Propeller & impeller generator with STEP & STL export
Design custom propellers, pump impellers and fan wheels. Shape them with sliders and curves, preview them live in 3D, check performance and printability, and export print-ready STL or Fusion 360-ready STEP.
What Propforge does
Design propellers and impellers
Start from a preset — RC plane, drone, boat, fan, water pump, jet pump — and shape blades with sliders and spline curves: diameter, pitch, chord, twist, rake, skew, airfoil, blade angles, splitters and hub bore.
Check it before you print
Thrust, power and pump curves come with uncertainty bands, plus tip speed, blade stress, cavitation and printability checks: thin walls, overhangs, support and the best print orientation.
Match a motor
Pick a motor or enter your own and see the real operating point on your battery: RPM, current, thrust or flow, with over-current and heat warnings. Fit the bore to the shaft and print a matching motor mount.
Export STL and STEP
Download a watertight STL for slicing or a STEP file with real solids that opens in Fusion 360, FreeCAD or Onshape, with the full parameter set so you can keep editing later.
Questions
How accurate are the performance numbers?
Propeller estimates use blade-element momentum theory and are checked against wind-tunnel data from the UIUC propeller database: typically within about 10 % in normal operation, wider near stall or zero thrust. Every number is shown with its range. Pump curves use 1-D turbomachinery theory and have wider bands.
Can I edit the part in Fusion 360?
Yes. The STEP export contains solid bodies in millimetres with the rotation axis on +Z, so it imports into Fusion 360 and other CAD tools as editable geometry. The ZIP also includes the parameters as JSON to reload the design here.
Which material should I print with?
PETG or nylon for most propellers and pumps; carbon-fibre nylon for fast, small props. The Performance tab shows a safety factor for your material at your RPM. Printed rotors can break at speed: always use guards and eye protection.
Is the flow view a CFD simulation?
No. The streamlines come from a simplified momentum-theory model (slipstream contraction and swirl for propellers, channel flow for impellers) so you can see how the flow behaves. It is illustrative, not CFD.