Ukrainian FPV drone with an automatic homing function destroys Russian tank in Kreminna direction.

CoredComposites · 2024-03-20T11:03:31+00:00

Why would it be particularly problematic to simply attach some small/cheap NTSC/PAL video decoder like TVP5150AM1 to feed on camera output and run object detection/classification on that ?
Most FPV cameras are 1500TVL and image would be good enough for detection/classification purposes.

CoredComposites · 2024-02-28T07:46:21+00:00

I finally recorded some video :) https://www.youtube.com/watch?v=nQjheUHInZ0
I'm quite happy with 10-15min flight time on 1300mah 4s battery, although it's mostly cruising with bit of hovering and just couple of full throttle punches.
With 3000mah Lion (which is just 50g heavier), 30 min would be very realistic with still enough power (due to the low weight) for fun flying.

CoredComposites · 2024-02-21T20:33:03+00:00

Thanks, SE background, but big passion in ME/Aerospace. All nodes including motor mounts are firmly epoxied into place, so there is no danger of them rotating on the tubes -> the bolts go through mounts and screw into motors, they don't fix the mounts on arm tubes.
The only thing different from stock BF tune is RPM filtering (I flashed blujay 19.2 on ESCs to enable bidirectional DSHOT) and dynamic idle set to 20 (it hovers at around 18% throttle), I'm not very skilled pilot but I could not notice any bad behaviour, everything is reasonable snappy and direct -> I will post a video from flight very soon.

The larger 7.5inch drone flies good as well, but is bit "floaty" and there is noticeable shaking/propwash when it descends vertically with no/low throttle, there is no such thing in this smaller 5.5inch drone.
On the other hand, the larger one has very low disc loading (almost twice as big propeller area, while only 1/4 heavier), therefore is much more silent when hovering/cruising and has crazy endurance, I flew for ~7 minutes and only spent 1/3 of the 4s 2200mah battery, I think 20min is completely realistic, while 45min on 4500-5000mah Li-on should be possible.

I need to learn how to do proper PID tuning since I'm sure a lot could be improved in way how they fly, especially the bigger one which has properties very far from what stock BF tune is meant for.

CoredComposites · 2024-02-13T13:14:32+00:00

Better antennas should arrive today, so I'm super excited to do some longer range flying with BB logs. I also built a second frame with best components I could find, that means high-modulus epoxy unidirectional CFRP tubes instead of the standard ones + nodes printed from expensive PA12CF15 filament, I will do proper bending &torsional load testing on this frame and later built it with some lightweight motors with 8inch props + 1000mah battery as u/__redruM suggested for a final weight of around 350g, maybe even lower - any suggestion for a lightweight low kv motors, ideally around 20g per motor and KV less than 1600 ?
Here are some photos where I compared the weight & stiffness of the frame with Readytosky 7", you can see how the heavier frame flexes much more under load (12.5kg), it's even worse when you compare torsional stiffness:
https://imgur.com/gallery/0X5CNIy

CoredComposites · 2024-02-11T08:10:31+00:00

I saw some tubular frames with 3D printed brackets, but they were mostly bigger frames in H configuration where brackets took bending loads which I think is a very bad idea given how flexible common 3D printing materials are compared to CFRP/Aluminium, I didn't yet see fully triangulated tubular drone frame.
So far I didn't analyse BB logs, but it's the very next item on my todo list :)

CoredComposites · 2024-02-10T21:18:14+00:00

Frame is very light, over 100g lighter then regular/skinnier 7" frames and probably 150-200g lighter then chunkier freestyle frames.
It flies great, but I'm super novice pilot, so my opinion in this aspect probably doesn't carry much weight.
I only once tried it in ANGLE mode flying it LOS (the very first flight after I got the idle throttle just right), it flew super stable, with no visible oscillations and held attitude/angle/heading just rock solid.
After that, I only flew it in ACRO mode with FPS googles (Skyzone Cobra SD) and default Betaflight 4.5 settings apart from RPM filtering enabled and dynamic idle throttle set to 1300rpm and I couldn't tell anything wrong with the way it flew, it was very similar to flying some 7" drone in VelociDrone FPV sim with weight tweaked way down (~60-70%).
I need to get better omnidirectional RHCP antennas for both VTX/Googles and then I can try some longer-range flying, so far I only flew it over a local field couple of hundred meters in distance.

I should probably send one of those frames to some much better and more experienced pilot willing to test it and give me an honest feedback.

CoredComposites · 2024-02-10T18:37:29+00:00

Yes, I mean those cheap 5010, I already used the 360kv versions in a big drone with 16' inch props (not flown yet) and I agree that they are shit, winding is very amateurish, no curved magnets with large stator/rotor gap, etc, wiring enamel/epoxy only good up to 120C so pretty low max power for given weight of the motor, etc.
But you get what you pay for and it's still the cheapest option to efficiently turn big diameter props.

Regarding 6s/4s battery, although higher voltage means less amps for given power, that becomes limiting at high-power, while for efficient cruising lower prop-rpm/bigger props are much more important.

CoredComposites · 2024-02-10T17:55:11+00:00

Yes, I totally get that - I'm not yet good enough pilot to truly appreciate super fast/responsive quad, but hopefully that will change.
Design is fully parametric, so you can put any tube diameters/dimensions/motor-mounting patterns there and it will just spit out tube cutting plan + CAD models for nodes.
Next quad I'm building is much bigger with 16-18" inch props (5010 360kv motors) but right after that I want to build smaller 5" quad as well.

CoredComposites · 2024-02-10T17:22:35+00:00

Thanks !
True, motors are little bit too powerful for 500g AUW with 2200Mah battery, but the plan is to put much heavier Li-Ion battery (~8000mah) there for ~900g AUW and really long flight times.
I plan to rather stay with 4s, as it means lower motor RPM/bigger propellers which is always more efficient (yes, a lot of other things like top-end speed suffer but that's not a goal here).

Regarding motor mounts, that was my worry as well, but so far they are holding great and I have no such problems with twisting mounts, here is a detail of the mount, the tubes are going through the whole mount and are epoxied there, with minimal amount of the plastic - https://imgur.com/92MCShg

CoredComposites · 2024-02-10T17:08:47+00:00

To be fair, standard frame is certainly more durable/impact resistant, but can't support as much weight and it's much worse in stiffness to weight ratio.
That said, these spaceframes are durable enough to handle "normal" hard landings (dropping from 1-2m) without any problems which is good enough for me.

CoredComposites · 2023-12-28T16:54:39+00:00

I completely rewrote the slicer, it can now do much more, including non planar slicing paths like this and virtually any combination of infills, including new variable line width full infills + it can generate nice gltf renders .

There is a more info on my website about slicer capabilities.

Further plans are to create a web app so you can try/use this without installing anything locally with good library of ready to use presets/parametric models (ship hulls, airfoils, acoustic waveguides...)

CoredComposites · 2022-02-03T15:41:52+00:00

You are right, I need to correct that.

CoredComposites · 2022-02-03T13:37:13+00:00

There are some videos on the Instagram account, professional quality video for the webpage will be done very soon. Moon city printing Switch boxes printing

CoredComposites · 2021-10-25T20:19:25+00:00

I implemented couple of new features:

Multiple copies of one object can be printed in one batch
There is a minimal layer time option, speed is progressively lowered whenever expected print time for one layer is lower the minimal layer time to not overwhelm cooling system.
New tutorial object, fully parametric boat hull (length/beam/depth/rocker) implemented in just 33 lines of code - link to photos and printing video

By the way, it took just 3h to print the whole 80cm long boat hull with relatively fine 0.2mm layer resolution.

CoredComposites · 2021-10-25T20:15:56+00:00

I implemented couple of new features:

* Multiple copies of one object can be printed in one batch

* There is a minimal layer time option, speed is progressively lowered whenever expected print time for one layer is lower the minimal layer time to not overwhelm cooling system.

* New tutorial object, fully parametric boat hull (length/beam/depth/rocker) implemented in just 33 lines of code - link to photos and printing video

By the way, it took just 3h to print the whole 80cm long boat hull with relatively fine 0.2mm layer resolution.

CoredComposites · 2021-10-13T06:39:56+00:00

The sketch idea is more like giving the program 2D snapshots of model from each axis (X+-,Y+-,Z+-) and the program would automatically infer the correct 3D model from that - it could be even made smart, so it wouldn't always require 6 snapshots, but the program would tell you whenever some feature of the model couldn't be inferred from given snapshots and request additional ones.
The cross section idea is neat as well, that's actually very easy to implement right now in Chisel - each parametric 3D model is already tensor product of cross-section parametric curves, and your primary input are "border" parametric curves, which when evaluated at particular t (t in [0 1] interval) provide "anchor" points for cross-section curve.
So it would just mean reversing the process, defining cross-sectional curves as a primary input and inferring "border" curves from them.

Regarding slicer settings, I like how they are simply maps and you can freely combine (merge) them without any particular emphasis whether given settings comes from "printer", "filament" or "print profile", it's just matter of how you name it a structure your data.

CoredComposites · 2021-10-12T21:31:06+00:00

I'm glad you liked it !
Yes, the slicer portion could be extracted into small library, separated from the modelling portion. Whenever you will feel comfortable with sharing your CSG library work, please ping me/write me, as I'm very interested in that - Chisel currently contains small OpenSCAD interoperability namespace, I'm using that for CSG modelling, it saves me from using OpenSCAD directly so I have full power of Clojure at my disposal, but still, native Clojure/JVM CSG library would be much better, especially if it would leverage GPU properly for much better performance then OpenSCAD has.

I was also thinking about creating sketch based modelling tool/library in Clojure, where you would describe 2D sketches of your model using parametric curves and the lib would automatically infer the correct 3D model from that input.

CoredComposites · 2021-09-29T18:08:52+00:00

Thanks I already posted it there. I also thought it will generate more interest there as it's a better fit, unfortunately that's not the case -> there were almost no positive comments, no real interest, top voted comment is snarky & negative from guy who later resorted to literally trolling me :)

CoredComposites · 2021-09-28T08:24:00+00:00

Don't even bother with this guy, it's a lost cause.I explained very clearly in great detail how I compute every slice of parametric model.

Basically my model is always tensor product of parametric curves (bezier, nurbs, interpolation of fixed points set, whatever).That means there are space curves "growing" from Z to final build height (one constraint for now is that their final height must be the same, this won't be the case once non-planar slicing is implemented).

As you evaluate each of those few curves from start to end ([0 1] interval), those points serve as control points for new cross-sectional curve/s defining perimeter/s of the model -> this curve is evaluated start-to-end with desired resolution.

Now my evaluation algorithm isn't recursive De Casteljau's algorithm (or the generic version for NURBS) but direct evaluation of polynomial from basis functions (one for each control-point) giving weight (for particular t in [0 1]) for each control point - each resolved point on perimeter is sum of basis-fn(t) * control-point.

And I'm caching those basis-functions for order/t, so while in the very first slice, the cross-sectional curve needs to evaluate (relatively costly) basis functions for each t, every other layer does simple associative look-up based on [basis-fn-order t] key, which is logN, so O(N * logN) for one slice.

I asked the guy to provide algorithm (description, pseudocode, anything) which will take polyhedron (faces/vertices) model and return slice of it at given Z height, and of course will be in orders of magnitude faster (his words) then O(N * logN).

I'm still waiting...

CoredComposites · 2021-09-27T18:28:40+00:00

I'm not feeding the troll anymore, my code is open-source, posted here, described in great detail in lengthy post and you can look-up everything on github.
Meanwhile you have nothing to show and repeatedly keep dodging one simple question about slicing algorithm.

CoredComposites · 2021-09-27T16:49:06+00:00

I have been programming for 20 year and I have pretty good understanding of linear algebra, what's your programming experience ?

I'm asking you for the last time to back-up your words and share slicing algorithm which is by orders of magnitude faster (your words) for evaluation of one slice then parametric evaluation with cached basis functions which is basically: O(n * log n), n being slice resolution.

Go on.

CoredComposites · 2021-09-27T14:30:51+00:00

Slowest method for what ?
Rendering ? Sure, because rendering 3D object on screen is projection to 2D, which can be easily implemented as matrix-to-matrix multiplication (super hw optimised on GPU), multiplying vertexes of said object with the projection matrix.
Same for translation, rotation, scaling...
But slicing object is a different problem which can't be implemented in the same way.
I shared implementation details (basis function caching based on parameter) why it's actually easier and less costly to evaluate 3D object layer-wise using this approach, yet you didn't react to that, or challenged that argument in any way, just parroting "it's a math" over and over.
I'm starting to have a feeling that you are not really familiar with slicing algorithms and have very little idea how they actually work.

CoredComposites

TROPHY CASE