Using the Polar3D "Bridge" Application to Connect Printers

Polar3D Bridge Overview

Polar3D Bridge is a cross-platform application designed to bring local network printers directly into the secure Polar3D ecosystem. By scanning your local network for Bambu Lab, Prusa, and Elegoo hardware, Bridge utilizes native local communication protocols to tether your fleet to our Status Server via an encrypted WebSocket connection.

Supported Hardware & Protocols

Quick Setup Guide

1. Install the App: Download and launch the Polar3D Bridge installer for your desktop operating system (macOS, Windows, or Linux).
2. Verify Network Access: Ensure the host computer running Bridge is connected to the same local network subnet as your 3D printers.
3. Run Device Scan: Open Bridge and select Connect Printers to initiate an automated local subnet scan.
4. Select & Authenticate: Check the boxes for the printers you want to connect and enter local credentials when prompted (e.g., Bambu Access Code or Prusa API key).
5. Confirm Connection: Verify that your selected printers report an active status on the Polar3D platform.

Requirements & Network Best Practices

• Background Operation: The host computer must remain powered on and running the Bridge application to maintain real-time status telemetry to the Status Server.
• Firewall Configurations: Ensure your network firewall permits local traffic for MQTT and HTTP/PrusaLink, along with outbound WebSocket communication.
• Static IP Addresses: Assigning DHCP reservations or static local IP addresses to your 3D printers prevents reconnection issues during local network resets.

Download Links 🔗

Detailed Setup Guides

Before continuing, please know that the bridge can connect both your Bambu Lab and Prusa Printers. As we expand compatibility, other manufacturers may be added to this list as well.

First Time Use

You'll need to start by downloading the appropriate software package from the list above. Then, follow the installation steps.

Once that's done, you'll need to enter your Username and PIN into the Credentials section of the app. The printers will be bound to this account, and then shared from within the Polar3D platform. Do not change the credentials here once the printers are connected.

Connecting Bambu Lab Printers

Most Bambu connection problems come from one of four things: LAN Mode or Developer Mode is off, the wrong IP address, an old access code, or a serial number from a different printer. Find the exact message Bridge showed you below.

Once you choose to add Bambu Lab printers, you'll need to scan your network to find them. The bridge will go through the IP addresses and identify any Bambu Lab units, then allow you to select them and connect them.

Alternatively, if you are trying to add one printer in particular, and you know the IP address, just enter it in the 2nd box and click "Check IP".

Please note that newer Bambu Lab printers will need to have the LAN Liveview turned on as well, in order to receive camera images. Please see below.

Tips:

• Read the access code right before you type it. It can change when LAN Mode is turned off and on, or when the printer's network is reset.
• Copy the serial from this printer's screen. Do not use the Polar Cloud id (it starts with BMBU), and in a room with several Bambus, make sure the serial and IP come from the same machine.
• Watch for look-alike characters in the serial: the letter O and the number 0, the letter I and the number 1.
• The computer running Bridge and the printer must be on the same network. School networks often keep devices apart (a separate Wi-Fi for printers, or device-to-device traffic blocked). If Bridge cannot see the printer at all, ask your IT team to allow the Bridge computer to reach the printer's IP.

Connecting Prusa Printers

Adding Prusa printers is done by entering the username and password of each printer into the setup wizard. Printers are then found on the network and connected.

Follow the rest of the onscreen instructions, and you're done!

FAQ

I sent a print to my Bambu Lab printer, but the print never started?

Very important! Check to make sure "Dev Mode" is enabled. This allows the printer to connect with local 3rd party controls.

If you've done that, make sure you have a FAT32 flash drive plugged into the USB port on your printer, if there is one. OR - use an SD card. Some of the printer models need removable storage in order to store the temp-file for the incoming cloud print.

Errors while finding the printer

These appear on the first step of Add Printer, before Bridge tries to log in.

“No printers found on your network.”

The automatic scan did not hear from any printer. Scans often miss printers on school networks, so this does not mean anything is broken.

• Type the printer's IP address into the box and select Check IP.
• Confirm LAN Mode and Developer Mode are both on (Settings → WLAN).

“No printer found at [IP address]. Confirm the printer is on this network and has LAN Mode + Developer Mode enabled.”

Bridge could not reach a Bambu printer at that address.

• Check the IP on the printer screen again. Printer IPs can change after a restart.
• Confirm LAN Mode and Developer Mode are both on.
• Make sure the printer is powered on and connected to Wi-Fi.
• If all of that is right, the network may be blocking the Bridge computer from the printer. Ask your IT team to allow traffic from the Bridge computer to the printer's IP.

“Enter the Bambu LAN access code first.”

Bridge needs the access code to read the printer's serial number. Type the 8-character code from Settings → WLAN → LAN, then try again.

“Could not read the serial automatically.”

Bridge found the printer but could not read its serial number.

• Turn on Developer Mode (not just LAN Mode). This is the most common cause.
• Re-read the access code on the printer and type it again.
• Or type the serial yourself from Settings → WLAN → LAN.

Errors when adding the printer

These appear after you select Add, when Bridge logs in to the printer to test the connection.

“The printer at [IP address] accepted the access code but closed the connection right away.”

Older versions of Bridge show this as: “Could not open MQTT to [IP address]. Check the IP, LAN mode, and access code.”

Your IP address and access code are correct. The printer let Bridge log in, then disconnected it. This almost always means the serial number does not match this printer.

1. On this printer's screen, open Settings → WLAN → LAN and re-copy the serial.
2. Compare it character by character, watching for O vs 0 and I vs 1.
3. Do not use the Polar Cloud id (starts with BMBU), the serial from the box, or another printer's serial.
4. If the serial matches, close Bambu Studio, OrcaSlicer, or Bambu Handy on other computers and phones, then try again. Some Bambu models only allow a few connections at once.

“Connected to the printer but got no status for serial [serial].”

The login worked, but the printer never sent status for that serial. As above, the serial almost always belongs to a different printer. Re-copy it from Settings → WLAN → LAN on this printer.

“Could not connect to the Bambu printer (…). Verify IP, LAN serial, and access code.”

Bridge could not log in. The text in parentheses tells you which value to check:

“Enter the Bambu serial number from Settings → WLAN → LAN on the printer.”

Bridge does not have a serial for this printer yet. Type it in from the printer screen.

“[text] is not a Bambu LAN serial.”

The serial you entered is not in the right format. A Bambu LAN serial is about 15 letters and numbers with no spaces or dashes. Polar Cloud ids (starting with BMBU) will not work. Copy the serial from Settings → WLAN → LAN.

Still stuck?

Contact Polar support and include:

• A screenshot of the exact message Bridge shows
• Your printer model (for example P1S, A1, X1C)
• Your Bridge version (shown at the top of Bridge and on the About page)
• Whether LAN Mode and Developer Mode are both on
• Whether other apps (Bambu Studio, OrcaSlicer, Bambu Handy) connect to the printer over LAN