diff --git a/writeup/3-lasers.md b/writeup/3-lasers.md index 5920025bbb3b2b408e92036a6c22c3cb7de1b528..3edfbc2872abe7f8d2a86880b1818dc4b056d9de 100644 --- a/writeup/3-lasers.md +++ b/writeup/3-lasers.md @@ -1,16 +1,19 @@ -Today we tried to make some test cuts to see if it was possible to make the leadframes that are stamped in the Molex connectors using EDM. +Today we tried to cut the connector leadframes using the Fablight and the Trotec speedy 100 flexx. -I designed a simple finger pattern with varying width fingers and we tried to cut it on the sodick out of 0.1mm thick copper shim stock. +The fablight worked extremely well. This is the resultant part cut out of 0.1mm thick copper sheet: - + -It was quite difficult to cut because the material is quite thin. We fixtured it the best we could across a corner of the base, but this still left a significant unsupported span that could be flexed easily by hand. +We just used the default settings for this thickness of copper and got good results. The top surface turned out perfect, with a very small kerf, indicating that this technology is probably the best way to make the connectors. Here is a picture under the microscope: - + -When we tried to cut it, we found that the machine would cut, but the wire would always break after a few millimeters. We think this is because the water jet around the wire vibrated the copper plate, causing it to contact the wire and break it. +The bottom surface was much rougher, mostly due to pitting and buildup of slag from the laser cutting process. However, there are some steps that can be taken to either cleanup the copper after cutting (such as running it under an orbital sander) or reduce the buildup of slag in the first place (such as layering two sheets of copper, cutting them as one sheet with double the thickness and then only using the parts from the top layer). - - + -It may be possible to eliminate the vibration by sandwitching the copper sheet between the sacrificial thicker plates of metal or slamping many copper sheets together, but a different fabrication technology is probably better suited to the task. \ No newline at end of file +Next we tried to make the same part on the Trotec. Having a significantly lower power than the fablight, it struggled to cut through the copper even after 20 minutes of repeated passes. This machine is better suited to etching the thin copper foil layers on PCBs, or very thin sheet metal for SMD stencils. \ + +Here is the result after 20 minutes of cutting: + + \ No newline at end of file diff --git a/writeup/bottom_microscope.jpg b/writeup/bottom_microscope.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6cde91cea9a3a7e30b3f5e77d7a9436f0d5d4fd5 Binary files /dev/null and b/writeup/bottom_microscope.jpg differ diff --git a/writeup/top_microscope.jpg b/writeup/top_microscope.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c88d70e12a441f81983431794565f0ce4f65472c Binary files /dev/null and b/writeup/top_microscope.jpg differ