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Celestrius Data Collection Guide (OctoPrint)

ยท 7 min read

This guide is only for the OctoPrint users. If you are using Klipper, please follow this guide.


This guide assumes you already have a nozzle camera installed on your 3D printer and connected to OctoPrint. If you have not installed a nozzle camera yet, follow the guide for Prusa Mini/Mini+ or Voron 2.4/Trident with Stealthburner

Required files/softwareโ€‹

The following files (also linked throughout the document) are required.

Step 1. Download and configure the Celestrius pluginโ€‹

1. Download the Celestrius Plugin and save it somewhere on your computer. You do not need to unzip the file.

2. Open the Octoprint interface in a web browser. Open the settings menu, scroll down and select the Plugin Manager.

3. Click get more. Scroll down until you see ... from an uploaded file. Click Browse and select the Celestrius Plugin on your computer. Click Install.

4. Once the plugin has finished installing, restart OctoPrint

Configure the Celestrius Pluginโ€‹

Once OctoPrint has restarted, you will be greeted by the setup wizard.

Read the policy on how your data will be collected and sent to the server. Instead of some fancy legal language, we tried to phrase the policy understandable for everyone. We want to look at only the data that you approve of. Once your data is uploaded, we will wait a period of seven days before accessing it. If, during that time, you notice you have uploaded data unintentionally, send us an email and we will delete the requested data.

1. Click the check box to accept the terms.

2. Enter the email you used when completing the Celestrius interest form, check the box to confirm that you agree.

3. Enter in Snapshot URL the URL for the nozzle camera you set up for project Celestrius. Ensure Celestrius is using the proper camera. Especially if you have multiple cameras configured in OctoPrint, double-check to make sure you have entered the correct URL.

4. Click the "Test" button to verify this URL works, and the image shows your nozzle camera as intended.

5. Click Finish.


If setup wizard does not appear, you can access it by opening the OctoPrint settings and clicking Celestrius Data Collector

How data collection worksโ€‹

By default, the Celestrius button will be off (grey) and not collecting data. To enable data collection, simply click the Celestrius button at the top of the OctoPrint interface to turn on data collection (green).

If you do not accept the terms, data collection will not begin. In this case, attempting to turn on data collection will result in a yellow Celestrius button at the top of the OctoPrint interface.


Once turned on, data collection will remain on until you turn it off. Be sure to turn off Celestrius after running data collecting prints to avoid sending unwanted/unnecessary data.

Step 2. Calibrate your first layerโ€‹

The most important thing before you do the test prints is to make sure your first layer is calibrated. Otherwise, it may signficantly impact the quality of the data collected from your nozzle camera.

1. Turn OFF Celestrius data collection

2 Download 1-t-rex.stl in this folder. Slice it with the settings you typically use when printing with PLA.

3 Check your print quality

Once the print finishes, compare your finished print with the one shown.

Keep an eye out for the following:


The view from the nozzle camera should look something like the image below.

  • The lines should slightly overlap each other so that when you remove the print from the plate, it is one homogenous surface with no gaps or voids.

  • The overall surface is flat and smooth.

Improve Print qualityโ€‹

If your print is not one homogeneous smooth surface, or there are gaps or voids in the print, try the following in order:

1. Level the bed. Do this before adjusting any other settings as it is the most common issue.

2. Adjust the Z-offset slighlty.

3. Ensure the nozzle is not clogged, and it is free from debris.

4. Calibrate the flow rate using Teaching Tech's tutorial.

Once your print is close enough to the examples above, your 3D printer is properly calibrated for a good first layer with proper bed adhesion and adequate flow.

Step 3. Print the baseline test modelsโ€‹

This folder contains five test models that only contain one .2mm layer. You will be asked to print each model twice. First, you will produce a high quality baseline print, and then you will adjust the flow rate to simulate a print with a poor first layer.

1. Turn ON Celestrius data collection


Please remember to turn on data collection. Otherwise your test print results won't get sent to the Obico Team.

2. Slice the file with the same properly calibrated settings from step 2.

3. Save the file with the naming convention as shown. For instance:

The gcode name for 1-t-rex.stl will look like:

4. Print all 5 models. Please make sure the first layer quality is as good as in the calibration step. If not, please go back to the calibration step and start over. Consider wiping the bed clean with isopropyl alcohol and re-leveling the bed in between prints to ensure consistent bed adhesion.

Step 4. Adjust your flow rate to make sure your printer will produce bad first-layerโ€‹

1. Turn OFF Celestrius data collection

2 Slice 1-t-rex.stl to produce an under-extruded g-code.

We will accomplish this by adjusting the extrusion multiplier in Prusa Slicer (called flow in Cura). Typically, your baseline prints will have used an extrusion multiplier ranging from 0.9-1.1.

Now, adjust the extrusion multiplier to 0.6. Depending on your setup, this may or may not be low enough to produce a significantly different result.

3 Print the gcode and compare the result to examples below

4 If the reduced flow does not result in an obvious difference from the baseline prints, adjust the extrusion multiplier from 0.6 to 0.5 and re-print the first model. Repeat the process until the print resembles the examples above. If you need to go lower than 0.5 extrusion width, reduce the extrusion width by 0.25. For example, go from 0.5 to 0.475.

The goal here is to ensure that the flow is obviously reduced so that the infill lines do not overlap or touch each other.

This will result in a print that is not a smooth homogeneous surface. Compare your model to the one shown above. If it is similar, move on to print the remaining models.


The view from the nozzle camera should look something like the image below.

Step 5. Print the test models again with the reduced flow rateโ€‹

1. Turn ON Celestrius data collection

2. Slice the model with the same reduced flow rate settings from step 4.

3. Save the gcode file with a different naming convention. For instance:

The gcode name for 1-t-rex.stl will look like:

4. Print all 5 models. Please make sure the first layer for all 5 look similar to what the reduced flow rate examples. If not, please go back step 4 and start over. Consider wiping the bed clean with isopropyl alcohol and re-leveling the bed in between prints to ensure consistent bed adhesion.

Step 6. Turn off data collection.โ€‹

Make sure you turn off data collection once you are done with step 1-5. Otherwise, the plugin may send unintended data to our server.

Optionally, you can go Celestrius settings page to review all the prints that have been sent to the server. If you find any prints that you didn't intend to send and want us to delete them, please email us to request data erasure.


Your uploaded data won't be accessed by the Obico Team for 7 days. This is the give you a chance to request data erasure in case they are sent unintentionally.