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Elegoo Mars 4 – Specs and Settings

4 min read
Elegoo Mars 4 – Specs and Settings

The Elegoo Mars 4 Ultra is a compact 9K mono LCD/MSLA printer in the budget class that delivers exceptional detail at an accessible price. With a 153 × 77 × 165 mm build volume, a 9K matrix and a longer-lasting monochrome LCD panel, the Mars 4 Ultra is the go-to choice for artists, dental technicians and miniature enthusiasts who need precision below 35 microns.

What it is

The Mars 4 Ultra uses mono LCD (MSLA) technology: a powerful UV LED array cures an entire layer at once through a monochrome mask, with exposure times measured in seconds rather than hours. The 9K resolution means 9249 × 4650 pixels spread across a 6.6-inch screen, yielding XY precision of ~18 × 24 µm. The monochrome panel passes more UV light than its color predecessors and lasts significantly longer. The printer targets users who want resin-grade detail without the price of an SLA laser.

Technical specifications

TechnologyMono LCD / MSLA (UV 405 nm)
Build volume153 × 77 × 165 mm
Resolution (XY)9K: 9249 × 4650 px (≈18 × 24 µm/px)
Screen6.6" monochrome LCD, ~12,000 h lifespan
Layer thickness (Z)0.01 – 0.2 mm (typical 0.05 mm)
Print speedup to 70 mm/h (resin-dependent)
Class / PriceBudget · ~€180

Who it’s for

  • Tabletop miniatures and figurines: exceptional XY detail (18 µm) for musculature, armor and textures unreachable by FDM (Hobby and collectibles)
  • Dental and orthodontic models: precise dental models, surgical guides and temporary crowns with biocompatible resin (Dental medicine)
  • Detailed prototypes and jewelry: castable wax resin for direct jewelry casting, or fine-grain design prototypes (Product design and jewelry)

Setup and calibration

  1. Level the build plate: loosen it, lower it to the FEP sheet using an A4 paper feeler gauge, tighten evenly and lock the level. Uniform first-layer adhesion across the entire surface, no lifted corners.
  2. Run an Exposure Calibration Test (Cones/R_E_R_F): print a test matrix with varying exposure times. Optimal Normal Exposure Time identified for the chosen resin, no over-cure or under-cure.
  3. Inspect the FEP film: hold it against light, no cloudy spots, punctures or crinkled edges. A clear and taut FEP ensures a sharp image and easy layer release.
  4. Fill the vat to the marked line: resin must cover the FEP but not overflow. Sufficient resin level for full adhesion without splashing when the plate lifts.

Common defects and fixes

Under-curing: layers are brittle, details crumble, the model delamminates or remains stuck in the vatIncrease Normal Exposure Time in 0.5–1 s steps; check that the UV LED array is clean; warm the resin to 25–30°C.
Over-curing / elephant's foot: the base is wider than CAD dimensions, fine holes are sealed, bottom details are lostReduce Bottom Exposure Time and/or Bottom Layer Count; check the anti-aliasing setting in the slicer; raise Z-offset by 0.05 mm.
FEP adhesion / print sticking to vat (the model does not follow the build plate but stays stuck to the FEP bottom) caused by a worn FEP, insufficient plate adhesion or missing support pillarsReplace the FEP film; increase Bottom Layers and Bottom Exposure Time; add more supports in the slicer; lower Lift Speed.
Suction cupping (enclosed cavities trap resin under pressure on every lift) layers warp or detachAdd drain holes (≥ 3 mm) to the model; tilt orientation by 30–45°; lower Lift Speed to 40 mm/min.

Resin exposure helper

Pick a resin type for starting exposure values (typical for mono-LCD machines). These are STARTING points: always run an exposure test, because the exact seconds depend on your screen power and the specific resin:

↑ Pick a resin type
Layer cure
Bottom cure
Bottom layers
⚠ Starting values. Print an exposure test (e.g. Cones of Calibration / R_E_R_F) to dial them in for your resin.

Conclusion

The Mars 4 Ultra proves that 9K detail does not require a high budget. The monochrome panel, fast UV array and compact form factor make it an ideal entry point for anyone stepping into resin printing, from the artist painting miniatures to the dental technician who needs precise models.

The full picture

This article is one page from The Big Book of 3D Printing: 704 illustrated pages covering every technology, material and fix in one reference.

Read it on Kindle →

Engineer, author of The Big Book of 3D Printing and additive manufacturing expert

Updated on 11 September 2026

This article was written with AI assistance; the facts were checked against the sources on 11 September 2026.