Tasnim Hussain | FAB Engineer 01| 01| 2019
Q1| Q1-5| Roland MDX-50 | Milling Machine DESIGN SOFTWARES : SRP Player CAM, ClickMill and Virtual Control Panel (VPanel) FAB FOUNDATION REFERENCES: http://fab.academany.org/2018/labs/fablabbrighton/media/pdf/ElectronicsProduction.pdf INTRODUCTION CNC stands for Computerized Numerical Control which is a programmable automation in which process is controlled by Numbers, Letters, and symbols. CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools like lathes, mills and grinders. The CAD tool works with design, or the initial creative step of any project. After that, when there is the need to manufacture it - and therefore CNC technology is demanded - another kind of software is needed: CAM is the software that creates the machine program from a digital design. Basically, CAM software produces a G-CODE that is a preparatory word, used as a communication device to prepare the MCU. The G-code indicates that a given control function such as G01, linear interpolation, is to be requested. The following block diagram illustrates the building blocks of a CNC router machine.
Input CAD 2D Design on the computer.
Interface
Output
CAM Software converts the CAD design into instructions for the machine to implement the design. These instructions are usually called a “Code”.
The code produced by the CAM software will be executed by the machine’s controller and will drive the spindle and motors to start milling/ cutting.
Roland MDX-50 MILLING MACHINE
This week assignment is a PCB that has an initial design and it is supposed to be edited. Further notes will explain better about Eagle 8.0 which is the design tool I used for PCB design. The MODELA MDX-50 is a fully automated, high-precision 3D milling machine ideal for fabricating design and working models. The MDX-50 has an Automatic Tool Changer and CAM software as standard and an optional rotary axis unit. The MODELA MDX-50 is capable of drastically reducing milling time and effort, and delivering true innovation to the design process. The MDX-50 benchtop CNC mill combines precise, automated milling and unmatched ease-of-use. An ideal solution for short-runs and prototypes, it reduces operating time and simplifies production so users of all abilities can mill on a wide range of materials. It follows the standard setup for the machine and tools we have here at Insper for FabModules and Roland MDX-40A. Input: this is an image file png that will describe the traces or cut need on the board. Select the image you need for each PCB. This exercise has this final board design for traces and this final board design for outline. Output format: Roland Mill (.rml) - this selection will set the FabMoludes to work with a milling machine. For the machine setup refer to the link and to read the user manual refer to this link.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Automatic Tool Changer The MDX-50 features a 5-station Automatic Tool Changer with an auto-sensing function to detect tool length and ensure milling accuracy.
Status Light
For monitoring machine status in busy classrooms and studios, current job status can be checked from a distance with multi color-coded LED status lights and email notiďŹ cations.
The VPanel serves as a computer-based virtual controller with all of the functionality of a physical on-board control panel, as well as tool life management and e-mail alerts.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Built-in Panel Screen and Functions
The built-in panel contains the frequently used functions. You can use it to perform operations while checking the machine's internal behavior.
Rate key
Axis selection keys
Select the level of precision of the hand-wheel feed. Lower scaling factors produce correspondingly slower movement, enabling you to accomplish precise positioning.
Select the axis to use as the target for hand-wheel feed and origin settings. Use the [A] key when the optional rotary axis unit is attached.
Coordinate System Selection key Press this key to change the coordinate system. The coordinate system is related to the display of the toolbar position and to the origin setting.
Origin Setting Key
Override Key
Hold down this key to set the origin to the current tool bur position of the selected axis.
Select the feeding speed override and the spindle rotating speed override.
Hand-wheel Menu Key Call up the submenu.
Spindle Key Start and stop the rotation of the spindle.
Set the hand-wheel feed for each axis and increase/decrease setting values.
Enter key ConďŹ rms operations.
Z0 Sensor Key Use this key when you use a Z0 sensor to set the Z origin.
Pause/Cancel Key Pauses and resumes cutting. When you press this key with cutting paused, you will be given the option of resuming or canceling cutting.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
PCB Manufacturing Process Steps
Prepare two seperate files for the PCB layout one for the traces and the other for board outline as PNG. Before saving, check that your images are the correct size for your circuit board (in mm, not dpi). Note: whatever is white will stay, black will be machined.
Go to fabmodules.org and click on “input format”. Select the format to be “image (.png)”.
Search for the image and open it.
The file will open and the board layout will appear as shown above. From “output format” select “Roland mill (.rml).
Output settings will appear on the screen. Here you need to add the machine details in terms of machine name, speed (mm/s), origin coordinates and homing.
Input all the data as shown above. Note that: ● For the machine selection, MDX-50 is not available but MDX-40 is similar to it. ● Zjog represents the Z level of the machine when it is traveling to a different location.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Select the process “PCB traces (1/64)”, automatically the process details will show on the right side. The tool diameter needs to be changed from 0.4mm to 0.09mm which approximately corresponds to the diameter of the V- tool shown in the picture. However, the V- tool is usually defined by angle (i.e. 45 degrees).
After that, download the RML file by selecting “Save”.
Check the Stock thickness which is the thickness of the material e.g. 1.7mm. Cut depth is the depth the tool will cut in one pass. This can be done in one go when selecting the depth to be equal or slightly bigger than the material thickness (e.g. 1.8mm cut depth can give very good cut through). Tool diameter is kept as the default 0.79mm for 1/32” tool. Then, Click “Calculate”.
Click “Calculate” to generate the RML file for the MDX-50. The circuit traces will be created with directed blue lines representing the machine milling path and red lines represent the jogs between different paths.
The same steps are repeated for the board outline with few modifications on the tool and the cutting parameters. Select Roland mill (.rml) as the output format and PCB Outline (1/32) as the cutting process.
After downloading the file, the machine should be settled up with the copper board mounted and the needed tools. First, prepare the copper plate sheet and make sure it is clean.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Power ON the machine, note that the machine LEDs will be blue in color and the screen will show the message “Hit Enter Key�. This should be done to initialize the machine and make it ready.
Open the cover to place the material/ copper board, to attach the tools and to probe the z level. When opening the door, any previous operation gets automatically stopped and the LEDs will turn white and the screen shows a message to close the cover.
Copper Board Wax Block
Place the Copper board over the wooden base and stick it with double sided tissue tape over a wax block. *Note that: the wooden base can be removed and the wax bock can be placed directly over the cutting bed.
Snap the tools/bits to the tool holder and place them over the automatic tool changer slots. Two tools are used, one for the traces milling which is the V-tool 45 degrees milling bit and another one for board outline cut of diameter 1/32 inches drilling bit.
Get the Z-probe ready and snap it over the special socket as shown. Also you need to make sure that the detection pin is loaded to tool slot number 6. Refer to page 24 in the manual.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
The tool is picked up.
Click on Menu many times until you get “ATC TOOL MENU” for the automatic Tool Changer. Use the hand wheel to select the tool with where the bit is attached to the tool holder. E.g. here TOOL6 which is the detection pin is selected. The spindle will move to get the selected tool then it will show on the screen that the selected tool is tool #6. .
Click Menu again multiple times until you get “USER (RML-1/NC CODE)”. For instance to change the x-coordinate, select it by hand wheel and then hit enter, after that with the hand wheel move to the positive or negative direction.
Use the hand wheel to move, the x and y to have the spindle directly facing the z-probe metallic piece. After that, click on Z0 SENSE from the panel. There will be a message displayed on the screen, to confirm Z0 SENSE click ENTER.
Again use the Automatic Tool Changer to pick the milling tool (V-tool) and then to pick the cutting tool (1/32” tool) after milling.
Before start with the milling process, the X and Y origin coordinate needs to be determined and the spindle speed needs to be asjusted. Open VPanel and select the gear icon “ ”. This will allow you to access the machine setting window. Select “Origin” tap and modify the XY positions to suit the position of the material. When you reach the desired point, select “XY” to be the origin position and click on “Set”.
Increase the speed of the spindle by increasing RPM from 4500 to 5500 rpm. Then select the spindle icon to fix the new speed. Finally, click OK.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
The previous steps for X and Y origin point and adjusting the spindle speed can be done using the panel keys alternatively to VPanel settings. Simply push X button to allow moving along the axis through the handwheel. When the desired point is reached, just push the ORIGIN button and hold on without removing your finger until the value change to 0.00 on the screen and VPanel accordingly. Same is done to the origin of the Y axis. The spindle speed can be changed also by selecting SPINDLE and then with the handwheel increase the value to the desired RPM speed. Refer to page 45.
Open VPanel and select “Cut” icon. This will allow you to upload your RML file for the PCB.
Upload the RML file, then it will be automatically added to the list of cut files.Finally make the file ready to cut by selecting the file and clicking “Output”.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Now to start the milling process, click on “Cutter Management” icon as shown. You will note that the Z-level will lowered to reach the board level.
The Machine will then start the milling of the traces and LEDs will turn White. When the process is successfully finished the LEDs will turn Blue and the VPanel will indicate that the process is finished.
After milling the PCB traces, the same process is repeated for cutting the board outline. The result after milling and cutting is as shown in the figure.
One final step is remaining, which is to assemble and solder the electronic components onto the board. Refer to the link for assembly and refer to the soldering tutorial in pages 55-64.
Notes: -
The Z-level need to be probed everytime when the board is moved or replaced. Refer to the tutorial as a reference.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Suppose that the above PCB needs to be produced. The ďŹ rst thing to do is to export the monochrome format of the PNG image for the top and pads layers. This will be used for generating the RML ďŹ le for PCB milling. REMARK: All the above steps are for a PCB with SMD components only. In case you have some through hole components or you need to drill placement holes few steps needs to be done as shown below.
Only show the pads layer.
Export the layer as image.
The holes need to be completely black except for the surrounding that need to be white. Thus, you need to use Gimp software to remove the text within the holes. Final image.
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Tasnim Hussain | FAB Engineer 01| 01| 2019
Use the select tool
to minimize
the size of the yellow frame to make it just right around the PCB as shown in the ďŹ gure on the right.
From Layer Settings, hide all layers and show only dimensions for the image export.
Image is exported using the same method as for the traces and pads.
Exported image of the dimension layer. This will be treated as the drill holes image in FAB Modules, where the cut depth is 1.8mm and the tool used in 1/32�.
The last image that needs to be prepared before moving to FAB Modules is for the outline. To do this follow the above steps.
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