Thanks for watching this video! We now have a reliable launcher, and we've got the flight computer working. We've got more flight time planned in February to do some more tuning flights and get some landing practice. Once we've proven we can do launch, stabilised cruise and landing reliably, we will then attach a stronger bungee to the launcher and maiden the Kingfisher. We're sorry that the timescales have been longer than previously promised - we want to make sure we have everything ironed out at the sub-scale to minimise risk to the main flight. This is from both a safety perspective and aircraft perspective - repairing the 3DP is orders of magnitude cheaper and easier than repairing the main Kingfisher. We're constrained to flying on weekends with good weather, since we work full-time engineering jobs in the week. Some of you may also be disappointed that we didn't drop the aircraft out of a helicopter, but we think a catapult is a lot easier to repeat for the full-scale. We also cannot afford a helicopter! Overall, this sub-scale flight campaign is about replicating the real flight as closely as possible, that's why we've matched the wing cube loading to Kingfisher, made the 3DP way heavier than it needs to be, and used a slightly overkill bungee system! Should also add, Chris was unavailable for this flight so we had a different pilot.
Excellent progress guys! Maybe ACRO mode was a bit ambitious, but you don't know until you try. Looks like you've got the roll damped nicely though, and a sweet airframe!
Perhaps there is some way, most likely in ArduPilot, that can alter control authority depending on airspeed. This likely won't work above a certain speed with how it's currently configured (since GPS prevents usage above 300mph I believe) however a pressure sensor like on actual airplanes could be used. It's fairly simple to math out as it's linear up until mach 1, so as soon as you see strange results at speed, you'd know you've hit the sound barrier. It'd probably be inverse square for how the control authority would be mapped, where you've got 100% initially, then the firmware would limit it exponentially as the speed increases. Especially helpful for preventing roll, but you'd probably be better off with a different set of math for the pitch authority, and even a potential 'emergency' mode toggle which would disable the limits and allow full authority to the user. The way I'd see it, this would likely feel very natural to learn, as as the speed increases, the amount the aircraft reacts would be the same, providing it is tuned correctly. The only difference would be distance travelled to rotate X degrees, instead of rate of rotation increasing with speed. It'd be helpful to the pilot as well as it'd feel "slow" to control, while being fully predictable, instead of having everything happen before any human could possibly react.
@@keatonhare7691 This is possible but we think it is likely the tune at this stage. The default ardupilot tune is very conservative with less control authority than the manual mode. According to the logs the top speed in level flight was 116 mph whilst during the dive it reached 110 mph and the pid outputs were never large enough to get close to the target value suggesting it is a tune issue. Aero forces are definitely going to be a bigger issue as we increase speeds further though, that's why we have 20 kg-cm servos on the full-size kingfisher! -Josh
@TheMachInitiative It’s probably too late for the main launch method - but I have found success testing high speed/large scale models by mounting them 2-5ft above a cleanish car(Tesla or other electric vehicle ideal) and accelerating up to flight speed - you can get a fairly good idea of basic systems and test servos/control surfaces/motor etc. This was the basic methodology for testing a lot of sub scale designs at NASA Armstrong for a long time
I wonder if you're going about the use of the flight control system backwards. I would recommend starting your flight out without flight control to get your trims, throws, and expo sorted out so that you can fly it "easily" up to 100mph. Only then would I turn on the flight control to help keep things stable for max speed runs, where a human couldn't possibly react fast enough to maintain proper flight envelope. Unless your idea of breaking the speed record is taking it up really high, then accelerating straight down and your top speed is what's recorded a millisecond before it hits the ground.
I think you're absolutely right that we need to get the trim, throws and expo (the basics) sorted first. In order to sort these out we've needed flight time and our major blocker has been the launch method. This video represents our process of sorting this out so now we should be able to get repeatable flights to sort these control issues out over the coming flight tests. The flight launched in manual and we were checking the different modes to work out what needs to change. The rest of the flights would've been adjusting the trim, c.g. and then tuning just like you are suggesting. Thank you for the feedback we really appreciate it! -Josh
LOL, yall aint even make it over 100 mph... my rc boat does 112!!! you also have a great example by the world record holder and you FOLLOWED NONE OF IT!!!! Your CG is also waaay off!! its why it flies like a Dolphin.
Thanks for watching this video! We now have a reliable launcher, and we've got the flight computer working. We've got more flight time planned in February to do some more tuning flights and get some landing practice. Once we've proven we can do launch, stabilised cruise and landing reliably, we will then attach a stronger bungee to the launcher and maiden the Kingfisher.
We're sorry that the timescales have been longer than previously promised - we want to make sure we have everything ironed out at the sub-scale to minimise risk to the main flight. This is from both a safety perspective and aircraft perspective - repairing the 3DP is orders of magnitude cheaper and easier than repairing the main Kingfisher. We're constrained to flying on weekends with good weather, since we work full-time engineering jobs in the week.
Some of you may also be disappointed that we didn't drop the aircraft out of a helicopter, but we think a catapult is a lot easier to repeat for the full-scale. We also cannot afford a helicopter! Overall, this sub-scale flight campaign is about replicating the real flight as closely as possible, that's why we've matched the wing cube loading to Kingfisher, made the 3DP way heavier than it needs to be, and used a slightly overkill bungee system!
Should also add, Chris was unavailable for this flight so we had a different pilot.
great progress. congrats !
06:44 The front fell off 💀
Haha!!
Gread vid; enjoying watching the progress! Strong work team!
Really enjoyed this video. Awesome effort!
Great update
Amazing work really impressive!!
really cool video, enjoying all the updates
Guys which cad programs do you use to build your project
Is windows good for your field or mac
We use Fusion 360 - its compatible with both but windows offers better support for cad packages in general
It’s so cool even if it crashed!
Excellent progress guys! Maybe ACRO mode was a bit ambitious, but you don't know until you try. Looks like you've got the roll damped nicely though, and a sweet airframe!
Thank you! Going forward, we’ll stick to stabilised until we have the tuning locked in
In french we call this : Bricollage 🛫😎
Have you guys ever thought about using an oblique wing to achieve higher speeds in the air and slower speeds while taking off/ landing?
Perhaps there is some way, most likely in ArduPilot, that can alter control authority depending on airspeed. This likely won't work above a certain speed with how it's currently configured (since GPS prevents usage above 300mph I believe) however a pressure sensor like on actual airplanes could be used. It's fairly simple to math out as it's linear up until mach 1, so as soon as you see strange results at speed, you'd know you've hit the sound barrier.
It'd probably be inverse square for how the control authority would be mapped, where you've got 100% initially, then the firmware would limit it exponentially as the speed increases. Especially helpful for preventing roll, but you'd probably be better off with a different set of math for the pitch authority, and even a potential 'emergency' mode toggle which would disable the limits and allow full authority to the user.
The way I'd see it, this would likely feel very natural to learn, as as the speed increases, the amount the aircraft reacts would be the same, providing it is tuned correctly. The only difference would be distance travelled to rotate X degrees, instead of rate of rotation increasing with speed. It'd be helpful to the pilot as well as it'd feel "slow" to control, while being fully predictable, instead of having everything happen before any human could possibly react.
Is it possible that the speed of the final dive overpowered the servos? aero forces on those big control surfaces may have limited the throw.
@@keatonhare7691 This is possible but we think it is likely the tune at this stage. The default ardupilot tune is very conservative with less control authority than the manual mode. According to the logs the top speed in level flight was 116 mph whilst during the dive it reached 110 mph and the pid outputs were never large enough to get close to the target value suggesting it is a tune issue. Aero forces are definitely going to be a bigger issue as we increase speeds further though, that's why we have 20 kg-cm servos on the full-size kingfisher!
-Josh
@TheMachInitiative It’s probably too late for the main launch method - but I have found success testing high speed/large scale models by mounting them 2-5ft above a cleanish car(Tesla or other electric vehicle ideal) and accelerating up to flight speed - you can get a fairly good idea of basic systems and test servos/control surfaces/motor etc. This was the basic methodology for testing a lot of sub scale designs at NASA Armstrong for a long time
Hello. Is this vehicle 70mm edf compatible ? If so, i have a few questions.
maybe add a rocket motor for when its up to speed =)
i wonder what the army think of this project?
probably drooling for a cheaper target practice drone
@gp8666 probably
I wonder if you're going about the use of the flight control system backwards. I would recommend starting your flight out without flight control to get your trims, throws, and expo sorted out so that you can fly it "easily" up to 100mph. Only then would I turn on the flight control to help keep things stable for max speed runs, where a human couldn't possibly react fast enough to maintain proper flight envelope. Unless your idea of breaking the speed record is taking it up really high, then accelerating straight down and your top speed is what's recorded a millisecond before it hits the ground.
I think you're absolutely right that we need to get the trim, throws and expo (the basics) sorted first. In order to sort these out we've needed flight time and our major blocker has been the launch method.
This video represents our process of sorting this out so now we should be able to get repeatable flights to sort these control issues out over the coming flight tests.
The flight launched in manual and we were checking the different modes to work out what needs to change. The rest of the flights would've been adjusting the trim, c.g. and then tuning just like you are suggesting.
Thank you for the feedback we really appreciate it!
-Josh
LOL, yall aint even make it over 100 mph... my rc boat does 112!!! you also have a great example by the world record holder and you FOLLOWED NONE OF IT!!!! Your CG is also waaay off!! its why it flies like a Dolphin.
very cool video and project, how about using a parachute for landing? 🪂