Projects:

[introduction] cad/cam, modeling, software

[press fit structure] laser cutter, vinyl cutter, plasma cutter/router

[printed circuit boards] pcb fabrication, board stuffing

[pcb component bag]

 

The third project was concerned with PCBs, or Printed Circuit Boards. Objective: make a circuit that uses a microcontroller to display “Hello World” on the computer Materials: soldering iron, solder, copper plate, end mill, microcontroller, resistor, capacitor, regulator, Molex   Procedure 1: Using the small end mill in the Modella CNC router, remove the copper from the copper plate that is not part of the circuit. Tape the copper plate to the bed of the router using double-sided tape, making sure that the tape overhangs for easy removal later on.  Tape the plate down, 2 squares up and 2 squares over.  Open Cam.py from the desktop or open the terminal directly and type “cam”.  Input “hello.cmp”.  Click “Auto Scale” to see the circuit at a larger scale.  First press “contour”, then “raster interior”.  There’s no need for an output file.  Take off “view” mode on the router to allow info from the computer.  Activate “view” mode to manaully move the mill.  From a terminal, type “move 1 1” (and X:1 and Y:1) w/ view mode off to orient the mill.  Replace end mill if necessary, with allen wrench found on the machine, leaving ~ 1cm sticking out.  Press “down” until the bit cannot go any further.  Press “up” for just a second to ensure clearance height.  Using your finger to guide the bit, drop it down to the surface of the copper plate.  Press “send to” to begin milling.  If something is not right, press “view” on machine to cancel the cut. Procedure 2: Using the Vinyl cutter, make a flexible circuit board Get the cam tool (vinyl cutter) The wheels must always be arranged under the white tabs on the machine. Use the clamp at rear of machine to raise and lower wheels Feed a small copper sheet (6”x12”) into the cutter and roughly center it, using the tool’s cutting path as the center line. Turn the machine’s power on Select “roll” or “sheet”, it doesn’t really matter Play w/ the force setting if the cut comes out poorly (usually around 50) Move stock (copper) around w/ arrows if necessary.  When done, press and hold “Origin” Select “contour boundary” and press “send to” Once the cutting is done, unclamp the material and remove it. Apply copper side to a piece of masking tape that overhangs the extents of the board Transfer the board from the masking tape to a piece of white/clear epoxy sheet Procedure 3: Solder the components onto the circuit board wet the yellow sponge set the temp of soldering iron to 700 degrees F turn on the fan to minimize fumes (mildly toxic) wipe off excess solder on the sponge use a “Quick Braid” to remove solder

 

[rigid pcb using modella cnc router]

 

[pliable pcb using roland vinyl cutter]

Links:

cnc router tutorial (N51)

www.matthewtrimble.com