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Reprap Hot End Comparison Essay

When browsing for your last printer, 3D printer nozzle size may well have been the last thing on your mind. It’s an often overlooked detail. Depending on what you need to print; the wrong setup could be holding you back.

Let’s take a look at the options, and why you might need to explore different 3D printer nozzles.

How does the 3D printer nozzle size affect prints?

The nozzle diameter directly affects the 3D printer extrusion width of each line in your print. This has an effect on a few elements of your print.

If you 3D print for business (or doing large quantities of very similar prints) you’ll want to make sure your extruder is laying down the right amount. Not too much (as you could be using more filament than necessary) and not too little (as your print times could be longer than they need to be).

Or perhaps you print various models, some very detailed and intricate, and some more practical prints (like a replacement door knob for example) that just need to be printed quickly, and for maximum strength.

Either way, you’re going to need the right setup for you so you’re not wasting your time, wasting filament or just coming out with an undesirable print quality. You can treat this guide as a sort of 3d printer nozzle size comparison.

There's no simple answer to what's the best 3D printer nozzle size, you need to weight up what you're trying to achieve and what elements matter most to you. 

Depending on your 3D printer, various nozzles can be interchanged reasonably easily (most are screw fit) and multipacks (with different sizes in) can be picked up quite cheaply.

Let’s look at the various nozzle size 3D printer options commonly available:

The most common standard nozzle sizes are the 0.4mm (or 0.35mm) nozzle used by most current 3D printer manufactures currently available. The reason for this, quite simply is that’s it’s a great all-rounder nozzle size. This means you can print exceptional detail, and it won’t take forever.

That's because you can print down to layer heights of just 0.1mm, or up to 0.3mm using a 0.4mm 3D print nozzle. The thinner the layer height, the better the detail (on the Z axis) and the thicker the layer height the fast your print will be, but with less detail.

This is more often than not, for most print jobs the best nozzle size for your 3d printer. 

Well, maybe some prints take forever – but at least it’s an acceptable amount of time. A common misconception is that if someone isn’t getting good enough print quality from their printer running a 0.4mm nozzle, they immediately think they need a smaller 3D printing nozzle size.

This is Zortrax M200 printing our ABS with the stock 0.4mm Nozzle and 0.2mm 3D Print Layer Height

Another common smaller size is 0.25mm. Some printers are now offering 0.2mm, 0.15mm and Mass Portal are even experimenting with 0.1mm 3D printer extruder nozzles. These create some incredible results for FDM machines, they managed to print the inner workings of a watch in excellent detail.  

3D Printer Resolution Explained:

Now in theory, smaller 3D printer nozzle sizes do allow you to achieve better precision. But for a lot of printers, especially lower priced or older models – a smaller sized extruder nozzle isn’t necessarily going to make a difference unless your printer supports the higher resolution necessary. It might be like putting low profile, performance tires on a stock Ford Anglia – it won’t make it go any faster or necessarily handle the corners better.

It’s similar to how 3d printer specifications on paper (such as advertised resolution) won’t always translate to better print quality on the finished article. Similar to how Ultimaker and Zortrax have very similar resolutions on paper, but in our unbiased opinion our Zortrax creates better quality prints than our Ultimaker 2 does – for example.

Check out the fine detail below for a 3D printing resolution comparison on very small nozzle sizes. 

3D printing fine detail: Close-up shot of an FDM print with a 0.1mm nozzle - Mass Portal. If you were wondering how small can a 3d printer print, then this will give you a good idea.

If you bought your 3d printer recently though, it’s likely you’re going to be able to benefit from a smaller nozzle size as the resolution across the board is getting really good. Let’s take a look at the pros and cons to printing with smaller nozzle sizes. Some are less obvious than others. Then we’ll take a look at the under rated larger nozzles available. Hopefully once you’ve finished this article you’ll be able to answer that “What nozzle size should I print with?” that you’ve likely been loosing so much sleep over.

You’ve likely guessed already that the smaller the nozzle in your extruder, in theory the higher detail you can print. This is great for those intricate prints, or if you need to print very thin walls for aircraft skin, or high transparency prints and similar reasons for example.

This photo of a ‘printed model plane skin was done in one layer thick on a regular 0.4mm nozzle. If we’d done it on a 0.2mm nozzle the weight (and strength) of the skin would be halved.

It’s worth noting though that a 0.2mm nozzle 3d printer does not extrude half the amount of filament that a 0.4mm nozzle does. Oh no, thanks to Area that means that halving the diameter actually means you’re looking at extruding just 25% of filament in an 0.2mm nozzle compared with a standard 0.4mm.

That could, if all other things being equal increase printing time by a large margin. In real terms though, it’s likely to increase by about two times longer, as you’ll usually use less filament as you print thinner wall thicknesses and thinner infill supports. So bear that in mind if you need really strong parts; high detail and strength can only both be achieved if you’re willing to wait a long time…

Download our FREE Cheatsheet to Get 100% Reliable 3D Prints

Basically the smaller the nozzle size, the higher you increase your chances of 3d printer problems. Especially if you're using cheap filament - it might work fine with lower detail, thick nozzles, but if you want specialist prints with small nozzles, it's key to using pure, high quality filaments. 

Other factors when printing with thin diameter nozzles are less obvious – like it’s harder to print with overhangs. This is because each layer has less width for the next layer to purchase on as your traverse an overhang for example. Bridging is also more challenging.

But there’s good news! Where overhangs are a little more tricky with a thinner nozzle, the supports are actually much easier to remove. Because of the additional precision, your slicer can use the minimum filament necessary between your model and the supports, so they’ll break away more easily – and have less broken contact area that needs sanding.

Once last point, that really is the elephant in the room is the ease with which very thin nozzles are clogged. If you get down to 0.2mm or even 0.1mm sizes, you only need a small particle to clog the hotend. We’re not trying to plug our own product here (well, maybe a little) but it’s increasingly important to print with excellent quality filament the thinner you go. No contaminants in your filament, and clean out the nozzle sufficiently and regularly and you’ll turn an otherwise problematic printing experiment into a reliable endeavor.

Before we consider a wider selection of 3d printer nozzle diameter, it’s worth taking a moment to understand the relationship between nozzle size and layer thickness. In short, the former dictates horizontal details (along the x and y axis) and the latter controls the resolution on the vertical, or z axis.

What is layer height in 3D printing?

Simply put, it's the thickness of each line of extruded material that makes up each layer of your print. The thinner the layer height (or layer thickness) the finer the detail of the print on the Z axis (the vertical dimension of your print), but the more layers it will need. Leading to a longer print time. 

They are related but not completely independent from each other. For example it is possible to print a thinner nozzle with a thicker layer height if vertical resolution is less important to you, and a thicker nozzle with very thin layer heights for visa versa priorities – but if you take this route to the extremes it will cause problems.

To maintain adequate pressure your layer height wants to be at the very least 20% smaller than the width of your nozzle - in most instances though we recommend it to be 50% for the best results. 

How do I gauge the correct distance from the nozzle to the bed? 

Getting this right can mean the difference between your print not even starting, and your print finishing with a perfectly smooth, glass-like surface under it. 

People assume a feeler gauge 3D printer setup is required - but even this can be too thick. We recommend using very thin paper, like receipt paper to gauge the correct distance of your nozzle from the bed. 

Please the receipt paper under the nozzle, and move the nozzle down step by step until the receipt paper has just a little resistance to it when you try to move it out. Printing at this height will give the bottom of your prints a professional glass-like finish. 

Here's our explanation for the best 3d printer layer height combo.

What's The Max 3D Printing Layer Height vs Nozzle Size?

You don't necessarily need a 3D printer layer height calculator, but a general rule of thumb is your max layer height is 50% the width of your nozzle. In some instances you can go higher (maybe 75%) but you may sacrifice reliability.

It's best to experiment with the parameters of your print, as long as you understand the relationship between 3D printer nozzle size vs layer height you'll be on track. 

So for a 0.4mm nozzle, you'll be looking to print at 0.2mm layer height, or up to 0.3mm. Your minimum would want to be around 0.1mm, any lower than this and you're just increasing your waiting time for not much benefit (on the same 0.4mm size nozzle). 

Just don't forget to adjust filament flow rate or extrusion pressure to compensate for any layer height vs nozzle size changes. Though most updated slicers should handle standard extrusion width vs nozzle diameter for you automatically. 

Here's our mini guide on 3D printer nozzle height; explaining the close relationship between nozzle size, layer height and pressure. 

For most cases we recommend printing thinner layers with thinner nozzle diameters, and thicker layers with thicker nozzles, generally. Just note that if you do print with a thicker nozzle diameter and a very thin layer height, you’ll need to bring your extrusion settings in the slicer way down to prevent over-extrusion.

It's also worth noting, regardless of size, you'll always want to make sure you have a clean 3d printer nozzle at all times. One of the easiest ways to do this is with high quality cleaning filament. You only need to use a few grams of it each time you clean, but it'll prevent carbon build up over time. 

Another point to note, if you're printing thicker layer heights (in proportion to nozzle diameter) your overhangs will look a bit messier. In contrast to thinner layer heights, or better 3d printer layer resolution, will improve the detail on Z axis. Here's a diagram to better illustrate layer height 3d printing.

So why would I use a 0.8mm or thicker nozzle?

These were more common on older machines, but they’re making a comeback. It’s all about using what you need, and no more. For a lot of prints, the stock 0.4mm that likely came with your printer could be overkill. If you want strength and speed and detail is less important, printing on a 0.8mm or even a 1.0mm nozzle could be your answer.

This is especially important if you’re printing for business. Need to get more prints in a shorter time frame from your machine and increase profits? Switch up the nozzle size – remember a 0.8mm could reduce print times down to ¼ of a print done with a 0.4mm. The savings could be massive. And don’t forget, prints done with 0.8mm can still be impressively detailed depending on your printer.

The only slight downside could be that you use slightly more filament, but with the thicker part walls you can likely get away with lower infill to compensate.

What Nozzle Size Should I Use For Composite Materials? 

It's worth noting that composite filaments (any particle based filaments like Woodfill, Copperfill, Carbon Fibre Nylon or Glass Reinforced Nylon) will have trouble extruding through a thinner 3D print head. 

That's because these filaments have particles that, although still nano sized, can have issues flowing through nozzles under 0.4mm diameter. We recommend printing with at least a 0.5mm nozzle, and for any metal, glass of Carbon Fiber materials you'll need a hardened nozzle. The brass one that came with your printer likely won't last, and will bore out to a larger size after a few hours of printing. 

A 0.5mm stainless nozzle or tungsten nozzle will last much longer for composite filaments. 

So if you’re still wondering “What extruder size to choose?” let’s recap with the pros and cons of smaller nozzles so you can work out the best nozzle size for your 3D printer:

  • Much finer details, providing your printer supports the additional resolution.
  • Can take significantly longer to print, but thicker nozzles can cut the time down dramatically. Spending 5 mins changing the size on longer prints could be worth the time investment!
  • Overhangs are a little more challenging to print, but supports break away more cleanly.
  • You need seriously good filament, or your nozzle could block easily. Is it worth the risk?

Hopefully this article has shed some light on the options available to you. If it has, or you have further questions related to this, please do comment below so we can help – we love to hear your thoughts or even see photos of experiences you’ve had with different nozzle sizes.

When experimenting with various types of nozzle and rate of using filament, it may be useful to know the length of the remaining filament on the spool. We've put down a chart for various spool sizes and filament diameters for the different materials, you can find our filament length guide here. 

And if you need some filament you can rely on for those really intricate prints, why not order a free sample of our PLA or ABS? You’ve got nothing to lose.

This post will help you understand the differences and the operation of most common temperature sensors used in 3D Printing.

Each type of sensor has many key performance aspects and the goal of this topic is to compare them in details.

Part 1 will explain the most common sensor types and will take a look at the boards.

Part 2 will go in details about the performance between sensors while keeping in mind the 3D printer application.

Part 3 will provide explanations regarding our choice to go with a thermistor. Finally, some common mistakes are explained regarding temperature sensors.

Do not hesitate if you have any comments or suggestions that could improve this blog.

Sensors types used in 3D Printers

The most common sensor types are the following:


Glass thermistor

Thermistor are resistor whose resistance changes with temperature. Most commonly used type in 3D printers is NTC, standing for "Negative Temperature Coefficient". When the temperature increase, the resistance decrease.

They are made from semiconductors, mostly silicon and germanium, and their resistance value can vary by many order of magnitude in their temperature range. A 100k NTC thermistor has a resistance of 100kΩ (100 000Ω) at room temperature (20°C) and drop as low as 100Ω at 300°C.


PT100 Probe

RTD are very similar to thermistors in term of operation. Rather than having a semiconductor, these are made from metals, mostly platinum, nickel or copper. RTD stands for "Resistance Temperature Detectors". Most commonly used type in 3D printers is PT100. It has a resistance of 100Ω at 0°C.

With a RTD sensor, the resistance slowly increase with temperature. At 400°C, a PT100 will reach 250Ω. The variation is almost linear.


Thermocouple exposed bead

Thermocouple operates in a totally different way than the other sensors. They are made from two different metals which generate a very small voltage depending on temperature. The most common type used in 3D printers is K and is made from chromel and alumel.

The voltage increase from 0mV to 20mV from 0°C to 500°C. As with PT100, the variation is almost linear at 41 µV/°C.

Please note that the picture show a welded bead sensor which shouldn't be used inside a 3D printer. The actual thermocouple should be inside an electrically insulated housing to prevent any noise or ground effect. Housing can be threaded, cylindrical or flat (crimped).

3D Printers manufacturer and motherboard sensor table

Here is a list of 3D printer manufacturers with the sensor types they are using.

The main driving part inside a printer for sensor choice is the motherboard. Each motherboard have unique components which decide what sensor is meant to be used. The most common is thermistor, which only require a pull-up resistor to work.

Both RTD and thermocouple require an IC (Integrated Circuit) built for processing their respective signal. These add-on boards are compatible with most boards via I2C and SPI pins for communication, or analog pins. Some specialized boards, such as the Duet Wifi, offer specialized add-on board to enable thermocouple and RTD readings.


Prusa, Robo3D, BCN3D, Kossel, Makergear, 
MendelMax, LulzBot, Printrbot, Mendel90,
And many more RepRap...


MakerBot, FlashForge, CTC, 
Wanhao Duplicator


8 bits

RAMPS, Rambo RUMBA, Melzi, Sanguinololu, Generation 6, Azteeg X1, Azteeg X3

Ultimaker PCB, Ultimaker Board

MightyBoard, Azteeg X3 Pro, Megatronics


32 bits

Smoothieboard, AZSMZ, R2C2, Generation 7, Duet, Replicape

Alligator Board


RAMPS 1.4 - 8 bits - Thermistor

RUMBA - 8 bits - Thermistor

AZSMZ - 32 bits - Thermistor

Thermal sensor performance

Below is a graphical comparison for certain key aspects of temperature sensing in 3D printers. Please note that these values are based on the most common microcontroller configuration used in 3D printing, which are 8 bits microcontroller with 10 bits ADC. Having a higher resolution will improve resolution. Most 32 bits microcontroller benefit from a 12 bits ADC.

Better resolution can be obtained with specialized measurement devices, such as MAX31855, AD595, MAX6675 for thermocouple and MAX31865 for RTD, but it is not the point of this topic. These specialized chips will be deeply analyzed if the following parts.

The key performance aspects will be explained and detailed in part 2.


  • Maximum temperature50%
  • Usually up to 300°C

    Special thermistor can read up to 1000°C

  • Cost100%


  • Maximum temperature75%
  • Up to 850°C
  • Cost66%
  • 10.00$-20.00,  circuit required
  • Resolution33%
  • 1.2°C
  • Response time33%
  • 15 seconds in air
  • Linearity100%
  • 0.8% error for a 1st order formula
  • Accuracy at 200°C100%
  •  ~0.6°C without calibration


  • Maximum temperature100%
  • Over to 1500°C
  • Cost33%
  • 15.00$-30.00,  circuit required
  • Resolution66%
  • 0.5°C
  • Response time66%
  • 5 seconds in air
  • Linearity66%
  • 2.5% error for a 1st order formula
  • Accuracy at 200°C33%
  •  2.2°C without calibration


Thanks for reading! This part was a short summary of thermal sensors used in 3D printer.

Follow on the next part, there will be a lot of interesting details about performance and in depth analysis!