We Are Learning 3D Printing Through Our Personal Experience…
One of the most annoying issues with 3D printers that extrude thermoplastic materials is when the filament jams inside the extruder causing a failed print and if the problem persists you need to figure out what is causing it. The problem is that there could be numerous thing that are causing the filament to jam and stop extruding from the nozzle and you need to check them one by one until you resolve the issue and are able to continue printing again. One of the most common causes, the one you should start with, is to check the build plate and try to level it again as often after a few prints the position of the build plate may change a bit along the Z axis and this may cause trouble for the filament to either stick properly or to come out normally from the nozzle.
If it the filament happens again after a bit of normal operation after you have realigned the build plate and you are sure that it is not the cause, then you might want to check the thermal insulation of the heated block of the extruder. Usually, as is the case with MakerBot Replicator 2, the heated block to which the nozzle is attached is insulated with special kind of insulation material that is taped with Kapton tape. If the insulation needs to be replaced as it is not functioning properly anymore you may need to replace it or it can cause the filament material to jam inside the nozzle. If you are having trouble with the insulation the actual temperature of the block that melts the filament may be lower than it is needed for normal operation with the specific type of filament used and this may lead to the filament jamming as it is not hot enough to come out at the desired speed from the nozzle. An easy thig you can usually do to check if this is the cause for the filament jam is to increase the extrusion temperature with 10-15 degrees Celsius over the normal one you use and if the jams do not happen anymore then it could be the insulation.
Based on our experience we have found out that anther cause for filament jams could be the nozzle that the extruded thermoplastic material goes through, even though it might seem just fine it can still be the cause. So you should always have a few nozzles as spare to replace them over time as they do wear out and the process is faster if you use composite filaments such as ones that contain chopped carbon fiber or other materials as a part of the filament.
Another different kind of issue that can appear over time that can cause jams or problems with proper extrusion of thermoplastic is the feeding mechanism of the extruder of the printer. If the extruder uses a spring to provide tension to the filament feeding mechanism after a while the spring may soften up and the tension may get inconsistent or too little for proper feeding of the thermoplastic material into the nozzle and as a result cause a jam.
Sometimes the 3D printer jams can be caused by various other things such as low quality filament, the use of exotic material that is not designed to be used with your specific 3D printer and so on, so it is not always easy to figure out what is causing the issues and you need to start checking and eliminating them one by one until you find the culprit.
Dual or multi-color printing on 3D printers that do have just one extruder can be a tricky thing to do, but it is still possible, though with dual-extruder printers it is much easier. We have been playing with our MakerBot Replicator 2 3D printer in order to make dual-color 3D prints, though the methodology is the same as if you want to be able to print with more than two colors. Essentially what you need to do is pause the printing process with one color, replace the filament, then resume printing and you should get a dual or multi-color printed parts as a result. Normally, if you are using a 3D printer that uses GCODE you are able to script the commands to pause the printer to change the filament directly from the 3D model that you are printing, but with Replicator 2 this is unfortunately not possible. The reason for that is the MakerBot Replicator 2 uses the binary X3G format for the model you are printing and scripting a pause in GCODE file and then converting it to X3G does not help resolve the issue either.
There are essentially two ways that you can print with dual or multiple colors on MakerBot Replicator 2 3D printer and they are both limiting and not very useful if you want to print a really complex colorful 3D model. You need to essentially pause the printing process from the device itself, either manually, or by specifying the model height at witch the printer to execute an automatic pause then replace the filament type or color and resume printing. This is just fine if you have a 3D model that has a base with one color and then something on top of it in another color, but if the used colors are being mixed in a single layer, then it is not possible to use this pause/resume solution. So a nicer and smarter solution for multi-color printing on the MakerBot Replicator 2 and other single extruder 3D printers like it would be the upcoming Mosaic accessory, but until then you should do with what you have available. There is also another option that does require you to replace the firmware on your MakerBot Replicator 2 3D printer with one that does support GCODE like the Sailfish Firmware, but we haven’t tried that yet.
Dual-color printing with manual pause:
– Start the 3D printing with the first filament color
– Monitor the printing process carefully and when you are close to the point when you need the second color manually pause the printing
– To manually pause the printing press the left arrow from the Replicator 2 keypad and choose Pause
– Go to Change Filament and Unload the old filament and Load the new color
– Manually Resume Build to continue printing and select Back to Monitor to get to the print status screen again
The drawback of manual pausing and resuming is that you cannot easily get to the same point if you need to make multiple prints of the same model, though it might still be fine if you manage to pause while the infill is being printed.
Dual-color printing with automatic pause:
– Start the 3D printing with the first filament color
– Press the left arrow on the keypad and select Z Pause Height
– Enter the value in millimeters for the height of the printed 3D object when you need the printer to automatically pause
– Set Pause Active to On in order to tell the 3D printer to activate the pause at the set position
– Go to Done and Back to Monitor and wait for the printing process to reach to the set point when it will automatically pause and activate the Change Filament menu
– You need to Unload the old filament and then Load the new color and then just Resume Build
The drawback of the automatic pause is that you can only use values that fractional such as 1.2 mm or 2.3 mm etc, you can use only 1, 2, 3 mm and so on ad object height on the Z axis. If you take this limitation into account when designing the 3D model of the object you are going to be printing it might be fine, but this could be a problem if you want to print an already designed model.
While both the methods described above do have their limitations and are far from perfect, you can still get pretty good results printing with dual colors or even more colors if you have the patience. Do note however that the more the colors the higher the chance of issues , our dual color test prints ended up quite well, though not perfect. Again a reminder that the the above options you have for the MakerBot Replicator 2 for pausing and resuming the print will work good if you don’t want to have multiple colors in a single layer of the object you are printing.