Propeller for RC Airplane (with Prop Saver)

Introduction

When first learning to fly RC airplanes, it's hard to overstate the importance of a steady supply of spare parts. Flying is quite easy; it is landing that's hard.*

The Ares Gamma 370 was not my first RC plane, but it was my first plane with a propeller on the front. Unfortunately, the front of the plane is very often the first to make contact with the ground when landing (or at least, it is when I'm landing). This printable propeller was made to help offset the cost of my aviation-skill-deficiency. 

Printing Orientation

When viewed from the side, the blades should gently slope downwards towards the build plate. (When mounted on the plane, the blades should gently slope towards the aft.)

Materials

Recommend PET-G or ABS. Both held up perfectly well in flight. I have not tested anything else. (In the photos, the white copy is ABS, and the gray copy is PET-G)

Material Height

The smaller the layer height, the less vigorous sanding is required. My white ABS model was printed with 0.1mm height. The gray PET-G model was printed with 0.5mm height. I didn't notice any appreciable difference in performance between the models.

Support

Recommend this everywhere, from the build plate.

Infill

A solid plastic end product is desired; I printed at 90% infill.

Finishing Details

In order to avoid a shimmy when the propeller is mounted, it's important to make sure both sides of it are the same weight. The model itself is symmetrical, but that doesn't guarantee your print will be once the support material is removed. Generally, balancing is done using a “prop balancer.” Essentially you put the prop on end and slide a tiny horizontal rod through the center. When you let the prop go, if one side rotates toward the ground, that side is heavier than the other and needs sanding. Once the propeller will stay in whatever orientation you leave it, then the propeller is balanced. Here are links to some prop balancers on Printables (https://www.printables.com/model/198887-propeller-balancer-equilibreur-helice) (https://www.printables.com/model/469432-du-bro-prop-balancer-tray)

Prop Saver?

This little piece of plastic is designed to sit directly aft of the propeller on the shaft. A rubber band secures the propeller to the prop saver. If attached properly, the setup allows the propeller to tip or bend off the axis without breaking. Please see photos of the ABS propeller attached to the plane to visualize the setup.

How It Was Made

The propeller model was made by taking a ton of photos of the original propeller and using Agisoft PhotoScan (now called Agisoft Metashape) to create the initial mesh. This mesh was then refined using a combination of Meshmixer and Lightwave 3D Modeler into its current form.

The prop saver model was created by finely measuring the original, and replicating it in Fusion360.

Footnote

* Pun intended.

Happy Flying!!