Monday, February 28, 2022
Friday, February 25, 2022
Monday, February 21, 2022
Sunday, February 20, 2022
Saturday, February 19, 2022
N.B. THE FOUR ARMS SHOULD HAVE BEEN 37.125" INSTEAD OF 38.125", SHIT HAPPENS.
Well with that out of the way, let's move on to construction of the 'drone itself and we start by taking those arms and applying a squeeze of silicone around the inside edges of all eight ends before tapping in the threaded M6 inserts... from which I have to say the average fabricator will draw a practically sexual satisfaction (or at least until those rivets are driven home).
I've opted for 4 x 12mm pop-rivets as a good all-rounder, and a 3.9mm drill-bit offers the tightest fit, although I've gone for a 4mm bit as it is available on any desert island. Apply those rivets to opposite sides as a belt-and-braces fix, and we'll see later that these opposing pairs need to be oriented methodically during assembly.
Airworthiness inspectors might question whether this meets required tensional specs and should this be a sticking point. Offer to hang them from the rafters with the same method and if the joints prove to be up to scratch, then you're clearly the winner...
Thursday, February 17, 2022
Wednesday, February 16, 2022
Tuesday, February 15, 2022
Friday, February 11, 2022
Sunday, February 6, 2022
Thursday, February 3, 2022
Among the many hundreds of experimental ventures worldwide in the field of ‘personal air vehicles’ or PAVs, the TELEDRONE was designed and built by Colin Hilton as a spin-off from his earlier entry into the Boeing-sponsored ‘GoFly’ challenge, which took place at NASA Ames in Silicon Valley early in 2020.
The development of air vehicles of this kind was made possible by the digital control of increasingly powerful motors, alongside improvements in batteries and electronic components derived in large part from the mobile phone industry. Effectively a scaled-up quadcopter, the operation of this scale prototype by radio-control was possible by registering it as a regular drone ~ an avenue open in both the UK and US up to a weight-limit of 25 kilograms or 55 pounds.
Further development is possible in the UK at weights of up to 150 kilograms by special permission from the CAA, and thereafter at greater weights again under Experimental Category. Thereafter however regular certification would be required, which is a process evolved over decades and aimed at piston and turbine types and as such, prohibitively expensive. It is not the case in the US however, where in an effort to stimulate the development of ‘eVTOL’ types the FAA allows for such aircraft as this to be flown largely without regulation up to a gross weight of over 115 kilograms so long as there is a pilot onboard. Consequently TELEDRONE types like the one seen here will be scaled up to adult size in order to be pitched to the US market in the form of rapid kit-builds.
Technically the airframe comprises a patented four-pronged cantilevered structure to support the centre-body, whose advantage is that it is effectively a two-dimensional construct adaptable to conventional fabrication in aluminium. In the case of this latest version of the machine, however, this is bounded by a 48” square perimeter frame that extends to four undercarriage legs in support of either skids, floats or casting wheels.
In order to pack the remaining components as practically as possible, the avionics are situated on the underside of the central section, and comprise a radio receiver linked to the V-aerial at one corner of the airframe, beside a Pixhawk ‘cube’ flight-controller (to which GPS signals are fed from a disc-shaped antenna located at another corner). The controller is wired in turn to each of four ESCs or ‘electronic speed controllers’ which control the four 6 kilowatt motors digitally as ‘virtual’ AC motors albeit running off a DC supply. The supply itself is drawn from a pair of 22000 mAh battery packs wired in series to produce around 45 volts.
The prototype thus has an endurance of between ten and fifteen minutes, with each motor requiring only a fraction of the potential 100 kilograms of installed thrust required to support the gross weight of 25 kilograms. The test-flight was undertaken on the 2nd of December in 2021 at Frome model aero club on the Somerset Levels, with the wiring, tuning and test-flying pursued by Angus Benson-Blair. The subsequent development phase would see the airframe expanded to 60” square and powered by 10 kilowatt motors driving 40” propellers in pursuit of elevating a mannekin by radio-control and thereafter an adult pilot onboard using hard-wired controls.
Max Speed 63 m.p.h. (FAA Part 103 Ultralight limit) in ground-effect
Empty Weight 20 kilograms
Capacity 1 child
Power 4 x T-motor 5.5 kilowatt motors (equivalent to 22 HP)