Eeeeeeeeeeeeeeeeeee BOOM 😂 That worked much better without the fuselage! I'm assuming it struggled to recover from the dive because the thrust vector fins at the bottom turned it into a dart. Maybe some folding fins at the top could move the centre of pressure towards the nose and reduce this? Just a thought, as it could possibly remove the need for the top motors. I wonder how high something like this could go, just shows how energy dense lipos are nowadays!
AWESOME!! I was thinking the same thing as Tom. Have passive folding fins at the top that will deploy when it is falling and automatically retract when it is in hover.
I don't think the fins would need to fold. Experiment with size until the centre of pressure results in the rocket free-falling at your desired attitude. For the rest of the operation, they would have little or no effect.
@@xaspar3011 No correction needed. I used the word resistance for a reason. Drag would not be something referred to as actively varying the amount of, but changing based on velocity. Whereas resistance is a better word as it indicates a changing variable say from a servo. Like a variable resistance device called a potentiometer. 0 to whatever. Please dont try to senselessly overcorrect people.
Hover snow plane , solar plane , long distance Skyhunter crash and recover / discover some history ...and now rocket quad , truly enjoy your channel , keep it up. 👍
Simplify the design. Install a nose with an open base to create drag (parachute effect) on free fall causing the rocket to have the highest proponent of drag at the top & the heaviest section at the bottom.
Where are the gridfins? No don't use gridfins but normal fins on the top. Gridfins won't realy work well at that scale Edit: What about drag brakes like on blue origins new shepard
I’m doing something similar with a rocket team of mine. In high powered rocket launches you get more points at competitions if you land closer to the launch pad. So we’re developing a nose cone that separates itself from the body, folds out into a quad, and then lands itself all with GPS at the pad.
Looked to me like the high position of the battery in the first test put the cg too high for the thrust vector fins to compensate. Maybe if the battery was lower like in the second test, there were some static fins mid-way up to help stabilise, and a smallish nosecone at the top to give some drag on the way down?
Other people have mentioned, but when in free all your airflow over the control vanes is reversed, so they're having the opposite effect than the flight controller is trying to do You could possibly just have the actuation taper down to zero at zero motor speed, and rely on your top mounted motor(s) only. And/or have fins fold out with reverse airflow to act as control surfaces
It creates a floating pendulum essentially. You used the weight of the bottom to swing the momentum down and the blades dampened it perfectly and made a perfect like, imagine playing with POY, and while in the arch youre doing you stop and use ur right hand (the fans) and dampen on your way to the bottom of the circle with the poy and you can stop it just like he did
The problem is very fixable and it's with your gyro!!!! I know why the fall tends to get out of control, when u fly up, the fins on the bottom work perfectly, but when you starting falling they are pushing the air in the opposite direction causing the plane to inevitably turn upside down as it's controlling the fins opposite of what the gyro is intending to do creating an unstable decent. You can see this in the free fall especially the one with the catastrophic failure(1:20) and once it flips the gyro works as intended. You can also see it here(4:33) with the "RCS thrusters" counteracting the fins as much as possible. To counteract this you could use some type of velocity chip that can tell what direction (and possibly what acceleration as a bonus for other hardware/software) the rocket is moving and can flip gyro controls if going down. Or a more temp solution is for you to have a switch on the remote that once switched the outputs of the gyro could be flipped, possibly even adding a servo to the gyro and flipping the whole gyro with the switch as another temp solution(if that would even work).
Yes, i was thinking the same thing. By inverting the fin control it might be possible to stabilize the rocket while falling down. But as you said, changing from falling mode to hover/ascent mode will be tricky and needs some experimentation :D Also, i dont think that adding some weights somewhere or some fins at the top will be the best solution. I mean, the fun part about this project is to control an unstable system, instead of just stabilizing it with even more weight - SpaceX certainly would want to save as much weight and air resistance as possible
Ya I contacted him and this was his reply, " It is true that the control fins would have the inverse effect if the rocket were falling down vertically, nose up. However, the rocket falls horizontally so the fins do not have any control authority. It is beneficial to fall horizontally because it has more drag and will fall slower than if it were vertical. " So it sounds like he's trying to recreate the SpaceX's starship design a bit, but staying horizontal with only tail fins would be impossible as the drag in the rear would turn the front down again causing the catastrophic failure. He'll need to also add fins at the top just like the starship design so that it could turn into an airplane almost flight with a massive steep fall down instead of forward. Just like the Space shuttle landing but more steep.
@@nicholascarr6251 Okay, that makes sense now. Some fins on top would be needed. I guess you could also use the vectoring fins for stabilizing it in a horizontal position if you add some motor thrust, but this would add a lot of ground speed aswell, which might be not that great. Anyway, great project :D It gets more difficult the more you think about it. I am curious what he will come up with
If you just expect it to hover down after it reaches the desired altitude, you should attach a remote parachute deployer on the top, just small enough to keep it upright.
I think the biggest problem with the first version in the video wasn't the lack of the extra motors up top, but maybe mostly due to the bottom acting as the tail to a dart and adding too much lift and foliage to the "back", keeping it falling face first.
It seems like it's top heavy. It will tend to flip. If you made it bottom heavy, the weight would help to stabilize it(point the bottom towards the ground).
Your videos are awesome! I don't think that you need the micro-quad on the top of the rocket, just some fins on the nose to move the center of pressure forward.
An alternative to thrust vectoring the top motor would be to duplicate what you already have at the bottom with the moving fins, perhaps in a different size. Or, as Tom Stanton suggests, just have top fins to achieve a more 'friendly' centre of pressure in the descent.
I think its the CG, with the heavy battery up top and no extra thrust from the motor you have not much force and a long lever to push. Top controls and power should work better
Exactly what I was gonna say. Went nose down because of the CG. Then the rear assembly also created a parachute effect that kept the tail up even more. At that point, thrust increases the speed, making it really difficult to pull out of the nose dive.
1. What is the material of the center rod made of? 2. At what angle from the rod are the top 4 thrust motors inclined? 3. What is the rating of the battery and motor used? 4. What is the system used for the turning of flaps according to tilting of the rocket?
Once it starts to fall the cg is in front of the cp so it wants to fall like a dart or regular rocket would. The little motors counteract the aerodynamic instability. you could have some ''folded winglets'' on top so in the ascent everything is cool and when starting to descend they get popped out and will change the center of pressure for it to fall steadily in the same orientation, That's one way you could do without the upper part. You could also do with air brakes on top which would help to slow it down more
What if you extended the thrust motors out for more stability and or added larger props..... also a parachute would be a nice failsafe add on. Could you increase the base frame to make it more stable....... Love the idea of the gimbal motor for the top for thrust vectoring. Maybe you need to look into some DJI hardware for your RTL autoland feature or INAV. Cheers from down under. Keep up the great work.
iNav has the RTH and landing features, I would look into that for the FC control. Pawel (iNav developer) has been working on a similar project, but not for the high altitude and land idea.
Make it so the angle of the top motors thrust is changed. The motors could all run from a single motor controller and same speed, only the angle of the thrust would change. Going up these motors could then fully contribute to the launch and then provide stability on the way down. Reduce 4>3?
Try it with the booster motors there but off completely. it may just be the forward drag helping right it. Or perhaps just put dummy motors there to simulate the weight and drag.
Just a idea! What about a flapping propeller on top which starts to autorotate on the way down ...like helicopters are able to do when the motor stops. This way it may stabilized the rocket in a vertical position and slows down the rate of fall - no motors and servos on top are required. Wish you great success with your project! ...creetings from switzerland, Pete
Also I just had a good idea that will be in the business. One big drone to fly 4 small drones really high then deply them, thus saving the fuel cost of getting the 4 up there
Cool Project. You had a sign error in your control algorithm when you turn off the the thruster at altitude. When the Rocket starts falling, the sign changes, the control fins are working in reverse if you want to keep the rocket vertical. Straight up and Straight down without Pitching or Yawing. I'd suggest when you get to altitude, run your thruster motor in reverse to thrust towards the ground. Sucking the air over your steering vanes and accelerating down, sign changes on your vane control algorithm. Or, you could launch your rocket right side up like you did. Then figure out how to launch your rocket up-side-down to figure out how to control it while sucking the air backwards over the steering vanes. One algorithm for going up, one for going down, while maintaining control. Vertical, pitch and yaw remain the same. Also, having the rotation axis of your steering vanes at the 1/4 chord is good (subsonic flow), consider rotating all steering vanes 180 degrees when in reverse flight. Or moving the rotation axis to the 1/2 chord (supersonic flow, which you will not achieve) and hope the servos can overpower the moments generated by the unstable 1/2 chord steering vanes.
If you don't need the top motors for lift, how about putting them at an angle of 90 deg to the body. That way they would be more efficient at correcting vertical tilt. maybe? Thanks for some really entertaining videos, keep up the good work.
Fantastic job bro well done. Uv got some amount of experts in the comments section. Some who don't even have a video uploaded😅😅😅 never mind the Vids u put up there all top class man. Top of the range🤓💜💜💜
Hey, great video and experiment. I think you may have missed something though. When you flew your mini quad to altitude and shut it down. It tumbled a few times then stabilized in the free fall due to it being heavier at the bottom and draggier (is that even a word?) at the top. In just a few seconds you can hear the rotors spinning up due to ram air on them. This added to the stability through gyroscopic effect of the spinning mass of the rotors and the motors. I'm fairly sure that was the case because you can hear the rotors stop and spin up the other way when you added the power for landing. I dont have the math chops that Tom Stanton has, but I think this could be proven. Tom, I would be happy to hear what you think about this. Also, I believe that you could do away with the motors and all the associated weight at the top of it by designing some downward facing flap-like panels at the top. The slipstream would hold them closed on the way up and they would just flip open when the airflow reverses as the rocket falls. A completely passive system, no elaborate mechanism required. I should note that this will only work as long as your design remains tail heavy. I've been watching you for a long time now and have enjoyed seeing the things you come up with over the years. I actually replicated one of your early designs a number of years ago. It was the "Long Duration" with googly eyes and a 5,000 mA battery on it. Mine had a 10' wing and I flew it with five 2,200 3S packs. I used it to learn FPV. With careful power management and a lot of long glides I could consistently turn in 165 minute flights. On a few occasions, with the help of thermals, I managed flights over 3-1/2 hours. Thanks for all the fun. Keep up the good work.
Needs fins at the top. Not even steerable ones. That should eliminate the need for the thrusters. I say that having built a lot of rubber powered helis like this. Works great.
Have you ever played KSP? Falcon 9 uses deployable grid fins for reason. Deploying the grid fins moves center of aerodynamic drag to other end of the rocket. The same with drag brakes on New Shepard. You only need to implement something like that. There is no use of motors on top if you want to launch to higher altitudes
Why not have the four thruster motors at 90°? Perpendicular to the body. That way it uses the full potential of the horizontal thrust to move that long moment arm back to vertical.
I'm fascinated with battery-powered things that fly. I have a tiny $10. machine that I play with. When I was a boy, I asked my dad if a motor could lift itself with a prop attached and he said it will never happen. This was in '66 and I was playing with high-voltage (90 volt) B batteries I scrounged out of the telephone office trashcans. I had a 12 auto heater motor taped to the end of a yardstick with a 12 in wood prop on the shaft. I held on to the tip of the stick and with a long wire "flew" it out to my dad in the front room. He was not amused.
Would be cool if you could experiment with some "grid fins" to see if you can make it work, kinda like the falcon 9. Probably want to use some flat material and not actual grids though. Also what makes this tricky is that with a rocket, when it's coming down it's used up most of it's fuel so it will be bottom heavy, while when it was going up it was top heavy, but this keeps the same centre of gravity going up and down.
From what I can see without the directional motors on top it wants to nose down, trying to get back vertical using the rear motor is adding energy towards the ground. The trick is to make it naturally want to fall tail down, I think you could do that just fine with a 2-3" section of the rocket body in a ring at the top of the rocket. The drag when the rocket is horizontal will let the tail drop, once that's happened the ring should keep it falling straight. Shouldn't cause much drag going straight up and will be much lighter than the extra 4 motors.
try to add the little stabilizer motors inverted on the bottom, using anhedral of motors instead of dihedral, then they will have more inertia to move around the centre of gravity from the far bottom, because the stream fluids merge, less thrust is lost vs dihedral.
Adding a solid rocket booster first stage would be rad, and relatively easy: add a small tube or 4 to the bottom for hobby-size estes rocket motors. the ejection charge will pop them out after they burn out for reduced weight after the first stage burn. 😀
can you pressurize a centralized chamber with a single brushless. then exhaust that pressure with flaps/ valves/doors in 3,6,9,12 o clock position. if the doors/valves/flaps work properly youll be able to use them as a wind brake and on the opposite side a nose cone thruster. youl also take your weight down by removing 3 motors and three esc's.
Gps gyro system would be the first thing id put on it. Would help with stabilization alot.and having a shell around it to reduce drag which can put it out of balance.
Totally needs booster rocket motors to get it to altitude, then keep going with the props as far as battery will allow. Auto shut down at a certain point. Free fall with guidance directing it back to the landing pad. Then engage the props to slow descent and land. Now that is really cool twist on quadcopters. So where would this fall into in terms of drone height restrictions?
Not sure if anyone mentioned this already, but the bottom vanes are stabilizing for downward thrust: when you start falling all the controls become reversed. Can you reverse control output in flight and try again?
Why don't you try to use a servo for the 4 little motors which moves them to 45 degree after take off? Like this you would have 90 degrees for take off and 45 degrees for landing!?
Now something like that could really spark a renewed interest in model rocketry. That was amazing. Sadly though, that type of vehicle would have to conform to the 400’ rule and registration as it weighs more than .55lbs. Funny how you can launch even a large model rocket as high as you want with absolutely no control over it and it’s perfectly legal.
Eeeeeeeeeeeeeeeeeee BOOM 😂 That worked much better without the fuselage! I'm assuming it struggled to recover from the dive because the thrust vector fins at the bottom turned it into a dart. Maybe some folding fins at the top could move the centre of pressure towards the nose and reduce this? Just a thought, as it could possibly remove the need for the top motors. I wonder how high something like this could go, just shows how energy dense lipos are nowadays!
Tom Stanton REEEEEEEEEEEEEEEEEE HITS GROUND DIES
AWESOME!! I was thinking the same thing as Tom. Have passive folding fins at the top that will deploy when it is falling and automatically retract when it is in hover.
Exactly. There's a reason SpaceX rockets have grid fins at the top
You need more subs tom
I don't think the fins would need to fold. Experiment with size until the centre of pressure results in the rocket free-falling at your desired attitude. For the rest of the operation, they would have little or no effect.
A single servo making flaps pop out at the top for enough resistance to stabilize would be just as effective as all that is currently at the top.
Now that's a interesting thought!!
correction for resistance: drag
@@xaspar3011 No correction needed. I used the word resistance for a reason. Drag would not be something referred to as actively varying the amount of, but changing based on velocity. Whereas resistance is a better word as it indicates a changing variable say from a servo. Like a variable resistance device called a potentiometer. 0 to whatever. Please dont try to senselessly overcorrect people.
Yes, like a canard
RCWeaven FPV sorry for that then:)
The fact that you got it flying and so stable is a real surprise. Congratulations and great job. It was so stable.
The „parachute“ effect of the top motors could probably be achieved with some aerodynamic resistance at the top only
Herbert Piereder yes, I was thinking a small nose cone would work well as a parachute as well as not affecting take off velocity too much.
I was thinking nose cone as well
I wonder if a small parachute could provide a parachute effect. /S
but really I think it could be done.
Collapsible grid fins?
Those props at the top are auto-rotating (like a helicopter in an emergency) on the way down. It's providing enough drag to help it stabilize.
The scene at 4:51 looks JUST like a Falcon 9 coming in. Same AOA and trajectory!
Hover snow plane , solar plane , long distance Skyhunter crash and recover / discover some history ...and now rocket quad , truly enjoy your channel , keep it up. 👍
Fantastic set of experiments. Fascinating!
Great Experiment!! That was very well done. Thanks for sharing!!
Simplify the design. Install a nose with an open base to create drag (parachute effect) on free fall causing the rocket to have the highest proponent of drag at the top & the heaviest section at the bottom.
Use a small parachute to stabilize it during descent.
I'm really enjoying the evolution of this project and can't wait to see what you do in the next video.
Thanks for sharing and as always Keep Building👍
Where are the gridfins?
No don't use gridfins but normal fins on the top. Gridfins won't realy work well at that scale
Edit:
What about drag brakes like on blue origins new shepard
Even a nose cone up top without a body would be like a one way airbrake.
Copying new shepherd would be cool to see.
Stratos2 - no videos here.
Try putting a foam nose cone on the top to act as a parachute to keep the rocket upright when descending.
MrDabrudda makes sense while it’s coming down the cone would make enough drag catching all that air that it going to help it get upright.
Nice man. I'm glad you do this so I can live vicariously through you
Congrats on success with this version! Love the vids brother, keep them coming!!!!
I’m doing something similar with a rocket team of mine. In high powered rocket launches you get more points at competitions if you land closer to the launch pad. So we’re developing a nose cone that separates itself from the body, folds out into a quad, and then lands itself all with GPS at the pad.
Looked to me like the high position of the battery in the first test put the cg too high for the thrust vector fins to compensate. Maybe if the battery was lower like in the second test, there were some static fins mid-way up to help stabilise, and a smallish nosecone at the top to give some drag on the way down?
Other people have mentioned, but when in free all your airflow over the control vanes is reversed, so they're having the opposite effect than the flight controller is trying to do
You could possibly just have the actuation taper down to zero at zero motor speed, and rely on your top mounted motor(s) only. And/or have fins fold out with reverse airflow to act as control surfaces
That was rad Daniel! Well Done!
Can't wait to see the gimbal setup. Seems like you might need a lot of servo throw or something...
Awesome. Excited how high it can go!
That quad sounded so old school, love it!
center of drag most be higher on the rocket (over the center of mass) so it falls straight, specex dose it by useing grid fins
It creates a floating pendulum essentially. You used the weight of the bottom to swing the momentum down and the blades dampened it perfectly and made a perfect like,
imagine playing with POY, and while in the arch youre doing you stop and use ur right hand (the fans) and dampen on your way to the bottom of the circle with the poy and you can stop it just like he did
The problem is very fixable and it's with your gyro!!!! I know why the fall tends to get out of control, when u fly up, the fins on the bottom work perfectly, but when you starting falling they are pushing the air in the opposite direction causing the plane to inevitably turn upside down as it's controlling the fins opposite of what the gyro is intending to do creating an unstable decent. You can see this in the free fall especially the one with the catastrophic failure(1:20) and once it flips the gyro works as intended. You can also see it here(4:33) with the "RCS thrusters" counteracting the fins as much as possible. To counteract this you could use some type of velocity chip that can tell what direction (and possibly what acceleration as a bonus for other hardware/software) the rocket is moving and can flip gyro controls if going down. Or a more temp solution is for you to have a switch on the remote that once switched the outputs of the gyro could be flipped, possibly even adding a servo to the gyro and flipping the whole gyro with the switch as another temp solution(if that would even work).
Yes, i was thinking the same thing. By inverting the fin control it might be possible to stabilize the rocket while falling down. But as you said, changing from falling mode to hover/ascent mode will be tricky and needs some experimentation :D
Also, i dont think that adding some weights somewhere or some fins at the top will be the best solution. I mean, the fun part about this project is to control an unstable system, instead of just stabilizing it with even more weight - SpaceX certainly would want to save as much weight and air resistance as possible
Ya I contacted him and this was his reply, "
It is true that the control fins would have the inverse effect if the rocket were falling down vertically, nose up. However, the rocket falls horizontally so the fins do not have any control authority. It is beneficial to fall horizontally because it has more drag and will fall slower than if it were vertical.
"
So it sounds like he's trying to recreate the SpaceX's starship design a bit, but staying horizontal with only tail fins would be impossible as the drag in the rear would turn the front down again causing the catastrophic failure. He'll need to also add fins at the top just like the starship design so that it could turn into an airplane almost flight with a massive steep fall down instead of forward. Just like the Space shuttle landing but more steep.
@@nicholascarr6251 Okay, that makes sense now. Some fins on top would be needed. I guess you could also use the vectoring fins for stabilizing it in a horizontal position if you add some motor thrust, but this would add a lot of ground speed aswell, which might be not that great.
Anyway, great project :D It gets more difficult the more you think about it. I am curious what he will come up with
Nice 👌👍😀 very nicely done!! Your goals are admirable and definitely manageable. You will complete everything this year 2019.
If you just expect it to hover down after it reaches the desired altitude, you should attach a remote parachute deployer on the top, just small enough to keep it upright.
I think the holes on the body tube for the thruster motors we're causing the drag needed to keep the nose up and stabelize
thats a GORGEOUS PROJECT !
Why not install something like grid fins in place of the top motors that guide it in free fall so that it stays vertical while falling.
You could try some canards in place of the little thruster motors to save power and weight
I think the biggest problem with the first version in the video wasn't the lack of the extra motors up top, but maybe mostly due to the bottom acting as the tail to a dart and adding too much lift and foliage to the "back", keeping it falling face first.
It seems like it's top heavy. It will tend to flip. If you made it bottom heavy, the weight would help to stabilize it(point the bottom towards the ground).
Your videos are awesome! I don't think that you need the micro-quad on the top of the rocket, just some fins on the nose to move the center of pressure forward.
Great work. keep it going!
Turns out I can hold my breath for bout 7 min 16 !
Great video
Very impressive,you can do it perfectly,don't give up,if your mind says you can do it....it will happen,just belive....nice work man....
Looking forward to the next rendition
An alternative to thrust vectoring the top motor would be to duplicate what you already have at the bottom with the moving fins, perhaps in a different size. Or, as Tom Stanton suggests, just have top fins to achieve a more 'friendly' centre of pressure in the descent.
Grid fins up top mate. At least the freefall will be somewhat controlled then.
Argus FPV grid fins are incredibly ineffective at small scales
I think its the CG, with the heavy battery up top and no extra thrust from the motor you have not much force and a long lever to push. Top controls and power should work better
Exactly what I was gonna say. Went nose down because of the CG. Then the rear assembly also created a parachute effect that kept the tail up even more. At that point, thrust increases the speed, making it really difficult to pull out of the nose dive.
1. What is the material of the center rod made of?
2. At what angle from the rod are the top 4 thrust motors inclined?
3. What is the rating of the battery and motor used?
4. What is the system used for the turning of flaps according to tilting of the rocket?
Needs some drag at the top on the way down to orient it back vertical great to see it work
Once it starts to fall the cg is in front of the cp so it wants to fall like a dart or regular rocket would. The little motors counteract the aerodynamic instability. you could have some ''folded winglets'' on top so in the ascent everything is cool and when starting to descend they get popped out and will change the center of pressure for it to fall steadily in the same orientation, That's one way you could do without the upper part. You could also do with air brakes on top which would help to slow it down more
What if you extended the thrust motors out for more stability and or added larger props..... also a parachute would be a nice failsafe add on. Could you increase the base frame to make it more stable....... Love the idea of the gimbal motor for the top for thrust vectoring. Maybe you need to look into some DJI hardware for your RTL autoland feature or INAV. Cheers from down under. Keep up the great work.
maybe a morphing umbrella thing near the top to help get out of a free fall
That diy radio box looks Interesting👍
A parachute that opens automatically would help a lot. good Job!
iNav has the RTH and landing features, I would look into that for the FC control. Pawel (iNav developer) has been working on a similar project, but not for the high altitude and land idea.
Add some grid fins!! The drag at the top of the rocket will stabilize it and you can just use the bottom motor for control.
Make it so the angle of the top motors thrust is changed. The motors could all run from a single motor controller and same speed, only the angle of the thrust would change. Going up these motors could then fully contribute to the launch and then provide stability on the way down. Reduce 4>3?
Try it with the booster motors there but off completely. it may just be the forward drag helping right it. Or perhaps just put dummy motors there to simulate the weight and drag.
Just a idea! What about a flapping propeller on top which starts to autorotate on the way down ...like helicopters are able to do when the motor stops. This way it may stabilized the rocket in a vertical position and slows down the rate of fall - no motors and servos on top are required.
Wish you great success with your project!
...creetings from switzerland, Pete
I'm glad the top stabilizing props worked you should give them ducts in the encased rocekt
Rocket
Also I just had a good idea that will be in the business. One big drone to fly 4 small drones really high then deply them, thus saving the fuel cost of getting the 4 up there
NO WAY!!! I JUST CAME UPON THIS VIDEO BY CHANCE!!! AWESOME!!!
Cool Project. You had a sign error in your control algorithm when you turn off the the thruster at altitude. When the Rocket starts falling, the sign changes, the control fins are working in reverse if you want to keep the rocket vertical. Straight up and Straight down without Pitching or Yawing. I'd suggest when you get to altitude, run your thruster motor in reverse to thrust towards the ground. Sucking the air over your steering vanes and accelerating down, sign changes on your vane control algorithm. Or, you could launch your rocket right side up like you did. Then figure out how to launch your rocket up-side-down to figure out how to control it while sucking the air backwards over the steering vanes. One algorithm for going up, one for going down, while maintaining control. Vertical, pitch and yaw remain the same. Also, having the rotation axis of your steering vanes at the 1/4 chord is good (subsonic flow), consider rotating all steering vanes 180 degrees when in reverse flight. Or moving the rotation axis to the 1/2 chord (supersonic flow, which you will not achieve) and hope the servos can overpower the moments generated by the unstable 1/2 chord steering vanes.
How about adding a small drogue chute to bring the rocket upright when free falling?
grid fins, or some form of fins on the top would be awesome.
If you don't need the top motors for lift, how about putting them at an angle of 90 deg to the body. That way they would be more efficient at correcting vertical tilt. maybe? Thanks for some really entertaining videos, keep up the good work.
Fantastic job bro well done.
Uv got some amount of experts in the comments section. Some who don't even have a video uploaded😅😅😅 never mind the Vids u put up there all top class man. Top of the range🤓💜💜💜
The rocket needs clear wings and two motors. Either front and rear, or on the wings for yaw control.
Hey, great video and experiment. I think you may have missed something though. When you flew your mini quad to altitude and shut it down. It tumbled a few times then stabilized in the free fall due to it being heavier at the bottom and draggier (is that even a word?) at the top. In just a few seconds you can hear the rotors spinning up due to ram air on them. This added to the stability through gyroscopic effect of the spinning mass of the rotors and the motors. I'm fairly sure that was the case because you can hear the rotors stop and spin up the other way when you added the power for landing. I dont have the math chops that Tom Stanton has, but I think this could be proven. Tom, I would be happy to hear what you think about this.
Also, I believe that you could do away with the motors and all the associated weight at the top of it by designing some downward facing flap-like panels at the top. The slipstream would hold them closed on the way up and they would just flip open when the airflow reverses as the rocket falls. A completely passive system, no elaborate mechanism required. I should note that this will only work as long as your design remains tail heavy.
I've been watching you for a long time now and have enjoyed seeing the things you come up with over the years. I actually replicated one of your early designs a number of years ago. It was the "Long Duration" with googly eyes and a 5,000 mA battery on it. Mine had a 10' wing and I flew it with five 2,200 3S packs. I used it to learn FPV. With careful power management and a lot of long glides I could consistently turn in 165 minute flights. On a few occasions, with the help of thermals, I managed flights over 3-1/2 hours. Thanks for all the fun.
Keep up the good work.
Needs fins at the top. Not even steerable ones. That should eliminate the need for the thrusters. I say that having built a lot of rubber powered helis like this. Works great.
Have you ever played KSP?
Falcon 9 uses deployable grid fins for reason. Deploying the grid fins moves center of aerodynamic drag to other end of the rocket. The same with drag brakes on New Shepard. You only need to implement something like that. There is no use of motors on top if you want to launch to higher altitudes
Really interesting content! Thank you!
Why not have the four thruster motors at 90°? Perpendicular to the body. That way it uses the full potential of the horizontal thrust to move that long moment arm back to vertical.
I'm fascinated with battery-powered things that fly. I have a tiny $10. machine that I play with. When I was a boy, I asked my dad if a motor could lift itself with a prop attached and he said it will never happen. This was in '66 and I was playing with high-voltage (90 volt) B batteries I scrounged out of the telephone office trashcans. I had a 12 auto heater motor taped to the end of a yardstick with a 12 in wood prop on the shaft. I held on to the tip of the stick and with a long wire "flew" it out to my dad in the front room. He was not amused.
You should totally use that to launch a second stage. Thats dope af
Why not shift the center of mass down so it won’t fall over once the motor is turned off?
Would be cool if you could experiment with some "grid fins" to see if you can make it work, kinda like the falcon 9. Probably want to use some flat material and not actual grids though. Also what makes this tricky is that with a rocket, when it's coming down it's used up most of it's fuel so it will be bottom heavy, while when it was going up it was top heavy, but this keeps the same centre of gravity going up and down.
From what I can see without the directional motors on top it wants to nose down, trying to get back vertical using the rear motor is adding energy towards the ground. The trick is to make it naturally want to fall tail down, I think you could do that just fine with a 2-3" section of the rocket body in a ring at the top of the rocket. The drag when the rocket is horizontal will let the tail drop, once that's happened the ring should keep it falling straight. Shouldn't cause much drag going straight up and will be much lighter than the extra 4 motors.
NICE... glad you got it going again
You need a way to hold the rocket vertical while falling, that way you only need one motor and it will recover and arrest the descent just fine.
you might need some drag fins at the top or a drag ring like Blue Origin so it can self orient when decending
Very creative experiment !
YOU FORGOT SOMETHING.. How about inverting the deflection of the control-surfaces when the vehicle moves backwards (negative acceleration)?!
When it moves backwards and the throttle is cut
Do a mount like an umbrella for the top motors with a mode for freefall and lifting with a servo pushing in the middle :-)
Try adding hobby rocket motors to assist its ascent and really get that thing up there
With a PCA9685 board and Inav 2.0 you can have 16 individually assignable pwm outputs.
why not duplicating bottom system at the top as well?
way more better without the body
awesome one dude cant wait for next video of this
I am using one bldc motor how to stop rotating it
Don't you have too small a base for landing?
Why not just use fins on top and no motor on top?
try to add the little stabilizer motors inverted on the bottom, using anhedral of motors instead of dihedral, then they will have more inertia to move around the centre of gravity from the far bottom, because the stream fluids merge, less thrust is lost vs dihedral.
Adding a solid rocket booster first stage would be rad, and relatively easy: add a small tube or 4 to the bottom for hobby-size estes rocket motors. the ejection charge will pop them out after they burn out for reduced weight after the first stage burn. 😀
Use kinards! It would be similar to the falcon 9's grid fins.
Maybe try to put more four fins at the top with gyro, without prop and keep the fins little big
What about tubing on the side of the rocket so you will have blowing air from them to get stability?
Always enjoy your vids!!
can you pressurize a centralized chamber with a single brushless. then exhaust that pressure with flaps/ valves/doors in 3,6,9,12 o clock position. if the doors/valves/flaps work properly youll be able to use them as a wind brake and on the opposite side a nose cone thruster. youl also take your weight down by removing 3 motors and three esc's.
When it descends isn't it acting like a reverse missile? Fins or a collar fuselage at the top?
Gps gyro system would be the first thing id put on it. Would help with stabilization alot.and having a shell around it to reduce drag which can put it out of balance.
Do you have any DIY videos on building drones or rockets? This is awesome!
Totally needs booster rocket motors to get it to altitude, then keep going with the props as far as battery will allow. Auto shut down at a certain point. Free fall with guidance directing it back to the landing pad. Then engage the props to slow descent and land. Now that is really cool twist on quadcopters.
So where would this fall into in terms of drone height restrictions?
Not sure if anyone mentioned this already, but the bottom vanes are stabilizing for downward thrust: when you start falling all the controls become reversed. Can you reverse control output in flight and try again?
Why don't you try to use a servo for the 4 little motors which moves them to 45 degree after take off? Like this you would have 90 degrees for take off and 45 degrees for landing!?
Now something like that could really spark a renewed interest in model rocketry. That was amazing. Sadly though, that type of vehicle would have to conform to the 400’ rule and registration as it weighs more than .55lbs. Funny how you can launch even a large model rocket as high as you want with absolutely no control over it and it’s perfectly legal.
I am interested to build this one...
Seems like you need better high torque servos. When it was falling you could see the servos having a hard time