Building a HIGH SPEED Rocket Plane

in this video you'll see what happened when I took an RC SR71 Blackbird and upgraded it to see how fast I could get it to fly I installed new Motors improved its aerodynamics and fitted a powerful solid rocket booster that could be activated midair I've been challenging myself to build faster and faster rocket planes here on Project air for a couple of years now slowly increasing their speeds with each new project solving problems along the way and trying my best to get them back without being completely obliterated in the process this plane would be quite different as it would be the first to use a new type of rocket engine with a super long burn time so the plan was to take a very standard RC jet and modify it to fly as fast as possible in a straight line on battery power alone stage two would be to then increase this top speed by activating a rocket engine midair which would cause the plane to accelerate to an even faster top speed it seems appropriate that we use the SR71 for one of these speed airplane projects the Blackbird was one of the fastest planes ever made the problem is though that this foam RC model isn't really designed for high speeds so maybe we could change it and make it more like the real thing firstly we needed to find out exactly how slow the plane was to begin with which meant getting it out of the box and getting it assembled for its very first test flight the plane came with two very small 40 mm electric ducted fans which Propel the plane through the air using power from the onboard LiPo battery to pitch and roll the aircraft the plane was fitted with four microl linear servos but these looked a little bit on the flimsy side would they hold up when we started to increase our air speeds for now it was time to head up to our normal flying field and put this thing in the air as it makers [Music] intended for some reason I'm getting a warning on my transmitter but it's in the sky coming around well it's is working doesn't seem particularly fast at the moment woo look at that that looks so cool let's go Full Throttle now and do a low pass wo that was pretty fast wasn't it so uh we've only got a couple of minutes battery so I'm going to just try and uh make the most of it oh okay I think it's telling me that it wants to land so let's bring it in right let's see how fast the plane went 108 km an hour that's 60 MPH I think so yeah let's see if we can improve this airplane back at the workshop okay so there are some very easy things we can do to this airplane to make it faster and it's important to make it as fast as possible before we add rocket engines to it to make sure that we're really optimizing the top speed of this airplane now one of the easiest modifications I can do to this airplane is to remove these codes on the front of the engine the cells we just want to get as much air into the ducted fans as possible and at the moment these are restricting that the next key thing that I needed to address was the streamlining of the airplane I absolutely needed to record the flight from on board to analyze what the plane was doing midair but the camera I was using was massively increasing the frontal area and overall drag of the otherwise quite slippery SR71 I decided to change to using a much smaller insta 360 go3 camera instead of the big bulky run cam with the new camera in place we now had a much more optimized setup for capturing Onboard video while making these initial modifications I also tested out some new batteries from Spectrum to see if we could get more power out of these ducted fans it turned out that these fresh new batteries made a big difference which you could also audibly hear now I was excited to see how these upgrades would affect the Blackburn's top speed ready so that's rolling this is definitely recording yep [Music] stop read 150 that's way faster look at that 150 we'd increased our top speed by a decent 27% but now I wanted to push the plane over 100 mph on battery power alone which would be much more difficult due to the problem of increased drag at higher speeds air resistance actually works in a bit of a strange way drag increases as an object moves faster through the air as it collides with more and more air molecules exerting an opposing Force as our SR71 increases its speed it will hit more of these molecules with more Force meaning theoretically if we want to fly twice as fast we would need to four times the power which is quite a tall order we'd already maxed out on battery power so now the best way to squeeze more thrust out of the electric systems would be to upgrade the blackbird's fans through this rudimentary smoke test I could visibly see the volume of air being sucked in by the electric ductive fans I could also see the speed of the air exiting the exhausts and it was really interesting to see that there wasn't actually that much air being moved here the original fans were quite small so increasing the fan size would allow us to pull in more air and Chuck it out the back faster I found some new larger fans that were repurposed from one of my ground Effect fan cards projects and after being quickly serviced were pretty much as good as new now I could remove the old motors from the SR71 which required a bit of aircraft surgery and then I could hook up the new fans directly to the internal flight computer to see if they would work it wasn't all straightforward though I found I had to remove quite a lot of foam from the intake and I also had to add nose weight to correct the balance of the plane which would add to our all up flying weight this would become a bit of an issue l on so would the fans move more [Music] air well there was a very obvious difference far more air was being sucked into the primary intake as well as into the secondary Vents and it seemed to be shooting out of the exhaust much faster this was a big step towards our stage one goal of getting this plane over 100 mph on electric power alone the problem was i' now made the plane much heavier so would it still fly she's got some power oh oh dear think we're okay after adjusting the trim of the elevators I can rely on the flight computer to keep the plane level and try again [Applause] with that hair raising takeoff out of the way I finally got the plane airborne and accelerating hard lining up I could do a couple of speed runs before I'd have to land yes 163 finally we'd achieved 101 MPH meaning stage one of the project was complete now we could turn attention to stage two and start experimenting with some rocket boosters a solid rocket engine operates based on a principle of combustion of solid propellant the casing of the rocket motor contains a solid propellant mixture composed of fuel and oxidizer when ignited the solid propellant undergoes rapid combustion producing hot gases which shoot out of the nozzle generating a thrusting force in the opposite direction now what's going to be different about this rocket plane to other rocket planes I've made in the past is to do with these Rocket Motors these fsize rocket engines burn for a lot longer than those I've used before these release their energy much more slowly allowing the vehicle to accelerate more gently this rocket plane here used a much more violent engine and it barely survived 3 2 1 fire if I was to use a much more gradual engine to sort of accelerate slowly then maybe this will be more easy to fly with and also more survivable for the airplane I wanted to test the rocket engines and gather data before strapping them onto the precious SR71 Blackbird for this I would use a Data Logger seen in previous videos on my channel that can be used to measure thrust such as the thrust from these giant rubber band motors used in my rubber a band plane video this load cell and Data Logger would need to be mounted to something and initially we thought about 3D printing a base from plastic but that might not have been the best idea as we were going to be dealing with Rocket Motors that get a bit hot so we realized that we needed to fabricate our test stand from metal but instead of doing this ourselves we got this part machined by PCB way who are actually sponsoring this video after waiting for the parts to arrive we could unpack them and quickly assemble the finished test stand complete with electronics for measuring the thrust of the rocket engines right I'll press this one it'll go D and then start all right so we're here with the load cell now we're going to do our first rocket engine tests we've got Emma here who's designed the load cell um so yeah we're going to to fire it off now we test fired three identical Motors and the data showed that we get about 100 Newtons of average thrust across a 7 to8 second burn so yeah pretty good thank you very much to PCB way for sending through all of the parts for this rocket engine test stand it's been really really helpful all you have to do is design some parts in CAD and then upload them to the website and you can send them off to be made for you it's really straightforward and there's loads of great tools on there to manufacture things in different ways so make sure to check out PCB way with the link in the description thanks very much to them for sponsoring this video okay now I've tested the rocket engines on the ground I can start work on mounting them to the RC plane as our speeds were increasing I'd actually found it quite difficult to keep track of the stealthy black airplane in the sky when I was controlling it so my solution was that we would paint this airplane a special color as you might have noticed previous rocket planes on my channel have been orange mostly however I wanted to try something a bit different with this particular airplane and paint it gold because I thought it might be a good opportunity to see whether the shininess of gold and the reflective nature of it might make it even easier to see airplanes orientation now with the gold paint the unique looking Blackbird could be reassembled complete with project air markings and of course my patreon's names as a thanks for signing up to my patreon you can sign up with a link in the description to add your name to my future builds now to make amounts for the engine using some cardboard tube now to make this rocket plane work electronically I found I'd have to make some big changes remember that flight computer from earlier well it turned out it wasn't actually very customizable this meant I'd have to switch to a brand new radio system this wasn't actually a bad thing as it gave me an opportunity to upgrade the radio system to one with much more redundancy and better range the trouble was with this bulky receiver there was simply no room left in this airplane to fit a gyro like had been built into the flight computer this was now going to be a totally analog experience which would require me to Pilot the plane with all the flying skills I had with the new Control Systems finally all wired up new stronger Sur installed and the powerful fans working at 100% again we could give the igniter circuit a test woo with that the plane was all finished and ready for what this video has all been leading up to the first rocket power test flight to see just what these long bird Motors would [Music] do transmitter power on seal hatch check control Direction igniter circuit LED plugin test igniter circuit camera start recording check all right so we've got the airplane here we're now at the Flying Field um and we've got the rocket engines that we're going to be using on this test we've got the 8sec burn this engine will burn for 8 seconds and give us you know a good solid boost of about a kilogram over you know constant thrust there's a very low odds of success with this whole thing you know it could all go very wrong very very quickly flight pattern is take off into the wind do a circuit and then hopefully if all's looking good if we haven't crash by that point we'll get the green light and go for an ignition of the rocket Let's uh see what [Applause] happens okay going to come around okay we've got the green light okay and then 3 2 1 throp up and [Applause] fire right trying to get orientation the gold paint's working okay we're down we're down I think we're down in the fields lost oh dear that was so uncontrolled it was such it was so difficult to keep it straight without the the uh gyro right I'm going to go and try and find it with the Scout drone I think we're only a couple of fields across thankfully it's gold so it' be quite easy to see that's it that's it found it found it we found it so we got a successful burn uh the airplane didn't crash on takeoff uh there's lots of positives not sure how fast we went though so that's what we're going to go and discover now let's see how fast it went with the GPS do you see it where's it gone it was here oh there it is well it's sort of in one piece it's a bit dug into the ground look at this it's proper stuck in oh my God it's actually wedged in I can't actually pull it out I cannot actually pull this out of the ground oh there we go so the big question how fast did it go okay so stop read 200 km an hour 200 km an hour exactly look at that that is sp that is pretty impressive right let's see how badly damaged the airplane is back at the workshop and then we can see if it'll ever fly again again so we tried to fly the airplane again but unfortunately ran into more problems with hand launching and unfortunately we weren't able to get the airplane back up in the sky the airplane was just too unstable and just ridiculously hard to keep level I had to take a really big run up to get the right air speed and yeah it was almost impossible I kept damaging the airplane and we had to keep going back to the workshop and going back out again to the field and yeah unfortunately on one of these tests or one of these attempts the airplane plowed into the ground and was instantly written off so this airplane is pretty much destined for the project Air Museum now but it's um yes we've definitely learned a lot from it so longb bur rocket engines will I be using these on the next aircraft well actually if you look at the test flight footage it seems that the airplane sort of ran out of space when it was still accelerating so I had to pull up and sort of bleed off speed in a turn and that meant that the airplane basically killed off some of it potential with how fast it might have gone if this was uh using all of its fuel up in a fraction of the time so I think I'll be going back to using sort of shorter burn more violent rocket engines in the future we got it in the air that one time and managed a pretty impressive top speed of 124 mph we actually doubled the top speed of the stock airplane or pretty much did it was I think 10 mph off so we've learned a lot from this part of my rocket plane program and in the next video probably going to be starting work on a brand new type of rocket propelled aircraft although it's going to be very different so if you want to check that one out make sure to subscribe so you get notified and also check out another video in the meantime while you're waiting for the next video on Project air to come out I think you'll like this one too so click on that one next thanks very much for watching this video and I'll see you on the next one

Channel: ProjectAir

Views: 1,178,499

Keywords: James Whomsley, whomsley, James, projectair, 3d printing, rc, r/c, airplane

Id: 0bb68p0hwK0

Length: 17min 53sec (1073 seconds)

Published: Fri Apr 26 2024