Fluorescent Tube Cover rockets

FTC

Fluorescent Tube Cover rockets (FTCs) are usually made from polycarbonate plastic and are tubes used to protect fluorescent lights. Most hardware stores in the US have them in the lighting section. There may be less expensive FTCs made from other plastics. You may want to confirm the composition with your supplier or the manufacturer.

They come in two widths: T8 is eight eighths or 1 inch, and T12 is twelve eighths or 1.5 inches. As far as I know, T12s are most commonly used for rockets. They come in either 4 or 8 foot lengths. Although several could be theoretically joined together, rockets this long and skinny can flex too much. The rocket on the left was left unpainted to detail how it was constructed.

Bulkhead Ends

Unlike making rockets with bottles, these tubes were never intended to have pressure in them, or ends for that matter. So, we'll just have to fix that. The most common ends are 20oz soda bottle necks, but PVC fittings have also been used. These are often glued on using PL Premium and are put either on the outside of the tube or on the inside. There is, of course, an art to exactly how the ends go on. You don't want them blowing off during a 1200 psi launch. This FTC has the 20oz soda bottle necks mounted to the inside.

Reenforcement

Reenforcement is required when the launch pressure will be exceeding 130 psi or so. Common types of reenforcement include wrapping the tube with Spectra of various tests and using carbon fiber. Spectra is the easiest of the two to get. Any sporting goods store has Spectra in the fishing department. Carbon fiber has to be special ordered. You also have to order a two-part epoxy to apply the carbon fiber to the rocket. The FTC on this page is spiral wrapped from both ends with 80 pound Spectra spaced at 1/4 inch. See the Spectra section for why I'll be doing it different next time.

Payload

You don't have much room. Most altimeters will fit in the tube without a problem. Cameras and video have been done but usually require dismantling the electronics and rearranging things into a more 'streamline' configuration. Your parachute and any internal recovery parts have to fit in there too.

Recovery

Recovery can be a trick if you have made a lot of 'fat' rockets and are now trying to figure out how to stuff your puffy parachute into such a tiny tube. Air speed flaps, chemical recovery and backgliding are common methods of recovering FTCs. The rocket on the left uses a syringe for chemical deployment of a parachute. Chemicals mix at apogee and cause gas to be produced. This forces the syringe open, pushing the nose cone off and the parachute out.

FTC Overview

FTC

Fluorescent Tube Cover rockets (FTCs) are usually made from polycarbonate plastic and are tubes used to protect fluorescent lights. Most hardware stores in the US have them in the lighting section. There may be less expensive FTCs made from other plastics. You may want to confirm the composition with your supplier or the manufacturer.

They come in two widths: T8 is eight eighths or 1 inch, and T12 is twelve eighths or 1.5 inches. As far as I know, T12s are most commonly used for rockets. They come in either 4 or 8 foot lengths. Although several could be theoretically joined together, rockets this long and skinny can flex too much. The rocket on the left was left unpainted to detail how it was constructed.

Bulkhead Ends

Unlike making rockets with bottles, these tubes were never intended to have pressure in them, or ends for that matter. So, we'll just have to fix that. The most common ends are 20oz soda bottle necks, but PVC fittings have also been used. These are often glued on using PL Premium and are put either on the outside of the tube or on the inside. There is, of course, an art to exactly how the ends go on. You don't want them blowing off during a 1200 psi launch. This FTC has the 20oz soda bottle necks mounted to the inside.

Reenforcement

Reenforcement is required when the launch pressure will be exceeding 130 psi or so. Common types of reenforcement include wrapping the tube with Spectra of various tests and using carbon fiber. Spectra is the easiest of the two to get. Any sporting goods store has Spectra in the fishing department. Carbon fiber has to be special ordered. You also have to order a two-part epoxy to apply the carbon fiber to the rocket. The FTC on this page is spiral wrapped from both ends with 80 pound Spectra spaced at 1/4 inch. See the Spectra section for why I'll be doing it different next time.

Payload

You don't have much room. Most altimeters will fit in the tube without a problem. Cameras and video have been done but usually require dismantling the electronics and rearranging things into a more 'streamline' configuration. Your parachute and any internal recovery parts have to fit in there too.

Recovery

Recovery can be a trick if you have made a lot of 'fat' rockets and are now trying to figure out how to stuff your puffy parachute into such a tiny tube. Air speed flaps, chemical recovery and backgliding are common methods of recovering FTCs. The rocket on the left uses a syringe for chemical deployment of a parachute. Chemicals mix at apogee and cause gas to be produced. This forces the syringe open, pushing the nose cone off and the parachute out.

Recovery

Intro

A variety of methods have been devised to bring a rocket safely down to the ground. While using a parachute seems to be the most popular, it isn't the only method. Even among those that use parachutes, there are many ways of deploying the chute.

[edit] Passive Methods

The main passive method is known as Back Sliding or Back Gliding. It involves designing the rocket so that it's center of mass is behind it's center of gravity. Once the rocket reaches apogee, it stalls and begins to fall horizontally. A horizontal fall is slow enough to prevent damage to the rocket. It is a neat, no moving parts system.

Another method involves using an energy absorbing nose cone and allowing the rocket to nose dive or "lawn dart" into the ground. Tennis balls and pieces from foam toys are popular. Having a long nose cone area to act as a crumple zone can also help.

[edit] Active Methods

These require something to occur before deployment of the recovery device. An Air Speed Flap is a thin sheet of plastic held against the rocket by the wind as it goes up. As the rocket nears apogee and slows down, the flap (under a light tension from above) is now able to hinge up. This movement releases a rubber band or string holding the nose cone or parachute.

Chemical Deployment is nothing more than a chemical reaction in a medical syringe. At apogee when the rocket turns over, chemicals are mixed together causing gas to be produces. This gas pressure causes the syringe to open up and can be used to push a parachute out of the top of a rocket.

A Tomy Timer is any plastic timer found in a variety of wind-up toys. At each launch, a guess is made as to how many seconds it will take the rocket to reach apogee. The timer is wound up that much and the rocket is launched. As it winds down it can be rigged to pull a string or release a mechanism that sends the parachute on its way.

[edit] Air Speed Flap Parachute Recovery

[edit] Chemical Deployment of a Parachute

[edit] The Basics

This method often uses a medical syringe. Inside the syringe can be a variety of chemicals, but usually there is a liquid and dry chemical that are separate. After apogee, as the rocket begins to go horizontal or nosedive, the chemicals are mixed together. This mixing causes gas to be produced and makes the syringe go from almost closed to open. This pushing can either literally push the parachute and nosecone out of the top of the rocket, or the opening syringe can move the nosecone up, causing a gap that allows the parachute out. The action of the syringe opening up can be used to trip a multitude of things.

[edit] Chemicals

Usually an acid and a base are mixed together to create a gas. This can be as simple as baking soda and vinegar. Some heat up the vinegar before adding it to the syringe, presumably to speed up the reaction. Another chemical combination is baking soda and citric acid. Both are in a powdered form and can be mixed together without a reaction. Once you have the mix, only water is required to cause it to gas off. The benefits of this combination are that you can mix it ahead of time and keep it in a bottle. When you go to launch, you only need water to complete the reaction, no stinky vinegar. And you should already have water with you. Citric acid can be found anywhere that sells winemaking supplies.

[edit] The Syringe

Syringes come in a variety of sizes. A 60cc syringe just about fills up the space in an FTC rocket and has a lot of travel. Syringes come in two tip styles: luer and luer lok. The luer tip has a smooth taper and items placed on the end are friction fit. The luer lok allows things to be locked onto the end of the syringe with a twisting motion. This is one you want. If you can get luer lok syringes with an end cap, all the better. Syringes can be purchased locally at most large animal feed stores or at medical supply stores. They can also be mail ordered.

After loading up the syringe, you need to be able to close off the end. Having a locking, twisting cap makes it easy and secure. If your syringe doesn't come with a cap, you'll have to make one by getting a large gauge needle made for the syringe and cutting the needle part off right at the base. Try to open the hole in the needle back up as best you can with some needle nose pliars. Put your now blunt needle on the syringe and suck up some PL Premium with it. When you see it just inside the tip, stop and take it off to set up. You now have your end cap.

Some syringes also have a few plastic tabs on the end of the plunger behind the rubber that make removing the plunger part difficult. They're like stops. Some syringes don't have these. Most of the time, the gas generated has enough pressure to pop the two part apart even with the stops.

You will also need a syringe with a needle to add the liquid to the other syringe. To make it easier to get the liquid where it needs to go, gently bend the needle to one side. File the sharp tip off of the needle for safety, it isn't needed. Even with the bend, you should be able to get the safety cap back on the needle for storage.

[edit] Separation

There has to be some type of separation between the chemicals in the syringe, but they have to be able to react when the rocket is turned on its side or in a nosedive. You also have to have a way of getting the chemicals in there and sealing it all up. One method for a 60cc syringe is to make a little 'cup' for the dry chemicals with a piece of 1/2 inch PVC pipe. Cut off a piece a little more than 1/2 inch long. Put a piece of tape on one end and put some PL Premium in from the other side, covering the tape. Give it a day to dry and remove the tape. Give it another day to dry. You should now have a small cup for your dry mix. If you use a smaller syringe, you'll have to find something smaller to use.

To prevent the cup from sealing onto the syringe when it is turned over, preventing the liquid from quickly contacting the powder, you can put a few small nails on the open end of the cup.

[edit] Push Plate

If you are using your syringe to push the parachute out of the top, you should make a push plate. This prevents the parachute from getting wedged between the syringe and the rocket wall. Use any thick plastic (peanut butter jar lid) and cut it into a circle so that it easily fits inside your rocket body. Don't make this a tight fit. Also cut a smaller hole so that it can be mounted onto the area around the luer loc of the syringe.

[edit] Leashes

After all of this work, you don't want your syringe to separate from your rocket at 500 feet, never to be seen again, so you'll want to tether it to the rocket. Tie a string to the end of the plunger and tie the other end to the bulkhead end of the rocket. Of course, make the string long enough to allow the plunger to come completely out of the top of the rocket for reloading. Because the syringe is a separate from the plunger, you have a couple of options. You can tie a string to this and the rocket as well, however, because this part moves, you want to make sure the line won't get snagged anywhere. Another simpler method is to pull the plunger almost out of the syringe, to the stops if it has them, and then drill a small hole just above the plunger. Now, as the plunger gets close to popping out of the syringe, the extra gas is vented out.

[edit] Loading the Syringe

Getting things all together is fairly straight forward:

• Separate the syringe and plunger pieces.
• Put your powder into the cup. 50-75% full.
• While balancing the cup on the top of the plunger. Place the plunger into the syringe.
• Slowly push the plunger until the nails from the cup are pushing on the top of the syringe.
• Using your syringe with the bent needle, add your liquid of choice into the top of the syringe, shooting it to the side of the cup and filling it about half of the way up the side of the cup. You may have to move the plunger down a little temporarily while you do this.
• Place your locking end cap on and the syringe is armed and ready.
• Carefully place it in your rocket.

You may want to put your rocket on the launcher before adding the syringe if you think there is a possibility of shaking things too much. As your rockets get longer and this movement is magnified, you'll have to do it this way.

Real Water Rockets

Remember, if you are going to launch something big, make sure that it will not do any harm wherever it lands.

And . . .

Never go near to or touch a rocket that is about to launch.

The pages are in an order such that if you start with the first, and work your way through, you will discover for yourself the thrill of the launch without spending too much to get to each stage. The first two are not particularly pretty rockets and they are not even very aerodynamic (the fins are designed to be built easily, made from materials that you will already have, withstand a large number of impacts and, due to their flexible nature, have a lower drag factor at higher velocities) but they do allow you to familiarise yourself with the basics - shaping the body, joining two bottles together, adding nose cones with parachutes, better fins and so on is something that can be done at a later date. Enough of the sentimental stuff and on with the real thing. . .

1. Basic 250ml Rocket. How to build and launch your first rocket - a modest size that will not do much damage. Includes how to make a simple connector, fins and use a bicycle pump to estimate pressure.
2. Basic 2 litre Rocket. An interesting discovery. This powerful beast is easier to build that the 250ml rocket but still requires the connector and pump for hand launches. Look at some pictures of a basic 2 litre rocket without fins.
3. More advanced 1½ litre Rocket. Single, modified pressure vessel with fins and aerodynamic stability. Still relatively easy to make. Look at the pictures.
4. 4 litre 2 bottle rocket that uses two 2 litre bottles fixed end to end so as to give a 4 litre capacity with the diameter of a 2 litre bottle. Look at the pictures.
5. Science Olympiad challenge rocket. No metal parts - stays aloft for a reasonable amount of time.
6. 6 litre 3 bottle rocket that uses three 2 litre bottles. Look at the pictures of this monster as it travels 270 feet down-range. Listen to it at launch [.wav or Real Media] during thrust phase (listen out for the two whistles as the upper sections depressurise once the water is used up).
7. 12 litre 5 bottle rocket made using 2 litre and 3 litre bottles. Look at the pictures of this little babe as it travels on its first launches.
8. 2 Stage rocket made using green 2 litre and 3 litre bottles. Look at the pictures of this one as it travels on its first launch (this is too tiring :-).
9. 1 litre Power Rocket made using a 1 litre black current concentrate bottle. Look at the pictures of this beast as it tunnels its way first into the stratosphere and then into the turf. Also listen to a launch and look at the Fourier transform [Real Media].
10. Silver 2 Litre Rocket made using three silver 2 litre bottles. Look at the pictures of this rocket that prompted enquiries as to the identity of the materials used in its construction. All wow factor. Also listen to a launch and look at the Fourier transform [Real Media].
11. 2 Litre Dart Rocket - a passive second stage rocket made from a 2 litre bottle and some uPVC pipe. Look at the pictures of this high altitude beast before it soars around 500 feet into the troposhere and then all but gets lost.

Water rocket

A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel—the engine of the rocket—is usually a used plastic soft drink bottle. The water is forced out by a pressurized gas, typically compressed air.

The term "aquajet" has been used in parts of Europe in place of the more common "water rocket" and in some places they are also referred to as "bottle rockets" (which can be confusing as this term traditionally refers to a firework in other places).

Water rocket engines are most commonly used to drive model rockets, but have also been used in model boats, cars, and rocket-assisted gliders.

How To Build A Water Thrusted Rocket

http://www.metacafe.com/watch/858984/how_to_build_a_water_thrusted_rocket/

How To Build A Water Thrusted Rocket

http://www.metacafe.com/watch/858984/how_to_build_a_water_thrusted_rocket/

Professional Water Rocketry

http://www.antigravityresearch.com/

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Bush: cessation of Hamas rocket firing, arms smuggling key to Gaza cease-fire

WASHINGTON, Jan. 10 (Xinhua) -- U.S. President George W. Bush has said that a lasting cease-fire in the Gaza Strip requires Palestinian militants to first stop rocket firing and arms smuggling, the White House said on Saturday.

"President Bush emphasized the importance of bringing an end to rocket-fire against Israel and preventing arms smuggling into Gazaas the basis for a durable cease-fire," said White House spokesman Gordon Johndroe in a statement.

President Bush on Saturday called his Turkish counterpart Abdullah Gul and welcomed "Turkey's support for the Egyptian-French mediation efforts" aimed at stopping the violence between Israel and Hamas in the Gaza Strip, said the spokesman.

The president also discussed, in a phone conversation, the Gaza situation with Czech Republic Prime Minister Mirek Topolanek, whose country holds the rotating EU presidency, said Johndroe.

The two leaders agreed on "the importance of bringing an end to the rocket fire against Israel, implementing a plan to prevent smuggling into Gaza, and ensuring humanitarian assistance reaches the Palestinian people," Johndroe said.

In retaliation to increased Hamas rocket attacks, Israel launched massive military strikes against Hamas on Dec. 27. The two-week-long strikes have killed over 800 Palestinians in the Gaza Strip, according to Palestinian medics.

Both Israel and Hamas have ignored a UN Security Council resolution that called for an immediate ceasefire. The Israeli government says the military strikes would be stepped up until Hamas is unable to fire rockets, while Hamas continues to fire rockets and mortars into southern Israel.

The United States has voiced its support for the Egyptian-French initiative, which calls for an immediate cease-fire to allow more aid into the Gaza Strip. Israel said it welcomes the initiative, but added that it will only accept a cease-fire that stops rockets firing into Israel and prevents the rearming of Palestinian militants.

Bush: cessation of Hamas rocket firing, arms smuggling key to Gaza cease-fire

U.S. President George W. Bush has said that a lasting cease-fire in the Gaza Strip requires Palestinian militants to first stop rocket firing and arms smuggling, the White House said on Saturday.

"President Bush emphasized the importance of bringing an end to rocket-fire against Israel and preventing arms smuggling into Gazaas the basis for a durable cease-fire," said White House spokesman Gordon Johndroe in a statement.

President Bush on Saturday called his Turkish counterpart Abdullah Gul and welcomed "Turkey's support for the Egyptian-French mediation efforts" aimed at stopping the violence between Israel and Hamas in the Gaza Strip, said the spokesman.

The president also discussed, in a phone conversation, the Gaza situation with Czech Republic Prime Minister Mirek Topolanek, whose country holds the rotating EU presidency, said Johndroe.

The two leaders agreed on "the importance of bringing an end to the rocket fire against Israel, implementing a plan to prevent smuggling into Gaza, and ensuring humanitarian assistance reaches the Palestinian people," Johndroe said.

In retaliation to increased Hamas rocket attacks, Israel launched massive military strikes against Hamas on Dec. 27. The two-week-long strikes have killed over 800 Palestinians in the Gaza Strip, according to Palestinian medics.

Both Israel and Hamas have ignored a UN Security Council resolution that called for an immediate ceasefire. The Israeli government says the military strikes would be stepped up until Hamas is unable to fire rockets, while Hamas continues to fire rockets and mortars into southern Israel.

The United States has voiced its support for the Egyptian-French initiative, which calls for an immediate cease-fire to allow more aid into the Gaza Strip. Israel said it welcomes the initiative, but added that it will only accept a cease-fire that stops rockets firing into Israel and prevents the rearming of Palestinian militants.

STERN rocket firing completed

September 26th, 2008 in Space & Earth science / Space Exploration

(PhysOrg.com) -- The performance of unpiloted, reuseable spaceplanes could be significantly improved thanks to the completion of the Static Test Expansion/Deflection Rocket Nozzle (STERN) engine test programme.

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A team of engineers from Bristol University finished the test programme last week [Friday 19 September] with 12 hot firings successfully completed. In each experiment the engine was held down on a heavily instrumented test stand providing data on pressures, temperature, flow rates and thrust.

The results will be presented by Dr Neil Taylor, Lecturer in Aerodynamics in the University’s Department of Aerospace Engineering at the International Astronautical Congress in Glasgow next week [29 September to 3 October].

The objective of the test programme was to explore the flow stability and behaviour in an unusual rocket nozzle known as an Expansion Deflection Nozzle. In theory these should allow very large expansion nozzles suitable for operating in the vacuum of space to also perform stably and efficiently within an atmosphere. If so, then the performance of single stage to orbit launch vehicles like Skylon could be significantly improved.

Dr Taylor said: “Test programmes like this usually take years and costs hundreds of thousands of pounds, but we’ve done this in 18 months and on a relative shoestring, the whole team has done a really good job but the guys from Airborne Engineering who designed, manufactured and assembled the test rig have worked near miracles. I’m looking forward to getting all the data back to the lab and seeing how it compares to my predictions.”

The STERN engine burns hydrogen and air, the same as Skylon’s Sabre engines when in air breathing mode. To maximise the engine’s life the test firings were held below the engine design values with measured thrust between 1500 and 2000 Newtons (1/5 tonne). Each firing was restricted to less than a second, as any longer and the (un-cooled) chamber walls could start to melt. This still provided sufficient time for the flow to stabilise, and all the required data to be obtained.

The initial results have confirmed that the flow within Expansion Deflection nozzles is stable across a very wide range of pressure ratios. In addition, broad agreement with computer simulations of their behaviour has also been achieved.

Although the basic principles of Expansion Deflection nozzles are now better understood, as anticipated by the research team the complex processes within the flow meant that optimum performance was not achieved by this first attempt. The ongoing analysis of the data produced by STERN will lead to a better understanding of the flow, enabling improved and optimised designs to be produced. It is expected this in turn will lead to future experimental work in a wider long-term project aimed at maximising the benefit Expansion Deflection Nozzles offer.

The STERN project is a collaboration between the University of Bristol, Reaction Engines Ltd, and Airborne Engineering Ltd. The final test firing has taken less than 18 months after a suggestion by Alan Bond, Director of Reaction Engines Ltd, over coffee at a conference.

Provided by University of Bristol

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STERN rocket firing completed

September 26th, 2008 in Space & Earth science / Space Exploration

(PhysOrg.com) -- The performance of unpiloted, reuseable spaceplanes could be significantly improved thanks to the completion of the Static Test Expansion/Deflection Rocket Nozzle (STERN) engine test programme.

Sponsored Links (Ads by Google)

Save up to 70% off list
Remanufactured and New Surplus Rosemount instrumentation
www.sullivanandsons.com

Flow Meters from Sierra
We Manufacture a Variety of Meters for Any Gas, Liquid, and Steam
www.SierraInstruments.com/FlowMeter

A team of engineers from Bristol University finished the test programme last week [Friday 19 September] with 12 hot firings successfully completed. In each experiment the engine was held down on a heavily instrumented test stand providing data on pressures, temperature, flow rates and thrust.

The results will be presented by Dr Neil Taylor, Lecturer in Aerodynamics in the University’s Department of Aerospace Engineering at the International Astronautical Congress in Glasgow next week [29 September to 3 October].

The objective of the test programme was to explore the flow stability and behaviour in an unusual rocket nozzle known as an Expansion Deflection Nozzle. In theory these should allow very large expansion nozzles suitable for operating in the vacuum of space to also perform stably and efficiently within an atmosphere. If so, then the performance of single stage to orbit launch vehicles like Skylon could be significantly improved.

Dr Taylor said: “Test programmes like this usually take years and costs hundreds of thousands of pounds, but we’ve done this in 18 months and on a relative shoestring, the whole team has done a really good job but the guys from Airborne Engineering who designed, manufactured and assembled the test rig have worked near miracles. I’m looking forward to getting all the data back to the lab and seeing how it compares to my predictions.”

The STERN engine burns hydrogen and air, the same as Skylon’s Sabre engines when in air breathing mode. To maximise the engine’s life the test firings were held below the engine design values with measured thrust between 1500 and 2000 Newtons (1/5 tonne). Each firing was restricted to less than a second, as any longer and the (un-cooled) chamber walls could start to melt. This still provided sufficient time for the flow to stabilise, and all the required data to be obtained.

The initial results have confirmed that the flow within Expansion Deflection nozzles is stable across a very wide range of pressure ratios. In addition, broad agreement with computer simulations of their behaviour has also been achieved.

Although the basic principles of Expansion Deflection nozzles are now better understood, as anticipated by the research team the complex processes within the flow meant that optimum performance was not achieved by this first attempt. The ongoing analysis of the data produced by STERN will lead to a better understanding of the flow, enabling improved and optimised designs to be produced. It is expected this in turn will lead to future experimental work in a wider long-term project aimed at maximising the benefit Expansion Deflection Nozzles offer.

The STERN project is a collaboration between the University of Bristol, Reaction Engines Ltd, and Airborne Engineering Ltd. The final test firing has taken less than 18 months after a suggestion by Alan Bond, Director of Reaction Engines Ltd, over coffee at a conference.

Provided by University of Bristol

Relevant stories

• Cocoa could be a healthy treat for diabetic patients
  May 26, 2008 | not rated yet | no comments yet
• First firing of STERN rocket
  Mar 26, 2008 | not rated yet | no comments yet
• For the first time the LHC reaches temperatures colder than outer space
  Apr 10, 2007 | not rated yet | no comments yet
• New wind tunnel aimed at making airplanes quieter to those on ground
  Nov 22, 2005 | not rated yet | no comments yet
• Research finds older women who are more physically fit have better cognitive function
  Jan 08, 2009 | not rated yet | no comments yet

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Move the slider to adjust rank threshold, so that you can hide some of the comments.