Custom props - work in progress

[Christian Holmstedt]

I've been working on and off on custom propeller designs for a while to see what can be done with 3D printing.

This is the first print in bronze of a 2-blade cleaver designed from scratch.

Started out by defining all the parameters (Diameter, Pitch, Rake, Cup and progressive pitch) in a spreadsheet than then calculated the blade profile in 16 sections.

This was then imported to DesignCAD 3D MAX where the basic coarse mesh was made followed by an export to Blender for final modeling.

Several test prints in nylon showed promise and this is the first print in bronze.

At some point this one will be tested on a P-Spec tunnel (when it is completed).

The blades are very narrow and a 3 or 4 blade version might actually work better.

Specs:

Diameter : 42 mm

Pitch: 55 mm

Leading edge pitch: 50 mm

Cup: +22 mm (77 mm)

Rake: 17 deg

 

[Terry Keeley]

Very cool!

What alloy specifically are you using? I thought 3D printing was mainly done in plastics...

 

[Christian Holmstedt]

The alloy available is 90% Copper, 10% Tin.

'Tin Bronze 907' would be the closest equivalent alloy (89% Copper, 11% Tin).

http://www.nationalbronze.com/pdfs/spec_reference.pdf

 

[Christian Holmstedt]

It took quite a while to come up with a design flow that worked well. Eager to test but need a boat first.

The model still needs a few tweaks. It is made for 3/16" shafts but the hole is just a hair to small now, cleaning out with a 3/16" drillbit should do it.

 

[Buckshot]

AWESOME!