Quantcast

Is this a good L3 rocket?

The Rocketry Forum

Help Support The Rocketry Forum:

Ez2cDave

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
4,281
Reaction score
1,231
You can build an L3 rocket for $150 if you:

- Have all the electronics already.
- You have a parachute that will work as a drogue.
- Buy a "play chute" for the main ($25) and sew you own extension line ($10).
- Buy cheap 1" tubular nylon on Ebay/Amazon ($25/20yards).
- Use concrete form tubing, two 8" 4ft pieces ($20). Bare. Cut a piece down for a coupler.
- Cheap 1/2" 5-ply plywood for fins and CR's and bulkheads, cut them yourself ($20).
- No motor mount tube. Just use CR's and a thrust plate (double up 1/2" ply).
- An ugly conical nosecone made from a large funnel ($10). Dirt for nose weight.
- Hardware and supplies ($40). No paint.

I've seen it done. It will take a lot more labor than a kit. You will not be proud of it. People will laugh at you.

Or, just enjoy flying more L1/L2 rockets and wait until you have a bigger budget. :cool:
(1) Borrow Electronics.

(2) Borrow Parachutes.

(3) Use Concrete Form Tubes. ( Fiberglassing or "Quasi-Glass" - Optional )

(4) Borrow a Nose Cone or or make your own, using the "Ace Fugue Shroud Method" https://www.ninfinger.org/rockets/US ROCKETS AIR-4 REPORT ACE FUGUE SHROUD METHOD.pdf

(5) See my post - https://www.rocketryforum.com/threads/is-this-a-good-l3-rocket.143795/page-2#post-1859241

My own Level 3 plans got "sabotaged" by a combination of the pandemic and "free-loading" family members ( prior to Covid - 19 ), in late 2019 and all of 2020 ( thanks to the virus ). So, for 2021, I think I might "change gears", "put my money where my mouth is" and do an "Extreme Low Budget" rocket for my Level 3 Cert . . . If I go that direction, I will do a build thread, with pictures and full documentation of the cost !

Dave F.
 
Last edited:

Conway Stevens

Tacos For 10
TRF Supporter
Joined
Aug 17, 2020
Messages
198
Reaction score
112
Location
Wellington, Co
When I did my L3 back in 2006 it was right around $2,500.

That included everything. Such as the AMW N2800W with 98/17500 hardware. Rocket rage main and drogue. Tubular Kevlar harnesses, all electronics, etc. Rocket was 5 inch diameter 98mm mount 15 ft tall all composite modified Intimidator kit.


I had flown a ton of years previously as L1/L2 flying. Never felt rushed to just jump at L3. It's not just a money thing but it should be a enjoyable experience thing that leads up to the event of going for L3.

I personally think going way to cheap can also be a way to potentially plan for failure. you absolutely should set a budget. But don't think of it as a budget you have to do all at one time. Start planning look at doing it right the first time. Get what you'd really like. Buy things here and there. You could set a total budget for the end of the project over a years time maybe $2k would be feasible. But save up get a good kit. Start working with it building and saving more to do more. You also need to reach out to your TAP or L3cc and get them involved. See what their input would be. what ever you do. Plan for success. Enjoy the fun and other flying that can be at level 2. Once your L3 how do you plan to budget for $300 to $2000 motors for a single flight. Not including hardware not including rocket. Just propellant.
 

FredA

Well-Known Member
Joined
Jan 19, 2009
Messages
2,170
Reaction score
347
Why get an L3 if you are not going to fly L3?
Buy once, cry once for stuff you are going to re-use.
 

Conway Stevens

Tacos For 10
TRF Supporter
Joined
Aug 17, 2020
Messages
198
Reaction score
112
Location
Wellington, Co
Why get an L3 if you are not going to fly L3?
Buy once, cry once for stuff you are going to re-use.

Merit badge maybe? Have known a few that were like that. Flew and got their L3 and dropped out of the hobby or never flew another L3 flight.
 

Ez2cDave

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
4,281
Reaction score
1,231
"Bucket List", "Merit List", "Bragging Rights", etc . . . What difference does it make ?

Every rocketeer has different motivations and goals.

Dave F.
 
Last edited:

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
9,795
Reaction score
1,765
Location
Pasco, WA
Why get an L3 if you are not going to fly L3?
Buy once, cry once for stuff you are going to re-use.
I dont get to buy or fly L3 motors often, but really enjoy doing so whenever I can, so yes a I have a large investment in motor hardware that only gets used once or twice a year....its worth it!
 

hobie1dog

Well-Known Member
Joined
Jul 26, 2009
Messages
4,064
Reaction score
461
good thread that makes me realize I'll never bother with an L3 rocket, simply financially impossible when you live on Social Security income.
 

NateB

Well-Known Member
Joined
Nov 6, 2012
Messages
1,630
Reaction score
1,496
Location
NE Indiana
I don’t know if I will ever work on an L3 project. If I do, it would be as a personal challenge and I probably wouldn't regularly or even annually launch M or larger motors. The journey sounds fun though.
 

Tim51

Well-Known Member
Joined
Jul 4, 2015
Messages
954
Reaction score
232
Location
London, United Kingdom
I dont get to buy or fly L3 motors often, but really enjoy doing so whenever I can, so yes a I have a large investment in motor hardware that only gets used once or twice a year....its worth it!
I like your approach/philosophy (and your Cherokee M was a memorable and inspiring build thread by the way). I do regularly think / draft up sims of possible L3 birds and also think of different ways of doing it (incl making the journey over to Balls or LDRS to do it in style with something fast and high, like a few other Brits I know have ; ) and will do L3 one day, on the same reasoning you did. Most L3 fliers here won't ever fly M + impulse more than a couple of times a year due to suitable site/airspace restrictions. But I know none of 'em I've talked to regret doing their L3 cert, and all feel it was/is worth it.
 

Ez2cDave

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
4,281
Reaction score
1,231
This is my original 2019 Level 3 design, "TRITON", prior to the "invasion of free-loading relatives" and Covid-19. It uses concrete form tubes ( same for couplers ), a PMC 7.5" fiberglass nose cone that I paid $40 for ( used ), almost 20 years ago, and 1/2" birch plywood. 100 % my own design and scratch-built ( no kits for me ). The 14ft. military surplus chute was gotten on eBay, back in 2005, for $35. I will be sewing my own harnesses, made from 1" wide, hollow, tubular Nylon ( got a 100 ft. roll off eBay for $25, back in 2005 ).

I may still use this design and do the "Barebones Budget" L3 project after I get my L3 Cert.

95% that I will be using an AT M650 "Moonburner" . . . It has enough "kick" off the pad, followed by a nice gentle, regressive thrust curve. My goal is to remain sub-transonic ( below 950 ft/sec . . . 647 mph ).

It will be launched off my 12 ft. Black Sky "Extreme Rail".

Altitude should be 5200 - 6000 ft AGL, based on a Dry Weight ( no motor ) of 30 - 38 lb.

Maximum Velocity should be between 483 - 568 ft / sec ( 329 mph - 387 mph ) . . . Low, slow, & gentle !

Dave F.

TRITON-1 -COLOR.jpg




par15f.jpg





AEROTECH M650.jpg




ROUGH SIMS - 30 LB DRY WEIGHT.JPG




ROUGH SIMS - 35 LB DRY WEIGHT.JPG




ROUGH SIMS - 38lb -8oz DRY WEIGHT.JPG
 
Last edited:

Igotnothing

Well-Known Member
Joined
Oct 26, 2014
Messages
874
Reaction score
93
(1) Borrow Electronics.

(2) Borrow Parachutes.

(3) Use Concrete Form Tubes. ( Fiberglassing or "Quasi-Glass" - Optional )

(4) Borrow a Nose Cone or or make your own, using the "Ace Fugue Shroud Method" https://www.ninfinger.org/rockets/US ROCKETS AIR-4 REPORT ACE FUGUE SHROUD METHOD.pdf

(5) See my post - https://www.rocketryforum.com/threads/is-this-a-good-l3-rocket.143795/page-2#post-1859241

My own Level 3 plans got "sabotaged" by a combination of the pandemic and "free-loading" family members ( prior to Covid - 19 ), in late 2019 and all of 2020 ( thanks to the virus ). So, for 2021, I think I might "change gears", "put my money where my mouth is" and do an "Extreme Low Budget" rocket for my Level 3 Cert . . . If I go that direction, I will do a build thread, with pictures and full documentation of the cost !

Dave F.
I RSO'ed one of those. Sent it back for rework. It flew a couple hours later when I was off duty. Spectacular disassembly when the motor went forward through the rocket several hundred feet AGL.

Not that it can't be done, and many have. I hope you are next with success. I look forward to the thread.

<<Heads to garage where some of the rockets are made with plotter paper roll tube.>>
 

Ez2cDave

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
4,281
Reaction score
1,231
I RSO'ed one of those. Sent it back for rework. It flew a couple hours later when I was off duty. Spectacular disassembly when the motor went forward through the rocket several hundred feet AGL.
Was that a Cert flight ?

If so, the TAP or L3CC should have caught that, before it ever got to you.

Obviously, either a poor design or poor building technique.

Dave F.
 

Igotnothing

Well-Known Member
Joined
Oct 26, 2014
Messages
874
Reaction score
93
Have you found a nosecone that fits well??? I have a whole pile of HP Plotter Paper tubes... about 2.25 dia x 42" long.
I cheated. I turned one on the lathe.
Side note: I made a rocket out of PVC pipe and used an end cap + an aluminum tip for a nose cone. I think the tip is optional. Nothing in the rule book says the NC has to be pointy.

1609980630894.png
 

DAllen

Well-Known Member
Joined
Jan 18, 2009
Messages
4,950
Reaction score
956
I've seen someone (many may know) do his L3 using 5 gallon buckets--those are pretty cheap!

From the Ether...
I remember seeing that at LDRS lol.

There are a couple of takeaways for the OP from this thread IMHO:

1. There are a lot of people who are quick to tell you "THIS IS HOW YOU ROCKET" and give you all sorts of rigid advice. These are the same people who will shake their heads in dismay at abominations like the 5 gallon bucket rocket mentioned above or the flying basket in my avatar. Avoid this in the box thinking wherever possible. YOU decide how to rocket. If you're within the rules of both operation and safety then there's nothing wrong.

2. At the same time, there's a lot sage advice floating around these parts so you have to pick it out and decide what works for you.

3. As others have said $150 is probably just too small of a budget for anything that can stand up to the thrust of a L3. I'll bet the L3 Bucket rocket (with chute, electronics and internal structure was well north of your $150 figure. I'm not saying it can't be done but you'd be hard pressed to complete it much less find a TAP to sign off on it.

Remember OP...If you come to TRF looking for advice you are often going to find some seriously passionate opinions with oodles of anecdotal evidence. Again, all I'll say is do the hobby within all the rules and you'll be fine but most importantly HAVE FUN WITH IT. It's a hobby after all. ;)
 

cbrarick

Wildman CT
Joined
Jan 23, 2009
Messages
2,576
Reaction score
314
ll that cost savings is shattered by the reload: 279.99 https://wildmanrocketry.com/collections/75mm-5120/products/m2050x
budget blown.

L3 is just flipping expensive. Focus on doing it right, not cheap.
It may be difficult to find a L3CC or TAP who will sign off on something too different. Don't forget odd-rocs are specifically not allowed for either group. I'd really have to be convinced about a PVC level 3 rocket, I'd be most concerned by the recovery plan.
 

EeebeeE

Well-Known Member
Joined
Aug 7, 2011
Messages
1,427
Reaction score
48
I have to echo the concern of build budget. Your L3 rocket is something you cannot cut corners with, and you may have trouble getting by a CC or a TAP with cheap and substandard parts. Plus, a 4" diameter rocket on an M is going to bust most waivers on the east coast, as well as Mach 1.

If you had $250, you could buy the Polecat Nike Smoke kit from Mad Cow. You can get it with a 75mm motor mount. The airframe is FG-wrapped cardboard so it is pretty strong and it's 5.5" in diameter. You are going to need to smooth out the airframe because it does not come smoothed out, but that isn't too hard.

The LOC Precision Yank Patriot is $260, and it comes with a lot of recovery equipment and has an inexpensive but reliable motor retention system I do suggest you glass-wrap the airframe, though.

As far as electronics go, a pair of stratologgers or RRC2's could work. The better redundancy is to use one of each because you lessen the risk of 2 devices having the same inherent flaws. By the time you're done, you're still going to have close to $500 into this. Then you need to buy a motor case and a motor.

Your first step though should be to talk to a CC or a TAP and see what he or she has to say. That person is going to have the final yay or nay.
 

Neutron95

Well-Known Member
TRF Supporter
Joined
Jan 17, 2010
Messages
309
Reaction score
136
Since I got my L2, I've been kicking around ideas for an L3 design. What I'm leaning towards should actually be relatively cheap in comparison to many other L3 projects.

Since I don't have the funds to fly M motors that often, I decided that I wanted something that could comfortably fly on L2 motors for most of its flights. I already have a 75mm minimum diameter rocket, so a 98mm design makes sense to open up motor options. I also have an AMW Fibermax that I'm planning on setting up with head end deployment, so that takes care of the nosecone and electronics. I also want to keep construction simple and stay under the 18,000 foot waiver at my usual launch site, so a tubefin design makes sense, since I know that a 98mm fiberglass tubefin doesn't require any composite reinforcement to fly on an N motor.

All in all, I'm going to need to buy a 60" length of fiberglass tubing, the tubefins, and probably another parachute. I'm not quite sure whether I want to cut the fins out of a section of tube myself or get them cut by the vendor yet. The nosecone and avionics bay will be borrowed from another rocket, and I can borrow motor hardware from my club for a cert flight. All in all it should be a quite versatile design that will fly fine on J motors, but that can be turned around for a flight on an N in a few minutes.
 

Tractionengines

Well-Known Member
TRF Supporter
Joined
Aug 29, 2020
Messages
121
Reaction score
50
Location
Northeast Ohio
I think tubefins are a lot of fun and a good potential for this. Designed right and built right they can fly on a huge range of motors for a given size compared to other designs. They are almost always stable, and the altitude can be kept low, due to the drag.
I plan to use them for my certification flights. The issue with a L3 is we will need to find CC's or TAP's who know enough about tubefins, to review projects; and willing to sign off on the flight. I am in no rush to move up certification ladder, but I do have a plan.
( One advantage I have is I make my own fiberglass tubes from from the ground up. We do them for an industrial application, so that really helps me keep cost down. )
 

Neutron95

Well-Known Member
TRF Supporter
Joined
Jan 17, 2010
Messages
309
Reaction score
136
I think tubefins are a lot of fun and a good potential for this. Designed right and built right they can fly on a huge range of motors for a given size compared to other designs. They are almost always stable, and the altitude can be kept low, due to the drag.
I plan to use them for my certification flights. The issue with a L3 is we will need to find CC's or TAP's who know enough about tubefins, to review projects; and willing to sign off on the flight. I am in no rush to move up certification ladder, but I do have a plan.
( One advantage I have is I make my own fiberglass tubes from from the ground up. We do them for an industrial application, so that really helps me keep cost down. )
I'd suggest pointing them towards the 4" Bluefin Tuba thread.
 
Top