Open Rocket

[Lt72884]

Here - Load this into Open Rocket and PLAY. There are no skipping steps in learning this stuff, no real shortcuts, and you really have to know what changes on part "A" are going to effect part "B". You have to understand why CG and CP are important. You need to know why fin size & placement are important. Change things around & see what it does to the simulation flight.

You sound like it may be a FANTASTIC idea for you to buy a kit to build just to learn from first, instead of going for a moon landing on your first try. I mean no insult at all - we've all been there

exactly. i know larger fins means more stability in some cases. We are purchasing a wildman kit this week to launch on october 10th i think..

Ill load that file and see what i can decipher from it all.

i loaded it and my OR has no rocket motors in the simulation. I wanted to plot it. but i cant haha. Do i need to install some rocket motors into the software?

thanks

 

[Alan15578]

Over-stating the obvious - getting a 9lb payload to 10,000 feet, with a successful recovery, is not an easy (or cheap) endeavor

Start with a class 1 payload rocket and get it up to 10,000 feet and back safely. Then just scale it up to the 9 pound payload.

 

[Hobie1dog]

Start with a class 1 payload rocket and get it up to 10,000 feet and back safely. Then just scale it up to the 9 pound payload.

great advice

 

[Lt72884]

Start with a class 1 payload rocket and get it up to 10,000 feet and back safely. Then just scale it up to the 9 pound payload.

is that a template in OR or do i have to build that one from scratch? Second, in OR i loaded a file that was given to me above, and i went to do the test flight, but OR has no motors installed. Do i need to install those or do i need to turn on a setting somewhere? thansk

 

[JackC]

exactly. i know larger fins means more stability in some cases. We are purchasing a wildman kit this week to launch on october 10th i think..

Ill load that file and see what i can decipher from it all.

i loaded it and my OR has no rocket motors in the simulation. I wanted to plot it. but i cant haha. Do i need to install some rocket motors into the software?

thanks

The program should have some motors in it. Make certain that you designate the motor mount tube as a tube that will hold the motor. Then when you go to the motor configuration tab, set up a configuration then click the select motor button. In the top right hand corner you should see a list of motor manufacturers. Click the box next to a manufacturer and a list of their motors should show up.

 

[Lt72884]

The program should have some motors in it. Make certain that you designate the motor mount tube as a tube that will hold the motor. Then when you go to the motor configuration tab, set up a configuration then click the select motor button. In the top right hand corner you should see a list of motor manufacturers. Click the box next to a manufacturer and a list of their motors should show up.

ok, once i went to configs, then selected the inner tube as the motor tube, i was able to select a tube. So far this is the best config i have come up with. I changed only the fins, about 15 times to see what happens. So far for this particular shape of fin and the motor, this is the highest and fastest i was able to get. Flies at a velocity of 0.98 mach. Next i will try elliptical fins

 

[PayLoad]

ok, once i went to configs, then selected the inner tube as the motor tube, i was able to select a tube. So far this is the best config i have come up with. I changed only the fins, about 15 times to see what happens. So far for this particular shape of fin and the motor, this is the highest and fastest i was able to get. Flies at a velocity of 0.98 mach. Next i will try elliptical fins

It was my scratch-built Level 1 certification rocket "Yo, Certify Dis" (I'm from Philly) I like 'em fast & high. Glad you liked it.

 

[JackC]

ok, once i went to configs, then selected the inner tube as the motor tube, i was able to select a tube. So far this is the best config i have come up with. I changed only the fins, about 15 times to see what happens. So far for this particular shape of fin and the motor, this is the highest and fastest i was able to get. Flies at a velocity of 0.98 mach. Next i will try elliptical fins

Well, for starters, a cone shaped nosecone is actually not the best cone if you want to go supersonic. A Von Karman nosecone would be better. Also, you want your airframe in 3 sections, the sustainer (the fin and motor section), the drogue parachute section, and the main chute section. We typically call the last two “bays”. Your altimeter bay goes between the two other bays and is formed from a coupler tube that fits inside your airframe. Take a look at the Tomahawk to see an example of this structure.

Also, you can find more designs if you Google EMRR and Rocksim. You can download a Rocksim file, open it in Openrocket then save it as a .ork file to keep your edits or changes.

 

[Lt72884]

It was my scratch-built Level 1 certification rocket "Yo, Certify Dis" (I'm from Philly) I like 'em fast & high. Glad you liked it.

ok, whoever said eliptical fins are best... i think is trying to fool me. According to the apogee rocket newsletter, they were saying eliptical fins are the best. no configuration of elip fins gets me higher than 800m with your lvl 1 rocket. As soon as i switch back to the trap fins, and in a reverse config, i get almost 1200m

 

[JackC]

A good book to use as a resource is Mark Canepa’s Modern High Power Rockets 2. You can find it on Amazon in one of their used books vendors. It’s a little dated but it is a great guide on all the concepts you will need to build and fly HPR.

 

[JackC]

ok, whoever said eliptical fins are best... i think is trying to fool me. According to the apogee rocket newsletter, they were saying eliptical fins are the best. no configuration of elip fins gets me higher than 800m with your lvl 1 rocket. As soon as i switch back to the trap fins, and in a reverse config, i get almost 1200m

I would say most high speed fins are clipped delta’s or delta fins.

 

[JoePfeiffer]

i loaded it and my OR has no rocket motors in the simulation. I wanted to plot it. but i cant haha. Do i need to install some rocket motors into the software?

OR includes a database of all current production certified motors (and a bunch of out of production). You do need to pick a motor to simulate a flight.

 

[Flyfalcons]

Is there a rocketry for beginners class that universities can offer before attempting a project like this? These questions being asked should be cause for great concern for any club or RSO hosting these types of launches.

 

[neil_w]

I'm still trying to understand if the students are given any instructions at all other than "Go build a rocket that goes 10,000' with a 9lb payload". Based on the questions we see here (over and over) I wonder.

 

[krislhull]

I'm still trying to understand if the students are given any instructions at all other than "Go build a rocket that goes 10,000' with a 9lb payload". Based on the questions we see here (over and over) I wonder.

The impression I got from reading this thread and the OPs first thread, is that a group of students heard about the Spaceport America Cup and decided they want to partake. That’s great and all, but the OP really needs to head the advice in both this thread and his other one and seek out the club local to him and take their entire group and meet with active members and flyers to get an idea of what they are dealing with, and find an experienced mentor to help them along the way.

 

[dhbarr]

I'm still trying to understand if the students are given any instructions at all other than "Go build a rocket that goes 10,000' with a 9lb payload". Based on the questions we see here (over and over) I wonder.

In my experience you can give students a handout, display slides of the major points of the handout, explain the handout in-person, have open-office hours regarding the said handout....

 

[user 30299]

Is there a rocketry for beginners class that universities can offer before attempting a project like this? These questions being asked should be cause for great concern for any club or RSO hosting these types of launches.

There are a couple of us on this thread, and Lt72884's other thread, that work with the university teams on the various competitions.

You could write a book on how each university and team develops the skill sets to tackle these competition rockets. This is why
we push the teams to get experienced mentors/advisors early in the process. There are also independent project reviewers that
spends months following the teams to make sure the designs are safe.

This is how we keep teams, such as Lt72884's, from doing harm to themselves and others - and possibly do irreversible damage
to the HPR sport/hobby. But we have no input when a university team does a project independent of a competition.

That's why when you see someone, or a group, post questions and request support that is clearly outside their wheelhouse,
it's important that we direct them to seek local advice. This way someone can get a hands-on view of the situation.

HPR has always been very hands-on. It keeps it interesting, it keeps it safe, and it fosters new ideas.

 

[tsmith1315]

But we have no input when a university team does a project independent of a competition

In those situations, are the students not bound by the TRA/NAR certification process?

 

[Alan15578]

In those situations, are the students not bound by the TRA/NAR certification process?

There are often special NFPA etc. exemptions for research activities conducted via a University, but you would have to check the current particulars on that.

 

[Alan15578]

is that a template in OR or do i have to build that one from scratch? Second, in OR i loaded a file that was given to me above, and i went to do the test flight, but OR has no motors installed. Do i need to install those or do i need to turn on a setting somewhere? thansk

I don't use Open Rocket nor Rocsim etc. I write my own sims from scratch as needed. But ya, if you install the right app you can probably print a diploma with a single click.

 

[user 30299]

In those situations, are the students not bound by the TRA/NAR certification process?

The best reply I can give you to that is "not exactly". This is where someone like Steve Shannon and others
can do the best job of explaining where universities fit into, or work around, the certification process.

It's the local clubs that regularly deal with universities that will "push" the certification process. Some clubs have
launch field requirements that are directed at the university teams. An example is requiring them to contact the
club a couple of weeks in advance of their attending a launch for the purpose of putting up a team rocket.
The club will also request that the team provide design and simulation info in advance.

These clubs have experienced people and RSOs that have had a share of surprises from teams over the years.
RSO's have a thankless job when a dozen students are not happy that you just told them "No" to a launch.
You want the students to have a good experience at a launch, but at times they don't grasp the safety
implications - or the potential lose of a launch field.

Some of the competitions prefer (require) that at least one team member be certified, and for sure have
a mentor and Flyer-of-Record that is certified for the level of motor. But this is the competition people
setting the certification requirements.

It's a challenging topic, and one that generates many well-informed & experienced opinions. My experience
is just one of many, and far from the final say. It's an ongoing learning curve.

In the end the first thing we want teams to do is to reach out to their local clubs. They represent TRA and
NAR, and will provide the necessary guidance for safety & design.

 

[tsmith1315]

is that a template in OR

No, a Class 1 rocket is simply any model rocket/large model rocket that falls within the definition*:

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."

Class 1 rockets don't require any FAA involvement to fly.


*Quoted from the new TRA Safety page:
https://www.tripoli.org/content.aspx?page_id=22&club_id=795696&module_id=520420#modelrocket

 

[Lt72884]

I'm still trying to understand if the students are given any instructions at all other than "Go build a rocket that goes 10,000' with a 9lb payload". Based on the questions we see here (over and over) I wonder.

Nope, no instructions. We have a year to complete the assignment. its for fall and spring semester. So for this semester, its about joining the utah rocket club, building a few lvl 1 and 2 rockets for testing, finding a mentor, making a gantt chart, finding the customer needs, etc etc etc. oh, and yes we are becoming lvl 2 certified, thats part of the assignment as well

The only thing we were told in a 2-minute discussion "build a rocket that can go 10,000 feet and carry 9 lbs. Eventually this rocket could be used for spaceport or at least used as a beginning concept to help next year's class to get to space port"

So yes, we do have to build a rocket that will need to go to 10,000 feet and carry 9 lbs BUT not compete in spaceport this year.

 

[Off Grid Gecko]

Nope, no instructions. We have a year to complete the assignment. its for fall and spring semester. So for this semester, its about joining the utah rocket club, building a few lvl 1 and 2 rockets for testing, finding a mentor, making a gantt chart, finding the customer needs, etc etc etc. oh, and yes we are becoming lvl 2 certified, thats part of the assignment as well

The only thing we were told in a 2-minute discussion "build a rocket that can go 10,000 feet and carry 9 lbs. Eventually this rocket could be used for spaceport or at least used as a beginning concept to help next year's class to get to space port"

So yes, we do have to build a rocket that will need to go to 10,000 feet and carry 9 lbs BUT not compete in spaceport this year.

Wow... n you gotta pay for any of this out of your own pocket too??? I guess you might as well join TRA or NAR, whichever of them is present at your local club.

 

[Lt72884]

Wow... n you gotta pay for any of this out of your own pocket too??? I guess you might as well join TRA or NAR, whichever of them is present at your local club.

no, we got a 3500$ grant for the assignment from the school haha

 

[Off Grid Gecko]

no, we got a 3500$ grant for the assignment from the school haha

hmmm, can I take that assignment from out of state?? lol. I'll build a rocket by golly!

 

[Alan15578]

no, we got a 3500$ grant for the assignment from the school haha

That is interesting, assuming it is not a haha. How much is your tuition? What happens if you go over budget, or under budget? What happens if you fail to meet the performance objectives?

 

[JackC]

no, we got a 3500$ grant for the assignment from the school haha

To receive additional funding, you might want to offer sponsorships to local businesses, particularly anything in aerospace. For significant funds, the sponsors get a logo on the rocket and any PR you do for your project.

 

[Lt72884]

To receive additional funding, you might want to offer sponsorships to local businesses, particularly anything in aerospace. For significant funds, the sponsors get a logo on the rocket and any PR you do for your project.

Damn, thats a great idea!!!! I live down the street from Thiokol who makes solid rocket motors for Elon

 

[PayLoad]

I would strongly suggest you learn about building rockets prior to looking for funding for your project. Very strongly suggest. Thiokol makes rockets for a few different people, I believe. Think Pizza shops & smaller companies