Thinking about going for my level 2 and could use advice please.

I have decided to go for my level 2 cert. I would prefer to scratch build it, although I don't know where to begin. Would you suggest using OpenRocket or some other kind of program like that?

Should I just buy a kit? If so which would you suggest?

Thank you very much for your time and any help!

If you have not designed a rocket before might I suggest starting smaller than your L2 rocket? Not saying you cannot do it, but your stakes are higher by it being a cert intended rocket.

I use Rocksim, but the basics are similar enough to Open Rocket. Years ago, on a forum far, far away, I created a few basic Rocksim instructional videos. Maybe they might be helpful. Username and password are both guest.

https://rocketryfiles.com/?p=home&d=FlightSimulation/Rocksim/MarksRocksimVideos/

That said, if you went with a kit for you L2 I would use dual deployment personally. Take a look at the Wildman Dual Deploy. You could adapt down and fly it on 38mm motors, or use the native 54mm mount.

https://wildmanrocketry.com/collections/3-fiberglass/products/wild2

Danielle Washington said:

I have decided to go for my level 2 cert. I would prefer to scratch build it, although I don't know where to begin. Would you suggest using OpenRocket or some other kind of program like that?

Click to expand...

Yes. Use OpenRocket. You'll want to simulate the rocket no matter what you decide to build.

And certainly scratch build the rocket, if thats what you want to do. This is a hobby. Do it however is the most fun for you.

That said, scratch building covers a lot of territory -- from kit bashing to fabricating your own airframe, nosecone, fins... Scratch building might mean copying -- or adapting -- an existing design, or building to an entirely original design.

Other than (presumably) having your L1, you don't say what you know how to do, to what kind of hardware you have access, what tools do you want to use, or why you want to scratch build. How deep do you want to dive into this?

If you are going to put the rocket together from off-the-shelf components, I might suggest you start with something (the airframe, the nosecone, motor mount, etc) and design the rocket around that part.

Constraints are important in a design: How large a rocket can you transport to the flying field (what will fit in the car, van, trailer). What motor do you want to use for the cert, and what is the biggest motor you want to fly in the rocket after your certify? etc.

I did my L2 cert in a Madcow 2.6" FG screech. Good kit, but it should have at least 3/32" fins. I put a K740 in it and the 1/16" G10 actually held up, but my cert was on a J500, so a baby J. I recommend having DD (Dual Deployment) and some sort of GPS tracking system. The BRB 900 is what I used. A kit is easier, especially if its fiberglass. I find it to be super easy to work with, especially using Rocketpoxy. You just have to make sure you are sanding the parts in a cross hatch pattern. L2 gets you to some pretty big motors. I recommend getting something that you can stuff a really big motor into if you so desire. My Screech was built with a 54mm mmt, and I recently flew it on an L935 to 14,400 feet. Unfortunately the lamination on the fins peeled away and I didn't get the 19,000 feet I wanted. Anyway enough rambling. If you are designing your own rocket and want to go with fiberglass construction, I highly recommend Upscale CNC. He is doing some amazing work for me making parts for kits that I will be selling. I also recommend going for something that has fins that have some sort of angle on the trailing edge away from the base of the rocket. This will make breaking a fin less likely. If you want to keep your sanity don't go with something too big. It is a learning process. Something in the 2.6"-3" range I believe is good for an L2, unless you have a very limited field size. I am very lucky that the clubs near me have some very wide open fields and high waivers. Best of luck to you, remember to study up for the written exam. If you have any questions feel free to ask.

-Matthew

Good for you! Are you a member of NAR or Tripoli?
What rocket & motor did you L-1 with?

If you found building that rocket easy, I would go for scratch build/design of your own. If it was a bit tough, opt for building another kit for practice & developing your skills, before attempting a design of your own.

Next Q is: was your L-1 paper or fiberglass kit. I recommend fiberglass for L-2 mainly for it's durability and being less likely to get damaged from travel/handling.
Paper is fine, if that's what you are comfortable with. Been around forever & most of us started with that also.
What is your timeframe for doing L-2?

You can just hang out here for awhile...if you are not in a hurry. Reading some build threads such as this is an education all by itself: https://www.rocketryforum.com/threads/how-to-build-a-stock-3in-darkstar-cj-step-by-step.55019/
it's pinned to top of High Power thread here.

It will take several days worth of time to be comfortable with Openrocket unless you are a program wizard.
Once again your timeframe will dictate how far & how much time you are willing to invest in this.
Don't forget you need to pass a written test for L-2 also.

After some answers the above Q's it will help in giving you more accurate advice.
Good luck & welcome to the Forum....... what ever you decide, I would keep it simple & basic design of 3 or 4fins and a nose cone.
Learn to design around stability according to ratio of center of pressure to location/relation of center of gravity. That and the basic rule of at least 5-1 thrust ratio. If you already understand these, you are half way there...if not..get ready for some homework.

To reply better,

-What types of rockets have you flown
-what style do you enjoy flying
- do you want to use electronics
-what size motor would you like to use
- how high do you want to go?

Level two covers A LOT of ground (and air). You can pop a tank a couple thousand feet in the air, or you can rip a 3" minimum diameter a little over 20,000'

What do you want to do for your L2? Do that! You can cert the easy way, the hard way, or any way in between, but it's about having fun while learning new things so think about what you want to do and learn how to make that happen.

I just did my L2 in May, I used a kit as I am still learning a lot. I used a Madcow rocketry Dominator G2 4", which was a Black Friday sale item. Just posted some pictures and video in the high power section of the forum link. Used a L1390G motor 75mm.
But if you have a limited budget, smaller rocket and motor will save you a lot of money. Dual deploy works great and I posted lots of questions about black powder charges and such here on the forum while slowly building it.
I am looking forward to the L3 build which I think will be scratch built/design.

It comes down to what do you want to do and how much you have to spend, both in time and money. If your desire is to do a L2 scratch build, then do it, use open rocket or rocksim, ask lots of questions and don't rush it. Enjoy the journey!

Thank you for the advice! To be more specific: I built my L1 from scratch it was fiberglass with an H motor. I found it fairly easy but definitely a learning experience which is what I'm most interested to get out of my L2 so I think I will go scratch for that too. I am planning on doing dual deploy. I have many tools at my disposal through my schools design center. I am a member of Tripoli and I hope to fly sometime late fall. I don't know what size motor I would like to use or how high I want to go. I have flown my L1 and helped with a larger rocket my school built on a team. I will definitely check out some of the links you have posted to get a better idea of what I'm doing.
thanks!

When building my L2, knew that there would be a 10,000 waiver so the design was to stay below that, as I wanted to push myself, I picked a larger motor size 75mm and one of the larger motors to cert on. If you are attending a Tripoli launch in fall for your L2, know the waiver hight and stay well below it. Found that though rocksim showed my rocket estimate to 9240 feet, it was well above that. Your local Tripoli can be a great resource, though I found for myself, the forums here are great, as I can ask questions, find answers and such when I have time. Dual deploy works great, and again I asked lots of questions here to address the questions I had, altimeter questions, BP charge calculations, parachute size, etc.
Knowing that the range is out in the desert, and the ground is hard, I did not want my rocket to come down hard and break a fin, so a larger main parachute, and fin design that allowed the rocket body to impact first, not a fin.
Good luck!

If you scratch built your L1, then you should be fine with scratch building your L2. I say go for it! If you're new to OR, how did you simulate your L1 to get motor delays/ejection right?

A couple of other pieces of advice:
4" is a nice size for a first L2 project. It's big enough to get your hands in and not so big it's hard to store later.
While it's a good idea to have tracking on board, I'd try to keep your L2 flight in visual range (~5000' for a 4" with reasonably good eyes) to help make it easier to find again.
[DD comment removed, didn't see that you were planning that anyway]

Danielle Washington said:

... I am planning on doing dual deploy. I have many tools at my disposal through my schools design center. I am a member of Tripoli and I hope to fly sometime late fall...
thanks!

Click to expand...

Since you are a student, something to study <smile>

https://www.rocketryforum.com/threa...pyrotechnic-deployment-by-jolly-logic.145149/

There are compelling arguments for sticking with proven solutions, but the state-of-the-art for dual deployment systems is a little clumsy.

Your response shows experience with needed tool & skills to work with fiberglass...outstanding.
What I would do:
Make my second rocket build be a 4in diameter standard 3or4 fin & nosecone with a payload section of 18-24 in. & fincan in the 48in long regime.
12 in coupler for avionics bay. plenty of room of fiddle with.
75 motor mount is optimum, offer more choices for altitude , will weigh around 13-17lbs ready to fly & go anywhere from 1500 ft on a 2-grain 54mm motor to 10-15,000 ft on big L-small M

If you go with 54 motor mount it will go 1500 on 2-grain 54mm to around 8-10 on full size L- [for 54, not overall Full L].

These basic dimensions, will almost guarantee a stable, fun rocket.[ I say almost, cause there is ALWAYS some way to screw it up...lol]

If you use a 3in airframe you can go about [should weight around 8-10lbs] 1500ft altitude with a medium 38mm motor all the way to around 15,000 ish with big 54 motors.

Don't forget to vent [small hole] fincan & payload section, so there is no separation of parts due to internal 'external airpressure differences.

So where you fly and your limit on altitude [Waiver] will be a big factor on choice.
My personal preference for all around sport flying , ease of transport, easy to prep for flight & not a pain to lug out of a field is a 3in. diameter rocket.
Versatility is word that comes to mind. I can fly it on so many different motors and dial in altitude to "fly the field" I'm at.

You could get your L-2 on the 3 in with a small 54 at around 3500 ft.
The 4in same motor around 1500-2000 ft.
[At J-315-R] in both cases for example]

My opinion [and that's all it is] you should learn standard dual deploy with altimeters if you plan on "learning" for future builds. Not saying anything bad about JOLLY Logic just saying you need to learn to use all the the tools in the toolbox.
So that's my 2 cents worth of very basic advice, based on 16 years of flying all over the country & what my friends have in their arsenal's!!!
Good luck with your build & most important....have fun!!!
Please share it with us, whatever you decide.

Could also do a really sweet 2.6" with a 54mm hole

Easy size to build and fly, doesn't take up a lot of room, but enough room for a lot of power.

Much good advice here. I support scratch building. I did that with my L1 and L2. Also the DD is a good idea. If you do sufficient ground testing, using the altimeter in an actual flight won't be much of a step.

As other have said, you need to take a lot of things into account when you design your rocket. I think the most important is where will you normally be flying? If your home field has a 10K waiver, your L2 rocket will probably be much different than if they have a 30K waiver. There are more things to think about and consider in your design than just rocket/flight issues, it's also then environment it will fly in. Average winds, waiver altitude, terrain, ground cover/trees, tracker RF propagation, etc. All those things may influence what you build. They may not, but you should consider them and determine how much influence they should have in the design.

Bottom line, have fun designing, building, and flying! It's a great hobby.

So I'm almost done with my design I want to do a 3" diameter with a 54mm motor. I'm not sure how to decide on size of the chute and drogue or what motor to use. Also, how do I know it is good, is there anyway of telling if it has a serious flaw in the design? I feel dumb asking but I am not totally sure.
Thanks for your help!!

Nice size. I'd start with using open rocket or rocksim to do a complete sim of your design, noting that it will certainly come in slightly heavier than just the material mass due to epoxy, recovery harness and fittings etc. This will give you a weight to work out parachute and motor sizes that are suitable, and you could upload the sim file here for recommendations.

Simplicity is the friend of success. Avoid overly complex recovery systems.

Danielle Washington said:

So I'm almost done with my design I want to do a 3" diameter with a 54mm motor. I'm not sure how to decide on size of the chute and drogue or what motor to use. Also, how do I know it is good, is there anyway of telling if it has a serious flaw in the design? I feel dumb asking but I am not totally sure.
Thanks for your help!!

Click to expand...

Post your OR file and you will get some feedback/criticism.

If you have a reasonable mass estimate you should be able to purchase a suitably rated chute, or work out the size using an online calculator (I don't know a specific link).

As for motor, choose brand/impulse/color that you want to fly . My advice is to not go with a short-burn motor so as to not hammer it too hard for the cert.

Enjoy the journey and good luck with the project.

The best on-line chute size calculator I've come across. Note: You can select between different styles of chutes (very important to get that right).
For example, a Wildman Recon chute will be of the Skyangle design. A Fruity Chutes Iris Ultra style isn't in there though, so you'll have to go with their weight chart.
That goes for all chute manufacturers, they'll all have a chart for weight vs. decent speed. Top Flight Recovery makes great chutes at great prices too. Go with a chute in your price range that will bring your rocket down around 20 fps and you'll be OK.

Danielle Washington said:

So I'm almost done with my design I want to do a 3" diameter with a 54mm motor. I'm not sure how to decide on size of the chute and drogue or what motor to use. Also, how do I know it is good, is there anyway of telling if it has a serious flaw in the design? I feel dumb asking but I am not totally sure.
Thanks for your help!!

Click to expand...

I like the 54mm for L2. It lets you fly all the J and K motors and some small L motors. The 3" vs. 4" is a choice you can make. I would recommend checking the waiver at your favorite fields. I built a 4" 54mm for my L2 and when I went for 10k ft on a CTI L935 I only got 9559 ft. but if your local waivers are 10k or less, you might want to up the diameter to be able to fly bigger motors without busting the waiver. You know that sooner or later you will put the biggest motor that will fit in that rocket and light the fire!

I liked the 4" tube as I can get my hands inside without difficulty. Made some assembly easier than the 3" I did for the L1. As others have stated, open rocket or rocksim it and see. KISS philosophy - keep it simple...

Here is what I have if anyone wouldn't mind taking a look. I just picked a random motor to have the weight in it. All critiques are welcome just remember I'm new to this lol.
thanks

Ok, but fins are not very aerodynamic.

I haven't done a super sonic flight yet...so I will leave the comments on fin shape (planform) to others, however some things did catch my eye. in the design file the nose cone has no shoulder, you should add one, the shoulder to be about 3" in length and move the bulkhead aft to match. the shock cords are about 180" too short, each. yes you will want a minimum of 15 foot of cord for each section(probably still learning the program ). did notice that you put the main parachute in the booster section where most folks put the drogue (not a problem if you are not using the motor eject as a backup to deploy the drogue). aside from that it looks like the rocket should work, main question you should be asking your self is, 'does the rocket do what I want it to do'.
Rex

Some more comments in addition to Rex R's. I would use a smaller motor. For me there is no reason to fly out of sight for a certification flight. Try to keep it down around 3000-4000 feet. I believe that my cert flight was just under 4000 ft and simed with OR to 4190 ft. Also super sonic flights are cool but if you don't build the rocket for it then you could be looking at a sky writer when the fins decide to leave the rocket at Max Q. What I have done on all of my scratch build rockets for each of my certification attempts is to take a rocket kit and make some changes to make it my own or take a model rocket and upscale it to high power size. My level 2 was a Semroc Lazer-X upscaled 3 times. The rule of thumb that I have been told and use for shock cord lengths is at least 3 times the length of the rocket for each shock cord. So in your case an 18 ft shock cord. A great place to get shock cords is One Badhawk Recovery (www.onebadhawk.com). Teddy can provide all the hardware and shock cords you need that will take anything you can throw at them. Another rule of thumb for parachute sizing is I like to stay below 16 ft/sec descent rate for the main, and usually around 50-60 ft/sec for the drogue descent and main deploy. I like perfect flight parachutes because they relatively inexpensive but you can get whatever you like. Good luck on your build and flight.

When thinking about your recovery setup consider how you would like to fly it. Some people use really slow sink rates, and others' faster. I personally go for about 100fps under drogue and 22fps (give or take) for main. It does depend on what you are landing on, rocket design and wind speeds etc. You design it for what will be a successful flight for you . So, what I am saying is to listen to advice but as designer/builder you have the ultimate choice.

I appreciate all the help! Does this look a bit better?

umm, you're launching from India? so now it looks much like a generic rocket(form follows function they all look much the same) you might want to look at your shroud line material (length about the same as chute diameter). hmm just thought of something...I'll be back...fins are kind of large and no centering rings, just as an example take a look at this.
Rex

We're getting there. A couple things which I had problems with too when I first started doing dual deploy in OR. The main parachute needs to be set for "specific altitude during descent" and then set the altitude to deploy at. I usually set that at 600 or 700 feet. One thing you don't want is it to be too low for the chute to deploy, open and fill with air, and then slow the rocket down. The other thing is there is a red ! in the flight simulation. If you hover over it tells you that there is a "recovery device at high speed". This is due to the drogue is deployed at apogee plus 3 seconds. I always set that at 0 seconds. I still would caution you at having a cert flight that goes supersonic. If you don't have the motor hardware already I would drop done to the 1280 case and fly it on a J415 for your cert flight. That is still almost 7000 ft. You can always push it with a bigger motor later. You could even do the K550. That is a really cool motor with a big white flame. The green K805 would be cool too but high performance for a cert. But to each their own. Something else you need to do is add the other items like U-bolts, motor retainers, batteries, av bay sled, etc. Just add them as mass components and then you can select the type of mass component like you did for the altimeter. You have a really high performance rocket design. Should be a really cool cert flight. Good luck. I have attached a new copy of your file with the things I have talked about here changed and a couple other motors selected.