## Characterize the specifications of your PCB production process
# Author : seunghwan-ji
This is pcb milling machine we use. It’s name is BANTAM now, which is other mill before.
Extensions supported by BANTAM are EAGLE (.brd), Gerbers, SVG (.svg), G-code (.nc, .tap, .gcode).
different to other milling machine like Roland, it has electronic tool length measuring function.
This is the material we use it called FR1.
It has thin copper on the top to flow electricity.
And phenolic paper under copper foil.
We used double sided tape to secure copper board to sacrificial bed.
FR4 is double-sided copper board and it has glass fiber fabric between copper foils.
It’s stronger to heat than FR1 but you should be careful to not inhale glass fiber dust.
These are tools we use for milling PCB board.
We use 1/64inch end mill to cut trace and 1/32 inch to cut outline.
And these endmill have different shank diameter.
we should use proper collet to each shank diameter to hold the tool tight.
And cut length is related to cut depth. We should use longer tool than cut depth.
When we set tool on the machine we should measure the tool length.
And this process is essential every time you change the tool.
When we change the tool and set tool on program, it automatically start tool measuring.
It moves to right part of sacrificial board and slowly goes down.
When the tool touches the board and electricity goes though and stop.
Each material has slightly different thickness.
So we should measure material thickness using Bitbreaker tool.
When we push Bitbreaker, we can set the location.
Measuring the part you will cut is better because FR1 board has slightly different thickness on each part.
There is black metal clip. When measuring material thickness clip should be on the material to flow electricity though the copper surface.
When we open .nc extension file created by fabmodule program show simulate image.
And we can set placement avoiding used part. So we left this paper beside to machine.
So that everyone using machine can set the unused placement.