For the second time the nozzle of the extruder blocked (with Velleman’s filament this time). After heating up the extruder the nozzle could be removed and cleaned easily. However, when mounting the nozzle I did not heating the extruder. Thank to the cold filament left at the screw-thread I had not a good feeling about the applied moment. This results in a broken brass barrel.
It appeared that some windings of the thread are still left and a test with a nut showed that the nozzle could be fixed strong enough to the barrel. The first step was to remove the broken part out of the nozzle. There are tools for this operation, but I did it by carefully drilling and using screwdrivers. It need some patience.
The nozzle can now be fixe to the brass barrel. However, even without the ring there is not enough space for the heater block. More space can be made by removing 1-2 mm in axial direction from the largest diameter of the barrel. I did this with a file. Eventually the heating block can be made thinner. Now the extruder can be assembled. To be more flexible I have equipped the heating block with some kind of connector.
Ofcourse without special precautions there will be leakage. In the first instance a good solution looks to solder the nozzle and brass together. That is why a I have modified the heating block so that it can be placed when the nozzle is in place. A diassapointing phenomenon was that the solder tin melts at 190 degrees (can perhaps be used as filament). As an alternative I have used a heat restant (1100deg) compound to seal the connection. In the first instance there was a slight leakage but after a while the leakage stops. The printer operates now as before. The canibalization of the heating block seems not to have any influence.
