Screw disassembly and assembly steps guide

01 Heating of threaded elements
Firstly, if possible, after using the screws, immediately process them when they have residual temperature, or put the screw shaft assembly back into the extruder and heat the shaft and components together. It is best to allow time for the components to slowly heat up (approximately 20 minutes).
Then remove the machine head and slide a portion of the components onto the high platform or cart at the end of the machine.
If it is necessary to remove the screw from the machine and heat it with fire, please be careful and evenly heat the entire component. Do not burn until the metal discolors, as this may affect the metallurgical properties. To heat them instead of burning them, be patient.
02 Disassembly of threaded components
After the component is heated, a punch made of wood or hard plastic is used to push the component off the shaft. Aluminum or brass drift pins can also be used, but be careful when using them as they can have a negative impact on the components. Using an electric impact hammer can be very helpful.
Please follow the following steps during this stage:
(1) Use heat resistant gloves;
(2) Support the screw in a suitable position so that it does not bend;
(3) Unscrew the power head and remove the components;
(4) When using lubricants, it is necessary to pull the components out of the shaft;
(5) Some stuck components may require more user-friendly operation;
(6) Select the appropriate punch angle;
(7) When heating, use a rubber hammer and hammer until the element moves;
(8) Disassemble one component at a time and ensure that the exposed shaft is brushed or scraped clean.
For components that are difficult to disassemble, an impact hammer is a noisy device, but it works well when loosening stuck threaded components.
03 Cleaning and inspection of threaded components
After removing the threaded components from the machine, at least preliminary cleaning with a wire brush or copper gauze may result in better results. After brushing, you can clean them in an oven or fluidized bath. But be careful not to exceed the rated temperature of the metal.
If there are black, burnt, or degraded materials, they will need to be removed using some form of mechanical wear. Brass or copper brushes are usually too soft to allow residual polymers to detach. If that's the case, you need to:
(1) Wear gloves and eye protection equipment;
(2) Use a hard steel wire brush wheel on a desktop grinder;
(3) Use a sanding machine (small pneumatic portable sanding machines can also be used);
(4) Use a sandblasting machine or dry ice sandblasting machine;
(5) Clean the keyway and spline hole.
After cleaning the threaded components, it is necessary to promptly inspect them for minor cracks and any nicks or grooves. Scratches and grooves may become cracks and should be gently smoothed with a file or grinding disc.
In addition, the end face should be polished with 320 sandpaper or polished smooth. This should be done on a horizontal, flat mechanical surface, such as marble slab or thick steel plate.
Lay sandcloth or 320 sandpaper flat on the surface, draw the surface of the threaded component in a zigzag shape, and apply sufficient pressure to evenly clean the surface of the component. If you want to record the wear rate, use a micrometer to check the size and record it.
Components with minor cracks should be discarded. If these damaged components rupture during equipment operation, it will cause abnormal torsion of the screw, damage the barrel, and cause catastrophic failure of the gearbox.
04 Additional suggestions for handling threaded components
Threaded components have sharp edges that, if not handled properly, may scratch the human body. When handling threaded components, gloves made of cut resistant fabric should be worn. Here are some additional suggestions:
(1) Clean the shaft core with a wire brush to remove any remaining foreign objects. This includes coupling splines.
(2) Check the threaded components and use the steps introduced in the previous section to remove foreign objects.
(3) Lubricant should be used every time threaded components are assembled on the shaft. You can use Gleitmo820, which is a white lubricating grease that does not degrade at high temperatures.
(4) Anti jamming should cover all shaft surfaces, but it should be used with caution (wiping on and off). When installed on the shaft, any anti clamping devices formed on the end face of the component must be removed.
(5) Position two axes as a pair parallel to each other. If the shaft fixture is available, use this fixture to keep the shaft in the correct position.
(6) If there is no fixture, clamp the shaft end between two wooden blocks at the correct distance from the centerline of the shaft.
(7) Threaded components should be installed in pairs. The relative position between the threaded component and the engagement component of the parallel axis must be correct.
(8) Once the first pair is placed in the correct direction, the remaining threaded components will be arranged "face to face". Usually, the first pair is moved to the end of the axis, so that the end contours of each component can be aligned and they match.