Best dlp projector for 3d printing

What is a DLP 3D Printer?

There are a lot of fancy terms and letter combinations floating out there when we talk about 3D printers. Simply put, there’s a whole bunch of different 3D printing technologies, and these names talk about how they vary from one another.

DLP stands for Digital Light Processing, which works by using a projector and a UV laser to harden liquid resin into a solid, finished product. 

Difference Between DLP, FDM, and SLA 3D Printer

DLP (Digital Light Processing) uses a projector to cure liquid resin. It’s one of the fastest 3D printing technologies out there, working up to 12 times faster than similar SLA printers. It has the affordability you might expect from FDM printers while still being accurate and fast, similar to SLA printers. 

It’s a worthy investment if you want an all-around good printer for both work and play. 

FDM, Fused Deposition Modeling, is probably the most common technology for 3D printing. FDM works by heating plastic filament until it melts. It then squeezes it out of a nozzle in layers onto a build tray to make a print.   It’s an inexpensive and accessible method which yields some sturdy builds – but it can often leave some layer lines on the finished product. FDM might not be for you if you’re looking for minute accuracy but rather for a durable and strong build. 

SLA (stereolithography) is also a type of resin printing process, but instead of a projector like DLP it uses a laser to cure liquid resin. SLA cures resin point by point, while DLP cures resin one layer at a time. SLA is generally more accurate than FDM and DLP printers, but it can get preeetty expensive. Also, it’s slower compared to DLP printers.

What to Consider When Buying a DLP 3D Printer?

Price

3D resin printers aren’t cheap, but you don’t want to go and buy a rip-off 3D printer from Amazon. As the cliche goes, you get what you pay for, and a lot of these printers are, simply put, a waste of money. 

Keep in mind not all lower-cost printers are rip-offs. There are budget options that come with great features! But there’s a difference between a lower-cost printer and an unbelievable $100 printer that would just end up being a waste of money, time, and effort. You’re better off spending that on 12 boxes of multi-colored rubber ducks — at least you’ll get your money’s worth!

Another tip to keep in mind: there are a lot of scammers and fakes out there, so we suggest always checking that you’re buying from a reputable, legit vendor.

As for lower-cost printers – while legit, some of them can be lower-quality in build, sometimes needing a bit of upkeep, DIY, or maintenance and support. This can end up being pricey in itself, so always keep in mind that with a reduction in price there can be a bit of a trade-off in quality. 

The fact is that a good 3D printer is an investment, and so you have to look thoroughly into the specifics, as well as what you need exactly, to make the best purchasing decision possible.

Resolution

A good 3D printer is a difference between a high-quality, detailed print or an unrecognizable blob of plastic or resin. 

There’s a spectrum when it comes to resolution and quality in 3D printers. If you’re looking for really high resolution, some printers offer that at a higher cost. Other printers offer decent resolution which would be fine for models and crafts but not as super-detailed as some other applications require, such as dentistry and jewelry.

Get ready for the 3D printer nerd talk…here goes. Okay. It’s a 3D printer, right? That means we’re working in 3 dimensions. So there are 3 axes — the X, Y, and Z axes. 

There are two types of resolution in 3D printers — XY resolution and Z-resolution, also known as layer thickness. XY resolution refers to the horizontal resolution, while Z is vertical.

The XY resolution determines the resolution and print quality, while the Z resolution determines how thick each layer can be. 

Applications like jewelry and dentistry require much smaller layer thicknesses, from 50 microns and below. As for XY resolution, just like for Z resolution — the smaller, the better. Smaller resolutions translate to highly-detailed builds and designs. 

There are some printers that can work for both professional and hobby applications. If you want pretty accurate models, a printer that works at 50 to 100 microns is what you need. Anything more than that isn’t going to be finely detailed and will have a rougher finish. 

Build Volume

Think about what specifically you need to print and how often. Do you want to print tiny objects or big ones? Do you want to build a lot of objects at once or is one or two enough? 

Think about your output. If you want to print an action figure or two every so often, you don’t need that much build volume. If you’re a business or you plan to build a lot of stuff, you’ll probably require a printer with a more substantial build volume. 

Reliability

Remember how we said a 3D printer is an investment? This means we have to consider how our printer’s gonna work for the long-term.   A good printer can last you up to 10 years — a bad-quality printer may not even make it past the 10 minutes mark. Or maybe 10 days or 10 months. That’s a bad printer. 

If you’re going to depend on your printer for work or your hobbies, then you have to make a well-informed decision and put money into a printer that’s not going to let you down. 

Customer Support

If you are going to invest in a 3D printer, you have to know that you’re in good hands. 

Running into any issues, whether hardware or software, can be an unpleasant experience. Some 3D printing manufacturers make it smooth sailing, and those are the ones whose products you should go for. You don’t want shoddy customer service or get hung up on when you’re having issues.

Sadly, not all printing companies offer good customer service, so keep an eye out for this factor when purchasing a 3D printer. 

So Which DLP 3D Printer Is The Best?

We’ve looked at a lot of options here, and each printer has its strong and weak areas. Let’s go through each category and figure out which printer shines best where. 

When it comes to accuracy, Asiga Max and Flashforge Hunter are both great choices. 

Keep in mind they’re both expensive but both solid and reliable and are worth the price if you’re working professionally and/or can afford them. 

Next, we have the best of both worlds, which is the Anycubic Photon D2. 

Its affordability and accuracy means it can offer really finely-accurate builds at a much cheaper cost than the Asiga and Flashforge. This printer also works really well if you want to print small figurines or similar objects.

If you want a speedy printer that is still very accurate, the B9 Core 550 is great for industrial and hobby applications.

If you want something really budget-friendly, try the Anycubic Photon Ultra. This machine is very affordable and still produce prints with amazing detail quality. 

Best resin 3D printers in 2023

What is the best resin 3D printer on the market?

Resin 3D printers are able to offer a very high level of detail and smooth surfaces. They are most commonly seen in dental labs and clinics as well as in jewelry workshops but are also increasingly popular with hobbyists and makers.

The way a resin 3D printer works depends on its technology: laser SLA (stereolithography), DLP (Digital Light Processing), or LCD-based (using an LCD screen to mask projected light).

All resin 3D printers involve the same workflows, however, requiring several post-processing steps such as resin removal and post-curing.

In this guide, we take a look at some of the best resin 3D printers available in each category (SLA, DLP, and LCD) and provide you with key concepts linked to resin 3D printing.

The best resin 3D printers (SLA/DLP/LCD)

Brand	Product	Build size	Country	Price Approximate starting prices based on supplier-provided information and public data. Prices may vary by region, over time and do not include additional products or services (taxes, shipping, accessories, training, installation, …).
Prusa Research	Original Prusa SL1	120 × 68 × 150 mm4.72 × 2.68 × 5.91 in	Czech Republic	$ 1,6991 599 €1,408 £228,971 ¥	Buy
Peopoly	Phenom	276 × 155 × 400 mm10.87 × 6.1 × 15.75 in	China	$ 1,9991 899 €1,657 £269,401 ¥	Contact
Formlabs	Form 3	146 × 145 × 185 mm5.75 × 5.71 × 7.28 in	United States	$ 3,4993 294 €2,900 £471,553 ¥	Quote
UNIZ	SLASH 2	190 × 120 × 200 mm7.48 × 4.72 × 7.87 in	–	$ 3,5003 295 €2,901 £471,688 ¥	Quote
FlashForge	Hunter DLP	120 × 67 × 150 mm4.72 × 2.64 × 5.91 in	China	$ 3,9993 765 €3,315 £538,937 ¥	Quote
DWS	XFAB	180 × 180 × 180 mm7.09 × 7.09 × 7.09 in	–	$ 6,6006 000 €5,471 £889,469 ¥	Quote
B9Creations	B9 Core 550	96 × 54 × 127 mm3. 78 × 2.13 × 5 in	–	$ 9,9559 372 €8,252 £1,341,615 ¥	Quote
Asiga	MAX	119 × 67 × 75 mm4.69 × 2.64 × 2.95 in	Australia	$ 10,99010 346 €9,110 £1,481,100 ¥	Quote
ETEC	Envision One	180 × 101 × 175 mm7.09 × 3.98 × 6.89 in	Germany	upon request	Quote

Expand to see more specs

The products in the table are ranked by price (low to high).

Brand	Product	Technology	Build size	Country	Price Approximate starting prices based on supplier-provided information and public data. Prices may vary by region, over time and do not include additional products or services (taxes, shipping, accessories, training, installation, …).
Prusa Research	Original Prusa SL1	mSLA	120 × 68 × 150 mm4.72 × 2.68 × 5.91 in	Czech Republic	$ 1,6991 599 €1,408 £228,971 ¥	Buy on Prusa
Peopoly	Phenom	mSLA	276 × 155 × 400 mm10. 87 × 6.1 × 15.75 in	China	$ 1,9991 899 €1,657 £269,401 ¥	Contact manufacturer
Formlabs	Form 3	SLA	146 × 145 × 185 mm5.75 × 5.71 × 7.28 in	United States	$ 3,4993 294 €2,900 £471,553 ¥	Get a quote
UNIZ	SLASH 2	mSLA	190 × 120 × 200 mm7.48 × 4.72 × 7.87 in	–	$ 3,5003 295 €2,901 £471,688 ¥	Get a quote
FlashForge	Hunter DLP	DLP	120 × 67 × 150 mm4.72 × 2.64 × 5.91 in	China	$ 3,9993 765 €3,315 £538,937 ¥	Get a quote
DWS	XFAB	SLA	180 × 180 × 180 mm7.09 × 7.09 × 7.09 in	–	$ 6,6006 000 €5,471 £889,469 ¥	Get a quote
B9Creations	B9 Core 550	DLP	96 × 54 × 127 mm3.78 × 2.13 × 5 in	–	$ 9,9559 372 €8,252 £1,341,615 ¥	Get a quote
Asiga	MAX	DLP	119 × 67 × 75 mm4. 69 × 2.64 × 2.95 in	Australia	$ 10,99010 346 €9,110 £1,481,100 ¥	Get a quote
ETEC	Envision One	cDLP	180 × 101 × 175 mm7.09 × 3.98 × 6.89 in	Germany	upon request	Get a quote

Overview of the best resin 3D printers (SLA/DLP/LCD)

This overview is divided into three sections according to the resin 3D printers’ technology (SLA, DLP, or LCD).

The best SLA 3D printers (laser stereolithography)

Formlabs has been one of the main players on the professional resin 3D printer market for years. The Form 3, evolution of the award-winning Form 1 and Form 2, is their latest model, along with the Form 3L (large volume). This professional liquid resin printer boasts an array of practical features that make it a great choice for many businesses.

In the past, users have praised Formlabs’ hardware quality and precision, while criticizing the company’s decision to limit compatible materials to expensive Formlabs proprietary resins only. Today, the Form 3 features an “Open mode” that allows the use of generic materials.

Contact manufacturer Get a quote Add to comparison

The Phenom is an affordable and large-format LCD (MSLA) 3D printer that is suitable for hobbyists and professionals alike. An advantage of this resin 3D printer is large-format. The Peopoly Phenom 3D printer also exists in larger versions: Phenom L, Phenom Noir, Phenom XXL.

Contact manufacturer Get a quote Add to comparison

DWS Systems is specialized in manufacturing professional and industrial-grade resin 3D printers. The XFAB stereolithography 3D printer is their most affordable option, but is capable of delivering high-quality results. One of this SLA 3D printer’s most interesting characteristics is its cartridge resin system.

This makes material handling much easier and cleaner than with non-cartridge systems.

Contact manufacturer Get a quote Add to comparison

The best DLP 3D printers (Digital Light Processing)

This professional resin 3D printer boasts a number of user-friendly features including a touchscreen, automatic calibration, and Wi-Fi connectivity. FlashForge develops its own resins, but users may also use third-party materials.

With its special jewelry support mode, the Hunter DLP mainly targets jewelers.

Contact manufacturer Get a quote Add to comparison

B9Creations’ Core series of 3D printers all provide fine levels of detail for professionals. According to the manufacturer, the B9 Core 550 resin 3D printer offers faster printing speeds (100+ mm/hour) than most DLP 3D printers in the same price range.

This digital light processing 3D printer is available with a smaller build volume (B9 Core 530).

Contact manufacturer Get a quote Add to comparison

The Envision One is a professional resin 3D printer produced by ETEC. ETEC, a German company known as EnvisionTEC before its acquisition by Desktop Metal in 2021, manufactures professional DLP 3D printers. The ETEC Envision One uses CDLP 3D printing technology. This 3D printer offers a build volume of 180 x 101 x 175 mm.

Contact manufacturer Get a quote Add to comparison

The Asiga MAX is equipped with a resin level sensor, automatic calibration function and touch screen. Asiga also provides free lifetime technical support.

This 3D printer is particularly suitable for the medical and dental sectors, being compatible with silicone resins.

Contact manufacturer Get a quote Add to comparison

The best LCD 3D printers (liquid crystal display)

For many years, Prusa Research has been famous for manufacturing reliable 3D printers. The Original Prusa SL1 is Josef Prusa’s first resin 3D printer, but there is no doubt that it has been endowed with as much quality as the award-winning Prusa MK3 FDM 3D printers.

This LCD 3D printer– which is also available as a DIY kit– is packed with features such as a tilted print bed, auto calibration, vapor extraction, and more.

Buy on Prusa Get a quote Add to comparison

The SLASH 2 is a desktop resin 3D printer produced by UNIZ. UNIZ is a 3D printer manufacturer based in China. The UNIZ SLASH 2 uses resin 3D printing technology. This 3D printer offers a build volume of 190 x 120 x 200 mm.

Contact manufacturer Get a quote Add to comparison

Resin 3D printers under $1,000

As LCD screens are very affordable, they have been the key to bringing resin 3D printing to the masses. Indeed, more and more manufacturers are launching affordable desktop resin 3D printers with LCD 3D printing technology, and the price drop is radical.

These affordable resin 3D printers obviously can’t be expected to provide the same level of detail and accuracy as the professional 3D printers listed above. However, they are great as an introduction to resin 3D printing and they do produce good quality prints.

Read our full-length budget resin 3D printer article for a list of affordable machines (starting from $149).

Post-processing for resin 3D prints: necessary steps

Resin removal

Since the objects are printed within a tank of resin, resin drips off of the objects as they are lifted up and out of the tank. There’s always a layer of uncured resin left on the object, and it must be removed with IPA (isopropyl alcohol).

This can be done manually by dipping the part in an IPA bath and gently scrubbing the part with a soft brush, but it is quite time-consuming.

For users that produce resin parts on a regular basis, there are machines called resin washers, or resin cleaners. Ackuretta, for example, markets Cleani, a dual-tank resin cleaner that can wash both the parts and the printer’s platform (yes, that needs to be washed, too.).

Post-curing

When removing a resin 3D printed part from the build plate, it is still soft and slightly malleable. To reach its final physical state the part must go through a post-curing step. This means exposing the object to heat or light. Various SLA post-curing techniques exist:

UV curing chamber / UV cure box

Professional users will definitely want to use a dedicated UV curing chamber for their parts in order to get the most out of the material (strength, for example). Most resin 3D printer manufacturers have UV curing chambers available separately.

UV nail lamp

For small parts, nail UV lamps can do the trick. There are dozens of nail UV lamps available for less than $50.

DIY UV curing chamber

Crafty people also have the possibility to make their own UV curing station!

How do resin 3D printers work and what are the differences between LCD, DLP, and SLA 3D printing?

SLA 3D printers, LCD 3D printers, and DLP 3D printers all use liquid resin as a 3D printing material. The resin, a photopolymer, becomes solid when cured (activated) by a specific light source.

That light source cures the liquid resin, which is stored in a tank or vat, to form the object layer after layer.

The resin solidification process (photopolymerization) is at the core of three main 3D printing technologies:

• Laser-based Stereolithography (SLA): a UV laser cures the resin in the tank to form the object point by point.
• Digital Light Processing (DLP): the resin is cured by a light projector one whole layer at a time. The light shines in a specific shape depending on the layer.
• Liquid Crystal Display (LCD) or Masked SLA (MSLA): An array of LED lights shine through an LCD screen. The LCD screen acts as a mask or stencil between the LED and the bottom of the resin tank, only letting light through in specific shapes.

All of these resin-based 3D printing technologies form part of the same family: stereolithography. That’s why some manufacturers include “SLA” in the name of their 3D printers, while they actually use DLP or LCD-based technology.

Laser-based SLA 3D printing technology

An SLA 3D printer cures the liquid resin spot by spot with a laser, so it is potentially more precise than DLP 3D printing.

Contrary to DLP 3D printing, the build volume is completely independent of the resolution of the 3D print. A 3D print with a laser stereolithography 3D printer can be of any size and resolution.

DLP 3D printing technology (digital light processing)

DLP 3D printers use a light projector. The layer’s shape is defined by reflecting or deflecting light with mirrors. With DLP, the 3D printer is able to cure a whole layer of resin at once. Therefore, a DLP 3D printer can potentially 3D print faster than an SLA 3D printer, as an entire layer is exposed all at once instead of one spot at a time with a laser.

However, a DLP 3D printer’s resolution depends on its projector and how many pixels/voxels are available (a full HD projector usually offers 1080p). A 3D printer with a large build volume has a fixed number of pixels, making it impossible to 3D print small details when building at full scale.

The projector used by the DLP 3D printer is less expensive and easier to change than the laser used by SLA 3D printers.

LCD-based resin 3D printing technology

Most LCD resin 3D printers use an LCD screen as a photomask– like a stencil– above another light source (LED, UV…). This is where LCD resin 3D printing is different than DLP 3D printing, which makes use of mirrors or other complex systems to direct the light into a certain shape. The technology is also called Masked Stereolithography (MSLA).

Since LCD screens are inexpensive, this technology has made resin 3D printing much more affordable than before and there are now dozens of low-cost, budget resin 3D printers available for a couple of hundred dollars.

In some cases, the light emitted by an LCD screen is used to directly cure the daylight-sensitive resin.

What is best between LCD, DLP, and SLA 3D printers?

The answer depends on the user’s needs in precision, speed, and budget. We can highlight that:

• Laser SLA 3D printers are best for 3D printing highly detailed and intricate 3D prints, big or small.
• LCD and DLP 3D printers are best for 3D printing batches of small parts, or quickly 3D printing large parts without too many details.
• LCD-based 3D printers are generally much more affordable than SLA and DLP 3D printers.

Main resin 3D printing applications

Resin 3D printers mostly target professional users. Indeed, they are suited for specific applications requiring high levels of detail and top-quality finishes. These applications include:

Resin 3D printers for jewelry

Jewelers use high-precision 3D printers to create molds with the lost wax technique and create incredible jewels.

SLA, DLP, and LCD 3D printers in dentistry

Dentists and dental labs are starting to use resin 3D printing to build dental crowns, mouth guards, surgical guides, and much more.

Resin 3D printing in medical and healthcare fields

SLA and DLP 3D printing can be used to create medical appliances such as hearing aids.

Hobbies: resin 3D printer for miniatures

Some tinkerers, DIYers, and cosplayers love 3D printing miniatures and figurines.

Key benefits and limitations of resin 3D printing

Benefits of LCD, DLP, and SLA 3D printing technologies

These are some of the advantages of 3D printing with resin:

• Ability to build small and very detailed parts or objects with fine, complex geometries
• Diversity of 3D printable resin materials (ceramic, metal, biocompatible, flexible, rigid, etc.)
• Smooth finish of the parts produced (no easily visible layers like with FFF 3D printers)

Limits of resin 3D printing

As with any technology, resin 3D printing has its limits:

• Post-processing is mandatory (removing delicate support structures, post-curing, resin removal, etc.) and requires a UV curing chamber for good results
• Requires time-consuming cleaning time (for the vat and for the 3D printed part)
• Very smelly and toxic fumes
• Safety precautions required when handling the material

Resin 3D printer price

Laser SLA resin 3D printer price

SLA 3D printer prices depend on many factors. The price for a basic SLA 3D printer kit like the Peopoly Moai usually starts at about $1,200. Industrial resin 3D printers, on the other hand, can reach several hundred thousand dollars.

DLP resin 3D printer price

The price of a DLP 3D printer generally starts around $2,000 or $3,000. DLP 3D printers with higher precision and more features cost around $10K to $20K. More expensive digital light processing 3D printers also exist.

LCD resin 3D printer price

LCD-based resin 3D printers are the most affordable resin 3D printer type. There are many LCD resin 3D printers available for under $1,000, and even under $300. Higher-quality LCD 3D printers may cost a few thousand dollars.

UV curing chamber price

Most resin 3D printer brands sell UV curing chambers separately, with prices starting around $300 to $500.

FAQ

What does SLA stand for in 3D printing?

In 3D printing, SLA stands for stereolithography.

What does DLP stand for in 3D printing?

In 3D printing, DLP stands for Digital Light Processing.

What does LCD stand for in 3D printing?

LCD stands for Liquid Crystal Display, which is a type of screen used in electronic devices (smartphone, TV, etc.). A growing number of resin 3D printers use an LCD screen’s light to cure light-sensitive resin and form objects in 3D.

What is SLA resin made of?

SLA resin is a photopolymer material, which is mainly composed of monomers, oligomers, and photoinitiators. Depending on the “recipe”, the stereolithography resin can be plastic, ceramic, or even metal-based.

How much does a resin 3D printer cost?

A resin 3D printer can cost anywhere from $500 to over $250,000. However, there are many resin 3D printers available for under $10,000.

What is a resin 3D printer?

A resin 3D printer (stereolithography) is a machine that solidifies liquid resin layer by layer to form an object in 3D.

Where are resin 3D printers for sale?

There are resin 3D printers for sale on major e-commerce sites like Amazon, AliExpress, GearBest, and Banggood. Online retailers specialized in 3D printing also exist, such as MatterHackers.

3D printer comparison in 2020

A variety of 3D printing technologies are available on the market today. Getting to know the nuances of each helps you understand what you can expect from the final models and decide which technology is right for you.

Stereolithography (SLA) and digital light processing (DLP) are the two most common 3D printing technologies using resins. 3D printers that use resin as consumables have become very popular due to their ability to produce highly accurate, isotropic and waterproof prototypes and models with high detail and smooth surfaces.

While these technologies used to be complex and prohibitively expensive, today's compact desktop SLA and DLP printers produce industrial quality parts at an affordable price and offer tremendous application flexibility through a wide range of materials.

Both of these processes selectively expose liquid polymer to a light source: an SLA laser, a DLP projector, forming very thin, hard layers of plastic that fold into a solid object. Although the principle of operation of these technologies is very similar, they can give significantly different results.

In this detailed guide, we will explain the features of these two 3D printing processes and see how they differ in terms of resolution, accuracy, print volume, speed, workflows, etc.

sample print

printing from my own experience. We will send a free sample of the Formlabs stereolithographic 3D printed model directly to your office.

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Desktop stereolithography 3D printers contain a resin tank with a transparent bottom and a non-adhesive surface that serves as a base for the liquid resin to solidify, allowing the newly formed layers to be gently peeled off.

The printing process begins with the platform lowered into the resin tank, leaving a free space corresponding to the height of the layer between the platform or the last finished layer and the bottom of the tank. The laser beam is fed to two mirror galvanometers, with the help of which it enters the desired coordinates on a series of mirrors. This allows a focused beam of light to be fed upwards through the bottom of the tank, under the influence of which the polymer layer hardens.

Then the hardened layer is separated from the bottom of the tank, and the platform rises higher, and liquid polymer enters the freed space. This process is repeated until printing is complete.

The Form 3 and Form 3L Low Force Lithography (LFS) stereolithography technology is a new step in the development of stereolithographic 3D printing.

In LFS-based 3D printers, the optical components are located in the Light Processing Unit (LPU). Inside the LPU, a galvanometer positions the high-density laser beam in the y-direction, passes it through a spatial filter, and directs it into a deflecting and parabolic mirror to ensure that the beam always remains perpendicular to the plane of the platform, ensuring print accuracy and reproducibility.

As the LPU moves in the X direction, the printed model is gently separated from the flexible bottom of the tank, which greatly reduces the forces on the models during the printing process.

LFS-based 3D printing greatly reduces the stress placed on parts during the printing process by using a flexible reservoir and linear illumination to deliver incredible surface quality and print accuracy.

This advanced stereo lithography technology features higher surface quality and print accuracy. The lower print tear force also allows the creation of lightweight support structures that can be detached without force, and the method itself opens up great opportunities for the further development of advanced production-ready materials. Learn more about stereolithographic 3D printing

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Desktop DLP printers use a resin tank with a transparent bottom and a platform that descends into the tank to layer upside down models. In this they are no different from stereolithographic 3D printers.

The difference between them is the light source. DLP-based 3D printers use a digital screen to project the image of the layer onto the entire platform, causing all the desired dots to solidify at the same time.

Light is reflected on a digital micromirror screen (DMD), a dynamic mask consisting of microscopic mirrors that are located in a matrix on a semiconductor chip. The rapid switching of these tiny mirrors between lenses that direct light to the bottom of a tank or radiator determines the coordinates at which the liquid polymer must solidify in order to form the current layer.

Because the projector is a digital screen, each layer's image is made up of square pixels, resulting in a three-dimensional layer of rectangular cubes called voxels.

When it comes to 3D printer specifications, resolution is the focus, but it often leads to confusion. The basic units of the SLA and DLP processes are different forms, making it difficult to compare printers by numbers alone.

In 3D printing, there are three dimensions to consider: two planar 2D dimensions (X and Y) and a third vertical Z dimension, which is used for 3D printing.

The resolution of the Z measurement is determined by the thickness of the layer that the 3D printer can print. Printers based on SLA and DLP technology have one of the best Z resolutions of any other process, allowing you to print layers with minimal thickness. Typically, users can set the layer height to between 25-300µm, allowing developers to trade-off between level of detail and speed.

In DLP printers, XY resolution is determined by the pixel size, the smallest detail that the projector can reproduce in a single layer. It depends on the resolution of the projector (the most common is Full HD (1080p)) and its distance from the optical glass. Therefore, most desktop DLP printers have a constant XY resolution of 35 to 100 microns.

In stereolithographic 3D printers, the XY resolution is determined based on the size of the laser spot and the number of steps that can be used to control the beam. For example, a Form 3 3D printer based on LFS technology has a laser with a spot size of 85 μm, but due to the constant line scanning process, the laser can move at a smaller step, and the printer can consistently print models with an XY resolution of 25 μm.

Resolution itself is often only an indicator of vanity. It gives some idea of ​​the performance, but does not necessarily directly correspond to the accuracy and quality of the print.

Learn more about resolution in 3D printing in our detailed guide.

Since 3D printing is an additive process, violations can potentially occur in every layer. The process of forming layers affects the level of accuracy and correctness of each layer. Accuracy and accuracy depend on many factors: 3D printing process, materials, software settings, post-processing, etc.

In general, SLA and DLP printers are among the most accurate. Differences in print accuracy are often more noticeable between printers from different manufacturers than between the technologies themselves.

For example, entry-level SLA or DLP printers may use off-the-shelf projectors, lasers, or galvanometers, and their manufacturers strive to achieve optimum performance from these parts. Professional SLA and DLP printers (such as Formlabs Form 3) have a special optical system that is adjusted according to the needs of users.

Precision is critical for parts such as mouth guards (left) and surgical guides (right).

Precision is critical for parts such as mouth guards (left) and surgical templates (right).

Equally important is calibration. When using DLP projectors, manufacturers face uneven distribution of light on the platform and optical lens distortion, which means that the size and shape of the pixels in the middle and at the edges are different. Stereolithographic 3D printers use the same light source for all parts of the model, ensuring uniformity, but they still need to be carefully calibrated to avoid distortion.

Even a 3D printer with the best components and the best degree of calibration can produce different results depending on the consumables used. Resin parameters have to be changed to ensure the best quality, but they may not be available for new materials that have not been properly tested with the appropriate 3D printer model.

What conclusion can be drawn from this? Knowing only the technical characteristics, it is impossible to get a complete picture of the quality. The best way to evaluate a 3D printer is to study the models printed on it or ask the manufacturer to make a test model for your project.

DLP printers have an inverse relationship between resolution and working volume. The resolution depends on the projector, which determines the number of pixels/voxels available. If you move the projector closer to the optical glass, the pixels will become smaller and the resolution will increase, but the working area will be limited.

Some manufacturers install multiple projectors side by side or use a 4K high-definition projector to increase the working area, but this increases the cost significantly. The price of such models is much higher than other desktop 3D printers.

Therefore, DLP printers are usually optimized for specific purposes. Some of them have a smaller workspace and allow you to produce in high resolution such small and detailed models as jewelry, while others can print larger parts, but with a lower resolution.

The stereolithography process is inherently more scalable because the print volume of an SLA printer is independent of model resolution. A single model can be of any size and resolution, and can be placed anywhere on the workspace. This allows you to print large high-resolution 3D models or large batches of finely detailed models to increase printer performance.

Another hurdle to increasing print volume in both SL and DLP printers is the release force. When printing large models, the forces applied to them increase exponentially as the cured layer separates from the reservoir.

With LFS printing, the flexible film at the base of the resin reservoir gently peels off when the platform pulls the model up, greatly reducing stress on the model. This unique feature has dramatically increased print volume in the first affordable large-format stereolithography printer, the Form 3L.

Form 3L is the first affordable 30 x 33.5 x 20cm large format 3D lithography 3D printer. compared to solutions based on other technologies. When we talk about differences, in most cases they are only visible on very small parts and models with a high degree of detail.