån 1-28-19 fre 2-01-19 5 0% 5
1.3 Rapport fre 2-01-19 fre 6-21-19 141 0% 101
1.3.1 Preliminär inlämning fre 5-10-19 fre 5-10-19 1 0% 1 1.3.2 Halvtidsrapport fre 3-15-19 fre 3-15-19 1 0% 1 1.3.3 Slutgiltig inlämning fre 5-31-19 fre 5-31-19 1 0% 1 1.3.4 Redovisning och
Opponering tis 5-21-19 tis 5-21-19 1 0% 1
1.3.4 Inlämning DIVA fre 5-31-19 fre 6-21-19 22 0% 16
1.4 UTEXPO ons 6-05-19 tor 6-06-19 2 0% 2
2 Kylning fre 2-01-19 fre 5-31-19 120 86
2.1 Undersökning fre 2-01-19 sön 3-03-19 31 0% 21
2.2 Utveckling sön 3-03-19 tis 4-02-19 31 0% 22
2.3 Utvärdering tis 4-02-19 tor 5-02-19 31 0% 23
2.4 Färdigställning tor 5-02-19 fre 5-31-19 30 0% 22
2.5 [Task] - ##### 0% -
3 Kylning - - ##### ########
3.1 Undersökning - - ##### 0% ########
3.2 Utveckling - - ##### 0% ########
3.3 Utvärdering - - ##### 0% ########
3.4 Färdigställning - - ##### 0% ########
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4 Design - - ##### ########
4.1 Undersökning - - ##### 0% ########
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4.4 Färdigställning - - ##### 0% ########
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Gantt Chart Template © 2006-2018 by Vertex42.com.
Week 2 Week 1 1-21-2019 (måndag)
28 jan 2019 21 jan 2019
Week 3 4 feb 2019
Week 4
11 feb 2019 18 feb 2019 2 Week 5
23 24 25 26 27 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 S S M T W T F S S M T W T F S S M T W T F S S
Week 8 11 mar 2019 9
Week 6 25 feb 2019
Week 7 4 mar 2019
krivare med avseende på kylning
fer Ylander Mikkelsen
Display Week 9
18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 3 4 5
LEAD START END DAYS %
DONE WORK
DAYS M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S
mån 1-21-19 mån 1-21-19 1
[Name] mån 1-21-19 mån 1-21-19 1 0% 1 mån 1-21-19 fre 2-01-19 12 0% 10 mån 1-28-19 fre 2-01-19 5 0% 5 fre 2-01-19 fre 6-21-19 141 0% 101 fre 5-10-19 fre 5-10-19 1 0% 1 fre 3-15-19 fre 3-15-19 1 0% 1 fre 5-31-19 fre 5-31-19 1 0% 1 tis 5-21-19 tis 5-21-19 1 0% 1 fre 5-31-19 fre 6-21-19 22 0% 16 ons 6-05-19 tor 6-06-19 2 0% 2 fre 2-01-19 fre 5-31-19 120 86 fre 2-01-19 sön 3-03-19 31 0% 21 sön 3-03-19 tis 4-02-19 31 0% 22 tis 4-02-19 tor 5-02-19 31 0% 23 tor 5-02-19 fre 5-31-19 30 0% 22
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Gantt Chart Template © 2006-2018 by Vertex42.com.
Week 10 Week 9
1-21-2019 (måndag)
25 mar 2019 18 mar 2019
Week 11 1 apr 2019
Week 12
8 apr 2019 15 apr 2019 Week 14 22 apr 2019
Week 13 Week 15
29 apr 2019
4 5 6 7 8 9 10 11 12 S S M T W T F S S
Week 16 6 maj 2019 5
9
kylning
Week 17
13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 3 4 5 6 7
DAYS %
DONE WORK
DAYS M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S 1
1 0% 1
12 0% 10
5 0% 5
141 0% 101
1 0% 1
1 0% 1
1 0% 1
1 0% 1
22 0% 16
2 0% 2
120 86
31 0% 21
31 0% 22
31 0% 23
30 0% 22
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Gantt Chart Template © 2006-2018 by Vertex42.com.
Week 18 Week 17
20 maj 2019 13 maj 2019
Week 19 27 maj 2019
Week 20 3 jun 2019
Week 24 1 jul 2019 10 jun 2019
Week 22 17 jun 2019
Week 21 Week 23
24 jun 2019
