Week 4:
Electronics Production

Mission objectives:

Make an in-circuit programmer by milling the PCB (programm it, so that you can use it later).

Explain any problems and how you fixed them.

Include a "hero shot" of your board.

Milling the PSB

Group assignment

Milling of the first clean board took time and learning by mistakes. Mistakes that we have made on the way could be usefull as warnings for the beginners. Try to avoid them.

Milling process with Roland MDX-20 milling machine video

The milling spindle speed was 10000 RPM. The job made in 4 offsets with 1/2 diameter of the tool stepover between offsets for traces. The direction was climbing and the path order was forward. The X and Y machine speed was 4 mm/s.

Detaching the milling tool requires to open the both locking Allen screws. Each one of them on the opposite sides of the axis shaft.
Same about the locking of the tool - remember about those both screws. You do not want to get of center - wider milling path, by locking just one side.

Make sure that the plexiglass bed surface is clean and straight before you stick the board on it.
Bumps, hills are created on it during a lifetime, so it should be replaced when it deformed or became rough. If you have differences in path deph(quality) on the same boar that should be the reason.

In our lab there is a simple hack - support rail with two locking plates. They hold the PCB board during the milling and prevent it from any movement in all the other directions that the sticky tape doesn’t.
This improvement had been made during FabAcademy 2013 on laser cut from thin plexiglass and have locking Allen bolt for each side.

While creating the origin (x;y) point for the milling path ,make some room on the PCB board around the parts final cut outline. Do not squeeze you parts on it, let them breath.

Do not forget to switch the tools and the fab module parameters, from 1/64 to 1/32 and back, when you change the tool function from path milling to outline cut.