F25 Barrel and Screw Inspection Procedure

• Torque Wrench (5.8Nm)
• Circlip pliers
• Lifting eye (M8)
• Metric Hexkey set

 

 

The following Personal Protective Equipment (PPE) is explicitly required for executing this procedure. This is in addition to any PPE requirements mandated by local regulations.

Table 1: Applicable PPE to use during execution of this procedure.

Symbol:	Explanation:	Applicable standard:
	Make sure you protect yourself with safety goggles with an EN166F rating.	EN 166:2001
	Make sure you wear foot protection with EN ISO 20345 S3 rating	ISO 20345:2011
	Make sure you wear gloves with EN407 with minimal level 3 contact heat rate (X3XXXX).	EN 407:2004
	Make sure you protect yourself with a mask with a EN149 FFP2 certification.	UNI EN 149:2001
	Make sure you protect yourself with a face shield with a EN166F rating.	EN 166:2001
	Make sure you wear a protective clothing with EN407 with minimal level 3 contact heat rate (X3XXXX)	EN 407:2004

Instructions step by step:

Before the inspection, it is necessary to purge the extruder and make sure the barrel & screw are free of all foreign material.

 

Pay attention to the orientation of the part, so you know how it’s supposed to be put together afterwards.

 

 

1. Unscrew the 6 bolts (pointed out with the arrow) that hold the assembly marked in 
red.

2. After unscrewing this part, the whole assembly marked in red can be lifted off of the 
barrel.

Warning! When you are taking the motor assembly off you should take out the 
watercooling hoses on the drive. The other connections for the watercooling can be 
attached so you still have active cooling for your hopper inlet. This prevents the hopper 
from melting.

 

3. Remove the "c-clip" with proper circlip pliers.

 

 

 

4. Remove the bearing housing which is mounted to the barrel with 6 bolts.

 

 

 

5. Place a lifting eye (M8) inside the end of the screw. 

6. You should now be able to lift the screw out. If this is not the case, you need to warm 
up the heaters first.

Make sure that the watercooling lines are attached and wear PPE if you are doing 
this to prevent burns.

 

7. Check if the screw is damaged. (should be in good condition) 

 

 

 Reassembly procedure:

 

1. Insert the screw into the barrel.

2. Mount the bearing housing on the barrel with 6 bolts. Apply Loctite Medium Strength 
on the bolts before tightening them. Use a Torque Wrench to tighten the bolts with 5.8Nm

 

 

 

 

 

 

 

3. Install the "c-clip".

 

4. Put the servo drive/cooling assembly back into place.

Pay attention to the motor orientation when putting it back into place.

 5. Reinstall the 6 bolts that mount the servo/cooling assembly to the bearing housing

 

 

6. Re-check all bolts and fittings to ensure everything is correct before you heat up the 
extruder and test the purge for the first time.