Southern Arizona Rocketry Association

  • 16 Feb 2021 21:55 | James Cramton (Administrator)

    Finding Local Launch Sites

    SARA's launch site in Marana is an excellent site for flying both high power and low power rockets, with largely open, flat terrain, nearby facilities, and expert rocketeers to help you learn to fly rockets safely. But what about sites closer to developed places for flying low power model rockets? We routinely get questions from rocketeers looking for local areas to launch model rockets. Because SARA is not present at launches outside our sponsored launches, we cannot vouch for independent fliers' safety practices, or whether the fliers have permission to fly at a particular location, so we cannot recommend specific sites.  But we can provide guidance on building and flying safely, identifying a suitable flying field, and obtaining permission to fly there. 


    Flying Safely

    It is the responsibility of every rocketeer to learn to fly safely and legally. The National Association of Rocketry (NAR) Model Rocketry Safety Code is a set of guidelines intended to help rocketeers to develop safe habits when building and flying model rockets.  Please start by reviewing the guidelines in the NAR Model Rocketry Safety Code: http://www.nar.org/safety-information/model-rocket-safety-code/.  These guidelines include information about construction materials, motors, equipment, range safety, and launch site dimensions. Familiarity and compliance with the NAR Model Rocketry Safety code is required, and will help inform your decisions when flying model rockets.


    Finding a Prospective Launch Site

    The NAR Model Rocketry Safety Code outlines the minimum launch site dimensions for each motor size, under optimal conditions, and this should be considered only, a starting point in selecting a location to fly.  The term 'minimum dimensions' is important here, because in real world practice, you should look for more space to safely and reliably recover rockets. In particular, do not fly close to busy public areas like soccer fields, parking lots, or near buildings like schools, businesses, or private residences.  If you are pressed for space, it is better to find a launch area that borders less than ideal recovery space, such as open desert or trees, so you do not interfere with others' use of public space or risk injury or property damage to buildings or cars. Some school yards may have suitable open space, but ball fields may be in use by other users. There may be public parks that have suitable space and allow model rocketry, but check with the property manager--also known as the Authority Having Jurisdiction--before you fly.


    A good first step in selecting a launch site is to measure the dimensions of the prospective launch range in Google Maps, by right-clicking one edge of the range and selecting Measure Distance from the menu.  Then click the other edge of the field to display the distance.  Measure the smallest dimension of the field. Once you have a prospective launch site in mind, set about obtaining permission to fly model rockets there.


    Obtaining Permission to Launch Rockets

    While it is tempting to think it better to ask forgiveness than permission, to do so not only puts you at risk of civil or criminal penalties, it jeopardizes the continued use of public spaces for all rocketeers. Be sure to ask permission before deciding to fly model rockets, whether that is at a school field, a municipal field, or apparently unused open space.  Someone owns all land, so do your homework and work to build a good relationship with the landowner or property manager. And when you arrive at a prospective launch site, even after you have permission, be sure to be friendly and communicative with other users about your plans, your impact on public space. If there are other activities at the site, cancel your plans and launch another day. Many people will be interested in your launch if you are friendly, cordial, and share your knowledge and excitement. Do your best to be a good ambassador and to maintain our hobby's reputation as a fun, safe, and educational hobby, and always aim to leave your launch site a little better than you found it. This means, at a minimum, collect any spent motor casings, igniter, or igniter plugs, and any recovery wadding you can conveniently reach. But it looks good when you are rummaging around in the desert for your wayward rocket to collect any garbage you pass.


    Here are some ideas of where to look to determine the Authority Having Jurisdiction:

    • For school fields, the principal's office is the best place to start, and you should make clear that your flights will take place outside of school hours and activities. But it is often the case that highlighting the Science, Technology, Engineering, and Math (STEM) aspects of model rocketry will win over a reluctant school administrator.  Offer to share your experience and grow the hobby, perhaps by teaching rocketry in an after school class. You can likely find the principle's email address on a school website.

    • For municipal parks, look online to find who manages the park; it may be a city or town park, or it may be a county park. Information on many parks and recreation websites is sparse, but often, you may find mention of model rocketry policies or ordinances in sections dealing with model airplanes or drones. It is fair to say that busy parks, like Reid Park in Tucson, are not good places to launch model rockets, but parks with large undeveloped spaces can be good candidates.

    • On private land, contact the landowner, demonstrate your knowledge, enthusiasm, and responsibility, and work to maintain good rapport.  If you don't know who owns a prospective property, review of public records available online can help.  Pima County maintains a good mapping system that includes property ownership details: PimaMaps Viewer.


  • 1 Jun 2016 11:50 | James Cramton (Administrator)
    All these steps include the following important note;

    HAVE FUN!

    Step 1: Decide you want to take the step of certifying as a High Power Flier.

    • This is the gateway to other certification levels
    • This gives you the ability to fly larger rockets, using larger engines and both of those = MORE FUN!
    • It is nothing to be intimidated by, everyone launched their first High Power Rocket at some point and we are all willing to help! That leads to step 2.
    • In planning and building your first Level 1 capable rocket,  you will understand building techniques, rocket dynamics, and safety protocols in a new light. Level 1 rockets are much heavier than sport models, and there is a lot of power in a Level 1 motor, so how your rocket flies and recovers truly matters!

    Step 2: Join a club and an organization!

    Now you need a place to attempt the flight, and a community to support you. That is where SARA comes in!

     Join SARA

    • You also need to be insured, since you are flying bigger rockets in a controlled environment, you need to be a member of the National Association of Rocketry (NAR) or Tripoli (TRA). These organizations also provide support and will give you your certification card to buy engines. Critically, they provide insurance for members who abide by the safety code. Both are great and SARA is affiliated with both. Key differences between these organizations are:
      • If you want to eventually experiment with making your own engines, Tripoli is the place for that.
      • If you also want to compete in low power competition, NAR is your organization. 
      • Tripoli's Junior (under 18) certification program starts at 12 years old.
      • NAR allows Juniors to certify to fly high power at 14 years old.
      • From a practical perspective, there are more NAR members in SARA who can mentor and approve your certification. If you need to certify with TRA, you will need to coordinate more closely with the Tripoli Prefect.

    Step 3: Review the safety codes. These are our guiding lights and are observed at all SARA launches. These set expectations and responsibilities for fliers at the field.

    Step 4: Mentor program. Now you will need someone to oversee your launch, at SARA we understand that there are many questions you may have prior to certification day. That is why you should get a mentor, a mentor can help with questions about engine selection, kit selection and construction. In many cases you have a rocket that will be suitable already in your fleet!

    Step 5: Read our resident super certification specialist Art Just. This article is fantastic and will help with the steps below.

    Step 6: Plan your build using a rocket simulation program. You can simulate flights on different engines and make sure its stable.  Art's article mentions the differences between the two programs.

    Remember that at SARA's launch site, our ceiling is usually 6,500 feet above ground level, so don't choose a skinny dart of a rocket that will soar above our ceiling. SARA (and you!) will get in trouble, and you likely won't see your model again. Low and Slow is more spectacular anyway, so shoot for something under 3000 feet for your certification flight, so you have an easy time recovering  your model. Plan for motors you might want to fly to higher altitudes in the future when calculating your model's center of pressure/center of gravity relationship; bigger motors will be heavier, so they will destabilize your rocket by moving the center of gravity backwards. Plan ahead to keep your options open.

    Step 7: Buy neat things! After consulting with your mentor or if you are confident in research you have done. 

    • HAZMAT Shipping: You will need to buy an engine to certify--only one. Once you are Level 1 certified, you may purchase as many motors as your wallet will bear. However, high power motors must be using HAZMAT ground shipping, which costs extra. You can work with your mentor or other SARA members to be included in one of their orders and share the fee, or you can buy during a vendor's site visit without shipping or just pay the approximately $30+ HAZMAT shipping surcharge.

    Step 8: Build your rocket (If needed).  Need help?

    • Work with your mentor
    • Build it strong, don't push limits, and if in doubt, set the epoxy down and ask your mentor.
    •  Reference tips from Art Just
    • Use rocketry forums, many people can help with your build, you can also search for your question and see if someone already answered it

    Step 9: Plan a date! If you do not have a mentor yet, email members@sararocketry.org that you would like to Level 1 and pick a launch date http://www.sararocketry.org/events

    • Someone will email you back and let you know where to find them at the launch. 
    • Download and print the application off NAR or TRA websites.
    • Make sure you have read the safety code and can answer questions about your rocket.

    Step 10: Launch!

    • Meet with your mentor, and be prepared to show him how you built your 
    • rocket and assembled your motor. You'll need to show the center of pressure and the center of gravity with the motor installed. 
    • Set the rocket up on the pad.
    • Grab a camera! A GoPro a few feet from the pad, looking up captures awesome footage.
    • 5.4.3.2.1 Launch!
    • If you can recover the rocket safely in a condition that can fly again with a new engine and no repairs, you are Certified!
    • Send in the application, and you will get a new card, you are now official!


  • 7 Feb 2016 11:07 | James Cramton (Administrator)

    As a Level 3 certification holder in both NAR and Prefect for Tripoli rocketry associations, I have witnessed quite a few Level 1 certification attempts.  The reason I say attempts is because there have been quite a lot of failures that would not have happened if the fliers had done the proper amount of homework, learning as much as they could about proper build techniques, stability issues, and safety.

    Planning your build is the first big step.  Whether you chose to build a kit or scratch build your rocket, the same basic principles apply.  I always suggest that for a certification flight you keep it as simple as possible.  You can always try more complicated steps after you get your certification.  Motor eject, electronic eject or both at Apogee is a stronger bet than trying dual deployment or other more complicated methods.  I have had several people try for their certification using dual deploy, minimum diameter, GPS tracking, and as large an I motor as they can find.  Guess what, most of them failed.  A simple build with single deploy, minimal electronics or none and a small H motor in a medium size rocket with 3 or 4 fins and a nose cone will be successful most of the time.  Know the safety codes and stability factors, such as center of gravity compared with center of pressure and what factors affect this relationship.  You need to know the weight of your rocket compared to the amount of initial thrust of the motor you choose.  What is that limit?  I am not going to give you all the answers, that is part of doing your homework and being able to answer correctly when the person doing your certification asks.   If you don’t know the answers to these basic questions, you shouldn’t be allowed to fly.  Having a safe stable rocket is our main goal.

    If you are building a cardboard tube rocket with wood centering rings and bulk heads, you need to have good tolerances where your couplers and nose cone are inserted into the airframe.  The reason for this is, if they are too loose, you might get drag separation when your motor burns out.  The momentum of the rocket will tend to want to have the heavier pieces of the rocket keep going up, such as the nose cone.  The pieces with more drag, such as the booster section with the fins, will tend to slow down faster.  This is drag separation, and it will cause your parachute to deploy early causing the shock cord to zipper the airframe.  If you get a big zipper, you will not pass your certification.  If you have the proper tolerances, you should be able to pick up your rocket by the nose cone and not have it separate.   You should be able to shake it a little and then have it separate.   You can adjust the fit by using a little masking tape, if it is too loose or sand the coupler a little, if it is too tight.  A little talcum powder at these separation points will help also.  If you have a fiberglass rocket or if your nose cone is heavy, you will want to use sheer pins at the separation points.  These are small nylon screws, usually #56, that are inserted thru holes in your airframe at the separation points.  Your black power charge(s) should have enough pressure to sheer these pins and cause separation.   It is important to know how much black powder to use, and the way you do that is to ground test your rocket.  You want to have enough pressure to separate your rocket, but not enough to blow it up.  There are websites that you can use to calculate the amount of powder so you have a safe amount to start with.

    More and more kits that are being sold are made of fiberglass.  This presents some build issues that you don’t run into with cardboard and wood.   Epoxy will not stick to fiberglass unless it is roughed up first.  By this I mean get your 40 or 60 grit sandpaper and scratch the surface of the fiberglass anywhere there is a joint with fiberglass and epoxy.   If it is a thru the wall fin design, follow the manufacturer’s directions for gluing on the fins.  Most will suggest that you add filets where the fin root attaches to the motor tube.  This can be done either by drilling holes in your airframe and using a syringe to inject epoxy or leaving the aft centering ring off until you filet the fin roots to the motor tube.  Again, make sure you have a good bond on the bulkheads for the nose cone and booster sections.  These are where your eye bolts are attached for your shock cords.  There is a lot of tension on these during deployment.   A good way to add strength for these bulkheads is to recess them a little ways into the nose cone or booster section and glue in ¼ inch wide band of material above the bulk head.  Again, scratch, scratch, scratch the fiberglass.  Adding a little ground fiberglass powder to your epoxy with help to strengthen the bond.  You can get this at several rocket suppliers or composite suppliers.

    One way that we can all learn, especially those that are going to try for their level 1, is to talk to other members about their rockets and what has worked for them and what has not.  I have personally learned a lot from talking to others and by observing how they do things. I have never run into anyone that wasn’t excited to show off what they have done and to share new ideas.  I know that it is a little intimidating to go up to someone you don’t know and ask for their help.  As part of the certification process, it is my responsibility to make sure the rocket is safe to fly and to make sure the flyer is aware of why he or she did certain things.  I can’t do the rocket setup myself, but I can observe, and if I know that, for instance, the way the parachute is packed, it probably won’t open, I can stop them from continuing.   In a case like that, I would demonstrate the proper way and then let them do it themselves.  It would have been better if they had asked a fellow flyer to show them so they could do it correctly the first time themselves.  If you are not sure, ask someone who knows, if you think the answer you get is not correct, ask someone else and have them explain it.

    Part of launching a rocket with pretty good knowledge of what it is going to do is to run simulations.  There are several programs available for this.  Apogee rocketry sells one called RockSim.   Another program that is free is called Open Rocket.  There is a little bit of a learning curve with each of these, but the results are worth it.  How high will your rocket go, will it bust the waiver?  What is a waiver?  All of these things are the responsibility of the flier.  Know what factors affect how your rocket flies; wind, drag, shape of fins and nose cone, weight, etc., and what the affects will be.

    This seems like a lot to learn for you Level 1 certification, but if you do it will be a safe and fun hobby.

     

    Art Just

    NAR level 3 Number 87145

    Tripoli Prefect Level 3 Number 12693


  • 6 Feb 2016 16:25 | James Cramton (Administrator)
     Our rocket workshops take many forms, subject to the needs of our work space, the type of projects we pursue, the time we have to work on our rockets, who shares our home, and all sorts of other factors--even what kind of pets we have!  I think it would be helpful from time to time to post articles here in our How To section that give us a look at different club members' rocket workshops. Few of us have the space to dedicate to our hobby the way we would like to do. I always like to pick up ideas from other modelers, and often, the work space they have carved out gives us ideas for how we can organize our own space. 

    So I'll start out this mini-series in the How To section with a tour of my own work space, such as it is; it is shoehorned around kids' dress up and art supplies in the back of the TV room, but also hidden on shelves in the garage and in my closet. Like many Arizona homes, the lack of a basement puts a premium on storage space, and as you may have noticed, rockets can take up a lot of space! Yet I don't like to look at unfinished projects all the time, so I try to have a place set aside out of the way where I can leave projects to sit for a few days or weeks when I am busy on other things.


    Primarily, I have a 6 foot by 2 foot folding table that I use for my low power projects--these days, mainly my competition models. Many of the boxes used in shipping rocketry supplies wind up being used as storage boxes for other supplies. 

    On shelves in the garage, I have a couple clear plastic hanging file tubs with various supplies in them. I have 8 or 10 in total, each storing items typically used together. Some hold small rockets ready for pre-flight check, while others hold small rockets in need of repair. One is dedicated to recovery supplies--parachutes, shock cords, streamers, etc. Another has nose cones and transitions.  Another fin material of various sorts and sizes.  Inside each bin, many items are stored in ziplock bags labeled clearly so I can grab just what I need easily. My kids are at an age where I like to be inside to keep an ear out during the time they may take to fall asleep, so I prefer to work inside.  The clear plastic sides on the tubs mean I can walk out to the garage and pick the bin or two that I need, and bring them inside to work for the evening. And the bins stack nicely so the bins can stay out from under foot. A longstanding rule in our house is that model rockets are never left on the ground, where clumsy things like feet and dogs and other objects under the power of gravity tend to trample cardboard models. Delicate competition models proliferate, and I found a nice way to protect our competition models--punching holes in an old shipping box and storing models vertically under the table.  Also tucked under there are separate tackle boxes and toolboxes for supplies, adhesives, and tools. Depending on the launch, I may take some or all of these tackle boxes along for the day.

    Cardboard body tubes and the ever growing collection of unbuilt models I picked up as a 'bargain' store nicely next to the table in an old shipping box with the top cut off. I tend to store tubes of the same size rubber banded together, although my coupler stock I use for making custom tubes I store nested inside themselves. A word of warning--floods can happen anywhere for the most ridiculous reasons, so always put cardboard boxes up on blocks off the floor; wood blocks or PVC pipe both work well. That laundry machine is half the house away, or that window never leaks, except when it does. You have been warned!


    High power models are built and live mostly in the garage, which, due to the bake oven
     effect in a Tucson garage, means I only work out there in the cooler months or late at night, after the temperature drops below 100 degrees. And due to their size, storage of 4, 6, or 8 foot rockets is a challenge left to the garage rafters.  Nylon webbing works well for heavy rockets solo on a rafter, while lighter rockets can store more compactly in a padded PVC A frame hanging from 2 rafters.  Both configurations can be slung above head height.


    Due to the temperature fluctuations in a Tucson garage, rocket motors can't live in the garage. To store motors safely, they must be in a spark-proof container at least 25 feet from sources of open flame.  In our home, that translates to the space under my desk. Black powder motors I store and organize in plastic toolboxes, and I have a tackle box full of my reload casings, brushes, closures, and other reloadable motor paraphernalia.

    High power motors, however, I store in a lockable steel trunk lined with plywood. I sort them into reused boxes or ziplock bags by manufacturer and diameter. Before each launch, I transfer the motors I may need to ammo boxes for transport.

    Then there is the question of where to paint.  We are fortunate that we have largely undeveloped desert behind our house, with an easement between our house and the neighbors' yards.  this lends itself well to paining, which we accomplish with the  help of rebar pounded into the ground.  Most rockets get painted vertically with the rebar through the motor mount, although overturned cat litter buckets serve well to hold models horizontally if needed. All this done well away from pavement and any foot traffic.

    If I were able to change anything about my rocket shop, it would be to have a climate controlled space dedicated to rocketry close enough to the rest of the house that I can keep an eye on what's going on without having to set up and put away rocket projects regularly.  Having all the rocketry supplies, tools, and work space in one undisturbed area is a luxury I don't have right now, so I have to get creative with the storage of rocket supplies and completed models.  Thankfully, I'm married to a goddess of patience and tolerance, who doesn't seem to mind sharing closet space with a full rack of model rockets and the smell of spent rocket motors.  We should all be so lucky!  Thank you, Rachel!


Copyright © 2021 Southern Arizona Rocketry Association (SARA)
Southern Arizona Rocketry Association is a volunteer run community educational organization in Tucson, AZ

Powered by Wild Apricot Membership Software