FT Spear "Bad Ass" Research Tool for Rain Forest

by techboycr | September 27, 2018 | (4) Posted in Projects

The FT Spear became a BAD ASS Research tool, from hobby diy project to Scientific platform. I have build many robots, quads, rovers and sensors, but this time is special. Flite Test community go beyond and this is a living prove of that. Costa Rica has 4% of the worlds bio diversity, and our tropical forests are rich in many things, thats why we are researching and trying to develop new ways to monitor and gather data from this amazing forest.

I work for Foundation Costa Rica for Innovation and we team up with CATIE (Agronomic Tropical Center for Teaching and research) to develop a platform that can be used for data gathering in the rainy tropical forest of Costa Rica. Pretty much the aim of this project was to create the local capacity of UAV's for this very diverse uses. Our specific intereset was tree height that we measure with DJI Phantom drones lightly modified, we added and external barometer and Lidar sensor so we could take the actual heigth of the drone and the distance from tree top to the drone. The result?  Barometer minus Lidar equals Tree height.

This preliminary testing was very promising.Now we are after imaging data from the forest so we can estimate the growth of the secondary forest, here is were the FT Spear comes into the picture. Strong airframe, lots of space, good wing span and very stable fly with cross and high speed winds. Costa Rican forest is all about high winds, thats why we added the center tips and in further test did worked GREAT! 

There is a very elegant rectangular hole in the center tips, bigger props that expected. Flite Test Power Pack C (Fixed Wing Large) came with a 10" props and we were expecting an 8" prop, my bad though, I was too excited when I ordered the parts and didn't pay attention to that little detail. But... It works as expected, obviously it would it's an FT Spear after all.

The muscle and bones of this version is pure FliteTest foam and hot glue, but the brain is a Omnibus F3 with iNAV 2.0.1, M8N GPS and 3S 5000mAh battery, we tried to give it as much juice as possible to ensure a long range autonomous flight.

Actually this build flew smoothly but was a little too heavy, and becasue that giant brick battery we needed to do something, so... Our product designer Gabriel Wheelock redesign the inner frame of the Spear center box to be 3D printed with an even liter material. He came up with this:

Pretty light, and reduce the build time significantly, you just have to assemble the wings place the center spars and drop this inside. Like stealing a candy to a baby (I haven't done such thing to a baby neither planning to). The result was a much more lighter airframe and faster to build.

In later testing this airframe 3D printed structure didn't perfrom as espected, couldn't survive the first crash and it broke like glass. BUT! performance was better, higher top speed and lower glide speed. It proves to be better for fotography and imaginery of the forest.

We prepared a Mighty Mini Arrow for a diferent purpose, but time ran out, have to wait for the next time that we go up to Turrialba, Cartago  Costa Rica. The fate of the arrow is going to be different. Because is and speedy platform we are going to use it for wireless data recovery from remote sensors on the forest. There will be wireless sensor around the forest that are going to save data in local memory and when the Mighty Mini flies over they are going to send all data wirelesly to the Mini Arrow.

Well... testing was successful. By far FT Spear is more that it looks and has a great potencial, we could sure use any other airframe like the Skywalker or something like it. But you have to remember that sometimes in middle of the forest lots of thing can go wrong, thats why the spear is perfect, gives and excelent performance for this kind of task and if crashes or brakes is very easy to repair.

 We take them to the very limits of performance and endurance, after all this is a research, so they die for science after many dicult test, and they end up like this...

They died doing what they were meant to be, fly and give fun, but this time the gave much more. My work place is awesome!!! But the oportunity to build tools that will lead us to a better and greater future has no words. Thanks FliteTest for this great platform!


Eggs Benedict on September 27, 2018
This is a really exciting and inspiring project! I like to see how techniques from our hobby can be applied to real scientific and engineering problems!
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techboycr on September 28, 2018
It is exciting! Pretty much has always being the other way around. As hobbiest we took engineering and simplify it to suit our purposes. Without knowing the effect of doing it, it causes a big leap in engineering.

Thanks of that we can make this kind of research now. But yes there is a lot more that to apply from the hobby world to the scientific field. Deep down we are the same.
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Jackson T on September 27, 2018
I really have to learn programming. All the cool stuff I could do with autonomous wings and stuff like that! You should program it to carry a payload (doesn't have to be big) and drop it at a pre-programmed drop point then fly home. That would be so cool!
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techboycr on September 28, 2018
Programming and technology is the closest thing to magic and superpowers! You should give it a try.

We did just with the wireless sensor whos data is recover by the FT Mini Arrow. But we have that flight pending.
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Jackson T on October 6, 2018
Could you write an article on the autonomus brain and the software needed for your Spear and Arrow? I am thinking about doing this, but I have no idea what hardware, software, and skills I need. If not, do you know of any resources I could learn from?
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techboycr on October 10, 2018
I am working on a post for the arrow, I will cover some of that in this writing.

But, as I mentioned before what I used as brain was iNAV a Omnibus flight controller but there are many other options for FC. The best place to start is the wiki of iNAV so give it a look for you to get started and I will make another post about this ASAP.

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Zapf on May 26, 2019
Any chance we could get a link to the STL or the original cad file for that 3d printed piece?
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FT Spear "Bad Ass" Research Tool for Rain Forest