The Olsson Block Kit FAQ

Advantages of the Olsson Block Kit

This upgrade will make it possible to use smaller nozzles for finer details or larger nozzles for higher speed. Up to about three times throughput can be achieved compared to the standard UM2 nozzle/heaterblock. This makes the printer much more versatile and makes it possible/reasonable to print more extreme designs. It expands your freedom to experiment.

If you experience a nozzle clog or some other issue with your nozzle that can't be fixed via an Atomic, you can quickly remove the nozzle for cleaning, or simply replace it if time is at a premium. The nozzle can be replaced within seconds, making it possible to get back to printing very quickly. As a bonus, the nozzles are cheap to replace.

The way that the heater and temperature sensor is attached has been improved. They are held securely in place but are also easier to remove. The addition of the two slotted holes on the underside of the block allows you to use a 1.5mm hex key (or similar pokey object) to push the heater and/or sensor out rather than pulling on them by the wires which can cause them to break.

It opens up the possibility for future experimentation with different nozzle materials or geometries to improve print performance.

Potential issues when using the Olsson Block Kit

There is a small risk of leaks between the nozzle and block if the nozzle isn't tightened properly, or if the nozzle is installed cold. Over tightening can cause something to break. However, if you use the printable torque wrench and make sure the block/nozzle is at print temperature, the risk for any of this happening is basically non existent

The amount of clearance between the block and the fan shroud is quite tight. It is therefore very important that you make sure that no part of the block, or nozzle, is in contact with the fan shroud. If they do come in contact the fan shroud will act as a very efficient heat sink, drawing heat away from the heater cartridge and eventually causing a heater error.

Depending on how new your printer is there might be a metal flap on the back side of the fan shroud that could cause interference with the block or wires. Simply bending it out of the way takes care of this.

When you start experimenting with larger nozzles it makes it possible to push things beyond the capacity of the heater. If you print a high temperature material such as XT or ABS and also have your side fans running at full speed you might run into a situation where the heater no longer can keep up. This will then cause the printer to stop and display "HEATER ERROR". Usually you can get around this problem by turning the fans off, or reduce their speed.

Do I need to do anything special when starting to use the Olsson block?

Changing nozzles

First and foremost, always, always change nozzles at printing temperature to make sure no left over plastic prevents you from fully tightening the nozzle into place, or, prevent you from unscrewing the previous nozzle. If a small sliver of cold filament gets between the nozzle and the block there's a chance that they do not make full contact and plastic can be allowed to ooze out and cause a mess.

If you switch nozzle size you need to adjust your nozzle-size setting in cura to match.

As a bonus you can perform a "lazy Atomic". By doing this you know that when you want to use the nozzle the next time, it'll be clean and good to go. No worry of your white plastic turning pink because of some left over red in the nozzle.

Smaller nozzle

If you are using a smaller nozzle than the standard 0.4mm you will likely need to adjust your first layer thickness. This defaults to 0.3mm which will be too much for a 0.25mm nozzle to handle. Try 0.1mm or less instead. Also note that you must be extra careful with bed levelling with such a thin first layer. With such a thin first layer, even variations in the surface of the glass might be an issue.

Additionally, with a smaller nozzle you may need to slow down. This of course depends on your layer height as well. Just know that the smaller nozzle means you can't push the same volume/second as with the larger nozzles since pressure is so much higher.

Larger nozzle

When you step up in nozzle size to 0.8mm you can of course expect to get slightly worse surface quality and you wont be able to produce as fine details as you can with the standard nozzle. With thick layers and high speed you will for example see that the z-scar will be much more pronounced.

As mentioned previously, with a larger nozzle it's possible to push through a significantly larger volume of plastic / second. This also means that the heater must work much harder to keep up and it might even fail to do so. Especially if you're printing fast, with fans on full and at a high temperature (such as 250C for XT). The firmware will detect that it is asking for a temperature of X but the temperature never reaches this point. This makes the printer think that something has gone wrong, like a failed temperature probe, and it'll shut the printer down to prevent damage.

Printing slower and/or slowing the cooling fans down can help with this problem. But at some point you will simply reach the limit and have to back off.

Another issue with pushing so much plastic so quickly is that there might not be enough time to cool the layers down properly. A very thick layer height like 0.4mm with a 0.8mm nozzle will obviously require more time to cool down than a 0.1mm layer with a 0.4mm nozzle. But if you're trying to print this rough and fast you're likely printing something fairly large so it might not be an issue.

Reduction in print height

The Olsson block protrudes a little bit further down than the stock nozzle. This means that if you've been printing at the very limit of the height available in your printer, those prints may now fail. The difference isn't huge by any means, it's a matter of a few millimeters, but it's something you need to be aware of. Depending on the version of your machine this might not be an issue, but to play it safe, give yourself 2-3mm of extra room at the top. Or simply measure the total height and adjust accordingly in cura. The maximum height is set via Machine -> Machine settings -> Maximum height