When you have finished smoothing the base you can make Cap Pieces. For this process you will use a 6.0mm drill. Select 8 Caps and place them on the base in rows of three with the Cap’s non-smoothed side face up. You will use the empty space that could hold another cap piece to find the Z0 of the base at various times in the procedure. Keep about 10mm between the individual pieces and at least 5mm between the edge of the base and the side of the piece, as shown in the picture. Secure the pieces into place using superglue. When the pieces are secure, place the base into the milling machine, the side with the Caps facing up, and secure it into place.
Open the Cap milling program by going to the start menu, programs, MODELA App Group, then open MODELA Player. Once the program has opened, go to “File,” “Open,” and then open the file named “Cap_2_16.stl.” If you have done this correctly you will see the following screen.
Next, make sure all of the screens have the correct data. Click on the “Direction” button of the main screen located in the upper right corner. Select the lower right elephant in the series of elephants. The “Direction” screen should look like the following screen when you are done. When you are finished with the “Direction” screen, click “Back” to get to the main screen.
Click on the “Dimensions” button, when you have done this you should see values for height, length, and width. They should already be set to height = 2.0, length = 6.4, and width = 6.4. If they are not, adjust the wheel on the right side of the screen to make those values. When you are done the screen should look like the following picture. When you are finished with the “Dimensions” screen, click “Back” to return to the main screen.
Now click on the “Cutting Depth” button located just below the “Dimensions” button. When you have done this you will see the picture that follows. Using the wheel, on the right side of the screen, set the “Depth” to 1.8mm. When you have done this click the “Back” button to return to the main screen.
Next, click on “Draft” located below the “Cutting Depth” button. When you have done this you should see a screen that looks like the following picture. On this screen make sure the tool diameter is set to 6.0mm, the flat head drill picture is selected, the material selected is MgO2, and the finish is draft. When all this is complete, click on the “Back” button to return to the main screen.
Now you need to obtain the lower left (X, Y) coordinates of each Cap piece. First, estimate the height of the Cap pieces, with your best eye judgment, using the “Z+” and “Z-“ buttons to adjust the drill along the Z-axis; when you have lined up the end of the drill with the top of the Cap piece, set that Z-axis value to Z0. Now, estimate the lower left (X, Y) coordinate, with your best eye judgment, using the “View” arrows. When you have found the lower left (X, Y) coordinate, add 300 to both of the values (this is to compensate for the drill diameter) and divide that number by 100 to get the point that you will use. The equation you can use is (X, Y) = ((X-axis value + 300) / 100, (Y-axis value + 300) / 100) when you get the coordinate write it down so you don’t forget it. Next, go to the options menu and click on “layout.” You should see a screen that looks like the following picture.
When the layout screen appears, look in the upper right corner for the area to type the lower left (X, Y) coordinate. Then, click on “OK” and then “Start.” Let the program run until the drill has made a visible square in the Cap piece. When the square is visible, stop the program by pushing the blue “Pause” button, then cancel the print job and wait for a minute while the print job deletes itself. Raise the drill and take a look at the location of the square on the Cap piece. By using your best eye judgment, estimate how you need to adjust your lower left (X, Y) coordinate in order to center the square on the Cap piece. Make a record or your new lower left (X, Y) coordinate for this piece. Do this process for all of the individual Cap pieces.
Once you have recorded the lower left (X, Y) coordinate for each Cap piece you need to smooth the surfaces of the Cap pieces. To do this, find the Z0 point for the base, use the “Z+,” “Z-,” and the large white circle to do this. When the top of the base is set as Z0, raise the drill +170 micrometers and set this value as the new Z0 value. Now it is time to smooth the surfaces of the Cap pieces. Click on “Options” in the task bar then “layout.” In the surfacing area of the screen set the “depth” as 0.15mm and you’ll need to measure the length and width of your base, you’ll generally want to enter 75mm or 80mm for each value. Enter -3.0mm as your lower left (X, Y) points. For example, this is what your surfacing area might look like.
Now click the start button in the surfacing section of the screen. While the Cap pieces are being smoothed you can send the machine commands to mill the Cap pieces. To do this, open the layout screen again. Next, enter a Cap piece (X, Y) coordinate, click “OK,” then click “Start.” Do this for each Cap piece. You do not have to wait for one piece to finish before typing in the next (X, Y) coordinates. When the machine is done with one of the pieces it will go right to the next one.
When the first milling process is over, you will need to smooth the Cap piece down so the height is 1.41mm. To do this use the area of the base where there is no Cap piece to find the Z0 point of the base. When you have found the Z0 point of the base, raise the drill +160 micrometers above the base and set that value as your new Z0. When you have done that go to the “layout” screen and look at the surfacing section. Set the depth of the drill as 0.18 and your length and width as the values you had them for the first Cap surface smoothing. When you have done that click the “Start” button in the surfacing section of the layout screen. After that change the depth to 0.01 and click start again. While the Cap smoothing is going you can set up for the actual milling process. Go to the main screen and click “Draft. When the new screen pops up click on “Draft” under the finish section of the screen. This will change the finish from draft to fine. Click the “Back” button when you have changed the finish. Now go to the layout screen and type the lower left (X, Y) coordinates of the cap pieces in the layout section of the screen, click “OK,” then click “Start.” Do this for all of the Cap pieces. You do not have to wait for one piece to finish before typing in the next coordinates. When the machine is done with one piece it will go right to the next one.
When the machine is done with the second milling sequence you need to drill the holes into the cap pieces. First, switch the drill from the 6mm drill to the ?mm drill. Next, add 3.42mm to each cap piece's X coordinate and 3.20mm to each cap piece's Y coordinate, this is to get the exact center of the cap piece. Using the ?mm drill, make a small indentation in the cap piece to see if the center point is correct. Once you have done that with all of the cap pieces, switch to the ?mm drill and find the Z0 point of the center point in the cap piece. When you have set the Z0 point of the center point you need to slowly drill the center hole manually by using the large white circle. Go to a depth of -200 micrometers, do this for all of the cap pieces.
When the entire milling process has finished, you'll need to dissolve the superglue in order to get the Cap pieces off. To do this, remove the base from the machine, place the base into a beaker with the Cap pieces facing up (any beaker will do as long as the base fits inside), completely submerge the side parts in an Acetone solution, leave the Cap pieces to soak in the Acetone over night, and in the morning the superglue will be dissolved so you can retrieve your Caps.