One of the best (and most unique!) features of the MOD-t is its simple calibration process. The MOD-t uses servo feedback to gracefully calibrate your MOD-t, regardless of your print plate’s starting location.
This means, you can place the print plate anywhere in the print bed and your MOD-t will still calibrate correctly. (Of course, you still need to make sure your plate is placed square on the pinion rods so that it can glide smoothly around the print bed! A good way to do this is by putting the plate against a corner or wall of the base.)
Your printer starts calibrating as soon as the file transfer is complete. There are currently three steps to the MOD-t calibration and we’ll keep you posted as we release more improvements to this process.
Update! We’ve changed our calibration process to make it faster and more accurate. Check out the new automatic calibration process below.
- First, it will home the X and Y axes. We’ve made this step much faster and your MOD-t will now actively work to align your build plate as it homes.
- Then, the carriage will lower the nozzle while the build plate moves side to side. Once the nozzle makes contact with the print surface plate, your MOD-t will have its rough Z position.
- Your MOD-t’s nozzle will heat up.
- Your MOD-t will repeat the second step two more times, with the MOD-t’s nozzle lightly touching the build plate to complete the high-accuracy homing. The entire process should take about 90 seconds.
- You’ve probably noticed that every print begins with a vertical stripe on the right side of your print surface plate. That’s what we call priming, or, more informally, the “Nose Wipe.” It’s your MOD-t’s way of cleaning excess filament off the extruder and priming the nozzle so you get fresh filament for your new print.
Feeling nostalgic? The following is our old calibration process. This is the process for MOD-ts running on firmware versions before 0.12.0
(1) The carriage lowers so that the hot end touches the build surface and then rises back up.
This is your MOD-t finding its rough Z-axis position.
This is done when the nozzle is at a lower temperature than when the printer is extruding. If the nozzle is hot (from a filament change or previous print job), the MOD-t will wait for the nozzle to cool before starting this step.
(2) The MOD-t moves the build surface.
This is the little dance your tray does in the print bed. (It moves right first, moves to the back next, moves left, then moves to the front.) This is how your MOD-t centers itself on the X-axis and Y-axis.
At each point, two of the print surface plate’s legs (on the bottom of the tray) make contact with the pinion rods the plate returns to the middle. Then it continues to the next panel. If the MOD-t fails during this process, it will re-try up to three times. If the tray was not placed correctly (as mentioned above), you will hear a chatter. Sometimes, the MOD-t will automatically fix this, but it’s best to just place the tray correctly yourself!
(3) The carriage lowers while the build surface swipes left to right.
(Note: There will be a pause before this step so the nozzle can warm up.)
This final step is when your MOD-t gets its most accurate reading of where the nozzle is in relation to your print surface plate. Your nozzle should not touch the build plate during this step. It should merely hover closely. Touching the build plate could cause inaccurate homing. You should also take care to keep your MOD-t base and pinion rods free of debris so homing is not affected during this final step.
Now that you understand how your printer calibrates, you can watch as your print surface and carriage do their little dances to help you keep making great things!