Propeller Design Competition

Intro video: https://youtu.be/oTpa0WVHspA

Link to hub CAD: Onshape Document

Link to the Holbrook Aero preliminary test props: Onshape Document

Holbrook Aero Prop Template Instructions: Here

Scope:

I’ll be measuring the thrust per watt of each propeller, from 2 m/s to whatever speed the boat reaches at full throttle (probably around 3.5 m/s). The propeller with the largest area under the curve wins.

Rules:

• It is likely that the volume of submissions will exceed my capacity for testing, so please only submit a propeller design if you're okay with the possibility of yours not being chosen

• No features (including leading and trailing edge) should be thinner than 0.6mm

• The propeller laying flat must fit in a 145x145mm square

• The propeller must use the mating feature of the hub provided in the Onshape link above. See design section below for more tips.

• The blade profile needs to be thick enough not to break during the test (5mm at the root has proven successful)

• Complex geometry that is difficult to print is less likely to be chosen. Unless its really cool

• All propellers will be made public, so do not submit any proprietary designs.

• No 1 bladed propellers (even if the mass is perfectly balanced). Already tried that and they still vibrate too badly.

Technical Info:

• Max power: 400W (controlled by VESC)

• Max torque: 1.3Nm (estimated)

• Max Rotational Speed: 3000 RPM (but the actual RPM will likely be much lower than this)

• Expected Boat Speed Range: 1 - 4 m/s for high preforming props

• Motor: 5064 Brushless Waterproof Outrunner

• Hull length: 130cm

• Hull width: 18.5cm

• Boat weight: 14.5kg, Draft: 10cm

• Raw data from the baseline prop: download

Design:

There are two main approaches you could take to creating the hub. The first is to simply download or copy the “Hub” part and add your blades onto it.

The second is to use the “Boolean Subtraction Tool” I made. This tool can be aligned with your own hub design and used to subtract out the inner volume. The resulting geometry will be a perfect fit on the propeller mount.