Elegoo Saturn 4K

The Elegoo Saturn 4K is the original 2020 Saturn that started the whole line: Elegoo's US store lists it as "Saturn 4K", the global store just calls it "Saturn", but it's the same machine. It was the brand's first attempt at a large plate for entry-level Mars money, and it worked — Tom's Hardware gave it an Editor's Choice award. It's long discontinued; the Saturn 4 and Saturn 4 Ultra are its descendants.

Build volume is 192×120×200 mm behind an 8.9-inch monochrome LCD at 3840×2400 and a 50 μm pixel. Layers run 0.01 to 0.15 mm, speed is 30–40 mm/h, and a normal layer cures in roughly 1.5–2 seconds. A 54-LED 405 nm matrix does the exposure and the Z axis rides two linear guides at 0.00125 mm steps. Unusually for a resin printer of that era, it has an Ethernet port and 4 GB of onboard storage, so files can go over the local network instead of on a stick.

Pros

• Best volume-per-dollar of its generation: a 192×120×200 mm plate against roughly a third of that on the Mars 2 Pro
• A stiff Z axis on twin rails and a thick lead screw — Tom's Hardware singles it out for keeping layer shift away
• Two-bolt leveling: TechRadar had it unboxed and printing within 20 minutes
• Ethernet plus 4 GB of onboard storage, still rare on resin printers even today
• A Chitu board with 128-level anti-aliasing — a teardown compares it against the 8 levels Anycubic offered at the time
• Four standoffs under the vat hold the film clear of the bench, so cleaning won't dent it

Cons

• No air filter at all — both TechRadar and Space.com flag it, and printing in a living space without ventilation is rough
• The bundled test file prints straight onto the plate and is brutal to remove, and the 0.4 mm leveling card gives a wrong zero
• Uneven LED matrix: a teardown found the centre module dimmer than the outer ones and the plate bowed by about 0.1 mm
• The UV lid lets light through — one workshop owner had resin skinning over in the vat within a couple of sunny days

The first Saturn is still a sensible used buy if you want a big plate for batches of miniatures and busts and 50 μm per pixel is enough. Beginners need patience: level with a feeler gauge rather than the bundled card, and plan ventilation from day one. For a new machine, go to the Saturn 4 with its 12K panel.

Bottom line: the machine that defined the cheap large-format resin printer. The mechanics age well and the weak spots are well documented — uneven exposure, no filtration, and a thin supply of replacement 4K panels on the used market.

Reviews

• Tom's Hardware — Elegoo Saturn Review: Large Volume, High Quality, Great Value (Editor's Choice)
• TechRadar — Elegoo Saturn review
• Space.com — Elegoo Saturn review: near perfect planetary printing