I think you need to know video edditing just right... because i can understand after the boosters you hear the wind so loudly... For people to love it without thinking this is a boring video it's hard.

MynameisJeff id rather hear wind noises then some cringey music covering up the sounds of the flight

Thank you for your nice comment. If you like please have a look at this rocket launch this summer where I used delayed ejection of the 1st and 2nd stages parachutes: kzfaq.info/get/bejne/gLOhZceIxLyYpas.html The reason for delayed ejection of parachutes of the 1st stage is to eliminate danger of damage of parachutes shroud lines if in contact with hot nozzles of the 1st stage rocket engines - because the 1st stage is unstable after separation and experiences fast arbitrary transverse rotation immediately after separation. The reason for delayed ejection of parachutes of the 2nd stage is to extend stable ballistic flight of the 2nd stage after its separation in order to catch attractive recording of in-flight ignition of the 3rd stage rocket engines by the camera attached to the 2nd stage and facing up: kzfaq.info/get/bejne/gLOhZceIxLyYpas.html?t=40 Some flights of my other multistage rockets possibly of your interest - enjoy: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/hN1nf8lyuJ3Tm2w.html kzfaq.info/get/bejne/oal8ldub29Soh3k.html

What a really nice thing to say.

Thank you and Happy Easter wishes from Moravia. If you like to have a look - here are my other multistage rocket models: 2 stage rocket HERKULES: kzfaq.info/get/bejne/epxmq650va-5e3U.html kzfaq.info/get/bejne/q9NndtdesJibf2w.html 2(+1) stage rocket HARPOON: kzfaq.info/get/bejne/oal8ldub29Soh3k.html 3 stage rocket SKYROS 3: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html

Gracias. Feliz Pascua para ti también

I like this rc flying field a lot - all infrastructure available for comfortable even several days stay. As far as I know this airfield was built by several local rc model airplanes enthusiasts together with local entrepreneur financing it. The entrepreneur is fond of rc models as well of course. I like beautiful countryside around it. On-board video flight recordings from this airfield look much more interesting than just flying somewhere in farm fields. It's a pity it is a long drive for me to get there.

During this annual meeting of local High power rocket enthusiasts three other large rockets were completely lost in the surrounding bushes and forests - due to rather stronger wind. I tried to compensate for the wind drift during parachute descend and inclined the rocket at launch pad slightly towards the wind direction. I had good luck and all stages landed back to airfield - but as you could see in the video the third stage landed just on the edge of the airfield only a couple feet from bushes and forest. So far I temporarily lost during a windy day 3 years ago the 2nd and 3rd stage of the rocket model SKYROS 3 - it happened because of wind drift and they landing too far from the launch pad. That launch was just at about sunset and I did not have enough time for search. I found the lost stages next day morning. In order to eliminate the wind drift it is common technique the large rocket models have often so called dual deployment of parachutes. But I am not using it yet at my rocket models.

same :)

There is not any active on-board stabilizer system - only the passive stabilization. The primary function of gyro-vertical is to initiate deployment of rocket recovery system in apogee. Another important flight safety function is emergency switch-off of all rocket engines ignition in 2nd and 3rd stage and ejection of payload with on board batteries if the rocket axes is more than 50 degrees out of vertical. My rather simple gyro-vertical device as built at the moment is not able to control or stabilize rocket flight direction. It is often difficult to eliminate rotation of usually faster upper stage of the rocket model in case of its passive stabilization by fins. Larger 3rd stage fins will reduce passive stability of the rocket flight in vertical direction especially immediately after launch when all three stages fly together. So increase in size of 3rd stage fins will require size increase of 1st stage and probably also 2nd stage fins. By the way the same scenario of 3rd stage rotation happened to my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html Miraculously stable was the following launch of my 2 stage rocket: kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html But it was just a good luck all aerodynamic and rocket motors jet propulsion forces were perfectly balanced regarding the rocket body rotation. Usually during other flights there is some small rotation present almost always. I am now working on gyro-stabilized rotation prevention system which will be flight tested next year - the only reason of using it will be to get more realistic recordings from on-board cameras.

Thank you for watching. If you like here you can have a look at my latest 3-stage model rocket DELTA IV HEAVY Parker Solar Probe: kzfaq.info/get/bejne/eruXo65zxL-8mWg.html Or several years old Little Joe I with fully functional rescue tower: kzfaq.info/get/bejne/eNKVftyVqt-5hIU.html However my the most crazy project was and still is SPACEX FALCON 9 CREW DRAGON: kzfaq.info/get/bejne/i9ekeaZz1cqxp5c.html

I slightly increased the voltage of power supply to get faster start of heavier flywheel and get higher RPM. The challenging can always be to properly balance the flywheel and gimbals. Simple contacts are used as switches to send the signal from gimbals. Other than that there are only two LED lights - one indicate the power supply and the second indicates the signal from gimbals contacts - just for easier testing of gyro-vertical unit. Some work in progress photos of 2 stage rocket HERKULES: kzfaq.info/get/bejne/epxmq650va-5e3U.html So far none of my 4 units of gyro-verticals failed - installed in 4 different multistage rockets and all units based on cooling-fan. However there is no need for long operation - the gyro-vertical is always switched on only about 30s prior to rocket launch and the active flight takes only max cca 15s. Therefore the cooling-fan electronics and bearings needs to work only about 45s/launch. I was more afraid of overheating by sun shine in hot weather as the gyro-vertical is just below the transparent cone of the rocket tip - but so far everything went out fine.

Petr Pavlík → Roger all that. Thank You!

I built the gyro in my home workshop. Actually I do not have detailed plans - I built/developed the gyro unit just using rather simple sketches and more or less by trial and error in my hobby workshop. Any person skilled in fine mechanics and electronics can built it. So far I built 4 slightly different gyro-vertical units, one smaller then this unit and two slightly bigger. The smallest I built for the three stage rocket SKYROS 3: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html where I used DC micro motor running vibration unit of very old NOKIA cellphone - just replaced the eccentric vibration wheel with much larger and balanced flywheel of gyro. For the rocket ROSON I used cooler fan SUNON MC25060V2-A99. Is it easy to pull out the rotor with blades, cut off all blades and slide on the rotor new brass flywheel ring secured by Second Fix glue. The electronics is very simple and processing of the signal from gyro-vertical unit is by simple switch modules using electronic components like TYRISTOR and MOSFET, and simple ignition delay electronic units. I am as a profession mechanical engineer therefore my electronic schemes are at the moment almost not publishable as they always present some kind of compromise regarding both the electronics circuit design and level of documentation because I design, build and test them our self. The only advanced electronics is the electronics already present in small cooling fans to run brush-less motor of the fun/flywheel - but this electronics is already present there as originally purchased and I am not modifying it anyhow. I only slightly increase the voltage of power supply to get faster start up of heavier flywheel and get higher nominal RPM. Supply voltage is increased from nominal 5 V to 8 V. The challenging can always be to properly balance the flywheel and gimbals. Simple contacts are used as switches to send the signal from gimbals. Other than that there are only two LED lights - one indicate the power supply and the second indicates the signal from gimbals contacts - just for easier testing of gyro-vertical unit. I already published some work in progress photos of 2 stage rocket HERKULES at about T 6:30 here: kzfaq.info/get/bejne/epxmq650va-5e3U.html

Lift-off weight is about 3.2 kg (=7.1 lb) as listed on the initial pages of the video. Rocket body is just layered paper tube partially strengthened on inner radius with plywood partitions and wood beams nad lacquer and also lacquer and paint on outer radius. Wings are sandwich - Styrofoam and fiber glass composite. It is rather small rocket though belongs to the class of high power rockets. (For more powerful rockets composite pipes are necessary for rocket bodies to withstand the higher flight dynamic loading at speeds close to sound speed or above.) Some of my similar design multistage rockets you can see here: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/gLOhZceIxLyYpas.html kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/oal8ldub29Soh3k.html

From about 11:22 there is a series of detailed photos with description. I use nylon line to bind the stages together and rubber band driven piston to separate burned booster and eject its parachute container. Small delay between booster separation and next rocket motor ignition is necessary not to damage jettisoned booster. However I am not aware if anybody else uses similar principle. For rockets with side boosters I use the following concept: There are two short steel hooks facing up at the bottom of each booster - they engage with the holes in beams at the bottom of rocket body tube. These hooks allow the booster only to rotate out of the rocket body tube or going downwards. The booster will not go down until the pin perpendicular to the rocket body tube located in the upper part of the booster engage with the hole in the rocket body. The trust the booster is not carried out by these steel hooks as they they are not strong enough. The booster thrust is carried out to the bottom of the rocket body tube by small push plate and partially by the wooden pin perpendicular to the rocket body tube. The boosters are hold in place again by nylon line. More details here: kzfaq.info/get/bejne/q9NndtdesJibf2w.html&spfreload=10 kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html

I'm not doubting that the Earth is round but that was just the fisheye effect...

It is often difficult to eliminate rotation of usually faster upper stage of the rocket model in case of its passive stabilization by fins. Larger 3rd stage fins will reduce passive stability of the rocket flight in vertical direction especially immediately after launch when all three stages fly together. So increase in size of 3rd stage fins will require size increase of 1st stage and probably also 2nd stage fins. By the way the same scenario of 3rd stage rotation happened to my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html In case of not using the on-board camera it is often desirable to get some rotation immediately after rocket model launch since the rotation of the rocket increases overal flight stability.

You are referring to FAA regulations 101(kites/balloons/rockets) There is no altitude restriction mentioned. There are however, restrictions on weight and propellant quantity. § 101.22 Definitions. The following definitions apply to this subpart: (a) Class 1 - Model Rocket means an amateur rocket that: (1) Uses no more than 125 grams (4.4 ounces) of propellant; (2) Uses a slow-burning propellant; (3) Is made of paper, wood, or breakable plastic; (4) Contains no substantial metal parts; and (5) Weighs no more than 1,500 grams (53 ounces), including the propellant. (b) Class 2 - High-Power Rocket means an amateur rocket other than a model rocket that is propelled by a motor or motors having a combined total impulse of 40,960 Newton-seconds (9,208 pound-seconds) or less. (c) Class 3 - Advanced High-Power Rocket means an amateur rocket other than a model rocket or high-power rocket.

Transparent nose cone is made from thermoforming material VIVAK. It is usually available in sheets in various thickness at RC plane hobby shops as iy is often used for RC plane cabins of model mockups. VIVAK sheets are suitable for thermoforming between temperatures 120 to 160 DegC. I am using positive template/hoof made from wood on turning lathe. Over the nose cone template I stretch the sheet of VIVAK sheet clamped/stretched in a frame and carefully preheated in kitchen oven. In case you are not familiar with this process I recommend you consult some RC mockup plane builder or try to find the process details or hobby recommendations on KZfaq. I used the same technology/process/material for nose cones of the following rocket models: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/oal8ldub29Soh3k.html For the following rocket model nose cone I used egg shaped plastic package from some big chocolate Easter egg, however it is not so durable as custom made VIVAK sheet nose cone so it already experienced several cracks by accidental collisions witch happened in flight in air after main parachutes ejection - smaller or bigger collision can sometimes happen between rocket 2nd stage and payload/e-bay section with nosecone: kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/nKpkaKynv7_Jpmw.html kzfaq.info/get/bejne/hN1nf8lyuJ3Tm2w.html

To get slow motion video smooth enough in playback it is necessary to use camera with higher fps (speed of recording in frames per second). I used used camera with recording speed 60 fps. When playing such video recording in 1/2 slow-mo the quality is perfect, and when in 1/4 slow-mo the smoothness of video playback is still of acceptable quality. Some flights of my other multistage rockets possibly of your interest - enjoy: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/hN1nf8lyuJ3Tm2w.html kzfaq.info/get/bejne/oal8ldub29Soh3k.html

I guess you asked about on-board flight recording cameras: Master on-board camera on top of third stage pointed downwards and second on-board camera mounted on the second stage and pointed upwards are action camera type "RePLAY XD 1080 mini". I purchased them about 5 years ago in USA. I still use them on other model rockets however they are now getting old and so the batteries are getting weak. But when I tried to order additional new of the same brand last year in Europe I was very disappointed - I received the camera of the same name nad looking exactly identical but heavier, much bigger size and with poor software, and basically almost useless. Some resellers/camera owners are still selling old original used RePLAY XD 1080 mini for about the triple of their original price - and these are very good. The auxiliary side view camera is miniature camera MD80, which however does not provide any good video quality - this camera I purchased about 7 years ago, but never happy with it.

The rocket lift-off weight is listed at the beginning of the video - at the bottom right. However correct value of lift-off weight is 3 1/2 kg. (3 1/5 kg is just misprint). In case you are interested in multistage rockets please have a look at my channel to see some more. Some of the rocket models are exceptional regarding model rocketry and worth and attractive to see. Thank you for watching.

The system of stages separation is described in video at about T11:27. I am using mechanical system of stages jettison. 1st stage separation: The separation initiation is by heat-cutting nylon fishing line. After the fishing line breaks 1st stage is pushed down from 2nd stage by styrofoam piston driven by 4 rubber bands. When the piston inside 1st stage starts moving up it also deploys cylinder container 1st stage parachutes. The same principle is used for 2nd stage separation and also for 3rd stage main parachute and payload deployment. 1st and 2nd stage separation is started by signal from small and simple akcelerometr. 3rd stage main parachutes deployment it is initiated by signal from electro-mechanical gyro-vertical when 3rd stage axes reaches horizontal position at apogee. This system of deployment works fine and reliable for "small" and "slow" rockets. It will probably not work for rocket model reaching supersonic speed of flight. My rocket models reach maximum speed of about 1/4 to 1/3 of supersonic speed. If you like have a look at my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html or 2 stage rockets: kzfaq.info/get/bejne/epxmq650va-5e3U.html kzfaq.info/get/bejne/q9NndtdesJibf2w.html and 2 and 1/2 stage rocket: kzfaq.info/get/bejne/oal8ldub29Soh3k.html For boosters jettison I use preloaded bamboo spring. Each booster is connected to the upper stage by two small steel hooks at the bottom and by wooden pin perpendicular to the rocket axes in about the middle of the booster length. The booster is pushed out to the side by preloaded bamboo spring and hold in place by nylon fishing line. The bamboo spring is part of the booster body and is partially hidden inside the booster. Booster separation is initiated by deceleration sensor which switches on simple electric circuit and heats up small resistance coil which in a fraction of second burns/cuts the nylon line. The parachute inside each booster is located just behind the nose cone and it is self-ejected during the booster rotation at the time of booster separation. The system of booster jettison and recovery is simple and very reliable.

Rocket body tube is just layered paper tube partially strengthened on inner radius with plywood partitions and wood beams nad lacquer and also lacquer and paint on outer radius. Wings are sandwich - Styrofoam and fiber glass composite - just standard airplane/rocket model building technology. It is rather small rocket though belongs to the class of high power rockets. Only the rocket engines are commercially available but they are tuned by custom machine turned copper nozzles and custom attachment brackets. Transparent nose cone is made from thermoforming material VIVAK. For high altitude rocket and high speed rocket - composite pipes - fiberglass, carbon fibre or light metal alloy body tube is probably more appropriate to withstand the higher flight dynamic loading at speeds close to sound speed or above. Some material ready for assembly of the rocket is in photos at the end of the following video of launch of my older 2 stage rocket: kzfaq.info/get/bejne/epxmq650va-5e3U.html

I just watched the video all the way to the end: *IT IS A FLOWFORM KITE.* You are my new hero. -- RocKITEman ;~)°

The red object is big kite at about 30m to 40m above the ground - somebody just parked the kite there to show the wind direction. You can also see the kite at 0:38 begining to appear above the runway in the camera view at the top - right of the screen.

Petr Pavlík → I *did not* previously notice it at 0:38. You are *correct* , there it is! :~)°

The sound barrier is too far from the technical possibilities of let's say almost classical paper and wood rocket model (a little bit of epoxy and fiberglass as well to be correct, ...). To your surprise the priorities of this rocket model are almost opposite in order to demonstrate/resemble the launch of true rocket spacecraft on rather small airfield: Fly as slow as possible to be able to follow the rocket staging and as low as possible to be able to see comfortably the whole rocket flight trajectory by naked eye - important for viewers around the launch pad. And last but not least to eliminate rocket recovery issues and to comply with flight safety restrictions. However there are other rocketeers which rocket models fly twice the speed of the sound and go to the altitudes on the edge of the true universe. But it requires very different skill set, different rocket motor and different rocket design - usually large restricted access airfield/rocket test area is necessary as well from legislation/safety reasons.

Types of cameras used are written in the following videorecording: kzfaq.info/get/bejne/qZ99iJNqmbvSk2Q.html Most useful is small size, small cross section and small weight mini-camera: REPLAY XD 80 MINI set for 60 fps therefore slow motion up to about 1/4 of normal speed is still of good quality for viewing.

There is not any active on-board stabilizer system - only the passive stabilization. The primary function of gyro-vertical is to initiate deployment of rocket recovery system in apogee. Another important flight safety function is emergency switch-off of all rocket engines ignition in 2nd and 3rd stage and ejection of payload with on board batteries if the rocket axes is more than 50 degrees out of vertical. My rather simple gyro-vertical device as built at the moment is not able to control or stabilize rocket flight direction. It is often difficult to eliminate rotation of usually faster upper stage of the rocket model in case of its passive stabilization by fins. Larger 3rd stage fins will reduce passive stability of the rocket flight in vertical direction especially immediately after launch when all three stages fly together. So increase in size of 3rd stage fins will require size increase of 1st stage and probably also 2nd stage fins. By the way the same scenario of 3rd stage rotation happened to my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html Miraculously stable was the following launch of my 2 stage rocket: kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html But it was just a good luck all aerodynamic and rocket motors jet propulsion forces were perfectly balanced regarding the rocket body rotation. Usually during other flights there is some small rotation present almost always. Additional active electronic model airplane RC gyro-stabilized rotation prevention system I use in latest model rockets - the only reason of using it is to get more realistic recordings from on-board cameras: kzfaq.info/get/bejne/eruXo65zxL-8mWg.html But for flight safety I still use simple electro-mechanical gyro-vertical for all of my model rockets.

@@pavlikpetr2010 Thankyouuu soo much!!!! for clarifying concept in depth 😀💟

Yes, it is. Small RC model airplane flying field in north Bohemia between towns Ústí nad Labem and Teplice.

The system of stages separation is described in video at about T11:27. I am using mechanical system of stages jettison. 1st stage separation: The separation initiation is by heat-cutting nylon fishing line. After the fishing line breaks 1st stage is pushed down from 2nd stage by styrofoam piston driven by 4 rubber bands. When the piston inside 1st stage starts moving up it also deploys cylinder container 1st stage parachutes. The same principle is used for 2nd stage separation and also for 3rd stage main parachute and payload deployment. 1st and 2nd stage separation is started by signal from small and simple akcelerometr. 3rd stage main parachutes deployment it is initiated by signal from electro-mechanical gyro-vertical when 3rd stage axes reaches horizontal position at apogee. This system of deployment works fine and reliable for "small" and "slow" rockets. It will probably not work for rocket model reaching supersonic speed of flight. My rocket models reach maximum speed of about 1/4 to 1/3 of supersonic speed. If you like have a look at my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html or 2 stage rockets: kzfaq.info/get/bejne/epxmq650va-5e3U.html kzfaq.info/get/bejne/q9NndtdesJibf2w.html and 2 and 1/2 stage rocket: kzfaq.info/get/bejne/oal8ldub29Soh3k.html For boosters jettison I use preloaded bamboo spring. Each booster is connected to the upper stage by two small steel hooks at the bottom and by wooden pin perpendicular to the rocket axes in about the middle of the booster length. The booster is pushed out to the side by preloaded bamboo spring and hold in place by nylon fishing line. The bamboo spring is part of the booster body and is partially hidden inside the booster. Booster separation is initiated by deceleration sensor which switches on simple electric circuit and heats up small resistance coil which in a fraction of second burns/cuts the nylon line. The parachute inside each booster is located just behind the nose cone and it is self-ejected during the booster rotation at the time of booster separation. The system of booster jettison and recovery is simple and very reliable.

There was no emergency shutoff in this launch video - this flight was pretty nominal and all rocket motors in all stages and other rocket systems functioned properly. In case of failure of one function there is back-up system to prevent loss or damage of the rocket. During nominal function of all rocket systems the primary signal for main parachute deployment is from gyro-vertical. In case of some failure of gyro-vertical the ejection of main parachute is by burning binding nylon line by thermal bridge from hot chambers of burnout rocket motors. Thermal bridge is used to delay ejection of the main parachute about 8 seconds after rocket motors burnout. For example in case of failure to ignite second stage rocket motors the second stage would not be jettisoned, but the gyro-vertical will deploy main parachute in apogee and the second and third stage will return together on main parachutes. The main on board batteries used for rocket engines in-flight ignition are in payload section, which is disconnected from the rest of the rocket after the main parachutes ejection. Therefore the system is in safe mode after returning to earth on main parachurtes and any later unpredictable ignition of any failed rocket motor is not possible. The video of the two stage rocket incomplete flight with emergency ejection of main parachutes is published in the second part of the video for HERKULES rocket model launch (from about T 11:15): kzfaq.info/get/bejne/oal8ldub29Soh3k.html In this case I forgot to switch on safety switch for the second stage rocket motors ignition therefore the in-flight ignition of the second stage rocket motors failed. Correct full 2 stage rocket model flight of the rocket Herkules is published here: kzfaq.info/get/bejne/q9NndtdesJibf2w.html or here: kzfaq.info/get/bejne/epxmq650va-5e3U.html

Wow! That's a lot! Great design. Will you post links to the gyro electronics you used?

I will probably publish some design details/photos from building this rocket ROSON as I have plenty of work in progress photos taken in the workshop at various stages of rocket construction. Maybe in about one or two months as I am rather busy at the moment with other activities. But there is probably not anything extra-ordinate. The electronics is very simple and processing of the signal from gyro-vertical unit is by simple switch modules using electronic components like TYRISTOR and MOSFET, and simple ignition delay electronic units. I am as a profession mechanical engineer therefore my electronic schemes are at the moment almost not publishable as they always present some kind of compromise regarding both the electronics design and level of documentation because I design, build and test them our self. The only advanced electronics is the electronics already present in small laptop cooling fans to run brush-less motor of the fun/flywheel - but this electronics is already present there as originally purchased and I am not modifying it anyhow. I only slightly increased the voltage of power supply to get faster start of heavier flywheel and get higher RPM. The challenging can always be to properly balance the flywheel and gimbals. Simple contacts are used as swiches to send the signal from gimbals. Other than that there are only two LED lights - one indicate the power supply and the second indicates the signal from gimbals contacts - just for easier testing of gyro-vertical unit. I already published some work in progress photos of 2 stage rocket HERKULES at about T 6:30 here: kzfaq.info/get/bejne/epxmq650va-5e3U.html (But you probably already saw them and I understand they are not enough to understand the details of electric wiring.)

The system of stages separation is described in video at about T11:27. I am using mechanical system of stages jettison. 1st stage separation: The separation initiation is by heat-cutting nylon fishing line. After the fishing line breaks 1st stage is pushed down from 2nd stage by styrofoam piston driven by 4 rubber bands. When the piston inside 1st stage starts moving up it also deploys cylinder container 1st stage parachutes. The same principle is used for 2nd stage separation and also for 3rd stage main parachute and payload deployment. 1st and 2nd stage separation is started by signal from small and simple akcelerometr. 3rd stage main parachutes deployment it is initiated by signal from electro-mechanical gyro-vertical when 3rd stage axes reaches horizontal position at apogee. This system of deployment works fine and reliable for "small" and "slow" rockets. It will probably not work for rocket model reaching supersonic speed of flight. My rocket models reach maximum speed of about 1/4 to 1/3 of supersonic speed. If you like have a look at my older 3 stage rocket: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html or 2 stage rockets: kzfaq.info/get/bejne/epxmq650va-5e3U.html kzfaq.info/get/bejne/q9NndtdesJibf2w.html and 2 and 1/2 stage rocket: kzfaq.info/get/bejne/oal8ldub29Soh3k.html For boosters jettison I use preloaded bamboo spring. Each booster is connected to the upper stage by two small steel hooks at the bottom and by wooden pin perpendicular to the rocket axes in about the middle of the booster length. The booster is pushed out to the side by preloaded bamboo spring and hold in place by nylon fishing line. The bamboo spring is part of the booster body and is partially hidden inside the booster. Booster separation is initiated by deceleration sensor which switches on simple electric circuit and heats up small resistance coil which in a fraction of second burns/cuts the nylon line. The parachute inside each booster is located just behind the nose cone and it is self-ejected during the booster rotation at the time of booster separation. The system of booster jettison and recovery is simple and very reliable.

I am not sure how many hours I spent building this rocket, maybe around 300 hours in rocket model workshop. But if not including the design and development time and provided there are perfect construction plans for every detail (so I need not often go trial and error) it could be probably much less. Real scale models (mock-up) of rockets often seen at some competitions take significantly more time to build - usually thousands of workshop hours. Rocket motors can be expensive but I use only cheap rocket motors ROS40 (total impulse 40 N.s) popular in Middle Europe for use in rocket models. Construction material purchase price is about 150 to 200 USD including wood, paint, glue, epoxy, electronic components, .... One on-board mini camera can be for about 100 to 200 USD.

Petr Pavlík really, wow that actually is pretty cheap

On board mini camera 100 to 200 USD ------------------------------------------------------------- I am not expert on the subject. So please excuse me if I am wrong. In eBay you can find spycameras at 10-12 USD. These are not of go-pro quality, but provide standard quality pictures. Of course you have to retrieve the camera later. Thanks

About 6 years ago I used for on board rocket model old unused cellphone camera. But it resulted in poor aerodynamics because of the cellphone size and shape, and also the weight was too high. 5 years ago I purchased small MD80 mini camera fro about 30 USD. The result were never satisfactory because of poor resolution, low FPS and basically no image stabilization. The recording from this camera which I now use only as auxiliary on-board horizontal camera, you can see in the video from T7:18. 4 years ago I purchased small action camera GoExtreme Nano for about 100 USD. Much better FPS, 60. But the resolution, image stability and resistance to vibrations are not very good. The recording from this camera which I still use as the auxiliary 2nd stage camera pointed upwards you can see in the video from T6:27. 3 years ago I purchased action camera RePlayXD 1080mini for about 130 USD. Low weight and excellent aerodynamic features because of tubular shape and small diameter. Good resolution, image stabilization and 60 FPS. The recording from this camera, which I use as the master on board camera placed at 3rd stage, you can see in the video from T0:13. The recordings from these cameras you can see also in my other multistage rocket model launches: 2 stage rocket HERKULES: kzfaq.info/get/bejne/epxmq650va-5e3U.html kzfaq.info/get/bejne/q9NndtdesJibf2w.html 2(+1) stage rocket HARPOON: kzfaq.info/get/bejne/oal8ldub29Soh3k.html 3 stage rocket SKYROS 3: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html

Your homework is pretty impressive. I now withdraw my suggestion. Thanks for enlightening me.

All stages have clusters of commercially fabricated rocket motors ROS40: 4 +2+2. One rocket motor ROS40 has total impulse 40 N.sec and burn out time of about 1.6 sec. This rocket motor was originally developed and fabricated in large series many years ago for military rocket flares and is still popular in central Europe for official use as motor for rocket models. The main propellant is solid based fuel "rocket diglykol" with starting charge of black powder. Because of the rocket motor small size there is also a flare compound at front of the rocket motor chamber to keep the diglycol grain burning stable. This rocket motor is easy to ignite quickly and is rather reliable, therefore suitable for multistage rockets, but it is relatively heavy. Unfortunately it is not fabricated any more and not available on the market any more (discontinued about years ago) and my stock is getting thin - so sooner or later I will have to look for some replacement. Some of my other rockets propelled by the same rocket motor: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/nKpkaKynv7_Jpmw.html kzfaq.info/get/bejne/hN1nf8lyuJ3Tm2w.html kzfaq.info/get/bejne/gLOhZceIxLyYpas.html

I have not been able to learn how to model a rocket so far

Yes - correct. The unit N.s mean Newton seconds (Newton x second).

There is simple limit switch activated by outer brass cage of the gyro. When the rocket turns more than 50° out of vertical the outer brass cage gets in contact with the limit switch and sends the electric signal to prevent any rocket motor ignition and at the same time initiate the rocket recovery system - the ejection of electronic bay with rocket head and parachutes. In the video at the time T12:11 there is a photo of the gyro system where you can see the limit switch on the lower left - the silver color contact. In the video at the time T13:28 the red led light on the right side indicates the limit switch contact with the outer cage. My earlier rocket gyro-vertical has additional set of limit switches also for the inner cage of the gyro gimbal but it is mechanically too complicated. This latest rocket gyro-vertical does not need inner cage limit switches because of the simple spring, which brakes relative movement between inner and outer cage of the gimbal for more then 50° angular difference between the inner and outer cages - more information regarding this, please see the description ion the video at about T12:07.

If possible can you provide supply plans so we can make one for our birds. I hope your smoke trails are straight an ture :)

Actually I do not have detailed plans - I buit/developed the gyro unit just using rather simple sketches and more or less by trial and error in my hobby workshop. So far I built 4 slightly different gyro-vertical units, one smaller then this unit and two slightly bigger. The smallest I built for the three stage rocket SKYROS 3: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html where I used DC micro motor running vibration unit of very old NOKIA cellphone - just replaced the eccentric vibration wheel with much larger and balanced flywheel of gyro. For the rocket ROSON I used cooler fan SUNON MC25060V2-A99. Is it easy to pull out the rotor with blades, cut off all blades and slide on the rotor new brass flywheel ring secured by Second Fix glue. However perfect balancing of the flywheel can be challenging. The electronics is very simple and processing of the signal from gyro-vertical unit is by simple switch modules using electronic components like TYRISTOR and MOSFET, and simple ignition delay electronic units. I am as a profession mechanical engineer therefore my electronic schemes are at the moment almost not publishable as they always present some kind of compromise regarding both the electronics circuit design and level of documentation because I design, build and test them our self. The only advanced electronics is the electronics already present in small cooling fans to run brush-less motor of the fun/flywheel - but this electronics is already present there as originally purchased and I am not modifying it anyhow. I only slightly increase the voltage of power supply to get faster start up of heavier flywheel and get higher nominal RPM. The challenging can always be to properly balance the flywheel and gimbals. Simple contacts are used as swiches to send the signal from gimbals. Other than that there are only two LED lights - one indicate the power supply and the second indicates the signal from gimbals contacts - just for easier testing of gyro-vertical unit. I already published some work in progress photos of 2 stage rocket HERKULES at about T 6:30 here: kzfaq.info/get/bejne/epxmq650va-5e3U.html (But you probably already saw them and I understand they are not enough to understand the details of electric wiring.) In case you are familiar with 3D electronic gyros - widely used to stabilize the gimbals of drone on-board cameras or also used for active control of flight of radio controlled model airplanes - I encourage you to try to built similar unit based on electronic gyro technology. It can be easier these days with wide availability of really cheap electronic components and micro computers like Arduino. Caution have to taken regarding max acceleration rating of these electronic gyros as rocket model acceleration can be very high.

If you have in mind on-board cameras: There are three on-board cameras. Master on-board camera is attached to the 3rd stage body tube aiming downwards. Auxiliary on-board camera is attached to the 2nd stage body tube aiming upwards in order to film staging and air start of 3rd stage rocket motors. Another auxiliary on-board camera is attached to the 3rd stage body tube aiming horizontally - but this particular camera is of poor resolution and too low fps. Air start of 3rd stage rocket motors was not catched during this launch but you can see it in the following videos: kzfaq.info/get/bejne/gLOhZceIxLyYpas.html kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html Another examples of placement of on-board cameras are here: kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/eph_atGEvLrDioU.html kzfaq.info/get/bejne/hN1nf8lyuJ3Tm2w.html kzfaq.info/get/bejne/oal8ldub29Soh3k.html

Petr Pavlík thank you very much

The principal of staging and rocket motors air start for model rockets is similar to the system of stage separation and air start of rocket engines used in real rocket industry. But in model rocketry burnout stages return back on parachute in order to get them reusable for the next launch and also from the flight safety reasons not to harm anybody on the ground. Some of my other model rockets with various booster/staging concept and with some description of the model rocketry systems: kzfaq.info/get/bejne/Zqx1iMmXzdyqpZc.html kzfaq.info/get/bejne/Y62IZ8WlmK-UXXU.html kzfaq.info/get/bejne/gLOhZceIxLyYpas.html kzfaq.info/get/bejne/gLOhZceIxLyYpas.html kzfaq.info/get/bejne/eNKVftyVqt-5hIU.html Very special in rocket models is the model rocket of SPACEX Falcon 9, which booster returns back to earth using only rocket motors for landing: kzfaq.info/get/bejne/i9ekeaZz1cqxp5c.html kzfaq.info/get/bejne/mrmRiMah2-DFaKs.html

@@pavlikpetr2010 thx

The max altitude of this flight was not anything special but was not measured during this launch. Max altitude is not a priority. It is rather a model rocket to demonstrate jettison of burned stages and air start of rocket motors and work of all other rocket components similar to real rocket flight. And still be able to comfortably watch from the ground by naked eye. Based on the other launch of this rocket model on June 24th, 2017 the apogee was around 2000 feet (610 m) - see the launch recordings at: kzfaq.info/get/bejne/gLOhZceIxLyYpas.html But again - max altitude is not priority - just an interesting show for spectators on the ground or watching video from on-board cameras later at home. Some more flights of my other rockets - if you like - see the end screen links of the following video: kzfaq.info/get/bejne/bJOcjLBlt8XHZ30.html However there are other rocketeers which rocket models fly about twice the speed of the sound and go to the altitudes on the edge of the true universe. But it requires very different skill set, different rocket motor and different rocket design - usually large restricted access airfield/rocket test area is necessary from legislation/safety reasons. Thanks for watching.

Sorry for mistyping. The correct description should be: Deployment of main parachutes and payload. However there is actually no payload at all as it is only a rocket model.