fable Posted at 2-3 05:07
You've tried these?
Are they reliable?

yes ma props are reliable in my experience.

The Saint Posted at 1-29 19:45
the m3p is already very quiet; however, may i suggest: https://www.masterairscrew.com/products/dji-mini-3-pro-stealth-upgrade-propellers-x4-red

How about for those of us with the FPV or Avata's that sound like a vicious swarm of bees?!

I'd love to but a set of these from DJI.  I think they're missing out on an opportunity.

Here's a one piece triple instead of the 2 piece double, but with a similar overall size and design.
I can make the double hub for mounting to a M3P, but I just started with this.

Lost Somewhere Posted at 2-3 08:00
Here's a one piece triple instead of the 2 piece double, but with a similar overall size and design.
I can make the double hub for mounting to a M3P, but I just started with this.

Excellent ! We feel the skills with Solidworks. Good job,

It should work. Have you tried printing them? Without even mounting them on a drone, build a test bench with a brushless motor and a load cell. This way you can compare the thrusts and the sound volume.

LV_Forestry Posted at 2-3 08:06
Excellent ! We feel the skills with Solidworks. Good job,

It should work. Have you tried printing them? Without even mounting them on a drone, build a test bench with a brushless motor and a load cell. This way you can compare the thrusts and the sound volume.

I won't be back to my printer for another couple weeks. So I'm just going to get a whole set of options ready.

The Saint Posted at 2-3 06:34
yes ma props are reliable in my experience.

pulled the trigger for a set for M3P and another for A2S.
Let's see

djiuser_StyKfK939bes Posted at 2-3 06:48
How about for those of us with the FPV or Avata's that sound like a vicious swarm of bees?!

I'd love to but a set of these from DJI.  I think they're missing out on an opportunity.

i have two types of master airscrew props for my dji fpv and they do not significantly alter the sound.  i haven't yet flown my avata but to be honest, i think the whole point of the dji fpv is the sound and to get a more pleasant sound but maybe not as whiny or high-pitch but certainly not eliminated or less sound.  my guess is ma props for fpv focus on performance and durability rather than sound.  for the fpv drones, those engines are what we hear the most.

Lost Somewhere Posted at 2-2 15:16
I think it's easy enough to put some mitigations in place.
Plus, as an engineer, half the reason to have a drone is to experiment with it. If this doesn't break it, something else will.
No sacrifice, no victory

Fair enough. Tell me how it turns out

fable Posted at 2-3 08:26
pulled the trigger for a set for M3P and another for A2S.
Let's see

i recall the ma prop for the m2z did wonders for sounds; 100% improvement.  the m3p is already super quiet so i bought those mainly for color.

One more while I'm at it. Easy to pattern this one to any number.

The Saint Posted at 2-3 08:34
i recall the ma prop for the m2z did wonders for sounds; 100% improvement.  the m3p is already super quiet so i bought those mainly for color.

Yes it would be great if it attenuated prop sound of A2S.
Thanx for the recomendation

I should have lots of options. I'll have to dial in the thickness of each to make sure it's strong enough.

I'm totally interested in this as well. going to try with my an old mavic mini i have. I think the 3 prop version might be best.  I was also thinking to get more blade surface area to have the center portion slide over the rotor a bit, maybe halfway.  

Does anybody have the files to 3d print a toroidal propeller?

Ed15 Posted at 2-3 17:42
Does anybody have the files to 3d print a toroidal propeller?

In a couple weeks when I can test mine out, if I get them working I'll post them.

Justgerald Posted at 2-2 19:12
Please consider offering toroidal propellers as they are very quiet and less of a nuisance.

Thank you for your feedback. We will coordinate this to our designated team for attention. Thank you for your valued support.

It would be interesting to see if this type of propeller can help us fly higher as well.

The Saint Posted at 2-3 08:34
i recall the ma prop for the m2z did wonders for sounds; 100% improvement.  the m3p is already super quiet so i bought those mainly for color.

I did the same @The Saint.  And like the new pitch it gave the M3P.   MAS props have not let me down.  (no pun intended)

Lost Somewhere Posted at 2-3 11:37
I should have lots of options. I'll have to dial in the thickness of each to make sure it's strong enough.
[view_image]

This is the most efficient and quiet design that MIT came up with after experimenting with a few variations. I suppose the "best" design could be different based on drone model, but I wouldn't expect it to be extremely different from this concept.

So 3 more to go before first test.  I used this model: https://www.thingiverse.com/thing:5828910 with the 35x3TM_CCW stl file  as a starting point.  I increase the size to 120.65mm and decreased the height to 4mm.  I also had to move the outer screw holes outward by 1mm each as they did not align properly with the screw holes in the mini.  

I'm currently printing with PLA using 100% fill with a concentric pattern.  The jobs take roughly 4 hours so maybe be able to do a test tomorrow.

devdazed Posted at 2-4 13:54
So 3 more to go before first test.  I used this model: https://www.thingiverse.com/thing:5828910 with the 35x3TM_CCW stl file  as a starting point.  I increase the size to 120.65mm and decreased the height to 4mm.  I also had to move the outer screw holes outward by 1mm each as they did not align properly with the screw holes in the mini.  

I'm currently printing with PLA using 100% fill with a concentric pattern.  The jobs take roughly 4 hours so maybe be able to do a test tomorrow.

Nice. Someone posted a video using them. Let us know how it goes. I was worried those wouldn't be very efficient with the uniform thicknesses out to the perimeter. There's quite a bit of vertical flat wall trapping air, where they should be thinning out to a shallow angle, but they do fly.

devdazed Posted at 2-4 13:54
So 3 more to go before first test.  I used this model: https://www.thingiverse.com/thing:5828910 with the 35x3TM_CCW stl file  as a starting point.  I increase the size to 120.65mm and decreased the height to 4mm.  I also had to move the outer screw holes outward by 1mm each as they did not align properly with the screw holes in the mini.  

I'm currently printing with PLA using 100% fill with a concentric pattern.  The jobs take roughly 4 hours so maybe be able to do a test tomorrow.

The weight difference must be at least double, perhaps even 3x, no?

Bashy Posted at 2-4 18:54
The weight difference must be at least double, perhaps even 3x, no?

using my kitchen scale, which may not be entirely accurate, stock props are exactly 1 gram while new one is 6.4 grams.

I'm hoping the increased number of foils may be able to make up for the weight difference.  I also might try with a lighter weight material, or maybe even use these as the model for creating an injection mold.
i also increase the size of the original model to be the same width as the two props fully extended. it might be possible to go to a smaller diameter and decrease weight while still keeping lift

So the props are too heavy, it won't even start up. the Mini thinks the motors are blocked. so we would need a way to significantly reduce the weight on these for them to work. or find a way to override the firmware

devdazed Posted at 2-5 10:37
So the props are too heavy, it won't even start up. the Mini thinks the motors are blocked. so we would need a way to significantly reduce the weight on these for them to work. or find a way to override the firmware

Yeah. I saw in his video how he had sketched the profiles and figured it would be hard. Props need more design and less kitchen sink. I did see he posted another video where he's doing a little more of what I was doing, at least he increased it to 5 guide curves, but it still didn't have the wing profile that narrows down at the ends. Mine use surfacing and the guide curves are projected on a curved plane to make 3D guide curves that allow for much more complex geometry.

Now I'm starting to compare and refine what I have before I get home and try to SLA them. I ran flow simulation on all 3 and the Bi-lobes produced 185 g of lift each, Tri-lobes were 131 g, and the Penta-blades were just 100 g. That will let me adjust the pitch of each design to dial them all in to the same lift force at 10,000 RPM.

I like the Bi-lobe because they still fold down pretty small without removing them. So I'll probably just stick with those, and see what I can do.

Does anyone know the optional lift force I should be looking for at 10,000 RPM?

Here's a link to the 3 sets of result images just in a PDF.
Flow Results

Lost Somewhere Posted at 2-5 11:14
Yeah. I saw in his video how he had sketched the profiles and figured it would be hard. Props need more design and less kitchen sink. I did see he posted another video where he's doing a little more of what I was doing, at least he increased it to 5 guide curves, but it still didn't have the wing profile that narrows down at the ends. Mine use surfacing and the guide curves are projected on a curved plane to make 3D guide curves that allow for much more complex geometry.

Now I'm starting to compare and refine what I have before I get home and try to SLA them. I ran flow simulation on all 3 and the Bi-lobes produced 185 g of lift each, Tri-lobes were 131 g, and the Penta-blades were just 100 g. That will let me adjust the pitch of each design to dial them all in to the same lift force at 10,000 RPM.

> Props need more design and less kitchen sink


this is it right here. I think the bi-lobes are going to be the way to go.  Compared to PLA we can shave weight by switching to ABS or Polypropylene.  The bi-lobe design also should be much lighter, although I don't see us getting to the 1 gram stock weight, so may still be some issues with the motors detecting something is wrong, unless we go with a home-built drone.  

The fact that DJI has to jump in with their "we do not recommend 3rd party ..." STFU DJI!! Just make products thats work, stop stealing peoples data, stop interfering in matters that aren't related to you.

Dude, if you or anyone is making TOROIDAL PROPS, PUT THEM OUT ON THINGIVERSE OR CULTS.

Too many drone enthusiasts jumped when they saw the MIT video.

Interesting project, but after watching this video on youtube I was wondering if anyone knows if it is possible to get 8 bladed propellers for the dji mini 3 pro?

djiuser_0KXuvHPBjx8c Posted at 2-6 02:22
The fact that DJI has to jump in with their "we do not recommend 3rd party ..." STFU DJI!! Just make products thats work, stop stealing peoples data, stop interfering in matters that aren't related to you.

Dude, if you or anyone is making TOROIDAL PROPS, PUT THEM OUT ON THINGIVERSE OR CULTS.

+1 on posts to Thingiverse!  This would be an awesome add if they produce less noise.  Additionally, if the weight problem is solved and you stay under 250, I can see the "not cause lacerations" provision in public assemblies being more within reach on this drone.  Love the creativity of this community (as well as the engineering chops!).

devdazed Posted at 2-5 10:37
So the props are too heavy, it won't even start up. the Mini thinks the motors are blocked. so we would need a way to significantly reduce the weight on these for them to work. or find a way to override the firmware

Hey, if you're really curious and want to try printing more. Here's a link to some M3P double toroid props.
No guarantee they will work as I haven't printed them and tried them out. But if you want to be the Guinea pig, be my guest. They are 1.7g each, 3.4g for a pair. You need to print 4 sets of these parts. I made them thicker and heavier than they were, just to help with strength.
STL File

Lost Somewhere Posted at 2-6 11:38
Hey, if you're really curious and want to try printing more. Here's a link to some M3P double toroid props.
No guarantee they will work as I haven't printed them and tried them out. But if you want to be the Guinea pig, be my guest. They are 1.7g each, 3.4g for a pair. You need to print 4 sets of these parts. I made them thicker and heavier than they were, just to help with strength.
STL File

awesome. would it be possible to lay them down so we don't need supports?  i think it will also add strength to them as the layers will be along the length of the prop

devdazed Posted at 2-6 12:16
awesome. would it be possible to lay them down so we don't need supports?  i think it will also add strength to them as the layers will be along the length of the prop

Yeah, I'd say give it a try.
On my SLA I might still do them vertical so that instead of having the small steps over to top and bottom of the wing from the layers, it should be a nice smooth surface that the laser can draw out. But for FDM you probably need the strength.

devdazed Posted at 2-6 12:16
awesome. would it be possible to lay them down so we don't need supports?  i think it will also add strength to them as the layers will be along the length of the prop

I guess to help with balance you might want to print 2 pairs at a time and keep them matched together since different ambient temp and humidity might change the overall weight from print to print.

The STL has 1 right and 1 left, so you have to pair the 2 rights and 2 lefts for each motor.

Let me know if the geometry looks right! It has a little screw head pocket on the top and bottom, but since I don't have mine to look at I'm not sure if that's right or not. That was just how the DJI model I had showed them. I also made the screw hole 3.1mm, so I'm not sure if that is too tight. I guess you can drill them out if they're small. But I can send you an update if you tell me what dimensions should be. Not having mine on hand makes it hard, but I figured that for those of you ambitious enough to try, I won't stop you. By the time I can make one you'll have gotten everything dialed in.

Lost Somewhere Posted at 2-6 12:38
I guess to help with balance you might want to print 2 pairs at a time and keep them matched together since different ambient temp and humidity might change the overall weight from print to print.

The STL has 1 right and 1 left, so you have to pair the 2 rights and 2 lefts for each motor.

ok, im printing both pairs now, under current settings it will be about 6 hours so will let you know tomorrow what needs tweaking.

I've printed them and done a bit of post-processing.  everything is good but the counter-sunk bit on top needs to be sunk in about maybe 0.1mm. to 0.2mm or so as it doesn't allow for movement.  I tried to compensate by grinding off the bottom bit but that makes the prop hit the drone when spinning.

also, using PLA they are clocking in at 3.6 grams for the pair (although with enough post-processing I may be able to shave off 0.2 grams.  I wonder if we reduce the surface area of each blade by half if it will produce similar lift to the stock ones with lighter weight?

devdazed Posted at 2-7 09:45
also, using PLA they are clocking in at 3.6 grams for the pair (although with enough post-processing I may be able to shave off 0.2 grams.  I wonder if we reduce the surface area of each blade by half if it will produce similar lift to the stock ones with lighter weight?

OK, Thanks for making them.

So the pocket on the bottom side is supposed to be there it sounds like, and I should maybe make the top and bottom pockets 0.1mm deeper each to prevent them from being clamped by the screw. The screws fit well otherwise?

Even without the props floating freely, did you try spinning up the props to see if the M3P complained about the weight?

How strong do you feel like the props are? Can I make them a little bit thinner and still have enough layers and strength?

Lost Somewhere Posted at 2-7 10:40
OK, Thanks for making them.

So the pocket on the bottom side is supposed to be there it sounds like, and I should maybe make the top and bottom pockets 0.1mm deeper each to prevent them from being clamped by the screw. The screws fit well otherwise?

I think the pocket on top should move downward as well as the pocket on bottom by 0.1mm maybe.  The length of the hole is accurate to the smooth part of the screw, but the lip on the bottom see below picture.  the threads should clear the bottom of the lip so when tightened its not clamped on.

I don't know that my printer can handle much thinner, maybe if thinner then going to SLA might be better.

I tried starting it up with the props (i ground off the bottom lip so they can move freely) It did complain about obstruction but it was unclear if that is due to weight or that the props were lightly grazing the top of the drone.  They are also about 30% longer than the stock props so maybe can reduce size that way as well?