Hair Brained idea for Level 1 cert?

[bad_idea]

Since you're on Linux, I'd recommend building the unstable branch of OpenRocket from source, as it has many small improvements since the last very old release. One you have the dependencies installed and have run the first git clone, updating whenever there's been a new commit is as simple as going to your source directory and typing:

git pull
ant

(Same actually for a Mac with Homebrew, though Apple is weird about letting things into the dock, whereas it's easy to set up a custom menu entry for OpenRocket in most Linux GUIs.)

 

[kbocket]

The Goblin NC looks like a slightly pointer facsimile of the Sprint parabolic cone. If I can find an affordable and effective way to get one closer to scale, that's my preference. The Goblin is a bit short as well.



The goblin cone is as close as you are going to get to the BNC50X of the original Sprint. I used a LOC nose cone and the pointiness always bothered me. I do wish I could find a better shaped Nosecone, but it works.

 

[R.E.Forrest]

Since you're on Linux, I'd recommend building the unstable branch of OpenRocket from source, as it has many small improvements since the last very old release. One you have the dependencies installed and have run the first git clone, updating whenever there's been a new commit is as simple as going to your source directory and typing:

git pull
ant

(Same actually for a Mac with Homebrew, though Apple is weird about letting things into the dock, whereas it's easy to set up a custom menu entry for OpenRocket in most Linux GUIs.)

Now I am totally lost lol.

 

[bad_idea]

Now I am totally lost lol.

Sorry, I forget sometimes that not everyone on Linux rolls their own, so to speak. In that case, use the appimage file from the releases page:

https://github.com/openrocket/openrocket/releases
It works fine.

 

[K'Tesh]

Here's a link to my Sprint and Sprint XL .ork files... I hope these might help. You might also poke around on some of the Binder Design 4" kits I've simmed up for other ideas.






FWIW... I too went scratchbuilt for my L1...

 

[OverTheTop]

There is lots of advice upthread you can draw from, but remember the flight is entirely your choice. If there is something you want to make and fly then do it, as long as it is in the rules of course! Just make sure you enjoy the journey .

FWIW I did all my certifications using larger motors than the minimum, so certified on I, K and N motors. My thoughts were that I didn't want to just make it across the line and wanted some added challenge. It is just what I did and not what I would expect others to do.

 

[R.E.Forrest]

Sorry, I forget sometimes that not everyone on Linux rolls their own, so to speak. In that case, use the appimage file from the releases page:

https://github.com/openrocket/openrocket/releases
It works fine.

Thanks

I am a computer moron, and definitely a not your typical Linux user. I'll play around and get it to work, eventually

 

[JackC]

that's my thinking. I don't intend to use one rocket for both certs. Time comes, I'll build specifically for L2 cert. Who knows, maybe it will be Sprintzilla

It should not be a problem to use for L1 then L2 if constructed properly. There are a lot of 38 mm J motors.

 

[High Desert Rocketry]

As others have said, nothing wrong with getting your certs (L 1, 2, & 3) on scratch built rockets...I got my certs on scratch builds; my L-2 used Formica countertop fins. Use a simulation program (I use Open Rocket, free download) to design it and check its stability and other flight characteristics. I recommend students I mentor not to go 29mm motors since you cannot do Level-2 with them and 38mm allows Level-0, L-1, and L-2 motor choices.

Don't stress if any of your attempts fail as there is no limit of the times you can try and even 'experienced' L-3 flyers crash rockets.

 

[MoreCowbell]

Building an upscale Sprint sounds like a great idea. I am also very fond of the old Astron Sprint, it being the first rocket I built and flew (and lost) many years ago.

IMO your motor mount size would depend on the construction materials you plan to use. If cardboard/paper airframe and plywood fins, 38mm makes sense. If fiberglass, then 54mm. Fly it for L1 on a fast H or I, then let it rip on larger motors later. Sounds like a fun project.

Since you have access to a good lathe, turning the nosecone from basswood should work well. I would not worry about the weight--those who built the old kit may recall that it came with a lead disc to attach to the nosecone and enhance the rocket's stability. The Sprint needs a little weight up front. Should you find that the NC is too heavy, then it is pretty easy to bore out the wood and lighten it as needed.

You could probably turn the tailcone from basswood too, but some air gap or insulating material between the motor tube and wood should be considered.

Keep us posted on progress, and good luck.

 

[R.E.Forrest]

Building an upscale Sprint sounds like a great idea. I am also very fond of the old Astron Sprint, it being the first rocket I built and flew (and lost) many years ago.

IMO your motor mount size would depend on the construction materials you plan to use. If cardboard/paper airframe and plywood fins, 38mm makes sense. If fiberglass, then 54mm. Fly it for L1 on a fast H or I, then let it rip on larger motors later. Sounds like a fun project.

Since you have access to a good lathe, turning the nosecone from basswood should work well. I would not worry about the weight--those who built the old kit may recall that it came with a lead disc to attach to the nosecone and enhance the rocket's stability. The Sprint needs a little weight up front. Should you find that the NC is too heavy, then it is pretty easy to bore out the wood and lighten it as needed.

You could probably turn the tailcone from basswood too, but some air gap or insulating material between the motor tube and wood should be considered.

Keep us posted on progress, and good luck.

since it'll be scratch built and my first HPR, I am inclined to go with cardboard BT. I won't use the same rocket for L2 cert, but I'd like it to be J/K motor capable once I'm certified on those motors.

ETA: I recall the lead weight. I'd much prefer an accurate repro of the Sprint NC as opposed to a kinda sorta facsimile.