All3 unveils second-generation Mantis for autonomous construction work
The electric quadruped adds autonomous stair climbing and screw-driving demonstrations, with a live construction deployment planned for early 2027.
All3 has unveiled the second generation of Mantis, a fully electric quadruped designed for construction sites. The platform weighs 135 kg excluding its arm and is designed to carry up to 100 kg while walking. All3 says it has demonstrated stair climbing with its 45 kg working arm attached, as well as locating and driving structural screws without an operator in the loop.
The chassis switches between a narrow 750 mm stance for passing through standard doorways and a wider working stance for stability. Its six-axis arm currently provides around 1.8 m of reach and supports interchangeable tools including a screw-driving head and vacuum gripper. A telescopic arm intended to extend reach to 4 m is in development.
All3 says Mantis can autonomously climb staircases of up to 35 degrees using onboard sensing. In repeated fastening tests, the robot located, aligned with and drove screws into eight of eight pilot holes, closing to 0.5 mm at the tool tip. That is a repeated demonstration outcome rather than a measured reliability rate.
The platform is being designed around a catalogue of 68 construction operations spanning installation, fastening, finishing and inspection; that figure describes intended operations rather than 68 validated capabilities. Two hot-swappable battery packs support battery replacement during operation. All3 reports motor power consumption of about 210 W while standing with 162 kg on board and around 400 W while walking. Those figures cover the motors, rather than total system power.
Control is split between learned systems for walking, planning and perception and a deterministic lower-level loop running at 1,000 Hz for force control, damping and emergency stops. All3 says the learned components are architecturally separated from the motors. The platform’s safety assessment remains in progress.
Mantis forms part of All3’s integrated construction stack, alongside RTA (Real Time Architecture), its AI-powered design platform, and robotic factory production for custom building components. Building models generated in software are intended to guide factory fabrication and on-site robotic assembly.
All3 raised a $25 million seed round in April 2026, led by RTP Global with participation from SuperSeed, Begin Capital, s16vc and VNV Global. The funding supports R&D in London and Belgrade and planned robotic deployments across its first commercial projects in Germany. WaVe-X, the corporate venture arm of WALTER GROUP, subsequently joined as a strategic investor in September.
The company is also developing multi-robot construction capability through a 12-month Innovate UK-funded programme that began in August. The work covers coordinated Mantis fleets, autonomous battery swapping and verification of completed work against digital building models. All3 plans to deploy Mantis on its first live construction project in early 2027. The company describes the launch as its second-generation platform while reporting three development generations over 28 months.
