OHAI: Open Hardware Assembly Instructions

1 Preparation

Access Mainsail: Ensure you can access the printer’s Mainsail web interface through a web browser. You'll need this for the software setup.

Save Your Files: If there are any gcode files on the printer, download them via Mainsail.

Turn Off the Printer: Power off the printer before proceeding.

Good Lighting: Move the printer to a well-lit area to clearly see the SD card slot.

Power off printer

2 Removal of the SD Card

Lift the Card: Use a small tool, like the edge of a metal ruler, to lift the SD card slightly.

Remove the Card: Once lifted, use tweezers to pull the card out completely.

Grab the SD card

Remove SD card

3 Flashing SD Card With Firmware

Insert SD card into your computer, using an adapter if needed.

Download the Raspberry Pi Imager software from raspberrypi.com and install the software.
Download the firmware zip from the firmware.lulzbot.com page and extract the .img contents to your computer.

Use the following instructions to select and flash the firmware to your micro SD card.
Note that the Pi imager software may update from time to time, but the process will largely be the same.

Open the Raspberry Pi Imager program.
Scroll down and select "No Filtering" then click Next.
Scroll down and select "Use custom".
Locate the Mini 3 firmware .img file and select it.
Click Next.
Select the SD card from the available storage devices.
Click Next.
Review the summary and if everything looks correct, click "WRITE".

A prompt will appear warning you that proceeding will erase all data from the selected drive.
- Click "I UNDERSTAND, ERASE AND WRITE"

The firmware will begin to write to the SD card then run through a verification process.

Once complete, click FINISH and remove the SD card from your computer.

Select no filtering

Select use custom

Select SD card drive

Review and write

Warning message

Image writing

Verifying

4 Installation of the SD Card

Locate the Slot: Ensure the SD card slot on the circuit board is visible. Be careful not to drop the card into the control box.

Insert the New/Flashed Card: Insert the card with the gold contacts facing down and to the right. Push it into the slot until it touches the bottom.

Align sd card with back of slot

Place SD card i slot

Gently push SD card into slot

SD card seated

5 Software Setup

Power On the Printer: Turn the printer back on.

Reconnect Wi-Fi: If you were using Wi-Fi, reconnect by selecting your network and entering your password.

Note the IP Address: When the IP address appears, use it in a web browser to access the Mainsail interface.

Configure Printer:

In Mainsail, go to Config and Updates and check the box to show hidden files.
Open the .printer_ids.cfg file.
Click Devices and refresh to detect the ID numbers. Copy the first ID, then paste it into the appropriate location in the .printer_ids.cfg file.
Repeat for the second ID, ensuring both are updated.

Save and Restart: After updating the IDs, save and restart the printer.

Enable show hodden files

printer_ids.cfg file

Refresh devices

UUID and where they go

UUID copied to the cfg file

Save & restart

6 Recalibration

BLTouch Probe Calibration:

From the touchscreen, go to More > Z Calibrate > Start > Probe.
When prompted, use a sticky note to calibrate the nozzle's height by adjusting it until it just touches the paper.
Save the new calibration value.

Z-Endstop Calibration:

Go to More > Z Calibrate > Start > Z Endstop.
Use the same process with the sticky note to adjust the nozzle's position.
Save the new Z-Endstop calibration.

7 Final Checks

Run a test print using the "5_Circles" print.

Adjust the Z-offset if necessary and save any changes using the Save Z-Endstop button.