====== Milling PCB workflow ======

(experimental)

Using Eagle, Tracespace.io, InkScape and Fusion 360


{{:isel_icv4030:eagle_circuit_and_pcb_layout.jpg|}}\\
Circuit and PCB layout

  * Make circuit and PCB layout in Autodesk Eagle (version 9.4.0)
  * ''File > Generate CAM data''
  * Click OK. This will generate a zip archive with Gerber files (2D vector files used for PCB manufacturing).
  * Unzip the .zip file and open the GerberFiles folder.
  * Open [[https://tracespace.io/]] to convert the desired Gerber files to SVG vector files.
  * Open the desired .SVG files in Inkscape.
  * use ''view > display mode > normal / outline'' to analyse the vector image.\\ {{:isel_icv4030:inkscape_-_normal_and_outline_view.jpg?400|}}\\ Seeing the image in the outline display mode (right), it becomes apparent that the traces have a width of zero mm.

  * ''edit > select all'' (''ctrl + a'')
  * ''object > ungroup'' (''shift + ctrl + g'')
  * the circles and squares are clones from hidden shapes. select one clone-object.
  * ''edit > select same > Object type'' (''shift + alt + a'')
  * ''file > clone > unlink clone'' (''shift + alt + d''). The clone objects have now been changed to circle and rectangle objects
  * ''edit > select all''
  * ''path > objects to path''
  * ''path > stroke to path''
  * ''path > break apart''
  * ''path > union''
  * ''file > save as'' Choose SVG.\\ {{:isel_icv4030:inkscape_-_proper_outline.jpg?400|}}\\ Now you have a proper outline

  * insert the SVG file in fusion 360
  * set scale to ''0,003779527597'' (The dimensions set in Eagle are correct in InkScape, but with scale set to 1, 1,27mm in eagle becomes 336,02083mm in Fusion 360)
  * select contours, extrude and configure setup and trace operation for milling

{{:isel_icv4030:fusion_pcb_setup.png|}}


==== Bad SVG's ==== 
=== Circles ===
{{:isel_icv4030:fusion_pcb_06.png?400|}}\\ 
When circles are actually 4 arcs they won't be selectable for a bore or drill operation.
  * Draw 2 construction lines between the 4 points of the bad circle.
  * Draw a circle to measure the diameter of the bad circle. Note the dimension and cancel the circle.
  * Delete the arc segments
  * Draw a the new circle with the measured diameter

{{:isel_icv4030:fusion_pcb_05.png?400|}}\\ These are proper circles.

=== Arcs ===
{{:isel_icv4030:fusion_pcb_07.jpg?400|}}\\ 
Some arcs are composed of multiple smaller arcs.
  * Select all the segments by dragging the selection box from left to right. Only the line elements that are fully inside of the selection box are selected.
  * Delete them
  * Add a tangent arc
==== Engrave toolpath ====

If traces come close together, the tool will lift, cutting a thinner trace. This allows to set a relatively deep trace over-all to accommodate flex in the PCB substrate. 
  * Select the area in between traces and push it down a small amount. The depth doesn't matter. **This creates a pocket we can use to select the engrave toolpath**.\\ {{:isel_icv4030:fusion_pcb_01.png?400|}}\\ 
  * Add an engrave toolpath strategy and select the traces. You don't need to select the holes yet, but **make sure to select a contour line around all the traces**. That way Fusion knows at which side of the lines the tool need to be placed. I tested 0.3mm depth, but 0,2mm or shallower should work better.\\ {{:isel_icv4030:fusion_pcb_02.png?400|}}\\ {{:isel_icv4030:fusion_pcb_03.png?400|}}\\ Here you can see the cut is made on the outside of the traces.

==== Small holes ====
{{:isel_icv4030:fusion_pcb_04.jpg?400|}}
  * Put one of the PCB drills from the Hyrel kit in a 1/8" (3.175mm) collet.
  * No need to ad these to the tool list in Fusion. Simulate them with a 1mm flat endmill. 
  * Take the CAM profile "PCB-Drill" from CAM Templates > PCB. This plunges the drill straight down. As it does not helix, the hole is the same diameter as the drill.