Hot-End Replacement Guide BFB 3000 plus & 3D Touch Pre assembly checks: Testing the hot-end before fitting: Check the heating cable: Set the multi-meter to read resistance (2000 ohms) Test the two outside pins (grey wires) The value should read 4.5 to 5.5 ohms Check the temperature thermistor: Set the multi-meter to read resistance (2M ohms) Test the inner two pins (violet wires) The value should read approximately 200 to 300 k ohms If at any stage the value is zero or OL, please do not continue and contact technical support.
The X-carriage: Removal of the motor belts and motors: Remove any filament that may be in the nozzles by heating and pulling Loosen the 8 screws circled in red and gently push the motors toward the extruder bodies to loosen the belts
Unclip the extruder power loom chain by using a thin flat blade screw driver between the top fins and pull the PTFE feed tubes back trying not to bend them too much Ease the wires from the acrylic plate
Disconnect the motor wires Ease the belts over each of the large pulley s as shown, gently turning the small pulley will help ease the belt free With the belts removed. Supporting the motor assembly, unscrew the 9 screws that are highlighted below.
Remove the motor plate and put to one side Disconnect the remaining wires from under this plate and remove the clear loom support brace, put this somewhere safe and secure the wires away from the head assembly.
Removing the extruders: Unscrew the 4 screws from the front of the acrylic top plate Unscrew the 3 screws from the rear of the acrylic plate, 2 screws also hold the small pcb.
The final 3 screws for the extruders are underneath the head assembly Lift the extruders off of the carriage and move the blue wire so that it passes through one of the larger holes next to it.
Removing the Z limit sensor: Using the 2.5mm ball driver or Allen key as shown and turn the grub screw counter clockwise to loosen. Caution: If this screw is accidentally tightened it will permanently damage the sensor. Gently pull the z sensor out and store safely
Loosen these screws using an Allen key and not the supplied ball driver. Unscrew the 5 screws highlighted in red and loosen the M5 belt tensioning bolt highlighted in green. Remove the belt from the belt clamp, if you wish to remove the heads to work away from the printer, follow the same step above on the opposite M5 bolt Loosen the grub screw holding the belt
Unscrew the 3 screws which relate to the hot-end you are changing Flip the steel plate over, push the centre pin on the plastic rivet and push out as shown in the photo. However if you have new rivets you can use these when refitting the pcb.
Refitting the hot-end: Take your new hot-end; Push the peek tube firmly into the aluminium nozzle, slide in the PTFE tube, and slide on the aluminium sleeve and mdf spacer. Screw into place with the M3 x 16 screws removed from your existing hot-end Caution: Try not to bend or flex the wires too much as this can damage the hot-end.
Replace the hot-end pcb and lock into place with the plastic push fit rivets. Note: Test all hot-end resistances before refitting extruder plate. To refit the x carriage, follow the manual in reverse. Pay close attention when refitting the acrylic parts as over tightening will crack them! When refitting the z-sensor, STOP soon as you feel light resistance DO NOT OVER TIGHTEN THE GRUB SCREW
Prepare the filament: Shape the filament to a rounded point, feed it through the feed tubes, tighten the pressure bearings and purge the nozzle Purging the nozzle: Move the bed down away from the heads. Set the print temperature to 200 for PLA and 260 for ABS Set the RPM at 45, once temperature is reached the motor will start Leave the nozzles to purge for approximately 5 minutes Congratulations you have completed the hot-end change
Happy printing BFB