3D Printer

3D printing is a process where material is deposited layer by layer to create a physical object from a digital model. It is used in the industry as well as among DIY makers. While industrial 3D printing uses various materials like plastics, metals, or ceramics, affordable DIY 3D printing focuses on plastic printing materials.

Quick Overview

Here is the typical process of generating physical objects via 3D printing:

• 3D Model: At the beginning, there is a 3D model that describes the design of the object. You can download 3D models created by others (i.e. thingiverse.com), or design your own models with a variety of 3D Design Software (i.e. AutoDesk Fusion, formerly known as Fusion 360).
• Slicer: Since a 3D Printer prints objects layer by layer, the 3D Model needs to be converted to a series of 2D layers. This is what a Slicer Software such as Ultimaker Cura does. Slicers receive 3D Models in certain file formats, i.e. STL, and send their sliced data either directly via WiFi or via a SD Memory Card to a 3D Printer.
• 3D Printer: Receives instructions on how to print a physical object layer by layer. 3D Printers work similar to a CNC machine and can move a print head in X and Y direction. A heated nozzle melts plastics and deposits it onto the print bed. Once a layer is finished, the print head moves its Z axis one level up, and starts printing the next layer on top of the previous one.

There are two different printing methods typically used at home: Filament and Resin.

Technique: Filament versus Resin

Filament 3D printing, or FDM (Fused Deposition Modeling), uses a spool of plastic filament that is heated and extruded through a nozzle to build objects layer by layer. It is generally more affordable, easier to use, and suitable for creating sturdy parts with a more noticeable layer structure.

Resin 3D printing, or SLA (Stereolithography), uses liquid resin that is cured by UV light to form highly detailed models with a smooth finish. Resin prints offer greater precision and surface quality but require more post-processing, like cleaning and curing the prints. Additionally, resin printing can be messier and more hazardous due to the chemicals involved compared to the relatively simple and cleaner filament process.

In a nutshell:

• Filament (FDM): Simple, easy to use, clean(er), with cheaper material cost, and not emitting hazardous fumes. The downside is limited resolution and visible layer lines FDM is used for functional prototypes, housings, large models and even mechanical parts.
• Resin (SLA): More complex, involving handling of fluids and potential hazardous materials, requiring good ventilation, but offering a higher resolution and smoother finish. Popular for printing miniatures, figurines, custom jewelry and highly accurate models.

To safely use a Resin printer at home, you need proper Ventilation, Protective Gear such as nitrile gloves and safety goggles, a proper storage for the Resin (cool and dark), and the appropriate post-processing equipment (isopropyl alcohol for washing prints, UV light curing station), and safe disposal of potential toxic waste. That’s why I do not use Resin. As you will see, modern 3D Filament Printers can achieve excellent resolutions and perfect results at a fraction of cost and effort compared to Resin.

3D Printer Differences

Since I am not using Resin printers for the reasons mentioned above, the remainder of this article addresses 3D Filament Printers only.

Today, you can choose from a huge number of 3D Filament Printer Models. Here are aspects to look out for:

• Build Volume: Make sure the print bed and head room is large enough to actually print what you’d like to print. Print beds shouldn’t be smaller than 200x200mm, and the build volume shouldn’t be less than 200x200x200mm.
• Materials: The maximum nozzle temperature determines which plastic materials you can print. With temperatures of at least 250C, you can print the two most popular materials PLA and PETG. With temperatures of at least 300C, you can also print more sophisticated materials like ABS. The maximum heat bed temperature should match the material, or else it won’t stick well enough during print.
• Multi-Color: Being able to print models with more than one color isn’t just a creative edge. Sometimes, it can be crucial for creating backlit panels or transparent custom buttons.
• Speed: Since printing 3D Models layer by layer is taking a lot of time, the print speed is a crucial factor.
• Resolution: Make sure you can easily adjust the diameter of the printing nozzle. Detail-rich prints may require a small diameter (such as 0.2mm), whereas printing large models may use a 0.8mm nozzle. The default nozzle size on most printers is 0.4mm.
• Vendor: It seems there are new 3D Printers and Companies surfacing (and vanishing) every other month. Make sure you pick a renown manufacturer that is established on the market. You may need support, you want to find plenty of community examples for your printer model, and you most likely will need replacement parts or different print heads over time. So you want the company to be still around in a few years’ time.

Materials

Material	Print Temperature (°C)	Bed Temperature (°C)
PLA	190-220°C	40-60°C
TPU	220-240°C	40-60°C
ABS	220-250°C	90-110°C
HIPS	230-250°C	90-110°C
PETG	230-250°C	70-90°C
ASA	240-260°C	90-110°C
Nylon	240-270°C	70-90°C
Polycarbonate (PC)	260-300°C	90-120°C
PEEK	360-400°C	120-160°C

The two most commonly used materials at home are PLA and PETG which are equally well manageable. PETG has better heat resistance and is easier to sand.

Multi-Color

If you are new to 3D Printing, you may want to stick to monochrome models. If you need more color, you can always paint your model later.

Printing in more than one color (i.e. filament type) may become a necessary in scenarios like these:

• Labeling: you want your housings or custom switches to have labels, and you may even want these labels to be backlit. In the latter, you may even need a third color (transparent filament) to allow for back lighting.
• Easily Removable Supports: 3D Models with overhangs need supports: since a new layer cannot start in mid-air, abrupt overhangs require printing support structures that keep them from falling down. Such supports can be printed automatically and removed later. When printed with the same material, though, supports are hard to remove, and leave behind marks. A better way is to use a water-soluble filament such as *PVA (Polyvinyl Alcohol) for supports that can simply be washed off after the print is done.

To print in more than one color (or filament type), it is necessary to change the filament in mid-print. This can be done in two ways:

• IDEX (Independent Dual Extruder): IDEX-printers have two print heads, one per color, i.e. Snapmaker J1). The printer is using the head with the color that is currently needed. While such printers are initially more expensive, this investment often pays off because printing models with two colors isn’t more expensive than printing monochrome models. IDEX printers cannot print more than two colors, though.
• Automatic Material Systems (AMS): Such systems are typically specific add-ons for certain printers (so you cannot hook up an AMS from one vendor to a printer from another vendor, i.e. Bambulab AMS). The AMS manages more than one filament spool, and can automatically and in mid-print change the filament that is used by the single print head. This allows for as many different colors as the AMS can handle. The downside is time, cost, and trouble: changing the filament takes time, slowing down the print time. It also requires that a lot of good filament needs to be purged so that the new color filament can be inserted, easily doubling the material (and cost) that is required for a print, especially when there are color changes in each layer. And since AMS have a lot of mechanical parts, it is not uncommon for these systems to cause malfunctions and require manual interaction.

Since IDEX printers have two independent print heads, they can also print at the same time, effectively printing duplicates or mirrored copies of a monochrome model. So when you need many objects of the same kind, IDEX printers can cut printing time in half by printing two objects at the same time. Unfortunately, this type of duplex print often requires vendor-specific slicer software.

Print Speed

Printing a large 3D Model can take many hours (smaller models print in a few minutes, too). That’s why print speed is a major factor.

However, print speed is not just affected by the printer speed:

• Printer Speed: defined as mm/s. The printer speed is typically the fastest speed under perfect conditions with perfect materials. Most printers do not reach their fastest speed in real world scenarios.
• Hotend: the “hotend* (the heated print nozzle and its diameter) limit the maximum print speed. If the diameter is very small (i.e. 0.2mm), if the print filament melts slowly (i.e. PLA or PETG), and/or if the heater capacity isn’t heating enough plastics per second, then a fast-moving print head won’t do any good.
• Filament: For fast printing, the filament material needs to melt quickly, and the filament quality must be uniform and good. Cheap filaments cause clogs and can interrupt printing.
• Print Quality: the faster you print, the poorer is the resulting print quality. Cutting print speed in half can improve the print quality remarkable, and vice versa.

For practical purposes and typical materials (such as PLA and PETG), a print speed of 100-180mm/sec is recommended: it provides good results with a reasonable speed. Most modern printers support this speed.

If print quality is crucial, you may want to reduce print speed to 50mm/sec or even less, even on high-speed printers. Let the printer do its thing over night, and enjoy a great result.

Resolution (Print Quality)

One of the most important advantages of Resin printers is their good resolution and smooth finish.

With the right setup and settings, you can enjoy similar results with Filament Printers, too:

• Small Nozzle Diameter: Reduce the nozzle size from the standard 0.4mm diameter to a 0.2mm nozzle size (don’t forget to set the new nozzle size in your Slicer Software).
• Quality Filament: cheap filament from unknown vendors often produces low quality print results. Expensive filament isn’t needed. Just make sure the vendor has a good reputation, i.e. Sunlu.
• Filament Heater: when using hygroscopic materials (i.e. PETG), keep it dry, and use a filament dryer when using filament that has been opened a while ago (or dry cautionsly in the kitchen oven at 70C for 3 hours). If you left such material in open air for a few days, your print results may degrade severely without using a filament dryer.
• Slow Print Speed: Slow down the print speed considerably. Do a few tests, and go as low as 50mm/sec to see where the sweet spot for your printer is.

Filament prices for PLA and PETG can be crazy: you may pay almost €30 at amazon for the very same filament that is sold at AliExpress for under €10 (shipped out of local warehouses within 2 days). Just make sure you are comparing prices* and *vendor. Cheap filament I got from unknown vendors was so bad that I could only throw it away, whereas filaments from renown Chinese vendors like Sunlu weren’t more expensive and have always performed excellently.

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