diy cr7 fdm 3 d printer
TRANSCRIPT
INDIANA UNIVERSITY-PURDUE UNIVERSITY INDIANAPOLIS
Purdue School of Engineering & Technology
Department of Mechanical Engineering
CR-7 FDM 3D PRINTER
Proff: Dr Tovar
Student’s Name: Satyajeet Udavant, Ravi Pasupuleti, Shuyi Zhou,
IUPUI,
Indianapolis
Satyajeet Udavant OBJECTIVE
The objective of the project is to learn assemble the CR7 FDM 3d printer. After completion this DIY printer is then used to print various
different prints, objective being to calibrate printer for good end product. And troubleshooting problems faced during the installation,
calibration and printing the objects
BACKGROUND FDM
FDM- stands for Fused Deposition Modelling
Fused deposition modeling (FDM) is an additive manufacturing technology commonly used for modeling, prototyping, and production
applications. It is one of the techniques used for 3D printing. FDM works on an "additive" principle by laying down material in layers;
a plastic filament or metal wire is unwound from a coil and supplies material to produce a part.
FDM begins with a software process which processes an STL file (stereolithography file format), mathematically slicing and orienting
the model for the build process. If required, support structures may be generated. The machine may dispense multiple materials to
achieve different goals: For example, one may use one material to build up the model and use another as a soluble support structure
or one could use multiple colors of the same type of thermoplastic on the same model.
The model or part is produced by extruding small flattened strings of molten material to form layers as the material hardens
immediately after extrusion from the nozzle
A plastic filament or metal wire is unwound from a coil and supplies material to an extrusion nozzle which can turn the flow on and
off. There is typically a worm-drive that pushes the filament into the nozzle at a controlled rate.
The nozzle is heated to melt the material. The thermoplastics are heated past their glass transition temperature and are then deposited
by an extrusion head.
The nozzle can be moved in both horizontal and vertical directions by a numerically controlled mechanism. The nozzle follows a tool-
path controlled by a computer-aided manufacturing (CAM) software package, and the part is built from the bottom up, one layer at a
time. Stepper motors or servo motors are typically employed to move the extrusion head. The mechanism used is often an X-Y-Z
rectilinear design, although other mechanical designs such as deltabot have been employed.
Satyajeet Udavant INSTALLATION
Step 1
As shown in Fig. 1, aluminum rails were fixed on the acrylic floor via M4-T nuts which initially should be kept horizontally and then
fastened vertically to the rail. The long rail represents the Y axis of printer and the short rail supports the perpendicular Z axis. During
the work, we need to take the inner threaded hole of rails to the outside.
Fig. 1 Base & rails of the 3D printer
Step 2
To increase the stableness between the short rail and the long rail, we put the 2020 corners to connect them. The Z axis shown in Fig.
2 was added to the short rail on the base also by 2020 corner. Then the Z axis limit seat within a limit switch and another Y axis---2040
Aluminum(250mm)Base---Acrylic floor2020 Aluminum(100mm) aluminum plate came separately to the side of Z axis downward the
base. Additionally, every part should be fixed on the rail by different sizes of T nuts.
Satyajeet Udavant
Fig. 2 Z axis & others
Step 3
The next work for us was to fix the one of the34 stepper motors to Y axis limit seat on the right side of the Y axis. There were another
limit switch aside the motor (see Fig. 3). 2020 ConersZ axis----2040 Aluminum(250mm)Zaxis limit seatLimit switch.
Satyajeet Udavant
Fig. 3 Y axis Motor & others
Step 4
There are many parts assembled shown in Fig. 4 and Fig. 5. Firstly, we connected the 34 stepper motor with M5 threaded rod via a
hose with 4mm and added Z axis motor mount seat to it. Secondly, we sandwiched three V wheels along M4×10, between the isolation
columns on each side, and also put all of them between the front and back of X-axis motor aluminums. Thirdly, we assembled X-axis
motor to the other side of X-axis motor, 34 Stepper Motor, Limit switch, Y-axis motor mount Y axis limit, seat back aluminum using 4
28mm copper studs. To let the motor rotate normally, we usually attached a synchronous wheel on the motor axis. Meanwhile we
fixed the extrusion seat upon the extrusion motor which is a 40 stepper motor. What’s more, the extrusion motor was connected to
the corresponding position of the X-axis motor front aluminum. Finally, we assembled the part above to the 2020 X axis but should
notice a special positon for the screw on the back.
Satyajeet Udavant
Fig. 4 X axis & motors
Step 5
Fig 5
Satyajeet Udavant Difficulty
The difficulties faced to our team are described as following:
1. The exact name of each part. The instruction doesn’t give a vivid picture of the each part corresponded to their name. We spent
lots of time to figure out which part is. Synchronous wheel X axis----2020 Aluminum(210mm)Extrusion wheel Extrusion seat X-axis
motor front aluminum V wheels Isolation column
2. The assembly sequence. A wrong sequence would decrease the speed of assembly. Sometimes we followed a wrong sequence that
would not only cause the decreased speed of assembly but also did extra dismantle work.
Step 5
As shown in Fig. 6, we assembled the LCD screen with acrylic screen cover. To support the screen cover, there are two through light
columns and one screw for each hole on the four corresponding position of screen cover and LCD screen. Additionally, the wire cable
from the back screen cover should be connected to the EXP1 port of the motherboard.
Fig.6 Control panel (Screen) & wire arrangement of motherboard
Then we dismantled the fan atop the motherboard to arrange the wire cables (see Fig.6). One of the wire cables has 4 branches, and
another has 3 branches. 4PIN and 2PIN hole, both ends of the cable terminals, is connected to the motherboard and the location.
Satyajeet Udavant
Fig.6 Motherboard and wiring diagram
What’s more, the wires from nozzle fan, nozzle and also the PCB fan (atop the motherboard) should be hooked up to the related
position on the motherboard. We noticed there is a reserved port.
Step 7
After the motherboard wire arrangement, we attached the wire cables to the corresponding position of motors and limit switches.
6PIN and 3PIN hole is connected to the motor position and limit switches (see Fig.7). Since we finished all the wire arrangement, we
started to put the handle on the top of Z axis, which is a rail perpendicular to the base.
Fig. 7 Motors and limit switches wire connection
Satyajeet Udavant Step 8
The last part of our work was to plug in the power adapter to run the control panel to see check if the X, Y, and Z motors work normally
or the limit switches are on the right position. The operation on the control panel was to find the mode-Autohome and select the
proper speed for running corresponding motor. While we found that the X limit switch was put on the opposite direction compared
with the limit position of X motor (see the red circle in Fig.8). Finally we took the X limit switch to the right direction and run the motors
again.
Difficulty
The difficulties faced to our team are described as following:
1. Since last Thursday we finished assembling all the parts shown on the assembly video, this Thursday we focused on the wire
arrangement between motors, limit switches, and also motherboard. One of the issues is that we need to dismantle the fan
atop the motherboard to get the wire cables connected. It’s wasting time to first assemble and then dismantle the fan. We
should read all the assembly instructions, including the electrical wire arrangement as well as the screen installation, first
rather than starting with the body assembly.
SOFTWARE CURA We installed the software as per the instructions and made the necessary changes to the settings as per our requirements. Which
included setting all the parameters and their understanding, pararmeters like temperature, nozzle, temperature, printer speed, fill
density, layer thickness, machine settings etc
PRINTING
This Thursday we finished printing our very first print successfully in the first go.
Step 1
Fig. 1
As shown in Fig. 1, we studied various modes and functions that we can perform on the screen. Above picture shows the home
screen, it shows the current temperature and the achieved temperature depending upon the materials used, PLA or ABS etc.
Currently it’s set to zero and room temperature both are circled black.
Satyajeet Udavant Step 2
Fig.2
This is the screen which further navigates us to prepare the initial setup like temperature, moving axis etc., control moves the same
with more precision
We have three modes of print
1 from SD card
2 from data cable
3 from software (if connected directly to wifi)
Here we are using the SD card
Step 3
Fig.3
As you can see in this image that we have inserted the SD card with the test file. Ready to print
For print we first set the nozzle to pre-defined coordinates of home, these are the upper most corner towards the PCB board, print
starts from here. Nozzle temperature is increased for the defined value it is usually observed that nozzle temp is defined at 180-200
Celsius degrees for PLA.
Satyajeet Udavant
Completion
Fig.4
Fig.5
Print quality as you can see in the black square, the print bottom is varying, it happened because of the first layer of the print was
not properly stick to the bed. Solution for this is to stick a tape and wet it with some spray, we used hair spray.
Difficulty
The difficulties faced to our team are described as following:
1. Feed motor was not properly installed so we moved the gear a little bit upwards and we achieved continuous feed.
2. Print quality as you can see in the black square, the print bottom is varying, it happened because of the first layer of the
print was not properly stick to the bed. Solution for this is to stick a tape and wet it with some spray, we used hair spray.
Satyajeet Udavant PRINTING CONTINUED
We realized to put some duct tape and hair spray for next print.
Fig.6
We decided to print this model, test probes part of the printing came later this week, and we changed the scale to 0.3 to save time
and print fast.
Fig.7
This is the result of our print. There is shift on the Z axis as you can see the shifts. It was due to loose platform belt drive. We
tightened it before next prints.
There is shift on the Z axis as you can
see the shifts.
It was due to loose platform belt
drive. We tightened it before next
prints
Satyajeet Udavant
Fig.8
After calibration as you can see there is a great improvement in the print quality.
TEST PROBES PRINTING
Test probes are used to gauge the quality of prints. These test probes are used to decide the quality of printer we built. We used
scores 0-5 t evaluate the prints , 5 being the best print.
Aspect
Printing parts Score
Negative Space Tolerance
1
Overhang Performance
4
Satyajeet Udavant
Dimensional accuracy
4
Mechanical Resonance in XY
3
Fine Positive Space Features Performance
3
Mechanical Resonance in Z
2
Bridging Performance
3
Satyajeet Udavant Considering the above evaluation we choose the negative space tolerance to be our test probe for fine calibration using the
following parameter setting
Experiment Parameters setting 1 𝐴 low, 𝐵 low 2 𝐴 high, 𝐵 low 3 𝐴 low, 𝐵 high 4 𝐴 high, 𝐵 high
Name assigned Parameter Low-High range
A print speed 40-50 mm/s
B print temperature 190-210℃
Prints:
4 factorial design Results of 4 parts in a batch Negative Space+
Replicate Score
I II III IV Total
(1) A low, B low
we did just one print
2 2 2 2 8
(a) A high, B low
2 1 1 2 6
Satyajeet Udavant
(b) A low, B high
2 1 2 4 9
(ab) A high, B high 3 3 2 3 11
Table 2
Calculations:
b=9 ab=11
a=6 (1)=8
𝐴 = 𝑎𝑏 + 𝑎
2𝑛−
𝑏 + (1)
2𝑛=
1
2𝑛[𝑎𝑏 + 𝑎 − 𝑏 − (1)]
𝐵 =𝑎𝑏 + 𝑏
2𝑛−
𝑎 + (1)
2𝑛=
1
2𝑛[𝑎𝑏 + 𝑏 − 𝑎 − (1)]
𝐴𝐵 =𝑎𝑏 + (1)
2𝑛−
𝑎 + 𝑏
2𝑛=
1
2𝑛[𝑎𝑏 + (1) − 𝑎 − 𝑏]
And 𝑛 = 4, replacing values in this experiment results:
𝐴 = 1
2(4)[𝑎𝑏 + 𝑎 − 𝑏 − (1)] =0
𝐵 =1
2(4)[𝑎𝑏 + 𝑏 − 𝑎 − (1)] =0.75
𝐴𝐵 =1
2(4)[𝑎𝑏 + (1) − 𝑎 − 𝑏] =0.5
Conclusion
From above results we can conclude, that when the given parameters (A or B) are increased to some level it produces different
results, but when we increase both simultaneously (AB) it gives a balanced result, an efficient one.
The objective of the project to learn assemble the CR7 FDM 3d printer was achieved.
Satyajeet Udavant Future Scope
FDM printer are easy to access in market for its cheap and easy of building and using the printer. But a lot of companies are now
working on using more than one material to create variety of prints. Companies like stratasys, makerbot etc
Multi axis printers are also one good field with heavy research.
5 axis 3d printer by Zmorph
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