3d printer nozzle jams - what to do next?

Whether you are new to 3D printing or a seasoned printer, the chances are you have experienced a jam of some sort with either your filament or nozzle not extruding as it should and if you do suspect your 3D printer has jammed, the first thing to remember is don’t panic! There are many things that can be done. We have made this in-depth article for you to follow should your printer jam in some way.

It should be noted that jams can be very tricky, so it never hurts to get as much information as possible. However, if you just want a basic rundown, I’ll try to help you out here.

The first thing to understand is that there are a number of factors that can contribute to a 3D printer jam with the most common type of jam being related to nozzle height, temperature and filament tension. It is important to note that although the three mentioned culprits can be the main source of your 3D printer jam, there could be other secondary reasons which you should rule out of the question before such as correct storage of your printer filament to avoid overexposure to moisture, understanding your printer tolerances and printer/nozzle itself. It is always a good idea to make sure that the last three are not the main cause of your 3D printer jam. Assuming the secondary culprits are in check, let's move onto the most common reasons people experience printer jams.



Let us start with temperature as this typically has many variables and nailing the correct printing temperature is key. The most important things to remember here is; heat creep and correct hot end temperatures.

Heat creep - This is typically when a filament is heated up beyond the point of this recommended printing or extruding temperature causing the filament to melt more than it should causing a literal 'creeping' effect through the heat break area, melt zone and eventually the nozzle and hot ends of your 3D printer.

In the first instance, I would recommend stopping the print and removing the filament and double-checking your manufacturers recommended printing temperature for your chosen filament. Make sure that the printer temperatures fall within that of the manufacturers recommended print temperature range. Remember; you can always start at the lower end of the recommended temperature range and work your way up in 5-degree increments until you achieve your desired print viscosity. Another important point to mention is to double check you have adequate active cooling for your hot ends and that your heater block/heat sinks are mounted well and doing their job of cooling the hot ends well.

Incorrect hot end temperatures - there are two very basic techniques to unclogging your hot end jams. The best ways are both are outlined below;

1. Start by heating your printer up to a slightly higher than normal temperature, and attempt to push the filament through. For instance, if you have a PLA jam, we recommend heating to 220°C (245°C for ABS). Usually, at these temperatures, they are much higher than is necessary for normal prints, but not high enough to be dangerous.

2. The second method you can try is to heat your printer up to the standard temperature and push the filament part of the way through. Then, allow the filament to cool to about 80°C (135°C for ABS). After it gets to that temperature, slowly retract the filament until the drive block is clear. In the best case scenario, you will pull up anything that the filament bonded with while hot, thereby cleaning the hot end and drive block. I would recommend that you do this once in a while anyway because buildup in the extruder can occasionally cause jams.


Nozzle Placement

Correct nozzle height in relation to the printing bed is one of the keys to a successful extrusion and 3D print. If your nozzle and printing bed is incorrectly aligned your prints will fail at some point in the printing process. Too high and your filament will print essentially in thin air with nothing to adhere to, whether the printing bed or the previously printed filament. Worse case scenario you won't have a jam on your hands, but rather a big mess of extruded plastic on your hands. Too close to the print and you run the risk of retrograde extrusion which will lead to choppy and compressed prints and most probably a jam later on at some point of the print. Running a print in either incorrect configuration will lead to either a print fail of some sort, whether a jam or a heap of plastic mess, so make sure you have this nailed.

The image below shows this really well. The print on the left was printed with the nozzle too close to the printing bed, resulting in a compressed type look as the filament is extruded tightly on top of each layer. The print in the middle shows a completed print with the nozzle aligned too high from the printing bed, leading to an uneven warped look. The print to the right shows the same print at the correctly aligned nozzle to bed placement arrangement.

[caption id="attachment_713" align="alignnone" width="800"]Nozzle placement - Digital Cubed Nozzle placement and their effects on final prints[/caption]



Bed Levelling

Another important aspect to consider and that goes hand-in-hand with nozzle placement is correct bed levelling. We already discussed the negative effects of improper nozzle levelling and how they impact your final prints (if they make it that far) and so if you want the best possible chance of your prints surviving, you will have to invest some time into correctly levelling your printing bed, which is a standard process with most, if not all 3D printers at the moment.

[caption id="attachment_715" align="alignnone" width="788"]bed-leveling Bed Levelling - courtesy of Ultimater.com[/caption]

How you level out your bed will ultimately depend on the type and brand of your 3D printer and so we would recommend perusing the manual of your printer and/or contacting the manufacturer of your printer to find out the best ways of levelling out your bed for your particular printer. Each step in this guide are related and either way, do not skip this step as it is an integral part of achieving excellent prints.


Filament Tension

Filament tension is not a deal breaker when it comes to successful prints, but it should be mentioned nevertheless as it can, in some cases, create printing issues. Just make sure when you mount and feed your filament into the extruder of your 3D printer that the spool can spin freely with no kind of external friction or tension that can cause the print to stop or become jammed. All printers are not created equal and so it is best to make sure you are feeding each filament in the most optimal way to maximise smoothness of prints.

As long as you cover these basic universal principles when tackling your 3D prints you should be in a good position to achieve the type of accurate and pleasing prints you want to achieve. All our filaments materials come with recommended guides on how to best use and print for optimal results and you can check them out at our filaments page here.

If you enjoyed this article and it provided you with some value then do leave us a comment with your experience or thoughts as it could help someone else with the same type of printer as you.