PCB Milling and Printing

• Board Design
  • If designing with Fritzing…
    • Open Fritzing > make breadboard > check circuit-diagram > lay out on PCB
    • Set board-type (1 or 2 sided, in info panel on bottom-right)
    • Autoroute traces (bottom bar)
    • Check design calculations (Routing > Design Rules Check)
    • Export as an Extended Gerber for the Voltera and as an SVG for the Carvey (bottom bar)
  • If designing in Eagle..
    • Open Eagle > make circuit-diagram > lay out PCB
    • Set board type (1 – multi-layered) by drawing in different layers
    • Formatting
      • If power-planes are desired, they can be added by drawing a “polygon” around the desired region > name it the same as desired signal> rats-nest > make sure the pad is connected to the proper signal by clicking the signal with “Name” tool (on the left)
      • Distance between paths and power-planes can be changed with a right-click on the polygon > properties > isolation
      • To remove power-planes use “RIPUP @;” in the command line
      • If you want to move component names without moving the components, use “SMASH”
      • “Design-Rules-Check” on the left-hand side provides and in-depth menu to change pad and trace widths and sizes (among other things)
      • Pad size can also be individually changed with the “Info” > diameter or can be changed in the component library. WARNING: changes made in component libraries will not auto-reset
• Autoroute traces (left-hand bar)
• Check design and electronics calculations (left-hand bar)
• View what the board will eventually look like with “Manufacturing” (right-hand side)
• File > CAM Processor > preview board > go to drill document settings > advanced > set integer to 2 and decimal to 4 (imperial standard)

Figure 1 - The Eagle PCB development screen showing where the main tools can be found. Side-bar: move, name, info, polygon, ratsnest, design-rule-check, electronics-rules-check, route, autoroute, group. Top-bar: CAM Processor, view, save, layer

• Board Manufacturing
  • If cutting with Carvey…
    • In Eagle, move board more than 1in up (as to not run into the clamp, groups > ctrl + right-click + “Move”) > center board on final workpiece (for 2-sided board) > CAM Processor > export Gerber file

• Open FlatCAM > load Gerbers > Tool (top bar) > Double-sided PCB Tool  > select bottom Gerber file > export mirror > select Gerber files under project tab > adjust relevant settings: tool-size (~.02in), isolation passes (2 an up normally), combine passes (check) > generate geometry > set CAM parameters (.iso file) > cut-depth (-.01) > export as g-code
• Now open Easel > load gcode file > load tool > clamp piece > adjust tool size (same as FlatCAM designation), workpiece dimensions, and feed speed (30 in/min) > follow print dialogue (feed-speed can be increased and decreased 100% after carving begins

Figure 3 - General Carvey tooling parameters for PCB milling.

• If printing in Voltera…
  • Open Voltera > load file > simple print > follow print dialogue (for board with preexisting components use the “aligned” option)
• If drilling and printing in Voltera…
  • Select ink > upload Gerber file for paths > load hole-map> follow print-dialogue
• If drilling with Carvey and printing in Voltera
  • Open hole-map SVG in Easel > mill holes (fill not outline) > open trace- and hole-map Gerbers in Voltera > aligned print > follow print dialogue