Add images in the document

docs/group_assignments/group2/assignment3.md

@@ -14,11 +14,16 @@ authors:
 # Group work for week 3 
 
 ## Cutting a test piece and measuring the dimensions
+
+![kerf](./assets/assignment3/kerf_meas_1.JPG)
+![kerf](./assets/assignment3/kerf_meas_2.JPG)
+![kerf](./assets/assignment3/kerf_material_thickness.JPG)
+
 drawing:
 20x20
 
 measurements:
-19.75x19.90
+19.77x19.87
 thickness 2.85
 
 ## Testing to change the focus of the laser cutter
@@ -28,6 +33,12 @@ We changed the focus 1 mm above and below the optimal focal point, and also 4 mm
 The results are shown in the Figure 1. We first used settings for MDF material but later we realized that the material was
 actually HDF, and we changed the settings. As can be seen from Figure 1, the difference...
 
+![kerf](./assets/assignment3/cut_focus.JPG)
+
+![kerf](./assets/assignment3/cut_focus-2.JPG)
+
+
+
 Figure 1
 
 
@@ -41,6 +52,7 @@ Focused
 
 Others were cut through but not the 4 mm above
 
+![kerf](./assets/assignment3/focus_laser_theory.JPG)
 Schematic figure
 
 As shown in the schematic figure, when the focus is above the laser need to burn more material, 
@@ -52,6 +64,7 @@ the energy is deposited to larger volume. This is probably the reason that the 4
 We tested the effect of laser cutting speed and power on the cut. We set different values for different squares. The result
 is shown in the following figure. We used RGB codes to control the speed and power.
 
+![kerf](./assets/assignment3/cut_power-speed-test_epilog-75W.JPG)
 figure on the cut squares
 
 We could see that for fastest cutting speed (S30) the laser was not able to cut through, even if the power was highest (P100).
@@ -60,6 +73,7 @@ Also, for the lowest power (P20) the laser was not able to cut through, even if
 
 ## Engravings and contrast of raster images
 
+![kerf](./assets/assignment3/cut_dpi-test_epilog-75W.JPG)
 Figure on engravings and contrast.
 
 Raster settings were applied. Default power in the figure is 100, and default speed is 80.
@@ -69,11 +83,15 @@ Effect of Dots Per Inch (DPI) setting on laser engraving.
 We tried to make engraving with different DPI settings. In a first attempt there was something wrong with the laser focus,
 and the material seemed to catch quite big flame. 
 
+
+![kerf](./assets/assignment3/laser_test_epilog-60W_burn-issue.JPG)
 Figure of the first engravings
 
 The material was changed to HDF and the laser was cleaned. After this there
 was no problem, and we could engrave with different settings. The results are shown in the next figure
 
+
+![kerf](./assets/assignment3/cut_dpi-test_epilog-60W.JPG)
 Figure of the second engravings
 
 With more dots per inch, there is more energy deposited per line length, and for this reason the material is burned more with 
@@ -101,9 +119,6 @@ mkdocs formatting examples (remove in the end):
 # 1st level heading
 
 ## 2nd level heading
-[University of Oulu](http://www.oulu.fi)
-
-![Testing and image](assets/assignment0/fablab_electronics.jpg)
 
 ## Another 2nd level heading