He said it better than i did. The sentiment I had in mind was "L1 is no big deal - do not be intimidated" and maybe the part that did not make it to the keyboard was "feel free to take it as seriously as you like, and have an awesome time doing it"
I'm starting my L1 cert. research
- Thread starter Cmac
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https://www.rocketryforum.com/threads/the-u-loop-shock-cord-attachment-method.137445/
The original image in that thread lacks reference to the protective sleeve that would shield the shock cord from getting the direct blast from the ejection charge.
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Cmac
Well-Known Member
Interesting. What kind of fire resistant sleeve are you using?
I guess one could cut a small slit in a 12" chute protector.
I guess one could cut a small slit in a 12" chute protector.
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Usually a sewn nomex or kevlar sleeve.
Yeah the sleeves are available from many vendors:
https://www.apogeerockets.com/Building-Supplies/Parachute-Protection/Shock-Cord-Protectors
https://www.madcowrocketry.com/shock-cord-protector-30/
https://locprecision.com/product/fire-resistant-shock-cord-sleeve/
...
etc
https://www.apogeerockets.com/Building-Supplies/Parachute-Protection/Shock-Cord-Protectors
https://www.madcowrocketry.com/shock-cord-protector-30/
https://locprecision.com/product/fire-resistant-shock-cord-sleeve/
...
etc
Nytrunner
Pop lugs, not drugs
And a strip of ductape folded over the shock cord close to the ejection charge is cheaper than all those options!
But not as preeeeeety!
This thread is long, so please forgive me if I'm repeating too much.
Ns is the unit of impulse and of momentum. N is the unit of force, average thrust in the case of rocket motor designations.
As to the motor codes, just remember that they are essentially the same for all the motors. Look for the letters that come after the average thrust and and after the delay number, and ignore them. The propellants that are represented by those letters do have different characteristics, those characteristics are 1) burn rate, which is already reflected in the average thrust number, and 2) cosmetic. Cesaroni places a number before the letter code for impulse; that's the (more or less) exact impulse, more precise than just the letter, but you'll see that anyway in the motor description.
As others have said, use simulation tools and ThrustCurve.org; keep it simple; and don't rush.
Finally, don't overthink it. If you follow the advice above, L1 certification really isn't hard.
There's a common misstatement that I usually manage to bite my tongue and keep quiet about, but not when someone is looking for basic educating. H motors range from 161 to 320 Newton-seconds (Ns) not Newtons (N).
Ns is the unit of impulse and of momentum. N is the unit of force, average thrust in the case of rocket motor designations.
As to the motor codes, just remember that they are essentially the same for all the motors. Look for the letters that come after the average thrust and and after the delay number, and ignore them. The propellants that are represented by those letters do have different characteristics, those characteristics are 1) burn rate, which is already reflected in the average thrust number, and 2) cosmetic. Cesaroni places a number before the letter code for impulse; that's the (more or less) exact impulse, more precise than just the letter, but you'll see that anyway in the motor description.
As others have said, use simulation tools and ThrustCurve.org; keep it simple; and don't rush.
Finally, don't overthink it. If you follow the advice above, L1 certification really isn't hard.
Cmac
Well-Known Member
I think that's worth noting. As a basic beginner, the interchangeability could confuse somebody. Once I learned that I was concerned with how fast a kilo could travel a meter I just assumed that's what was meant.
I've really been craving Fig Newtons. Too bad they only come in two serving packs.
Once I get my Windows machine back I'll be downloading my 2 month free trial of rocksim.
Nope, no overthinking. We're keeping it petty simple. After doing a lot of reading, I'm contemplating if I'm even going to use epoxy or not.
ThirstyBarbarian
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Eat the first serving if you feel like having Newtons, and eat the second serving if you feel like having Newton Seconds.
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And if you burn the newtons... you might want to check out this thread...
https://www.rocketryforum.com/threads/the-2020-newton-tally-thread.156897/#post-1949036
https://www.rocketryforum.com/threads/the-2020-newton-tally-thread.156897/#post-1949036
Cmac
Well-Known Member
Good one ThirstyBarbarian.
By "overthinking" I don't just mean overcomplicating the rocket. Don't spend lots and lots of time reading everything and weighing every option either. There are lots of ways to do this successfully, so just pick one and jump in.
Oh god, is he going where I think he's...
Yup, that's where he went.
This is really true. The best way to prepare for your L1 is to build and fly at least a few rockets that take his thrust G motors. Then put an H in it and fly it the same way. It’ll go higher.
gna
average joe-overbuild member
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ThirstyBarbarian
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Thanks for playing along! It seems like no one else really gave a fig.
ThirstyBarbarian
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They do overhang a bit, but I still think it’s a pretty reasonable choice based on the features and the price. Another kit I like, the LOC IV, also has a bit of everhang too. If you are flying on some really hard surfaces, you might want to avoid that, but it should be OK on most grassy fields.
stop the punishment..
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Why? A good pun is its own reword.
John Taylor
Well-Known Member
Binder Designs Excel single deploy 3" diameter with 38mm motor mount. Less than 80 bucks.
Very tough all inclusive kit. Fins not hanging down. Reduce down to 29mm for certification flight .
This is the rocket I used for my level one certification flight.
Pop it at the top with baby H motor. Hard to go wrong. Then this rocket is so robust it will easely fly on much more powerful motors. Just use a chute release on I motors and it will satisfy you guaranteed.
Very tough all inclusive kit. Fins not hanging down. Reduce down to 29mm for certification flight .
This is the rocket I used for my level one certification flight.
Pop it at the top with baby H motor. Hard to go wrong. Then this rocket is so robust it will easely fly on much more powerful motors. Just use a chute release on I motors and it will satisfy you guaranteed.
o1d_dude
'I battle gravity'
What Thirsty Barbarian said.
A big cardboard/plywood rocket from Loc Precision will do everything you want.
Doesn’t need to fancy or high tech. You want to learn on a “beater”.
I have a crayon rocket that fills that niche for me. No paint, just a motor sled.
Once you have some experience under your belt, choose a rocket for the aesthetics and paint it to your heart’s content.
A big cardboard/plywood rocket from Loc Precision will do everything you want.
Doesn’t need to fancy or high tech. You want to learn on a “beater”.
I have a crayon rocket that fills that niche for me. No paint, just a motor sled.
Once you have some experience under your belt, choose a rocket for the aesthetics and paint it to your heart’s content.
This is a relatively new seed, not a rehash of the same old pun topics. So maybe it will bear fruit in a new ton of good ones.
tOD
Sinking in the quicksand of HPR
Then you could do something so people would say, "You got your L1 with a WHAT?"
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The only rocket for which a CATO is also a successful blast off.
Ramjet
Mars Lander Man
I am in tOD's camp, the picture in my Avatar is my L1 Rocket. Yes, it's a 1.6X Upscale of an Estes Mars Lander (Tango Papa kit). I spent nearly 6 months building it. And as I told the Safety Officer, If you can't run with the big dogs, stay home on the porch. He put me on Pad #13. Best Flight I ever had. Straight up w 1/4 roll, laid on it's side directly above me pointing at the cars, and I watched the Parachutes unroll, Yes I was Hyper. I got a good cheer from the crowd and I did it on the 4th of July 2005. My L2 will be with a 3X Mars Lander. I did the CAD myself in Solidworks (3D modeling program) And YES, tOD, I have had that reaction, I Love it.
