pcb-msla

Expose PCBs on your Elegoo Mars, Anycubic photon or any compatible 3D printer using standard gerber files. pcb-msla can convert standard .gbr/.drl files into .cbddlp/.photon files.

It also features an exposure series function which helps to determine the correct exposure time for your 3D printer in a single pass.

Features

• Exposure test series function to determine the correct exposure time in a single pass.
• Setup PCB-Mode use the buildplate to hold PCBs in place during exposure.
• Convert gerber into cbddlp to use them directly on your elegoo mars.

Getting Started

Before installing, make sure you have installed python 3 as well as cairo. Proceed installing pcb-msla using pip:

$ pip install git+https://github.com/ingobecker/pcb-msla@master

You should now be able to invoke pcb-msla from the commandline.

Enable PCB-Mode

The first thing to do is to setup PCB-Mode on your printer. That is what the gcode subcommand is for. It generates a .gcode file to setup PCB-Mode (setup.gcode) and second one to restore your printer back to normal operation mode(cleanup.gcode).

In PCB-Mode, your printer uses the buildplate to clamp down the PCB before it starts the exposure. It also disables the peeling motion which in normal operation mode seperates the printed layer from the FEP film.

In order to clamp down a PCB correctly, the z-axis zero point has to be modified and the printer needs to know the exact distance from the buildplates new zero point to the upper side of the PCB when placed onto the printers LCD.

To offset the zeropoint upwards, use some tape to attach a little strip of paper to the metal part that reaches into the photo interruptor of the printer. The paper strip should be around 15 mm. With the paper attached open the printers menu for manual positioning home the printer. It should home the buildplate about the length of the attached paperstrip above the printers LCD.

Place a PCB and some padding material in between the buildplate and the display. Lower the buildplate in increments of 1 mm until the PCB is clamped down firmly. The number of millimeters is the offset you will need for the pcb-msla gcode <OFFSET> command.

Copy the generated .gcode files to a usb drive and connect it to your printer. Select the setup.gcode file. The printer is now operating in PCB-Mode.

Exposure Series Test

If you are using your 3D printer for the first time with pcb-msla or you have changed the type of photoresist PCB you have to determine the correct exposure time first. With the help of pcb-msla test you can generate a exposure test series pattern. With this feature, you cant test different exposure times in on run. To expose a test series with 4 different exposure times starting at 6 minutes incrementing the the for each successive exposure by 60 seconds run the following command:

$ pcb-msla test --start 360 --steps 4 --interval 60 test.cbddlp

For more details run:

$ pcb-msla test --help

Convert Gerber file

Converting a .gbr file into a .cbddlp file is simple. Run the following for an exposure time of 9 minutes:

$ pcb-msla convert -e 540 input.gbr output.cbddlp

Blank?

Every generated <OUTPUT_NAME>.cbddlp-File is accompanied by a file ending with <OUTPUT_NAME>_blank.cdbdlp. This file will expose an area with the size of the bounding box of the actual PCB. It is useful to expose the remaining photoresist on the traces after the etching process and removing it by giving the PCB another bath in the developer.