> ## Documentation Index
> Fetch the complete documentation index at: https://stem-docs.intellectualpoint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Extruder carriage on the bar

> Slide the extruder print-head carriage onto the extruder bar, oriented correctly.

## Adding the print head

Now you slide the **extruder carriage** - the print-head assembly with the fan - onto the bar you just started. Getting the orientation right here matters: the fan and QR code must face the same way.

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<Info>
  No screws for this step - the carriage simply rolls onto the bar's track on its rollers.
</Info>

## Step-by-step

<Steps>
  <Step title="Check the orientation">
    The extruder carriage has three rollers on one side and a fan on the front. Make sure the **fan and the QR code on the feeder face the same direction** (the front).
  </Step>

  <Step title="Feed the rollers onto the track">
    Line up the carriage's rollers with the top and bottom of the bar's V-slot track and slide it on. It should roll smoothly back and forth.
  </Step>

  <Step title="Confirm the cable direction">
    The carriage's power cable should trail toward the **back**, up and over the bar - never trapped underneath it.
  </Step>
</Steps>

<Check>
  The extruder carriage rolls freely along the bar, the fan and QR code both face front, and the cable runs to the back over the top of the bar.
</Check>

## Up next

Next you cap the end of the bar with the **roller bracket** that keeps the belt aligned.