Prototype hardware, from CAD to flight test
jfw.engineering develops battery systems, heavy-lift drones and the electronics that connect them, and builds the first units in-house: spot-welded packs, printed and machined parts, custom PCBs.
Current work
Most of it is open hardware, designed and documented in public, so you can look at the actual CAD, boards and parts lists.
Caribou heavy-lift hexacopter
Six Hobbywing X15 drives on 63-inch folding propellers, a carbon sandwich frame with CNC-machined aluminium adapters, and our own battery-connector and main boards. Designed for a maximum take-off mass of 220 kg.
Open the build guide
Longshot battery pack
126 cells of 21700 in a 14S9P pack: printed cell holders, spot-welded busbars, the Tattu 4.0 connector and latch. Every part, screw and assembly step is in the build guide.
Open the build guide
PT3 battery system
Six independent 24S5P packs of Molicel P45B cells, 11.7 kWh in total, with BMS, contactor and precharge, for Arrow Air's PT3 heavy-lift drone.
Read the documentationWhat we do
Mechanical and electrical development in one place, so the battery, the boards and the structure are designed together.
Battery systems
Cell holders, busbars, fusing, BMS integration and housings, with prototype packs spot-welded in-house.
Drone airframes
Heavy-lift multirotor frames from tubes, carbon sandwich plates and machined adapters, with harness and mass budget.
PCB design
Power distribution, precharge, CAN and signal boards in KiCad, ready for assembly at JLCPCB.
Testing and simulation
FEM, thermal imaging, our own thrust stand, and charge and discharge tests on packs and cells.
Prototyping
PETG-CF printing, CNC routing, laser-cut sheet metal and tubes, and 3D scanning of existing parts.
Documentation
Drawings, parts lists with suppliers, and step-by-step build guides that other people can build from.
Build guides anyone can follow
For Caribou and Longshot the documentation is a website: the full 3D model, every part with its files, and the assembly in order.
- ModelEvery part and screw, with part numbers, drawings and STEP files.
- PreparePrint, machine and cut lists, plus the test pieces to check fits first.
- SourcingQuantities per build, with suppliers in the US and the EU.
- AssemblyStep by step, showing which parts and screws go in at each step.
In the workshop
Prototypes are built in-house, which keeps the loop between design and test short.
Where it started
In 2016 we converted a 1953 Buick Roadmaster to electric drive: 80 kW and 250 km of range. It was a private project, and it set the direction for everything after it: batteries, drives and the mechanics around them.