# Rat Rig V-Core 4.1: specs, SimplyPrint compatibility and setup > **Compatible** (We're sure). It's known to work with SimplyPrint, from documentation, the protocol or owners' prints. - By Rat Rig, Portugal - Launched December 2025 - Canonical page: https://simplyprint.io/compatibility/rat-rig-v-core-4-1 ## Rat Rig V-Core 4.1 at a glance The V-Core 4.1 is Rat Rig's open CoreXY kit, sold in 300, 400 and 500 mm sizes, with Hybrid and IDEX upgrades and optional carbon filtration. It is for experienced makers who want a Klipper printer they build and tune themselves. - Build volume: 300 x 300 x 300 mm - Enclosure: Partly enclosed - Motion system: CoreXY - Prints well: PLA, PETG, TPU & flexibles, ABS & ASA, Nylon (PA), Polycarbonate (PC), Carbon-fiber & glass-filled ## Connect the Rat Rig V-Core 4.1 to SimplyPrint | Way of connecting | Status | What you need | Notes | | :--- | :--- | :--- | :--- | | SimplyPrint | Compatible | | Through Klipper (Moonraker) | | Klipper (Moonraker) | Compatible | Nothing extra: the printer runs Klipper as it ships | Runs RatOS 2.1 (product page), Rat Rig's image of Klipper + Moonraker + Mainsail. ([Source](https://github.com/Rat-OS/RatOS)) | | OctoPrint (Directly, over USB) | Not compatible | | Runs Klipper; OctoPrint only on top of it. ([Source](https://github.com/Rat-OS/RatOS)); Ships with Klipper: OctoPrint only runs on top of it, through the OctoKlipper plugin | - [How to set up SimplyPrint on Rat Rig V-Core 4.1](https://simplyprint.io/setup-guide/rat-rig/v-core-4-1.md) - [How to set up Mainsail on Rat Rig V-Core 4.1](https://docs.mainsail.xyz/setup) - [How to set up Fluidd on Rat Rig V-Core 4.1](https://docs.fluidd.xyz/installation) ### What works with SimplyPrint Connected through Klipper (Moonraker), SimplyPrint supports most of what it offers on the Rat Rig V-Core 4.1: the camera and AI failure detection, remote printing, skipping objects, temperature and movement control and AutoPrint. Not yet in SimplyPrint through Klipper (Moonraker): download the file before the print starts. ## What slicer to use for the Rat Rig V-Core 4.1 None of the slicers in SimplyPrint's cloud has a ready-made profile for the Rat Rig V-Core 4.1, but it takes standard G-code: start from a similar printer's profile and set the bed size, height and nozzle to match. - [PrusaSlicer](https://simplyprint.io/features/slicer/prusaslicer): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [OrcaSlicer](https://simplyprint.io/features/slicer/orcaslicer): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [BambuStudio](https://simplyprint.io/features/slicer/bambustudio): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [ElegooSlicer](https://simplyprint.io/features/slicer/elegooslicer): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [CrealityPrint](https://simplyprint.io/features/slicer/crealityprint): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [Cura](https://simplyprint.io/features/slicer/cura): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud - [Kiri:Moto](https://simplyprint.io/features/slicer/kirimoto): No profile for the Rat Rig V-Core 4.1 · Runs in the SimplyPrint cloud We only list slicers you can use in the SimplyPrint cloud, so there may be others for the Rat Rig V-Core 4.1. ## The app for the Rat Rig V-Core 4.1 Rat Rig doesn't make an app for the Rat Rig V-Core 4.1. SimplyPrint works as its app: on your phone and in any browser, with a slicer in the cloud. - An app for iPhone and Android, the same in any browser, and a slicer in the cloud. - More than monitoring: a print queue, AI failure detection, AutoPrint and accounts for a team. - Printers from many brands in one place, side by side. - Hosted in Frankfurt, Germany, under the GDPR. [Connect the Rat Rig V-Core 4.1 to SimplyPrint, free](https://simplyprint.io/setup-guide/rat-rig/v-core-4-1) · [App Store](https://apps.apple.com/app/simplyprint-3d/id1519749400) · [Google Play](https://play.google.com/store/apps/details?id=com.simplyprint.appdev) ## Automate the Rat Rig V-Core 4.1 **CoreXY printers push their prints off.** The Rat Rig V-Core 4.1's bed only moves up and down, so the usual way to automate it is a G-code routine that lets the toolhead push the cooled print off the front of the plate before the next job starts. ### Ways to automate it - [Push prints off with the toolhead](https://simplyprint.io/features/autoprint/push-off): On a CoreXY printer, a G-code routine can push the cooled print off the front of the plate before the next job starts. - [Your own ejection G-code](https://simplyprint.io/features/autoprint/custom): Write the routine that clears your plate, and AutoPrint runs it after every print. - [A robot arm, or anything with an API](https://simplyprint.io/features/autoprint/api): Tell SimplyPrint the plate is clear through the API or a webhook, from a robot arm or your own system. - [Clear it by hand, keep the queue](https://simplyprint.io/features/autoprint/manual-mode): AutoPrint waits for you to mark the plate clear, then starts the next job. [How AutoPrint works](https://simplyprint.io/features/autoprint). AutoPrint comes with the Pro plan and up. ## Rat Rig V-Core 4.1 specifications: bed size, print height and more ### Size - Build volume: 300 x 300 x 300 mm - Bed type: Square - Bed size: 300 x 300 mm - Max print height: 300 mm ### Printing - Enclosure: Partly enclosed - Motion system: CoreXY - Max extruder temperature: 350 °C - Has heated bed: Yes - Max bed temperature: 120 °C - Number of nozzles: 1 - Toolheads: 1 - Direct drive: No - Probing tool / Auto Bed Leveling: Yes - Filament width: 1.75 mm ### Multi-material - Toolchanger or hotend changer: No - IDEX (independent dual extruders): No ### Connecting - Supports serial printing: No - Shipped firmware: Klipper ### Files and slicing - Supported file formats: G-code (.gcode, .gco, .g) ### The printer - Printer manufacturer / brand: Rat Rig - Printer model name: V-Core 4.1 - Made by a company from: Portugal - Launched: December 2025 - Still made: Yes [Read more by the manufacturer](https://ratrig.com/products/rat-rig-v-core-4-1) ## What filament can the Rat Rig V-Core 4.1 print? Filament compatibility for the Rat Rig V-Core 4.1: the materials Rat Rig lists for it. | Filament | Suitability | Notes | | :--- | :--- | :--- | | PLA | Great | On the maker's list of materials for this printer. | | PETG | Great | On the maker's list of materials for this printer. | | TPU & flexibles | Great | On the maker's list of materials for this printer. | | ABS & ASA | Great | On the maker's list of materials for this printer. | | Nylon (PA) | Great | On the maker's list of materials for this printer. | | Polycarbonate (PC) | Great | On the maker's list of materials for this printer. | | Carbon-fiber & glass-filled | Great | On the maker's list of materials for this printer. | ### Best filament for the Rat Rig V-Core 4.1 Filaments the Rat Rig V-Core 4.1 prints well, Rat Rig's own first, then the best known. - [Bambu Lab PLA Basic](https://simplyprint.io/filaments/bambu-lab/pla-basic): PLA, 190-230 °C - [Bambu Lab PLA Matte](https://simplyprint.io/filaments/bambu-lab/pla-matte): PLA, 190-230 °C - [ELEGOO PLA](https://simplyprint.io/filaments/elegoo/pla): PLA, 190-220 °C - [SUNLU PLA](https://simplyprint.io/filaments/sunlu/pla): PLA, 200-240 °C - [Anycubic PETG](https://simplyprint.io/filaments/anycubic/petg): PETG, 230-250 °C - [Anycubic PLA Basic](https://simplyprint.io/filaments/anycubic/pla-basic): PLA, 190-230 °C - [Anycubic PLA Plus](https://simplyprint.io/filaments/anycubic/pla-plus): PLA, 190-230 °C - [Bambu Lab ABS](https://simplyprint.io/filaments/bambu-lab/abs): ABS, 240-270 °C ## When to choose the Rat Rig V-Core 4.1 Choose the V-Core 4.1 if you enjoy building and customising your printer and want it to grow: Rat Rig's page offers a size choice, electronics included or not, a Hybrid upgrade with higher acceleration and an IDEX upgrade for two materials or copy and mirror modes. Enclosing panels are not included (Rat Rig supplies DXF files), so it is not ready for ABS or classrooms as bought. We found no independent review for this version. If you want a printer that arrives ready to run, the Prusa CORE One+ is the easier route. ### Pros - Sold in 300, 400 and 500 mm sizes, so you pick the build volume (Rat Rig). - Hybrid and IDEX upgrades add higher acceleration or a second extruder for two materials or copy and mirror modes (Rat Rig). - An optional Rat Pack carbon filter for ABS, ASA, PC and nylon fumes (Rat Rig). - Open design with a plug-and-play wiring harness in the electronics kit (Rat Rig). - Works with SimplyPrint through Klipper. ### Cons - A kit you assemble yourself, with the enclosing panels not included (Rat Rig). - Not an out-of-the-box printer: tuning and Klipper configuration are up to you. - Some parts are on backorder or pre-order, and the final cost depends on size, electronics and upgrades (Rat Rig). - We found no independent review of the 4.1. ### Who it suits - Schools: Not a good fit. An open kit that students would have to build and tune; the open frame leaves moving parts exposed. - Hobbyists: Great fit. A flexible Klipper platform for tinkerers who like building and upgrading. - Businesses: Can work. Capable and configurable, but variable by build and not supplied ready to run. - Print farms: Not a good fit. Every unit is a custom build to assemble and tune, so a fleet would be uneven and slow to deploy. ## Compare the Rat Rig V-Core 4.1 with similar printers - [Kentstrapper Zero HS](https://simplyprint.io/compatibility/kentstrapper-zero-hs): Compatible, 315 x 315 x 315 mm, Similar build volume · Also prints ABS & ASA, Nylon (PA), Carbon-fiber & glass-filled - [Creality K3](https://simplyprint.io/compatibility/creality-k3): Expected to work, 260 x 260 x 260 mm, Similar build volume · Also prints ABS & ASA, Nylon (PA), Polycarbonate (PC), Carbon-fiber & glass-filled - [Creality K1 Max](https://simplyprint.io/compatibility/creality-k1-max): Compatible, 300 x 300 x 300 mm, Similar build volume · Also prints ABS & ASA, Nylon (PA), Polycarbonate (PC) - [Bambu Lab H2S Combo](https://simplyprint.io/compatibility/bambu-lab-h2s-combo): Verified by SimplyPrint, 340 x 320 x 340 mm, Similar build volume · Also prints ABS & ASA, Nylon (PA), Polycarbonate (PC), Carbon-fiber & glass-filled - [Compare the Rat Rig V-Core 4.1 with other printers](https://simplyprint.io/compatibility/compare?compare=rat-rig-v-core-4-1#choose) ## Where to buy the Rat Rig V-Core 4.1 - [Rat Rig's global store](https://simplyprint.io/buy/8352) (Official store): €878.57 (Price at Rat Rig, checked October 23, 2026) ## About Rat Rig Rat Rig is a Portuguese company near Faro that designs and sells do-it-yourself kits for large CoreXY 3D printers and CNC machines, mostly to buyers abroad. Its V-Core printers come as kits you assemble, run on RatOS, Rat Rig's Klipper distribution, and suit makers who want a big machine they can upgrade and repair themselves. - Founded: 2014 - Headquarters: Near Faro, Portugal - Ownership: Privately held; founder and CEO Miguel Carvalho (2024) - People: About 30 employees (2024) - Website: https://ratrig.com Openness: Open (5.0 of 5) Published designs, a GPL Klipper distribution, standard parts and no cloud leave the owner in control. The one limit is that the design files may not be reused commercially. - Firmware and custom firmware (5 of 5): RatOS, Rat Rig's Klipper distribution, is developed in the open on GitHub under the GPL-3.0 and was still being updated in 2026 (2.1 release line); plain Klipper and Mainsail can be used instead. - Local control and integrations (5 of 5): RatOS runs Klipper, Moonraker, Mainsail and KlipperScreen on a Raspberry Pi in the printer, on your own network, and Moonraker's API is documented. Rat Rig has no printer cloud or account. - Third-party filament, slicers and parts (5 of 5): The machines use standard parts (MGN and HG rails, Gates belts, LDO and BigTreeTech electronics, Orbiter extruders) that Rat Rig and others sell, any filament, and any slicer; OrcaSlicer ships V-Core 3, V-Core 4 and V-Minion profiles. - Repairs and spare parts (5 of 5): Rat Rig sells parts one by one and publishes CAD, STL files, bills of materials and step-by-step build guides on its wiki. The design files are licensed CC BY-NC-SA 4.0, so they are free to use and modify but not for commercial reuse. - Data and privacy (5 of 5): Printing needs no account and everything runs on the printer's Raspberry Pi; RatOS's setup script even turns off the telemetry of the web framework its configurator uses. Rat Rig's privacy policy covers only its web shop. - Community and documentation (4 of 5): Rat Rig says its user communities (Facebook groups, plus an unofficial Discord) have many thousands of active members; documentation is public on its wiki and the RatOS site, and RatOS is developed openly on GitHub (by Mikkel Schmidt, per the RatOS docs). The documentation is split across the two sites. ### Pros - Large build volumes, up to 500 mm, at kit prices. - Open, documented designs and standard parts make repairs and upgrades straightforward. - RatOS gives a ready-made Klipper setup that runs entirely on your own network. - Upgrade kits (Hybrid, IDEX, 4.1) keep older machines current. ### Cons - Sold as kits: you assemble, wire and tune the printer yourself. - Design files are licensed for non-commercial use only (CC BY-NC-SA), unlike GPL projects. - Documentation is split between the Rat Rig wiki and the RatOS site. ### Track record - 2026: Rat Rig began selling the V-Core 4.1, a revised kit with a steel X gantry and newly written build documentation, together with a 4.1 upgrade kit for V-Core 4 owners. - November 2024: 3D Printing Industry shortlisted the V-Core 4 (IDEX and Hybrid), released earlier in 2024, for Desktop FFF 3D Printer of the Year. - September 2024: Dinheiro Vivo reported that Rat Rig had received about 200,000 euros of regional development aid for its first expansion and had been granted about 100,000 euros more from the Algarve 2030 programme for trade fairs and equipment. - August 30, 2024: Rat Rig released the IDEX upgrade that adds a second toolhead to the V-Core 4; it told Dinheiro Vivo it sold hundreds in the first 24 hours. - December 2022: Rat Rig won the 3D Printing Industry Award for Company of the Year (Personal). - 2021: Rat Rig released the V-Core 3, a high-speed CoreXY kit in 200 to 500 mm sizes, with its design files on GitHub. How Rat Rig compares with every other brand: https://simplyprint.io/articles/best-3d-printer Affiliate disclosure: Some links on this page are affiliate links. We may earn a commission if you make a purchase, at no extra cost to you. As an Amazon Associate, we earn from qualifying purchases. ## Frequently asked questions ### Is the Rat Rig V-Core 4.1 compatible with SimplyPrint? Yes. You can connect the Rat Rig V-Core 4.1 to SimplyPrint via Klipper (Moonraker), then slice, queue, start and monitor prints from your browser or the mobile app. ### How do I connect the Rat Rig V-Core 4.1 to SimplyPrint? Follow our step-by-step setup guide for the Rat Rig V-Core 4.1. It shows how to connect it via Klipper (Moonraker), what you need for each, and which to pick. ### What slicer should I use for the Rat Rig V-Core 4.1? Cura, PrusaSlicer and OrcaSlicer all work with the Rat Rig V-Core 4.1, and you can run any of them in SimplyPrint's online browser slicer - no install needed, on any device. ### Can I use OrcaSlicer with the Rat Rig V-Core 4.1? Yes, but OrcaSlicer has no built-in profile for the Rat Rig V-Core 4.1 that we know of: start from a similar printer's profile and set the bed size, height and nozzle to match. ### What filament can the Rat Rig V-Core 4.1 print? Rat Rig lists PLA, PETG, TPU & flexibles, ABS & ASA, Nylon (PA), Polycarbonate (PC) and Carbon-fiber & glass-filled for the V-Core 4.1. ### Does the Rat Rig V-Core 4.1 work with OctoPrint or Klipper? The Rat Rig V-Core 4.1 works with Klipper (Mainsail and Fluidd), and SimplyPrint connects to it through them - so you get cloud access, a queue and camera monitoring on top. ### What is the Rat Rig V-Core 4.1's bed size and build volume? The Rat Rig V-Core 4.1 has a 300 x 300 mm print bed and prints up to 300 mm tall, a build volume of about 300 x 300 x 300 mm. See the full specifications table above for bed type, temperatures and more. ### When did the Rat Rig V-Core 4.1 come out? Rat Rig launched the V-Core 4.1 in December 2025. ### Can the Rat Rig V-Core 4.1 eject prints automatically? There's no kit for it that we support yet, but SimplyPrint's AutoPrint can push prints off with the toolhead, or run your own ejection G-code, and then start the next job from your queue. ### Where can I buy the Rat Rig V-Core 4.1? From Rat Rig's own store, which has shops for everywhere else. The links on this page go to those stores; some are affiliate links, so we may earn a commission at no extra cost to you. --- © 2026 SimplyPrint. All rights reserved. This page and the compatibility, specification and review data on it are compiled by SimplyPrint and may not be copied, scraped, reproduced or republished, in whole or in part, without prior written permission. Printer images are the property of their respective manufacturers and are shown for identification purposes only; SimplyPrint claims no ownership of them. Quoted reviews belong to their authors.