U.S. Water Rockets all new Radial Parachute Deploy System
Posted: Sat Apr 12, 2014 11:39 pm
The U.S. Water Rockets Radial Deploy System
About a year ago we came up with a list of experiments we wanted to document using regular water rockets that anyone could build and fly, but we felt that a lot of people were reluctant to risk flying anything that costs more than say $5.00 because they did not trust any recovery system to work reliably.
We decided that we needed to find out what people were thinking, so we formed a focus group of students who were given the task of finding plans for a parachute system, building it, and then flying it. At the end of the focus group we had them fill out a survey to discuss what they did and how it could be improved. The results were very interesting.
Every participant of our group managed to find plans online for similar "Side" deploy systems, which appear to all be based on the "Horizontal Deploy" that Robert Youens developed over 10 years ago. They all operated on the same principal, and differed only in materials and subtle changes in assembly that appear to merely be the plan author attempting to personalize the existing designs and make them his or her own "unique" system. This style recovery system has a compartment to hold the chute built from common sheet material or wood, and a trap door on the side of a bottle with an ejector spring made from a bottle or rubber bands to push the chute out. The focus group had a number of issues with the traditional design:
1) It is made from 16-20 custom made pieces.
2) All pieces must be built to tight tolerances to fit together and work.
3) The system can only be attached to the rocket at the top where it is most likely to be damaged in a crash.
4) 3-5 moving parts must work correctly or the deploy will fail.
5) There are numerous places where the chute can pinch or snag.
6) Assembly takes a very long time with some plans having 55-65 discrete steps.
7) Damage from a crash can make repairs difficult or impossible.
With this all in mind, we took a look at the current "state of the art" and decided that not enough work has been done in this field in spite of a surge in popularity of water rockets. We felt that coming up with a new system that solved all of these issues would be a great project.
The first brainstorm we had was to replace the hinged trap door and ejector plate with a parachute cover that would be forcefully flung open thanks to the centripetal force of the rubber band used to hold it closed. The force of the unwrapping rubber band is applied radially around the central axis of the rocket, giving the system a feature that was new and unique.
Once the radial actuation idea was proven to work, we realized that the meticulously built internal compartment and doorway could also be totally eliminated if the parachute cover was simply not cut so small. We could use the neck area surrounding a tornado tube to house the parachute. We could also recreate the same neck area using an extra bottle taped to the top of the rocket. This means the system can mount anywhere on the rocket.
Having gotten rid of all those tricky to make parts, we reduced the complexity and time to build the system. This met all of the requirements we set out to meet. The new system has the following improvements:
1A) It is made from only 2-3 custom made pieces.
1B) The remaining 2-3 pieces are all used in unmodified form with no alterations needed.
2) No tight tolerance parts need to be made.
3) The system can be attached to different locations on the rocket, possibly preventing damage in a crash.
4) Only 1 moving parts must work correctly.
5) Eliminated all places where the chute can pinch or snag.
6) Assembly takes a very short time, having only 8 simple steps.
7) Damage from an unlikely crash is no big deal.
We are pleased to share the idea for this deploy system with the community. Please visit the tutorial on our website to see how to make your very own version, or watch the video link at the bottom of the tutorial page to see it in action!
http://www.uswaterrockets.com/construct ... torial.htm
About a year ago we came up with a list of experiments we wanted to document using regular water rockets that anyone could build and fly, but we felt that a lot of people were reluctant to risk flying anything that costs more than say $5.00 because they did not trust any recovery system to work reliably.
We decided that we needed to find out what people were thinking, so we formed a focus group of students who were given the task of finding plans for a parachute system, building it, and then flying it. At the end of the focus group we had them fill out a survey to discuss what they did and how it could be improved. The results were very interesting.
Every participant of our group managed to find plans online for similar "Side" deploy systems, which appear to all be based on the "Horizontal Deploy" that Robert Youens developed over 10 years ago. They all operated on the same principal, and differed only in materials and subtle changes in assembly that appear to merely be the plan author attempting to personalize the existing designs and make them his or her own "unique" system. This style recovery system has a compartment to hold the chute built from common sheet material or wood, and a trap door on the side of a bottle with an ejector spring made from a bottle or rubber bands to push the chute out. The focus group had a number of issues with the traditional design:
1) It is made from 16-20 custom made pieces.
2) All pieces must be built to tight tolerances to fit together and work.
3) The system can only be attached to the rocket at the top where it is most likely to be damaged in a crash.
4) 3-5 moving parts must work correctly or the deploy will fail.
5) There are numerous places where the chute can pinch or snag.
6) Assembly takes a very long time with some plans having 55-65 discrete steps.
7) Damage from a crash can make repairs difficult or impossible.
With this all in mind, we took a look at the current "state of the art" and decided that not enough work has been done in this field in spite of a surge in popularity of water rockets. We felt that coming up with a new system that solved all of these issues would be a great project.
The first brainstorm we had was to replace the hinged trap door and ejector plate with a parachute cover that would be forcefully flung open thanks to the centripetal force of the rubber band used to hold it closed. The force of the unwrapping rubber band is applied radially around the central axis of the rocket, giving the system a feature that was new and unique.
Once the radial actuation idea was proven to work, we realized that the meticulously built internal compartment and doorway could also be totally eliminated if the parachute cover was simply not cut so small. We could use the neck area surrounding a tornado tube to house the parachute. We could also recreate the same neck area using an extra bottle taped to the top of the rocket. This means the system can mount anywhere on the rocket.
Having gotten rid of all those tricky to make parts, we reduced the complexity and time to build the system. This met all of the requirements we set out to meet. The new system has the following improvements:
1A) It is made from only 2-3 custom made pieces.
1B) The remaining 2-3 pieces are all used in unmodified form with no alterations needed.
2) No tight tolerance parts need to be made.
3) The system can be attached to different locations on the rocket, possibly preventing damage in a crash.
4) Only 1 moving parts must work correctly.
5) Eliminated all places where the chute can pinch or snag.
6) Assembly takes a very short time, having only 8 simple steps.
7) Damage from an unlikely crash is no big deal.
We are pleased to share the idea for this deploy system with the community. Please visit the tutorial on our website to see how to make your very own version, or watch the video link at the bottom of the tutorial page to see it in action!
http://www.uswaterrockets.com/construct ... torial.htm