This replacement applies to Ultimaker 3 and Ultimaker 3 Extended printers.
- 2mm allen key or 2mm hex head screwdriver
- small flathead screwdriver (optional)
1. Remove filament from printer. Go to Material --> Print Core 1 and/or Print Core 2, and choose to unload the material in the unloading wizard. Wipe the nozzle tips clean with a paper towel while they are still hot.
2. Slide the white, horseshoe shaped clips sideways out of each of the white collets in turn.
3. Push down on the white collets while pulling up on the bowden tubes to free them from the printhead. Note: if the filament could not be ejected from the printhead, you can still remove the bowden tube, and cut the filament off above the collet.
4. Using your 2mm hex head screw driver, unscrew the 2 long screws at the rear of the printhead, highlighted in green below. Then, press your screwdriver into the slot indicated by the red arrow to remove the top-rear plastic piece--you may find a flathead screwdriver easier for this step, though your 2mm hex head will also work.
5. Press your screwdriver against the plastic flap on the front of the connector to release the printhead cable from the printhead.
6. Tilt your left and right sliding blocks until the printhead shafts come free from the block; repeat this process on the front and back sliding blocks.
Hold the printhead carefully so that neither shaft slides out, and rotate it 45 degrees. You should then be able to freely pull the printhead and shafts out of the printer housing.
7. To replace the printhead, press the printhead cable into the connection port on the printhead and make sure you hear it click into place, to let you know it's fully seated.
8. Thread your longer printhead shaft through the bearing running left to right in your printhead, and your shorter printhead shaft through the bearing running front to back. Position the printhead at a 45 degree angle, and rotate it to line it up with the sliding blocks.
9. Push the printhead shafts into each of the blocks one at a time--it's easiest to start with the front to back shaft. Hold the block steady to make sure that the rod snaps into it straight--tilted sliding blocks will cause errors with the automatic leveling. The printhead shaft running front to back should be positioned with the back of the shaft flush with the back of the rear sliding block. The printhead shaft running left to right through the printhead should be positioned about a fingernail's distance or so from the left side panel. You want to make sure that the shaft will not scrape the left panel, but that it will engage the metal trigger arm on the red Y-stop well.
10. Press the top-rear plastic piece back into position and screw the printhead screws back in place. If possible, apply a little removable thread-locker to the ends of the screws before screwing them in. When tightening the screws, make sure that all parts of the printhead block are well aligned.
11. Push both of your bowden tubes back into their respective positions on the printhead as far as they will go. Then, raise the collets to slip the horse-shoe shaped clip in place under the collet. This clip is vital for helping your bowden tube remain seated securely during printing.