Online 3D Printing Service | Stereolithography (SLA) 3D Printing Service

Overview

Our SLA 3D Printing Service

What is SLA

SLA is stereolithography. Use a laser with a specific wavelength and intensity to focus on the surface of the light-curing material, so that it is sequentially solidified from point to line, from line to surface, and completes a layer of drawing work, and then the lifting platform moves a layer height in the vertical direction, and then solidifies Another level. In this way, layers are superimposed to form a three-dimensional solid.

How Does SLA Work?

First, design a three-dimensional solid model through CAD, use a discrete program to slice the model, design the scanning path, and the generated data will precisely control the movement of the laser scanner and the lifting platform; the laser beam passes through the scanner controlled by the numerical control device, according to the design.
The scanning path irradiates the surface of the liquid photosensitive resin to cure a layer of resin in a specific area of the surface.
After one layer is processed, a cross section of the part is generated; then the lifting table descends a certain distance, and the cured layer is covered with another layer of liquid Resin, then scan the second layer, the second cured layer is firmly bonded to the previous cured layer, so that the three-dimensional workpiece prototype is formed layer by layer.
After the prototype is taken out of the resin, it is finally cured, and then polished, electroplated, painted or colored to obtain the required product.

Features of SLA Technology

Advantages

Technologically mature

SLA is the earliest rapid prototyping process with high maturity and time-tested.

Easy and fast

The prototype is directly made from the CAD digital model, the processing speed is fast, the product production cycle is short, and no cutting tools and molds are required.

Prototype with complex structures

It can process prototypes and molds with complex structures or shapes that are difficult to form using traditional means. Provide samples for experiments, and can verify and check the results of computer simulation calculations.

Remote control

It can be operated online and remotely controlled, which is conducive to the automation of production.

Drawbacks

Equipment cost

The cost of the SLA system and maintenance is high, and the SLA system is a precision device that operates on liquids and has strict requirements on the working environment.

Material defect

Finished parts are mostly resin, with limited strength, stiffness and heat resistance, which is not conducive to long-term storage.

Available materials for 3D SLA Printing

Here is a list of our standard 3D printing materials available through our online platform.

SLA 3D Printing Plastics

Resin
Standard white material (UTR 8360)	UTR Imagine Black	UTR-8100 (transparent)
PWR Dark Black	UTR-8100 (translucent)	Somos ® Ledo
UTR 8220	Somos ® Taurus	UTR 3000
UTR Therm	Somos ® EvoLVe 128	Formlabs ESD Resin
Somos ® PerFORM

Custom Material

The materials available on the online system may not be exhaustive of all materials available on the market. If the materials you need are not listed on the order page, please select "custom" under the material menu, and our engineers will review and purchase.

Our standard surface finishes

Spray painting - Matt paint

Spray painting: Using spray guns with air pressure to disperse into uniform and fine droplets and apply the painting to the surface of the object.

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Spray painting - High gloss paint

Spray painting: Using spray guns with air pressure to disperse into uniform and fine droplets and apply the painting to the surface of the object.

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Vacuum plating - High gloss paint

Vacuum plating mainly includes vacuum evaporation, sputtering and ion plating.

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Vacuum plating - Matt paint

Vacuum plating mainly includes vacuum evaporation, sputtering and ion plating.

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#1000 sanding

Sanding is the use of fine abrasive sand particles to rub the surface of the product to produce a diffuse, non-linear texture effect.

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Silkscreen

Silkscreen generally refers to screen printing, which is the process of pressing ink through a stencilled mesh screen to create a printed design, graphics and text.

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Laser engraving

Laser engraving is the use of laser technology to engrave text and pattern on objects.

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Dyeing

Dyeing is done in a special solution containing dyes and particular chemical material.

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View more surface finishes

Our SLA 3D printing capability

Requirement	Specification
Max part size	2100800700mm
Minimum wall thickness	0.8mm
Typical surface finish	3 – 10 microns RA

The table below depicts the general tolerances for industrial-grade stereolithography (SLA) services. Stresses during the build, support strategy and other geometry considerations may cause deviation in tolerances and flatness. Improved tolerances may be possible with a manual quote review, after successful completion of a prototype build, and must be approved on a case-by-case basis.

Tolerances

Length(L)	Metric units
L≤100mm	±0.2mm
L>100mm	±0.2%*L

3D Printing Design Guidelines

We have summarized recommended and technically feasible values for the most common features encountered in 3D printed parts.

1. Wall thickness

The wall thickness directly determines the strength of the printed object, and also determines whether the model can be printed.
Once the model is printed, it also goes through support removal, grinding and sandblasting, which determine the minimum wall thickness for different materials. The model is printable only when the wall thickness meets the minimum requirement.

Process	5*5mm	10*10mm	50*50mm	100*100mm	200*200mm
SLA	0.5mm	0.8mm	1mm	1.2mm	1.5mm
DLP	0.5mm	0.8mm	1mm	1.2mm	1.5mm
SLS	0.8mm	1mm	1.2mm	1.5mm	2.0mm
MJF	0.8mm	1mm	1.2mm	1.5mm	2.0mm
SLM	1mm	1.2mm	1.5mm	2.0mm	2.5mm
FDM	1mm	1.2mm	1.5mm	2.0mm	2.5mm

2. Embossed and engraved detail

As the height or depth of detail is less than the minimum detail requirements, it will not be able to print accurately, can not be polished, paint and other post-processing. It is recommended that you increase the height/depth, or remove the section.

Process	Min embossed detail	Min engraved detail
SLA	0.5mm	0.5mm
DLP	0.5mm	0.5mm
SLS	0.8mm	0.8mm
MJF	0.8mm	0.8mm
SLM	1mm	1mm
FDM	1mm	1mm

3. Threads and screws

Pitch refers to the axial distance between the corresponding points of two adjacent teeth on the thread. Profile angle refers to the angle between the two sides of the whorl profile. Your design needs to meet the requirements of minimum pitch:0.6mm and minimum profile angle:20°

4. Hole diameter

The following is the minimum diameter can be achieved.

Process	Min diameter
SLA	0.8mm
DLP	0.8mm
SLS	1.5mm
MJF	1.5mm
SLM	1.5mm
FDM	1.5mm

5. Sharp surfaces

When the wall thickness is very small, models with sharp surfaces can be easily damaged during support removal, grinding, packaging, and transportation. If sharp surfaces exist, the angle should be greater than 20 degrees.

6. Clearance

Parts clearance refers to the distance between any two parts, thin wall or column, as shown above. The min clearance is 1mm. When the clearance is small, it will not be able to remove the supporting material. It is recommended that you increase the clearance size or choose other materials required by the clearance. If the independence of the two parts is not important, it is recommended that you merge them into one part.

Assembly clearance refers to the distance between any two parts to be assembled, as shown above. The min clearance is 0.2mm.

FAQ's

What is the maximum build size for your SLA 3D printing?

We support a maximum build size of 2100×800×700mm for SLA printing, capable of manufacturing large-scale prototypes and structural parts in one piece. Please note that oversized items over 1.2 meters will incur extra long-size surcharges via FedEx and DHL. Light but bulky parts will also result in high volumetric weight costs. For large or bulky orders, please select "Other Shipping way" on our website, and our customer service team will recommend the most cost-effective logistics solution for you.

What is the minimum wall thickness requirement for SLA printed parts?

The universal minimum printable wall thickness for SLA is 0.8mm. For small-sized parts (55mm), the wall thickness can be controlled to 0.5mm with high precision, while the wall thickness needs to be increased to 1.5mm for large parts (200*200mm) to ensure structural stability.

All design files must have no broken holes. Keep main wall thickness above 1.2 mm, and ensure the thinnest feature is at least 0.8 mm. Thinner structures will bring printing failure and post-processing risks.

What are the dimensional tolerances for SLA 3D printed parts?

For parts with length ≤100mm, the tolerance is controlled at ±0.1mm for high precision; for parts with length ＞100mm, the tolerance is ±0.1% of the total length, which is superior to the industry standard and ensures high consistency of batch products.

What is the minimum hole diameter that SLA printing can achieve?

Our SLA printing can stably form holes with a minimum diameter of 0.8mm, and for high-precision micro-hole requirements, the aperture can be controlled to 0.05mm with professional process adjustment.

What are the minimum embossed and engraved details for SLA printing?

We can achieve ultra-fine detail processing for SLA printing, with the minimum embossed detail and engraved detail both at 0.5mm, which can clearly restore fine patterns, small characters and delicate structural features.

What are the requirements for threads and screws in SLA printing design?

The design of threads for SLA printing needs to meet the minimum pitch of 0.6mm and a minimum profile angle of 20°. Standard metric fine and coarse threads can be stably printed, ensuring smooth assembly and repeated screwing use.

What clearances are required for SLA printed parts?

The minimum part clearance (between two independent parts, thin walls or columns) is 1mm for convenient support removal and post-processing. The standard assembly clearance is 0.2mm, and for modular spliced large parts, a clearance of 0.1-0.3mm is recommended for precise fitting.

What are the requirements for sharp surfaces in SLA printing design?

If the model has sharp surface structures, the included angle should be designed to be greater than 20°. Sharp angles smaller than this are prone to chipping and damage during support removal, grinding, packaging and transportation, affecting the integrity of the parts.

What surface finish and post-processing options do you provide for SLA parts?

For SLA resin parts, our standard post-processing includes UV secondary curing to enhance part strength, followed by support removal and basic cleaning. We support the following surface finishing options: #1000 fine sanding, matte spray painting, high-gloss spray painting, matte vacuum plating and high-gloss vacuum plating.

What materials do you offer for SLA 3D printing?

Our standard SLA printing resins include UTR 8360 (standard white), UTR Imagine Black, UTR-8100 (transparent/translucent), PWR Dark Black, Somos® Ledo, UTR 8220, Somos® Taurus and other engineering-grade resins with toughness, heat resistance and ESD properties. Custom material options are also available upon request.