DJI Mini 3 Pro Toroidal Propellers

These props are for a DJI mini pro 3.

These are version 50 of the prop, so I have been designing and iterating for over a year on these. These shouldn't cause any "ice" warnings that there is too much torque, and they shouldn't over heat if made properly. But they do have a little more drag than the standard props due to the additional lift surface, so they do run a little hotter than standard props. Land immediately if you get a warming as that means the print job wasn't accurate enough and there is too much drag. I would also spin up the props before takeoff, and make sure they spin freely and that the drone doesn't rotate on a smooth surface or shake, as that is a sign they are not balanced and you shouldn't try to take off. There is a lot of precision to making props, so test at your own risk and take safety precautions in case the props fly apart or the drone looses one and crashes in an uncontrolled way. All the steps outlined are critical to them working well.

They are 1.1g, while the standard ones are about 0.9g, so they are very thin. Print at your own risk as thin parts at high RPM out of the wrong material are likely to shatter. I suggest using an SLA to print them, as FDM really isn't suited to making props. I used a mix of a tough resin (Siraya Tech Build) 60% and GratKit Ceramic 40%. This helped to make it both strong and ridged. When you lift the drone by the prop tips they shouldn't bend too much or be too ridged. Be careful to remove the supports without changing the weight of the props as any imbalance will cause issues. I printed them vertical to have minimal supports, and only put supports on the bottom side to keep the top surface smooth and improve laminar flow. Grabcad won't let me upload a sliced file, but you can see an example image. I usually print 5 sets so I have one extra. Once printed, you'll want to use 600 grit sand paper to get them perfectly smooth, buy again, try not to over sand them and sand them equally so the weight stays the same. You also need a 3/32" drill bit to clean out mounting holes. Make them just free to move freely, without making it too loose, such the the prop is loose when lift on the tip.

Let me know how it goes and if you have suggestions for improvement.