Update, I kind of wanted to run 3" props on this build but was afraid I would not be able to re design the ducts.  Well I gave it a go and was able to successfully re do the ducts to accept 3" props.  The original design had almost 2mm gap between the 2.5" prop and the duct so I tightened the tolerance a bit so that the props only have about .5mm clearance.  I was also able to adjust print settings to reduce the duct weight by 3 grams each even though they are bigger.  So now will be running 3" props with 12 grams weight savings.  

Well, I swore I had some tri blade 3" props but I actually have a bunch of bi-blade 3018 props.  That was not going to do what I wanted  but I have a ton of Avan Schimitar 3.5" props that I originally got for my Pirat 3.5.  I was not a fan of them and have since switched to gemfan 3525's.  Sooo, I quick printed a prop cutter and trimmed the Avan props to 3"  Very curious to see how this will fly lol

I dig your prop cutter.

I might have to make something similar, but adjustable.

(20-Jul-2023, 07:20 PM)Lemonyleprosy Wrote: I dig your prop cutter.

I might have to make something similar, but adjustable.

There are adjustable ones out there. I almost did an adjustable one but wanted something quick. I may re print another some day.

I have some minor issues to resolve, mainly the antenna and XT30 plug need a new mount.  One of the props is slightly rubbing so need to sand down the duct but overall it flies amazing.  For some strange reason the 3" props are much quieter and it has a lot more thrust.  All said and done I lost about 6 grams. I was originally thinking it was going to be 12 grams lighter but I forgot the 3" props weigh more also. Still pretty good in my book.

Moving to 3" props and more important is the very small gap between the props and the ducts should give you much more power. I would think that your flight time should also increase. Personally, I don't think I would worry about the XT30 connection as it looks like it is far enough away from the props.

Looking really good...

Are you printing these ducts individually or are the four ducts now a single piece but using two colors?

Also, are you printing with a standard PLA?

(21-Jul-2023, 08:56 PM)brettbrandon Wrote: Moving to 3" props and more important is the very small gap between the props and the ducts should give you much more power. I would think that your flight time should also increase. Personally, I don't think I would worry about the XT30 connection as it looks like it is far enough away from the props.

Looking really good...

That was my guess as to the final result. It was loud!!! with the 2.5" props.

(21-Jul-2023, 09:14 PM)Mike C Wrote: Are you printing these ducts individually or are the four ducts now a single piece but using two colors?

Also, are you printing with a standard PLA?

For now I am printing them individually. I want to print and probably eventually will print as one piece. They are just a hair too big so I have to sand a flat spot on the side where they touch. My problem is I cannot find a dimensionally accurate phantom bottom plate to upload into tinkercad. If I had that I could line everything up and slice it all together in piece. Without the bottom plate template I have no way of making sure all the bolt holes line up when one piece.

I am using Sunlu PLA+ the other two are black becuase I ran out of white filament lol. I am printing 10% infill with 2 walls sides and bottom and 3 walls on top. this makes each duct 12 grams. I probably could have printed 0 infill also but it was only like .5 grams savings so I wnent ahead and did 10% for some internal structure. As is the frame would break before the ducts. They are pretty stout. I am not sure who to give credit for the original design but they are well designed for strength and structural integrity.

Hi B4tn,

I realize that the picture below is just a picture, however, you might be able
to import it and scale it to size with an measurement between two points from 
your actual frame. Plus, entire frame kits are only about $ 18-24 USD depending
on what version you get and the vendor. The HD version is about $ 22 from RDQ.
This bottom plate can also be purchased at RDQ for $ 8.49 USD.

Over the years, I have bought several Phantom frame kits and just bottom plates because I like them. 
Since top plates are so simple to fabricate (out of many different materials), I often just buy the bottom
plate and then cut a top plate.

I hope that this helps.

Later, My Friend, iFly  

(21-Jul-2023, 09:35 PM)B4tn Wrote: ...My problem is I cannot find a dimensionally accurate phantom bottom plate to upload into tinkercad.  If I had that I could line everything up and slice it all together in piece.  Without the bottom plate template I have no way of making sure all the bolt holes line up when one piece.  

You are only mounting @ the 4 motor hole locations right? I'm getting 125mm x 125mm spacing on the HD 3mm thick frame.

Hi B4tn,

You already have an actual frame; it is on the quad. Measure between tween two
of the motors and use that to scale the image. When they match, you have it. I
have done things like this many times. You might have to play with the scaling
a bit, but it can be done.

Take the original image and print it. Measure it. If it is too small, scale the image
up. If it is too large, scale the image down. Measure it. Repeat. Thing is, I can do
this with MS-Paint, so any better graphics program should surely be able to do it
as well.

Here is another  measurement, the motor mount holes. If you print the image
and the motor mount holes are too close together, then it needs to be scaled up.
If the holes are too far apart, then it needs to be scaled down.

The image is pretty clean. I might use it as a pattern myself. 

Nothing ventured, nothing gained. 

Anyway, give it a try.


Later, My Friend, iFly  

Hi Hifly, it would be easiest/most simple to paste a duct onto 125mm centers, rotated as needed to align motor holes. Instead of sanding, just vulcan mind meld them together at the periphery edges.

But... did find this/have not measured but he said it was "scanned".:

geprc phantom bottom plate from scan
https://www.thingiverse.com/thing:5104131/files

edit to add template to paste over:

(22-Jul-2023, 04:45 PM)skywanderer Wrote: Hi Hifly, it would be easiest/most simple to paste a duct onto 125mm centers, rotated as needed to align motor holes. Instead of sanding, just vulcan mind meld them together at the periphery edges.

But... did find this/have not measured but he said it was "scanned".:

geprc phantom bottom plate from scan
https://www.thingiverse.com/thing:5104131/files

edit to add template to paste over:

Thanks all for the super useful input.

So I had the thingiverse frame and it is not a match to my frame. It’s just slightly bigger. However. The svg you provided is an exact match!

But….. life lol my wife has a visitor so I have been playing island tour guide, I ran out of filament, and I stripped a few motor holes taking them in and out for test fitting. So ordered some new filament and going to try out some m2 helicoils

50pcs Thread Repair Installation Kit Stainless Steel Helicoil Type Set (M2 x 2D) https://a.co/d/hbez7dx

Wife went grocery shopping. Had the house to myself so used tinkercad and above measurements to make a one piece design.

https://www.tinkercad.com/things/9MKsj8s...uLZDeUwEpU

(28-Jul-2023, 11:27 PM)B4tn Wrote: Thanks all for the super useful input.

So I had the thingiverse frame and it is not a match to my frame. It’s just slightly bigger. However.  The svg you provided is an exact match!  

But….. life lol my wife has a visitor so I have been playing island tour guide, I ran out of filament, and I stripped a few  motor holes taking them in and out for test fitting. So ordered some new filament and going to try out some m2 helicoils

50pcs Thread Repair Installation Kit Stainless Steel Helicoil Type Set (M2 x 2D) https://a.co/d/hbez7dx

Cool beans, gotta like qcad:

QCAD
https://qcad.org/en/





What are the thread inserts for? Have you tried heatserts (brass sert holder end thingy that goes on your soldering iron)? I can give you a couple linkies... hold a few, I'll go find them... back:

350Pcs Threaded Inserts M2 M2.5 M3 M4 M5 M6
https://www.amazon.com/M2-M2-5-M3-M4-M5/dp/B0C2HGNYLX

Heat Set Insert Tips for Sizes M2, M2.5, M3, M4, and M5 - Soldering Iron Tips for 3D Printer Users
https://www.amazon.com/Virtjoule-Heat-In...B08B17VQLD

https://cnckitchen.store

(29-Jul-2023, 01:08 AM)B4tn Wrote: Wife went grocery shopping. Had the house to myself so used tinkercad and above measurements to make a one piece design.

https://www.tinkercad.com/things/9MKsj8s...uLZDeUwEpU

Nice, I'll trust you coz I can't see a pic, apparently you have to register(?) to be able to view? dunno