high altitude model rocket

i want to do the same thing this https://www.ddeville.com/derek/CSXT.htm team did but i want to build the rocket out of fiberglass and want an overall weight of 50 to 75 lb can any one tell me if this would work
:confused2:

Considering that their rocket contained over 400 pounds of propellant, I would say the short answer is "no". Is your goal the same altitude?

my goel is just reaching that altitude and to retrieve it

questions, questions:
What certifications level are you? You need a L3 to fly a rocket that large.

How much are you willing to spend? Rocket like that cost $7,000+ (just a guess)

Where are you located? Currently the only place i know to fly rockets that high is Black Rock desert, Nevada.

have you made you own motors before? You need to be extremely good at making smaller successful motors to attempt something this big.

Have you done any research into all the legalities involved with a flight like this? I would start there before you commit to anything, you might be surprised at what's involved. I'm by no means an expert on the subject, but I know there's a lot to do.

yes i have don alot of research

Then I guess you're all set, let us know how it turns out.

can any one tell me if fiberglass well be a good material for the rocket my thought is the rocket well hit any where from mach 3 to mach 6

Here's the problem as I see it: You're new here, and until people get a reading on what your level of experience is you will probably not get much help. Especially because what you are proposing is at the extreme limits of the hobby. What is your HPR certification level? What type of rockets have you built? Where do you fly? Are you a member of a club? Until some more remedial questions get answered, you will probably not get much support. No offence, but you're trolling waters that are seldom fished...

I don't have any experience in rockets of this type, but I feel that fiberglass would not be strong enough to survive the stresses created during the flight. Most of the rockets I have seen or heard of doing this use a large amount of metal in their construction. You can check out this link to the Q8k rocket which only went to 121,000 feet. That might give you some ideas into construction techniques.

https://ddeville.com/derek/Qu8k.html

no i am not member of a club of a club but i have help and seen some high power rocket build and i have flow some mid power rocket.
the thing is that the Q8k rocket was build from aluminum which has a Melting point of 1220.58 °F but fiberglass retains approximately 50% of room temperature tensile strength at 700°F (371°C); approximately 25% at 900°F (482°C); with a softening point of 1555°F (846°C) and a melting point of 2075° F (1121 °C).

Fiberglass to mach 3? Sure. Fiberglass to mach 3 for an extended amount of time? I don't know but don't guess so. Fiberglass to mach 6? No. I wouldn't try it.

most high power rocket are build from aluminum which has a Melting point of 1220.58 °F but fiberglass retains approximately 50% of room temperature tensile strength at 700°F (371°C); approximately 25% at 900°F (482°C); with a softening point of 1555°F (846°C) and a melting point of 2075° F (1121 °C)

Check out the first parts of this one:

https://www.rocketryforum.com/showthread.php?t=26383

Check out the bottom of this one...
https://www.rocketryplanet.com/forums/showthread.php?t=9477&highlight=n5800

Nobody in this hobby really goes faster than Mach 3. USC hit Mach 4.2 with a carbon fiber rocket but they had phenolic leading edges on the fins to protect it. The most people who hit Mach 3 and up are usin aluminum. Everybody is using than it must work.
Here is a pic of what Mach 3 does to Fiberglass and Carbon Fiber:
https://highpowerrocketry.blogspot.com/2009/02/p-to-n-flight.html
Not my rocket by the way.

Tominator 2 said:

Nobody in this hobby really goes faster than Mach 3. USC hit Mach 4.2 with a carbon fiber rocket but they had phenolic leading edges on the fins to protect it. The most people who hit Mach 3 and up are usin aluminum. Everybody is using than it must work.
Here is a pic of what Mach 3 does to Fiberglass and Carbon Fiber:
https://picasaweb.google.com/m/view...hkey:Gv1sRgCLns8-GV0dj8Yw/5659844961918521218

Click to expand...

Errr, it turns into a tugboat? Or a leprachan?

Ah dang it, it was a picture of Robert Dehates rocket with damage from Mach 3. I'm on my iPhone so that's why it didn't show up

king said:

i want to do the same thing this https://www.ddeville.com/derek/CSXT.htm team did but i want to build the rocket out of fiberglass and want an overall weight of 50 to 75 lb can any one tell me if this would work
:confused2:

Click to expand...

Quite simply no. A 75 pound high power rocket will not get the same performance as an amateur Class 3 or 4 rocket.

Snce you're new to rocketry, you are not aware the GoFast team spent cost over a half million dollars by the time it flew. Furthermore there is really only one location in the US where such a flight can be attempted (after complying with all FAA requirements), Black Rock Desert in Nevada, one of the more isolated areas in th lower 48. Supporting a team the size of the GoFast team costs well over $10K per week.

There are several High Power launches at Black Rocket each year, Balls being the most notable. A 75 pound rocket is common place at this event however you are more likely to get Mach 3 and 50 Kft to 100 Kft from a well designed one. L3 certification from TMT would be required.

Bob

Adrian A thank you for the info and bobkrech cant you just scale down the factors of the rocket the GoFast team did also Tominator 2 i could not find the photo

Fixed the link....

king said:

...bobkrech cant you just scale down the factors of the rocket the GoFast team did...

Click to expand...

As a first order approximation for scaling up/down the design:

• Mass fraction and maximum operating pressure stay the same, independent of the scale factor
• Burn time scales linearly with the scale factor
• Surface area, and therefore drag, scales with the second power of the scale factor
• Mass and total impulse scale with the third power of the scale factor

In other words: Drag will prevent you from attaining the same altitude with a smaller rocket of the same design.

Reinhard

but wont the drag be lower because of the smaller surface area

It is relative. Think of it like ice cubes. Crushed ice cools your drink faster because of the greater proportion of surface area when compared to large cubes.

king said:

but wont the drag be lower because of the smaller surface area

Click to expand...

Yes. But simply put, as you go up in diameter, the increase in the amount of propellant that can be used outpace the drag penalty imposed.

If you look at the altitude records, there is a general trend that the larger impulse class, the higher the record.

king said:

no i am not member of a club of a club but i have help and seen some high power rocket build and i have flow some mid power rocket.

Click to expand...

i want to do the same thing this https://www.ddeville.com/derek/CSXT.htm

Click to expand...

really? It takes a lifetime of experience and knowledge to build a rocket of that sise and have it work as well as it did. Most of us will never reach a level as advanced as that. There is a lot of people out there who just want to "jump" into rocketry and start building rockets that take M+ motors. It's very understandable. Here is my suggestion, take it slow and enjoy the ride!
Sorry if this post is offensive in any way!

This kid doesn't even have the basics of spelling and grammar down yet. Let's not worry about him reaching Mach 6.:roll:

new2hpr get a life i bet you i know more about rocket then you

A fiberglass rocket to 120k…….
Yes it is possible. It would take a lot of work to do it.
It would not work as a direct scale down.

Being a new member, with no information such as where you are located, you are not likely to get much help. Being confrontational will guarantee you will get no help. We have no idea of who you are and the only thing we have to judge you by is what you have written.


Mark

A few THOUSAND dollars to burn up too?

I know I don't, I like A-E engines only............................For now :dark:

Time to stop the feeding...