Connect Your Old 3D Printer to Your Network with a Raspberry Pi

This is a step by step guide to putting almost any USB 3D printer on your home network with a Raspberry Pi 3, OctoPi and OctoPrint. Once it is set up, you can send sliced files straight from PrusaSlicer, watch and control prints from a browser, and get ready for safe remote monitoring. No more walking an SD card back and forth.

The Raspberry Pi becomes a small print server that sits between your computer and the printer:

PrusaSlicer on your PC
        |
        |  Wi-Fi (home network)
        v
Raspberry Pi 3 running OctoPrint
        |
        |  USB data cable
        v
Your 3D printer

With this setup you can:

• Send G-code from PrusaSlicer without moving an SD card.
• Start, pause, cancel and watch prints from a browser on your network.
• See live temperatures and printer status.
• Later, add a webcam and secure access from outside your home.

The Raspberry Pi must stay powered during any print that OctoPrint is controlling.

Will this work with my printer?

OctoPrint does not care which printer you have. It talks to the printer over a USB connection and sends it G-code. So this works with most filament (FDM) 3D printers, even older ones.

It works if your printer:

• is a filament (FDM) printer, not a resin one,
• has a USB port you can plug the Pi into, and
• runs Marlin or similar standard G-code firmware (most Creality, Anycubic, Sovol, Artillery, Elegoo Neptune and similar models).

It is not supported for:

• Resin, SLA or DLP printers.
• Printers with closed firmware that do not accept standard G-code over USB.
• Printers that already have their own network, such as Prusa with PrusaLink or PrusaConnect and Bambu Lab, or a Klipper web interface.

The steps in this guide are the same for every compatible printer. You only swap a few values for your own machine:

• Build volume: your printer's real size.
• Heated bed and origin: match your hardware.
• Nozzle and filament size: for example 0.4 mm and 1.75 mm.
• USB cable: USB-C, micro-USB or mini-USB, depending on the printer.
• Baudrate: AUTO, or 115200 or 250000 if AUTO fails.
• Slicer profile: load your own printer's profile.

Example setup

These are the parts for the Ender-3 S1 Pro example used throughout this guide. Yours may differ, but the list shows what a typical setup looks like.

Required

Optional, for later

• USB webcam for monitoring.
• Switched power strip or smart plug for easy Pi power control.
• Remote access with OctoEverywhere or a private VPN.

Which Raspberry Pi?

The example uses a Pi 3, but you are not locked to it. Most models work, because OctoPi runs across the Pi range:

• A Pi 3 or Pi 4 is the best choice. The Pi 4 has more power, which helps with a webcam or higher-resolution streaming.
• A Pi 5, Pi Zero 2 W or Pi 2 also work. The Pi 2 has no built-in Wi-Fi, so it needs a USB Wi-Fi dongle or an Ethernet cable.
• The original Pi Zero or Pi Zero W works but is slow, and webcam streaming is poor. Only the oldest Pi 1 is too weak to recommend.

Two things change with newer boards: a Pi 4 or Pi 5 needs a stronger USB-C power supply and some cooling, and with a brand-new board you should pick the latest OctoPi image, because the stable image can lag a few weeks behind a just-released model.

Set it up, step by step

Do these steps in order. Each step lists the exact actions to take. Tips add small details the original guide leaves out, and warnings are safety notes.

Example: We use the Creality Ender-3 S1 Pro as the example throughout. The steps are the same for any compatible printer. Just use your own values where they appear, as listed under "Will this work with my printer?" above.

Step 1: Flash OctoPi onto the microSD card

1. Download and install the Raspberry Pi Imager on the computer you will use for setup.
2. Insert the microSD card into your computer. If your computer has no SD slot, use a USB card reader.
3. In Raspberry Pi Imager, click Choose device and select your Raspberry Pi model (Pi 3).
4. Click Choose OS and drill down to OctoPi:

Other specific-purpose OS
 -> 3D printing
    -> OctoPi
       -> stable

5. Click Choose storage and select the microSD card.

Tip: The Imager is free from raspberrypi.com/software (Windows, macOS, Linux).

Warning: Writing erases everything on the selected card. Make sure you pick the SD card, not another drive. Do not press Write yet. Set the network details in Step 2 first.

Step 2: Configure, write the card, then boot the Pi

1. Still in Imager, open the settings before writing. Click the gear icon, or choose Edit Settings if it asks whether to apply OS customisation.
2. Enter these values:

3. Click Write and wait for it to finish writing and verifying.
4. Safely eject the card from your computer.
5. Insert the microSD card into the Raspberry Pi.
6. Connect the Pi to its own power supply to switch it on.

Tip: The Pi has no power button. It starts on its own as soon as it gets power.

Step 3: Open OctoPrint in a browser

1. Wait a few minutes for the Pi's first boot to finish.
2. On a computer connected to the same home network, open http://enderpi.local
3. If that does not open, look in your router's list of connected devices for enderpi, octopi or raspberrypi, and open its local IP instead, for example http://192.168.178.42
4. Bookmark whichever address works.

Step 4: Complete the first-run wizard

When the OctoPrint setup wizard appears, work through each screen:

• Access control: keep it enabled and create an OctoPrint username and strong password. This protects the printer controls. It is separate from the Raspberry Pi system login.
• Online connectivity check: leave it enabled. It lets OctoPrint check whether the Pi can reach the internet for plugin and update checks. It does not make your printer reachable from the internet.
• Plugin blacklist: leave it enabled.

Then set the default printer profile. For the Ender-3 S1 Pro example:

Leave advanced speed and feed-rate settings at their defaults unless you have a specific reason to change them.

Step 5: Connect the printer over USB

Power and cable, in order:

1. Power the Raspberry Pi from its own USB power supply.
2. Turn the printer on normally.
3. Connect the Pi to the printer with a USB data cable (not charging-only).
4. Open OctoPrint.

Warning: Do not rely on the printer to power the Pi.

Then, in the Connection panel, set Serial port to AUTO, Baudrate to AUTO, and the Printer profile to your printer, and click Connect. A successful connection changes the status to Operational, and the Temperature tab shows live nozzle and bed temperatures.

First-connection check:

1. Confirm OctoPrint shows sensible nozzle and bed temperatures.
2. Use the Control tab only cautiously.
3. Do not move axes into a physical stop.
4. Keep your first print small and familiar.

Step 6: Add OctoPrint to PrusaSlicer

First, get the API key:

1. In OctoPrint, click the wrench icon (Settings).
2. Open API.
3. Copy the API key used for external applications.

Warning: Treat this key like a password. Never paste it into chats, screenshots, public documents, or GitHub repositories.

Then create the physical printer in PrusaSlicer:

1. Go to the Printer tab.
2. Open the printer-management menu next to the printer profile selector.
3. Choose Add physical printer.
4. Name it Ender-3 S1 Pro OctoPrint.
5. Set Host type to OctoPrint.
6. In Hostname, IP or URL, enter http://enderpi.local (or the Pi's IP if that fails).
7. Paste the API key into API key / password.
8. Click Test.
9. Save when the test succeeds.

Step 7: Send your first print

1. Slice the model in PrusaSlicer.
2. Click Send G-code. For the first few prints, upload only and start the job manually in OctoPrint.
3. In OctoPrint, before starting, confirm that the selected file is the intended one, the printer is clear, the correct filament is loaded, the sheet is clean and installed, and the expected nozzle and bed temperatures are correct.
4. Start the print while you are nearby, so you can watch the first layer.

Tip: Once you trust the workflow you can enable automatic start after upload, but manual start is safer for everyday use.

Daily workflow

Start up

1. Turn on the Pi and wait 2 to 3 minutes for OctoPrint to boot.
2. Turn on the printer.
3. Confirm the status is Operational.
4. Check the printer: filament loaded, plate clean, bed clear.
5. Slice, send, check the file, and watch the first layer.

During the print, monitor print progress, nozzle and bed temperatures, the current file and estimated time, and keep the pause and cancel controls handy.

Warning: Do not switch off, reboot, or unplug the Pi while a print is running.

After the print, let the bed and nozzle cool as needed, remove the part, clear the build plate, and decide whether you will print again soon.

Power use. A Pi 3 running OctoPrint uses very little power: about 3 to 5 W with no webcam, or 4 to 6 W with a USB webcam. That is about 26 to 44 kWh per year if you leave it on all the time, which is roughly 9 to 15 euro per year at 0.35 euro per kWh. You do not have to leave the Pi on all the time.

Safe shutdown. In OctoPrint, open System and choose Shutdown system. Wait for the full shutdown, then cut power at the strip or smart plug. If there is no shutdown option, use SSH:

ssh user@enderpi.local
sudo shutdown -h now

Remote access and webcam

Right now your setup works on your home network only. To reach it from outside, add a remote-access tool. Do not use router port forwarding, because exposing OctoPrint directly to the internet is unsafe.

• OctoEverywhere (beginner friendly): a plugin for remote access without port forwarding. Open Settings, Plugin Manager, Get More. Search for it, install it, restart, then link your account. Test it on mobile data.
• A private VPN such as Tailscale: gives your own devices secure access without publicly exposing OctoPrint. It is more technical, but stays within your device network.

A webcam is optional. Start with a simple USB webcam, use 720p or lower and a modest frame rate such as 10 fps, and mount it so it sees the nozzle and first layer without blocking movement. The Pi 3 has limited power, so avoid high resolution or frame rate.

Before starting a remote print, confirm the build plate is empty, the filament is loaded, the correct G-code is selected, nobody is near the printer, and the printer is in a safe area. A camera helps, but it is not the same as supervision.

Fixing common problems

enderpi.local will not open

1. Confirm the Pi is powered and had time to boot.
2. Make sure the computer is on the same network.
3. Find the Pi's IP in the router's device list, then open http://192.168.x.x directly.
4. Consider reserving a fixed IP for the Pi later.

OctoPrint does not detect the printer

1. Is the printer switched on?
2. Is the USB cable a data cable, not charging-only?
3. Is it fully inserted?
4. Set serial port and baudrate to AUTO, then disconnect and reconnect.
5. Try another data-capable cable. If AUTO fails, try baudrate 115200.

PrusaSlicer connection test fails

1. Confirm OctoPrint opens in a browser first.
2. Use the same address that works in the browser. Try the IP instead of enderpi.local.
3. Check the host begins with http://
4. Copy the API key again carefully. Make sure your computer and the Pi are on the same network.

Pi switched off by accident, or a plugin misbehaves

• Try to boot normally. If OctoPrint behaves strangely, the microSD may be damaged. Reflash OctoPi and set it up again.
• Avoiding sudden power cuts is the best prevention.
• If a plugin causes problems, use OctoPrint Safe Mode to turn off third-party plugins.

Warning: Never cut power during an active print. Sudden power loss can end the print and can eventually corrupt the Pi's microSD card.

Quick checklist

Before every print

• Raspberry Pi is running.
• OctoPrint status is Operational.
• Printer and build plate are clear.
• Correct filament is loaded.
• Correct model and G-code are selected.
• You can see the first layer.

After every print

• Part removed after cooling.
• Bed cleared.
• No active job remains.
• Pi shut down properly before cutting power.

Maintenance habits

• Install OctoPrint updates from time to time, but not right before a long print.
• Install only the plugins you really need.
• Keep the OctoPrint login password strong, and treat API keys as passwords.
• Keep a spare microSD card if you use this setup often.
• Check the USB cable and Pi power supply now and then.
• Watch the first layer for new files, new filaments, or changed settings.

Official references

• OctoPrint download and OctoPi setup
• OctoPrint API authorization documentation
• PrusaSlicer: sending files to OctoPrint
• OctoPrint guidance on safe remote access

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