Precision Aerial Surveying & Mapping
The purpose of this blog is to document a comprehensive, custom build of the XUAV-Talon for precision surveying and mapping. Content will include build process, tips and tricks, hardware choices, 3D print modifications, CAD drawings (Sketchup), photos, software for aerial data processing and short video segments. As I have recently attended several conferences concerning the latest FAA rules and regulations for small(under 55lbs) commercial drone operation in the United States; I will be posting my interpretation of the laws and options available to fly drones legally in the US National Airspace(NAS).
Reverse engineer Talon with sub-millimeter Creaform handheld scanner.
I now have a sub-millimeter Polyworks model(inside and out) of the Talon in which I can create custom components for the build.
Due to the size of the polygonal model I had to clip areas of interest for import into Sketchup.
Design and 3D plot with Makerbot enclosures for 1.3Mhz video transmitter, 433 Diversity EZUhf receiver, 800TV Line board camera, Sony Nex 7 mount, and Pixhawk.
Within Sketchup used Creaform scan as mentioned above to precisely fit contour of Talon tail section and nose enclosure of 1.3mhz video system.
Sketchup Model, EZUhf Enclosure with Talon Surface
Sketchup Model, EZUhf Enclosure.
*TIP: I used the Sandbox Terrain generator to create a new surface that had fewer triangles over the existing high res scan surface so that I could work with model more efficiently in Sketchup.
Sketchup Model, 1.3Mhz Enclosure
Makerbot 3D on build plate complete!
*TIP: When I first started printing with Makerbot 2X and ABS I had the hardest time keeping the edges from warping even with a heated build plate. Solved this problem by covering the build plate with masking tape and then bathing it with a solution of acetone and discarded ABS support material(glue type texture when mixed well). Found this trick on forums. Works great... almost cannot get parts off of build plate it sticks so well.
Final 3D prints along with 800tv line board cam on far right for nose installation. Notice I wrapped the tail section with 3M Carbon Fiber film.
*TIP: When printing parts in ABS I always scale the original part up 1% to overcome shrinkage. So in the prints below I scaled up the enclosures 1% but did not scale up the hatches/covers so they would slip right into place. You may also find that the inserts at the end of the hatches may need to be trimmed to fight comfortably into the enclosure. No big deal!!
Test fit of parts in Talon! You may also notice a support ring for Sony Nex 7. This ring provides a clean hole for the 20mm lens and support platform to hold the camera level. Very basic design but saves on weight.
FITS LIKE A GLOVE!!
STEP 3: (4/30/2015)
Design and 3D plot Nex 7 "Landscape Mount" Option
The native orientation of the Sony Nex7 within the stock camera configuration of the Talon is Portrait. Major customization and modification is required to orient camera in Landscape. Using the sub-millimeter scans I designed a mount to receive the Nex7 in Landscape.
Notice extruded slot in blue section for IR camera trigger installation.
Main carbon fiber spar had to be cut in order to load the camera from the top. Loading the camera from the bottom could have been an option however would have added complexity to the camera trigger mechanism that I chose to avoid. The 3D print is in two parts but when clued together and glued to foam fuselage more than replaces the strength lost by cutting the carbon fiber rods.
Orienting the camera in Landscape mode will allow me to maximize the spacing between flight lines for aerial mapping therefore shortening the flight time needed or allowing me to capture more area per flight.
3D Print Build Photos:
*TIP: Although hard to see in picture, I had to trim off metal strap holders to make room for camera to fit landscape and not puncture hole in side walls.
*TIP: I used 3M Carbon Vinal Tape to cover the exterior shell of the lower component as shown in picture. Works much like "Monocote" when heat applied.
All fits very well.
STEP 4: (5/14/2015)
Reinforce Nex 7 Mount with Carbon Fiber and Join Fuselage together
Because of the size of the Nex 7 camera mount it had to be printed in two pieces before installation. Those familiar with 3D printing know that parts are weak when stressed between print layers. For that reason I had to add carbon fiber to the insides of the mount to add strength to the support arms. Carbon Fiber was secured to the mount with White Gorilla glue. End product was an extremely strong mount to replace the carbon fiber spar I had to cut to get the camera to fit landscape.
A BIG STEP! Install hardware and join fuselage halves together. I first used while gorilla glue to coat the mating surfaces then after the halves were joined I supplemented the gorilla glue with foam safe CA to help those problem areas that needed a quick set to bridge the gaps.
Overall once complete total system is very strong weighing in at 638.5 grams, 1.41lbs (foam fuselage, kit hardware and custom 3D printed parts, No wing, tail section or electronics) as shown in picture.
STEP 5: (6/2/2015)
Nose retrofit with Mobius Gimbal
Just completed design for Turnigy Mobius Gimbal with Tarot Controller. Setup is small, lightweight and perfect fit for XUAV-Talon. I will show install pictures after I 3D print. Glass dome is standard with Talon, however I had to redesign cowling and back plate for rear motor mount. Notice controler mounts behind rear motor mount. Gimbal is hard mounted while cowling and glass dome can easily be removed to access mobius.
Turnigy Mobius Gimbal with Tarot Controller installed but not tested. Install went very well and it all fits nice and snug. Clean fit. Here are some picts of the install.
STEP 6: (12/2/2015)
Talon complete and all construction final. All components in working order. Added wing extenders because of added weight of Talon. Total wing span 2 meters.
STEP 6: (12/15/2016)
Initial test flight proved about 50 minutes with 12x6 prop and 16000 mah battery.