⬢Take two M3x10 screws and insert them in the holes. Doing this now makes the assembly slightly easier, but both holes are shallow and the screws might fall out. If this happens, you can continue without them and put them back later on (you will be noticed). Also note, that in few upcoming pictures the screws might be missing.
Hotend assembly was completely reworked from MK2.5 to avoid bad placement. Also any future maintenance is much easier.
⬢Place the hotend next to the Extruder-body, see the grooves in the printed part, which are in the shape of the hotend.
⬢Correctly placed hotend. Cables should point in the direction behind the hand, we will align them in the next step.
Following cable management is CRUCIAL for the extruder TO WORK PROPERLY! Read the instructions carefully.
Before you assemble the X-carriage, check the nuts in the Extruder body are still in place. The upper nut sometimes falls out.
⬢Grab the X-carriage and place it onto the back of the extruder assembly as shown in the picture.
⬢Make sure the motor cable follows the channel both in Extruder-body and X-carriage. In the X-carriage the motor cable will follow the path of the IR-sensor cable.
⬢ENSURE NO WIRE IS PINCHED! Then use the M3x10 screw and Allen key with ball end to connect both parts together. If you are inserting the screw at this moment, it will be slightly inclined in the beginning, but it will "straighten up" after few turns. Don't tighten the screw completely, we need to adjust the IR-sensor cable.
⬢Turn the extruder to the other side and if needed insert the second M3x10 screw. Don't tighten the screw, we need to adjust the IR-sensor cable.
The fan has two sides, one has a Noctua sticker. Make sure, this side is facing inside the extruder.
⬢First, create a loop on the cable. Make sure the black protective wrap is close to the edge of the fan. See the picture.
⬢Place the fan on the extruder and proceed in the following way:
⬢Start by placing the fan's cable in the upper channel
⬢Slide the fan close to the X-carriage and GENTLY PUSH the cable in using an Allen key. Before you push the fan all the way to the left, place the cable in the X-carriage channel.
FINAL CHECK! The fan is oriented with the cable facing up, then the cable goes through the upper channel all the way to the X-carriage. In the X-carriage don't forget to use both channels. Make sure the CABLE ISN'T PINCHED along the way!
The fan-shroud was initially designed for M3x18 screw, but based on the feedback and to make the assembly more convenient, use M3x20. If your extruder bag includes only two M3x20 screws, please use another one from the spare bag.
⬢Using right hand rotate the motor to its original position and hold it (tension is applied to the belt).
⬢Using two fingers on your left hand push the belt together. Very small force should be needed for bending the belt, BUT the belt shouldn't be bent by its own weight before being pressed with your fingers, it must be straight.
If you are struggling to rotate the motor back into position, the belt tension is too high.
⬢Depending on the belt being under or overstretched, adjust the amount of the belt in the X-carriage.
⬢When done, rotate the motor to its original position and tighten the M3 screws again.
⬢Use the technique described below to test if the belt is properly stretched.
⬢Use pliers to hold the X-axis motor shaft.
⬢Move the extruder towards the X-axis motor. Don't use excessive force.
⬢If the belt is stretched properly, you should feel a resistance and the extruder won't move at all. If the belt is too loose, it will deform (create a "wave") and jump over the teeth on the pulley.
Belt too loose? Return to step 49 and repeat all steps until now. You have to rotate the motor and retighten the belt in the X-carriage. Shortening the belt length by moving one or two teeth outside X-carriage should be enough.
For the following step we recommend getting a white marker, but you can also trim the belt without it.
⬢Measure the part, which must be trimmed and gently take the end of the belt away, from the X-carriage, but make sure at least 3-4 teeth are still in the X-carriage, as you don't want to lose the tension. If possible make a mark, where to cut the belt.
⬢Ensure again your mark is in the correct position and the belt is still stretched.
⬢Using pliers cut the belt and push it inside X-carriage. Use screwdriver or Allen key, if needed.