3D Printing Info

Printer comparison

Formlabs Form 4 vs Rat Rig V-Core 4.1

Compare hardware, build volume, printing specifications, dated prices and sources.

2 selected · all documented properties

Formlabs Form 4 vs Rat Rig V-Core 4.1 — documented properties and sources
PropertyFormlabs Form 4RESINRat Rig V-Core 4.1COREXY
Identity
BrandFormlabsRat Rig
ClassRESINCOREXY
Identity & Market
Manufacturer & exact marketed model name (verify the exact product identity first)Formlabs Form 4 3D Printer[1][2]Rat Rig V-Core 4.1, described by Rat Rig as a large-format open CoreXY 3D printer kit[3]
Street price (USD; dated snapshot per entry)Starting at $2,625.00 at GoEngineer, in stock, checked Aug 2026. Formlabs sells the printer as part of packages (Form 4 Complete Package etc.), so package prices are much higher than the printer-only figure[2]Not documented
Variants & sibling models — and how to tell them apart (spec-contamination risk)Three machines share this platform and are constantly conflated. Form 4: 200 x 125 x 210 mm, 50 um pixels, 18.3 kg, 480 W, one resin cartridge, NOT biocompatible. Form 4B: identical hardware but validated for 38 Formlabs materials including 15 biocompatible. Form 4L: 353 x 196 x 350 mm, 46 um pixels, 58.5 kg, 900 W, two cartridges[1]Three sizes, all at the same base-kit price. Acceleration is the size-dependent figure and the one most often mis-quoted: 15,000 mm/s2 at 300 mm, 12,000 at 400 mm, 8,000 at 500 mm. IDEX is a configuration option and changes the usable area per toolhead (copy mode 150x150x300 at the 300 size, mirror mode 95x95x300). Base kit excludes electronics. Rat Rig prices the base kit only in EUR (EUR 873.90 on sale from EUR 971.00, Aug 2026); no USD list price is published, so no USD street price is recorded here[3]
Market position: superseded? successor announced?Not documentedCurrent revision, replacing the V-Core 4; Rat Rig sells a 4.1 upgrade kit for existing V-Core 4 machines[3]
Physical & Frame
Build volume X×Y×Z (mm) — advertised vs actually usable200 x 125 x 210 mm (Formlabs quotes 5.25 litres)[1][2]300 x 300 x 300, 400 x 400 x 400 or 500 x 500 x 500 mm. Sortable value is the 300 mm kit[3]
Machine footprint (mm) & clearance needed (cable/spool overhang)398 x 367 x 554 mm[1][2]623.2 x 583 x 785 mm (300); 723.2 x 683 x 885 mm (400); 823.2 x 783 x 985 mm (500). Sortable value is the 300 mm kit[3]
Net weight (kg)18.3 kg[1][2]Kit weight 35 kg (300), 45 kg (400), 55 kg (500)[3]
Frame construction & materialNot documented30-series aluminium extrusion; the 4.1 adds a steel X-axis gantry for rigidity[3]
Enclosure: open / enclosed; panel material; door/lidEnclosed cabinet with a hinged UV-blocking cover. Operating temperature 18-28 C[1]Open frame in the base kit[3]
Kinematics & Motion Hardware
Kinematics (bedslinger i3 / CoreXY / other)Masked stereolithography (MSLA). Formlabs brands the engine Low Force Display; straight-lift peel[1][2]CoreXY; Hybrid CoreXY and IDEX are configuration options[3]
Speed & Acceleration
Max acceleration (claimed, mm/s²)Not documentedSize-dependent: 15,000 mm/s2 at 300 mm, 12,000 at 400 mm, 8,000 at 500 mm (manufacturer claims)[3]
Extruder
Type (direct drive / bowden) & design nameNot documentedFull-metal skeleton toolhead, new in the 4.1[3]
Hotend & Nozzle
Max nozzle temp claimed AND firmware max temp limit (both values)Not documented350 °C maximum nozzle temperature (manufacturer claim)[3]
Stock nozzle size & sizes included in boxNot documented0.4 mm hardened steel and 0.6 mm included[3]
Heated Bed & Surface
Max bed temp claimed AND firmware limitNot documented120 °C maximum heatbed temperature (manufacturer claim). The 400 and 500 sizes get 8 mm thick beds in the 4.1[3]
Cooling & Air Handling
Part-cooling fan(s): count, size, ducting designNot documentedImproved part cooling, listed by Rat Rig as one of the 4.1 changes[3]
Electronics & Power
Input voltage (110/220 V, switch or auto)100-240 VAC, 4.8 A, 50/60 Hz, 480 W[1]Not documented
Total rated power draw480 W[1]Not documented
Firmware & Openness
Firmware base & current version (Klipper fork / Marlin fork / proprietary)Proprietary. Print preparation is PreForm; fleet management is Formlabs Dashboard[2]RatOS 2.1 (Rat Rig's Klipper distribution)[3]
Connectivity, UI & Camera
Display: size, type, touch?7-inch interactive touchscreen, 1280 x 800 (control panel — not the masking LCD, see W1)[1]Not documented
WiFi (band/standard), Ethernet, USB ports, SD/flash-driveDual-band Wi-Fi, Gigabit Ethernet (1000 Mbit), USB-C 2.0[1][2]Not documented
Calibration Routines & QoL
Assembly level & time from unbox to first printNot documentedSelf-assembly kit; the 4.1 ships pre-made cables that need no crimping, with rewritten step-by-step build documentation[3]
Materials Support
Officially supported filament listFormlabs resins across rigid, tough, general purpose, flame retardant, silicone, elastic, ceramic and castable families. Biocompatible resins require the Form 4B, not the Form 4[1]PLA, PETG, ABS, ASA, TPU, PET, PA, PC, PVA, PLA-CF, PETG-CF, ABS-GF, ASA-CF, PA6-CF, PA6-GF, PAHT-CF, PPA-CF, PET-CF[3]
Independently Measured Performance
Dimensional accuracy measurements (third-party, with numbers)XY dimensional tolerance +/-0.15% — a manufacturer specification, not an independent measurement[1][2]Not documented
Resin & MSLA
Masking LCDLow Force Display masking LCD with a 50 um pixel size and pre-tuned anti-aliasing. Formlabs does not publish the screen diagonal or pixel count[1][2]Not documented
Light sourceBacklight unit with 60 uniform-wavelength high-power LEDs behind collimating lenses, with integrated cooling[1][2]Not documented
Vertical print speedmm/hMaximum 100 mm/h; average 40 mm/h at a 100 um layer height (manufacturer figures — GoEngineer publishes both, which is unusually explicit about the basis). Formlabs separately claims most prints finish in under 2 hours[2][1]Not documented
Layer height range25-200 um per Formlabs' own tech-spec page; GoEngineer's listing for the same machine says 25-300 um. Unresolved[1][2]Not documented
Resin vat & feedingSingle next-generation resin cartridge; Formlabs claims 5-10x faster filling and 63% less waste. Resin tank rated for 75,000+ layers with any Formlabs material. No vat capacity published[1][2]Not documented

Manufacturer claims, independent measurements, packages and test conditions retain their source wording. FDM linear speed and resin vertical speed use different units and are not directly comparable. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.

Sources for this comparison

  1. Formlabs resin printer technical specifications (Form 4 / 4B / 4L) formlabs.com · 2026-08 · vendor
  2. Formlabs Form 4 3D printer listing store.goengineer.com · 2026-08 · vendor
  3. Rat Rig V-Core 4.1 product page ratrig.com · 2026-08 · vendor