Resin Printing
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This section covers essential practices for newcomers to resin printing seeking a similar machine setup.
While resin printing provides high-quality results, the extensive cleanup is often unmentioned. Cleaning the vat and entire setup after each print can take approximately one hour.
A dedicated workspace is necessary. Select a part of the workspace that is easy to clean and can handle minor spills. Silicone mats and contact paper on workbenches facilitate scraping prints and cleaning surfaces.
Spilled resin is toxic, difficult to clean, and will damage carpet. Proper ventilation and/or air filtration are necessary due to the strong odor.
Resin printing is best suited for specific projects or when multiple prints are lined up. Leaving resin sitting in the vat for extended periods should be avoided; ideally, clean everything within 24 hours. While resin can remain in the vat for a few days if shielded from UV light, it must be mixed before the next print. Limiting the time resin sits in the vat is recommended.
Resin printing offers unmatched quality but requires awareness of the cleanup process.
Upgrading to a flex plate can simplify print removal. These magnetic build plates can ease the process.
Removing prints from the build plate will be more difficult in resin printing than in FDM printing. Caution is necessary to avoid making a mess, and some prints can be difficult to remove without damage. Lifting prints off the build plate or printing them at an angle is often recommended, as large flat surfaces can be challenging to remove.
Flex plates are crucial for simplified parts removal. A simple bend of the flex plate separates parts.
A well-equipped workstation is necessary for removing and cleaning resin prints. Essential items include a large silicone mat, contact paper, a flexible build plate, and nitrile gloves. Latex gloves should be avoided.
Resin should be kept off skin, requiring frequent glove changes. Gloves are needed when pouring resin into the vat and cleaning prints. Expect to use at least one to two pairs of gloves per print.
Since resin cures via UV light, sunlight or UV exposure to the resin vat should be avoided. Printing a cover for the vat is recommended when it's not in use, and leaving resin in the vat for extended periods should be avoided. If there are large windows that let in sunlight, the lid should be on the resin printer. Even with minimal light exposure, minimizing UV exposure to the vat is important.
Isopropyl alcohol is necessary for cleaning. Denatured alcohol is an alternative. Substantial quantities of isopropyl alcohol are needed, especially for larger prints. Isopropyl alcohol is useful for cleaning the vat and tools such as scrapers.
The FEP film on the underside of the vat is a consumable that will need replacing. Extra FEP films sized for the printer should be purchased.
Budgeting for resin printing includes the cost of the printer, flex plate, silicone mat, contact paper, alcohol, replacement FEP films, resin, vats for cleaning, gloves, and other essentials for the workstation.
Resin printing typically relies on slicers like ChiTuBox, commonly used with printers such as those made by Elegoo. Setting up a new printer in ChiTuBox is usually straightforward, with default settings that often provide good results. However, exposure and curing times can vary significantly depending on the specific printer and resin used.
Monochrome LCD printers allow more UV light to pass through, resulting in faster curing times compared to standard LCD printers. Transparent resins also cure more quickly than opaque ones—sometimes in half the time. For instance, with a monochrome printer like the Elegoo Saturn 3 Ultra, transparent layers at 50-micron heights may cure in about 3 seconds, whereas black opaque resin layers might require around 6 seconds. Thicker layer heights also demand longer curing times. Note that this applies specifically to LCD resin printing, which cures entire layers simultaneously. Laser resin printers like those from FormLabs operate differently and tend to be slower.
When configuring support structures, many experienced users reference support-setting guides or video tutorials. A commonly cited method involves placing heavy supports on floating sections, medium supports on steep angles, and light supports on small features. Manually adding supports can be time-consuming but is often more reliable than automatic support generation, which may damage prints or leave unsupported areas.
Print orientation in resin printing also differs from FDM printing. Avoid large, flat surfaces contacting the build plate. Instead, angle prints so that only minimal surface area touches the plate or lift the entire model using the "Z Lift Height" setting—typically around 5mm—and add supports to the floating areas. Large flat contacts can make removal from the build plate difficult to near impossible.
Resin slicing supports only solid or hollow prints—there is no option for specific infill percentages. Most prints are done as solid models, which use more material than typical FDM prints. When printing hollow models, escape holes must be added to allow uncured resin to drain out. Without these holes, resin remains trapped inside, posing curing and structural risks. Increasing wall thickness helps avoid warping in hollow prints, but overhangs may still create issues since the slicer may generate support structures within the model.
Before removing a print from the build plate, prepare a vat of isopropyl or denatured alcohol large enough to submerge the print. Using two vats can be helpful—one for initial rinsing and another for final cleaning. This method prevents rapid contamination of the cleaning solution and helps conserve alcohol when processing multiple prints.
Removing supports before placing parts in alcohol is ideal to avoid damaging the model. Once supports are off, place the part in the first vat and scrub it with a toothbrush to remove uncured resin. Wearing nitrile gloves is recommended during this process. Agitating the alcohol helps with cleaning, and devices like the Elegoo Mercury or Mercury XS can simplify this process by combining agitation and curing functions in one station.
After the initial wash, transfer the model to a second, cleaner vat for 10–15 minutes. Periodic agitation during this time improves results. Once the first vat becomes too contaminated, it can be cleaned (as described below) and swapped for the second, continuing the cycle with fresh alcohol.
After the second bath, the part should be UV cured. This can be done with a curing station or a DIY setup made from a box lined with reflective material and fitted with UV LED strips. A rotating platform like a lazy Susan ensures even curing. Alternatively, parts can be cured under direct sunlight for approximately 15 minutes. However, excessive UV exposure can lead to over-curing, causing brittleness.
Post-curing, transparent parts may appear cloudy or lose their gloss. A quick spray of clear gloss coat can restore transparency and improve the visual quality of the print.
Cleaning used alcohol is not simple and should never involve pouring it down a drain. A safe method involves placing the container in sunlight (with a secure lid to prevent evaporation), allowing the UV rays to solidify most of the resin particles. The mixture can then be filtered through a strainer, separating cured resin from usable alcohol. The solid waste can be safely discarded in regular trash once cured.
All resins used in SLA printing cure with UV light, which continues to affect the material even after initial curing. Over time, this leads to increased brittleness, as prolonged UV exposure continues to harden the material. This is a common limitation among most available resins.
For example, resins like eSUN Hard-Tough may initially offer strong, impact-resistant parts. However, after additional UV exposure over days or weeks, these same parts can become brittle and prone to cracking. To mitigate this issue, a UV-blocking primer can be applied to prevent further exposure. While this may alter the appearance of the print, it helps preserve the part's strength over time.
For applications that demand high mechanical strength, SLA resin printing may not be the ideal solution. While there are anecdotal reports of improved results by mixing tough and flexible resins—such as combining Siraya Blu and Siraya Tenacious with Siraya ABS—results can vary and require testing. Protective topcoats, like clear gloss sprays, may help retain part durability and appearance.
Despite its challenges, resin 3D printing excels in producing high-detail parts, especially for small or intricate designs. However, it also presents more safety concerns and process complexity than FDM printing. With proper safety measures and equipment, resin printing can offer exceptional results for specific applications.
It is highly recommended to watch a comprehensive YouTube video on resin 3D printing for beginners. This video can provide guidance on setup and address common issues. We suggest this one by .
