Darth Maul dark eye probe droid

As you said, the only official measurement is 0.3m (about 13"), which is consistent what we see in the movie.
As for what part that measurement represents? I think it's probably the widest part of the main body. (The diagonal line across the center from the 'electronics bulge' to the freestanding plate opposite it.)

I'm at the very beginning of the process of trying to build one of these around a quadcopter. Does anybody have any good technical measurements of these to work from?
 
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There's a little bit of discussion on rebeldroids about the size & stuff. Seems like ~.3m 11 1/2" -​
http://www.rebeldroids.net/forum/showthread.php?tid=236&pid=2897#pid2897
-​
http://www.rebeldroids.net/forum/showthread.php?tid=410&highlight=DRK
and​
http://www.rebeldroids.net/forum/showthread.php?tid=411&highlight=DRK
are some threads.

Specifically in the first link at the end I pulled out some frames of it near people's head's and it's definitely about head sized. (I'd originally thought it was much smaller, like softball sized, but clearly I was wrong)

I have a poor 3D file I'm trying to improve. http://www.rebeldroids.net/gallery/displayimage.php?pid=1408​
 
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Ah. Yep, that's what I get for doing the math in my head. I worked from 1/3m, and came up with a hair over 13".
But, that'd be the difference between .3m and 1/3m. 11.811".
An even foot in diameter would be 0.3048 meters. Either way, I don't think anyone's going to be complaining if you're off by 0.19" or .5mm in either direction.

Knocking it down from 13" to 12" does give a few more options as far as base materials for the shell, and puts the 11.9" diameter foam bowls I'm figuring for the outermost layer right at the sweet spot, with room for a polyurethane hard-coat to finish it off.

There's a model on sketchfab seems pretty accurate based on the *one* decent model shot I've found.
Dark Eye Probe Droid.jpg

That modeler responded pretty quickly when I asked for a version of the model that could be converted for 3D printing. Unfortunately, my back-of-the-envelope estimate puts a 3D print (2mm thick) at about 6 lbs, which makes it *entirely* impractical for my purposes. That's just far too much weight for a 5" drone to carry around, and that's as big as can reasonably be squeezed entirely inside when you add the extra space for the propellers. I've noticed a tiny flaw with the rear center detail, where the truncated cone is slightly off center, as if the rest of the model has been rotated a couple degrees. Unfortunately, that's beyond my ability to fix.
(Or, looking more closely at the render, it may be an invisible shape that is being rendered in SketchUp. Hmm...)
Someone with some 3D modeling experience might be able to do the necessary cleanup and tweaking to turn it into a good STL for printing.

I'm starting to look for places that CNC form foam to see if I might be able to source a ready-made shell. Definitely more expensive to go that route, but then I wouldn't be relying on my completely untested sculpting capabilities beyond the prototype stage...

<wishfulThinking>Anybody know someone who does that sort of stuff on the cheap, and can clean up models, too?</wishfulThinking>

Not sure what I'm going to do about that main lens, though. I need to be able to park a camera behind it to fly the droid FPV when I'm done, and the RunCam lens is only 11/16" across. Either that, or I need to put it in one of the 'pods'. (Hmm... that could work.)

-----

I took a long shot last night, and fired off an email to the LucasFilm publicity contact to see if there were any way I could get my hands on some better pictures.
I figure it's almost certainly a dead end, but it can't hurt to ask, right?
 
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Maybe a 3D model to make a vacuform mold from? I wonder if that's possible? There are a lot of decent photos on the screencaps from the film from various angles. I posted lots of those on the RebelDroids gallery. If you have a 5" drone INSIDE, then you're going to need ducts or openings for the air, so that's going to be pretty tricky! The shell near the fans would have to be a bunch of slats or nearly non-existent or something.

You could also scale it down, I'm not sure anyone really expects it to be that large. (My initial presumption was about softball sized until I started getting prodded and really taking a look at the size).

Where's that photo from?
 
Yeah, the ducts will be a bit of an issue, especially since it needs to be pretty much unobstructed at the exit. If I've done my math right, though, they should be *mostly* hidden by the left & right side plates, so long as the props are kept small enough (currently figuring about 1.75" diameter). It's a tricky balancing act to pull off, but I *think* I've got a handle on it, especially since I'm not looking to make this thing race or anything.

It's not going to be a simple mold to make for vacuum forming. By my best guess, it'd take a minimum of 7 independent moulds (maybe more, depending on how the bottom plates are actually shaped.
1) 'Hat'
2) Main Body Front
3) Main Body Rear
4) Side 'Electronics Pod'
5) Bottom Plate
6) Left Plate
7) Right Plate
And that leaves off the two camera pods. (Though they appear to be basically spherical with add-ons, so that's not a hard part to deal with.)

Scaling it down just makes it even harder to fit a drone inside, without offering much up in exchange. The smallest drones (Tiny Whoop class) still end up needing about 4" including the ducts, but get even less flight time, and have even less room to add mass and still get off the ground. Honestly, scaling it *up* would probably be better, so long as I could keep the weight down.

Don't remember where I found the photo. It's been sitting in my project folder for a while now. A reverse image search only seems to turn it up on Pinterest.

I've put out feelers to a couple places that do CNC milling of foam, to get an idea of what it would cost to do this as a 3-piece for the main body, based on the sketchfab model I linked above. (I even got a response back from one of them already, asking for a bit more info, so it at least didn't sound *totally* impractica to them.) I figure, I might have to save up for a bit, but if it's doable, getting a professionally done shell would be awesome. Especially since I don't have any particular experience with sculpting foam.

I keep moving 1 step forward on getting my prototype started, and realizing that I either don't have a tool I'll need for the next step, or having to figure out how to *actually* do what I want to do. For example, I was all ready to start carving, when I realized that knives weren't going to do the trick at this size, so I needed to get myself a 'hot wire' setup. Then, my first step is to carve a 'filler' for one of my EPS bowls from a block of foam to make the bottom part of the prototype. Unfortunately, while I can measure and draw, and all of that (now that I've bought myself a simple compass), I've realized that, if I cut the block round first, I have no way to mark the curve I need it to match. So, I'm going to need to get one side of the block cut to that curve, and *then* sit it on a nail and spin the rest of the curve in (which is going to require setting something up to do that, too). So, now I need to set up some sort of fence guide, and anchor the hot wire tool so that I can run the block along it, adjust the wire, repeat until I have the curve cut.

EPS isn't exactlly the best material for the shell, either. Better would be EPP (which is effectively impossible to find locally, and costs about 2-3 times as much), or even surfboard foam, which is pretty dang hard to start with, and about the same weight (1.3 lbs/cubic foot). Hollowed out, and carved, that should bring the shell in at about half a pound, which is heavy for a drone this size to lift, but not undoable. Unless the polyurethane coat adds a *lot* more than I'm thinking it will. (But that's what prototyping is for, right?)

Ideally, my timeline is to have it ready to fly by GenCon, which is still several months away. But the more I look, the less of a presence I see for any droid-builder groups, so I'm not sure it'd be a great venue for a debut.
 
I've printed "really thin" stuff (of course, then it's pretty fragile). Unfortunately it isn't very flat, flat is easier to print "thin". You might also be able to print ribs and use something lighter for the "skin" (I'm thinking of that old flying tech: rubber band powered planes, which even used tissue paper and very light skins on wings with very very thin ribs:)

Foam seems light, but that's because it's got a lot of air in it. I'm not sure that for strength/weight it'd be much better than you could get with (very thin) 3d printed stuff. You could print in black too. (and maybe save paint). I'm sure I could print thinner stuff than I could carve from foam (but I'm a foam clutz!)

This kind of thing makes me wonder - http://www.sfgate.com/bayarea/article/Just-Plane-Remarkable-Bud-Romak-has-spent-60-2948549.php - The lightest weight stuff isn't reasonably paintable as that'd destroy the weight. But some of the thicker films have colors.
 
From what I've seen, including a 3D-printed RC plane, 3D printed would need to be at least 1.5-2mm to hold up well enough, and that's going to run in the neighborhood of 4.5-6 lbs. Way too much. The alternative is a *lot* of internal structure for bracing, but that'll add as much weight or more.

The foam looks to run less than 1/2 lb. (The raw bowls and block I'll be working from for my prototype, including all the material that will be cut/carved away, weigh in at a grand total of 8.2oz. Even if the glue, hard-coating & painting doubles that, it's still lighter than printed by a big margin. The drone itself (minus the battery) weighs in at about 11 oz, the batteries I'm looking at (3S or 4 S @ 850mah) will weigh in around 1oz or less. That's to All Up Weight of as much as 1.75 lbs.
 
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Well, I'll be starting to accumulate project pictures shortly. (I'm going to try carving the filler/platform piece into the solid hemisphere I need tomorrow.)

Unfortunately, with as loud as drones are, I won't be mounting a sound system for audio effects. Nobody would hear them anyway.
 
Just saw the pictures of SavageCreature's model on the RebelDroids.net thread.

It looks to be *much* higher resolution than the one I'm working with. (But otherwise, they seem to match pretty dang well.)

I've signed up on the droid forum, but I can't post yet, because my application hasn't been handled. I don't suppose you could poke and see if Savage can check whether my planned duct positions are as clear of obstruction as I think they'll be?

My plan is for 50mm ducts, vertical through the shell 110mm out diagonally from center.
I *think* that'll be clear of the bottom center 'plate', and mostly clear of the bottom left/right 'plates', but I'm working from estimates based on low-rez motion stills, and off-angle shots, so I can't be certain. Using the front-on picture of his model, it *looks* like the duct holes would actually be almost completely disguised by the plates from the side.
(I'm basing all my measurements on the assumption that the .3m official size is the diameter of the outer 'sphere', drawn from one of the bottom plates to the outermost point of the 'hat'. That would make the inner 'ball' somewhere in the neighborhood of 8-9".

I'm willing to sacrifice small bits of those bottom 'plates' for purposes of clean airflow, but if I need to tweak the size of the quad, I can still do that at this point without changing much else parts-wise.

Edit: And my account on RebelDroids was just approved...
 
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My progress had stalled a bit while I hunted for the lightest true-x 215mm frame I can get my hands on. And of course, I'm running into the Chinese New Year at the same time. It *was* looking like 60-70g was going to be as light as I could get without figuring out how to have one completely custom designed.

But, today I've officially found a frame to use. Ordered, and expecting it on Monday.

The iFlight Ultra Lite 5 inch X-Lite 210mm is a *touch* smaller than ideal, but weighing in at 54.5g it's roughly half the weight of the earlier alternatives, which will cause less issues with the undersized motors & props.
 
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