20 HP Mercury and 20 HP Tohatsu Racing Propeller

[Ron Hill]

With encouragement from Bill Gohr and a few other from APBA, I', making a racing prop for the 20 hP Four Stroke.

The colored props are 3 D Print made by Winrace Propellers in Norway.
3D Printing is the future of racing propellers.

[dandrews75]

I was wondering when this was going to happen. Friend of mine who was making props had suggested it to me 15 years ago. Nylon props are nothing new. We have one from Mercury, 2 blade blue in colour for the 22 ci 20hp Mercury circa 1978 there abouts. I had recently did the torque calculation for a 20 HP motor and it is just over 10 lbs and as the rpm goes up the torque output goes down. So these small engines put out very little torque so you don’t need to get into an exotic overly complicated material.

[Albert]

This is just too cool. Imagine being able to print your own prop from nylon resin at home? I wonder what the longevity is going to be like?
Ron will you be printing these yourself or having someone local to you do it?
Did you receive your motor yet? Wish you were closer I’d love to help test this set up and learn about it first hand.

[Ron Hill]

Propellers are usually made in wax, then cast in Stainless Steel. This is called the lost wax process.

3D printing a prop in plastic, plastic will replace the wax.

The propeller will still be cast in Stainless Steel and be finished by hand of a CNC mill.