These instructions apply to all models in the Ultimaker 2 family.
BEFORE BEGINNING: Remove the filament from your machine. Attempting to change the nozzle tip while filament is loaded will result in a broken nozzle.
If there is no material in the machine, it is possible to remove the tip while the printer is cold. However, to reduce the risk of damage, it is suggested that you remove the old nozzle tip while the nozzle is set to the last printing temperature. Remember if the nozzle is hot, you will not want to grasp it with your bare fingers. You can put the new tip on once the machine has cooled. You can monitor the nozzle temperature via the menu by going to MAINTENANCE->ADVANCED and hovering over HEAT NOZZLE. The temperature of the nozzle will be displayed below.
1. Depending on where you Olsson kit came from, you will either have a small wrench or a socket.
The socket is meant to affix to either a handheld socket wrench, a ratcheting wrench, or a printer Olsson Torque Wrench (shown below, 3D print file can be found on here to print and use). You can use the socket by hand.
If you have a wrench, hold the wrench laterally (as shown) and slide the open slot onto the angled sides of the nozzle tip.
If using the socket tip, slide the tool over the tip of the nozzle until fully seated against the fan shroud.
Looking down at the top of the printer, turn the wrench/socket clockwise to begin unscrewing the nozzle tip. (You are working upside-down.)
Continue turning the nozzle until it begins to significantly loosen. After the nozzle is loosened partially, you may be able to finish removing the nozzle tip with your fingers. Please note that while unscrewing the nozzle tip, you may here a slight squeaking noise; this is normal.
Once the nozzle tip is completely unscrewed from the Olsson Block, lower the tip straight down from the block. There may be some hardened filament stuck inside the nozzle tip. This is normal. If a piece of filament is sticking out further than the metal threads, simply snap off the protruding filament with your fingers or a pair of pliers. (Be very careful not to damage the metal of the nozzle if you use a metal tool.) Set this nozzle aside where it won’t get lose, such as in your nozzle tip kit. Throw away the filament you broke off, if there was any. The result will look like this:
2. Choose and install the new nozzle tip. The tip hole diameter size is usually etched onto the edge of the nozzle tip. Locate the size etched and verify you are installing the correct one. (If your nozzle tips do not list a size in numbers, there will be a series of dots. Your Olsson kit should have a key. If not: 0dots= .25mm; 1 dot= .4mm; 2 dots= .6mm; 3 dots= .8mm)
Holding the new nozzle tip between your fingertips, align the threads of the hole in the fan shroud. Keeping the nozzle upright and straight, being rotating the nozzle tip to screw it into the recess in the Olsson block in the opposite direction that you removed the old one. If you’re looking down from the top of the printer, you will be turning counter-clockwise to insert the new nozzle tip.
Verify that the nozzle goes in straight and upright to prevent cross-threading. If the nozzle does not screw on easily and upright, unscrew it and try again. Continue turning until the nozzle tip is finger-tight.
3. Care must be taken to ensure the new nozzle tip is not too tight or too loose.
If you are using the wrench or using the socket by hand, tighten the nozzle until it is firm. Do not force the nozzle further.
If you are using the printed Olsson Torque Wrench, the tool will automatically stop turning at the needed amount of torque.
If you have a measured torque wrench, set the torque to between 1 and 1.5Nm (Newton meters). Never tighten your Olsson nozzle with more force than 2Nm. I
Do not apply excessive force to the nozzle tip to tighten as much as possible. It is fully possible to damage the threads of the nozzle or even strip them out completely. It is important to tighten the nozzle tip at least hand-tight and firm, however, as not tightening the nozzle tip enough could leave a tiny gap between the threading of the nozzle tip and the threading of the Olsson block, which would allow melted filament to seep through and flood the threading and other components.
4. If you are installing a different diameter of nozzle tip, you will need to adjust your code files in Cura (or other slicer) to compensate for the new diameter. Not doing so will affect extrusion rate, print quality, and possibly cause your filament to jam up. Before beginning your next print after changing out the nozzle, always re-run your bed leveling. Your new nozzle may be slightly taller or shorter than your previous one and it's vital that your bed is always leveled to the right height, otherwise your print may come off the bed.