Replace the thermocouple of the Filament Maker

This article will provide the necessary information required for replacing the thermocouples.

The thermocouple is the part tightened in the bandheater. The thermocouple ensures that the temperature of the bandheaters is measured. It may happen that one of the thermocouples fails. The faulty thermocouple can be replaced with a new thermocouple. This guide describes step by step how the old thermocouple must be removed from the bandheater and how the new thermocouple can be installed. 

Before you start

Collect the following items:

• soft cloth or towel
• hex key 2.5mm for M4 bolts
• tie wrap
• rubber gloves (for handling insulation wool)
• wrench 10
• piece of foam or wood to bring the machine up to height
• service package: new thermocouple, metal tie wrap

Step 1: Prep the machine

Remove top hood

Follow these instructions to remove the top hood first and after finishing continue to Step 2. 

Raise the machine

The machine must be brought up to height to remove the winder cover. Use a piece of foam or something similar to bring the machine to the right height. 

       

Remove winder plate

Remove the winder side plate. First unscrew the adjusting knob by hand.

       

Now unscrew the 6 bolts with the hex key.

First unscrew 5, shown with the red arrows. Loosen the bolt with the blue arrow indicated last. 

           

Step 2: Locate thermocouple

Depending which thermocouple must be replaced, cut and remove the first, second, third or the fourth tie wrap. Thermocouple number 1 is located at the front of the machine at the nozzle. Thermocouple number 4 is located at the end of the barrel, closest to the hopper.

Open up isolation wool and spread to such an extent until the failed thermocouple is exposed.

Step 3: Remove the thermocouple

Carefully unscrew the thermocouple with a wrench from the heater, but make sure to do it gently. 

Cut with a cutter the tie wraps which belong to the faulty thermocouple. 

Unplug the faulty thermocouple free from the DevoBoard, which is placed on the side of the machine. The first left plug is for thermocouple 1, next to it is the plug for thermocouple 2, 3 and 4. 

           

Step 4: Place the new thermocouple

Take the new thermocouple out of the packaging and place it back in the bandheater. 

Tighten the thermocouples hand tight and then another eighth turn (1/8) to a quarter turn (1/4) carefully with the wrench.

         

Step 5: Tidy up

Lay the cable of the new thermocouple again gently through the frame and connect it with a tie wrap.

Plug the cable into the DevoBoard. 

Fold the isolation wool back around the extruder and use new tie wraps to hold the isolation wool in its place. 

       

Finally, follow this guide in reverse order to mount the top hood on the machine.