My MEGA-NUK Arrived!!!

[PGerringer]

I want to build her, I want to build her, I want to build her NOW!!! I took some pics of the kit:

https://www.cybergatetech.com/phpgraphy/?dir=Rocketry/MegaNuk

It looks like a pretty simple design. I will let you decide if it was worth $350 or not. It pretty much came with everythign except the Alt Bay so I get to design that. And I'm a little confused, it didn't come with assembly instructions and I ended up with an extra bulkhead that I don't know what to do with. An email to Smokin Rocketry should fix that though. So far I have gotten great customer service from Smokin. But like I said, I will leave it up to you if it was worth the scratch.

But now I wanna build!!!

 

[rstaff3]

My suggestions:

1. Log off
2. Send wife and kids to visit grandma
3. Call in sick to work
4. Buy twice as much of everything as you think you'll need.
5. On the way home from buying 4, stop and get extra coffee and your favorite sugar filled junk food.
6. Take it all to basement (or garage, or whatever). Don't forget cell phone in case you need to order pizza.
7. Log on and off as required to provide progress reports.

 

[Austin]

Dick, your kill'in me man!!! Sounds like me! hehehe


...still laughing...

OK Phil...first off, it's an L3 kit...if you don't know how to assemble it by now without instructions...send it back. You should have the skills by now to figure it out !!! I am guessing al ot of L3 kit mfgrs DON'T send instructions, just for that reason...seriously.

Now for the BIG QUESTION...

...HOW in hades did you get to open it!!!!!????? You MUST have done some serious sucking up to "Da Boss"!!!

Tell or be told on!

I DID save all our emails today, just in case we needed blackmail, so fess up!

Carl

 

[rstaff3]

Carl, I guess great minds think alike

Phil, it will be interesting to see where those extra parts go. I could come up with things to do with them, but prolly would not be right.

 

[Austin]

I hear ya Dick...I LIKE that!


Phil...I am sure the Mrs. could find a place for those parts...but, they aren't extra...

Carl

 

[Jase]

Kim wasn't home. That's how he got it open.

 

[MarkABrown]

Nah, I know she was home because she called him at work and said, "There's another big box here...". I'm not sure what the rest of the sentence was.

 

[PGerringer]

Gentleman, Kim wasn't home when I got home so that gave me an hour alone. Just me and my rocket.

Actually, I know how to build the rocket, I just have never seen a kit without instructions. I usually don't build based on instructions anyway, but isn't that the definition of a kit? Without instructions, it is just parts right?

I'm going to take this one slow and fill out all the paperwork first. Complete the design, etc. Then slowly build. At least that is the plan unless the fevor should take me, which it has been known to do.

 

[ibeblip]

WHO'S YOUR DADDY?

 

[Milo]

I expect the wife and kids have already left.

Phil it is great to see you are still alive.

 

[kat3595]

Just looked at the pics of the kit. Looks like you have a lot of fun ahead. Just one question - Why did they send a battery??????

LOL

 

[PGerringer]

LOL!!! The Battery was for scale... I added it.

 

[PGerringer]

Well, folks I have survived another night without building the Mega-Nuk. Man this is tough. Some of you will be pleased to know that the garage is now clean and I'm folding laundry. Geesh the things you have to do to keep peace in the house.

 

[rstaff3]

Yeah, but let's hear you talk that way AFTER you get your L2. I bet the addiction is complete and irreversable at that point. Lawn tools and dirtly laundry everywhere!

 

[JohnK]

Having built a Mega-Nuke (check out the pic on the Smokin Rockets website of the guy on the ladder arming a Mega-Nuke. That's me ), let me suggest you spring for the extra money to buy the altimeter bay. I did and it was worth it. Not a lot of money extra and it had all the parts I needed to put in two altimeters for my L3 project. Saves headaches. My altimeter bay was the coupler and attached with bolts to the payload tube. This allowed me to assemble the altimeter bay, hook up the recovery bridle, then slide the bay into the payload tube and pack chutes.

Seriously think about putting in a motor retainer ring (I prefer the Giant Leap Slimline retainers the best) when you build it. I wish I had.

After two layers of 6oz. glass, semi-professional paint job (I had an autobody shop paint it, but they made me sand it!) and assorted hardware, etc, it weighed 40lbs on the pad and climbed to just under 6000ft. on a Kosdon M1130.

 

[rstaff3]

On a quick pass, I missed the one on the ladder, but saw it taking off. Unless there is another John K. with a Nuk on the site... I suspect you aint as purty as the Nuk anyway

 

[JohnK]

https://members.aol.com/SMOKINRKTS/MEGANUK.html

The picture to the right.

 

[rstaff3]

I'll take a look. I went right to the users pictures page.

 

[PGerringer]

That is you, JohnK? Very cool. I like the kit but ended up ordering a 24" extension that will behave like the alt bay. You can get to my drawings by going here:

https://www.cybergatetech.com/?parent=project&child=rocketry&sub=rocketry/MegaNuk

I can't wait to get this done. Keep an eye on the site for any updates. Thanks for the suggestions.

 

[ibeblip]

Please forgive me if I seem dense, or you have already revised the simulations. . . But why is the velocity so high at deployment?

 

[Austin]

ibeblip,

With "M" class motors, they have a much longer burn than the 1-3 second burns found with most J motors or smaller. My M motor will burn for 7 seconds...and due to this fact, altitudes average between 5000-9000' for most launches.

Carl

 

[ibeblip]

I understand . . . But it is easy to adjust the delay for deployment at apogee when an altimeter is going to be used.

Look at the Optimal Delay recommended on the far right-hand end of the simulation. Reload the same motor and enter that amount of time in the delay window. Now, launch the rocket again and see what happens.

 

[PGerringer]

Um... I'm not sure I understand you. The drogue fires at apogeee which comes close to 0fps. Then it falls to 750' and deploys the main chute. At the time the main chute deploys I expect it will be falling pretty fast. I had thought the deployment speed was for the main. Is that what you are referring to?

 

[rstaff3]

The velocity at deployment is when the motor has burned out and the delay has expired. Using a 0 sec delay, this is the same thing. You can see this if you graph one of the sims. I think another way to solve this dilema is to select ALL for the motor delay. The simulation runs the same but the ficticious ejection at burn out goes away (replaced with an asterisk). In the test case I ran with your design and the 1419 motor, it really doesn't matter if you can ignore the alt and vel at deployment columns. All these delays give the same max altitude and total 'in air time' - 0, ALL and the optimum 15.14 sec. Using ALL will keep you from updating the delay parameter as you change the rocket's mass ,etc.

 

[ibeblip]

I'm sorry Phil, and thanks to Dick for clearing up the matter.

Have you done any experimentation with optimal mass predictions?

 

[rstaff3]

ibeblip,

You are welcome for my clarification, but don't be sorry about questioning stuff. Your comment was constructive. I personally wasn't sure until I played around a bit.

In fact, I didn't get the answer I expected. I actually thought Phil's max altitude would have been low due to Rsim deploying a chute before apogee. That's how I thought it worked anyway. But, like I said, the ALL and 15.1 values didn't seem to make a difference.

 

[PGerringer]

I haven't done much in the way of calculations outside the basic RockSim. I still don't have a good idea of how much this bird is going to weigh. I need to go back and redo the sim based on the weights I know now.

Could that be a bug in RockSim? It sounds like when using dual deployment, no matter what you put for the delay, you can pretty much ignore the Vel at Deployment.

I tell ya, I'm learning alot. It just aint as easy as slapping some fins on a tube, adding paint, and then lighting with a match. There is actual math involved.

 

[rstaff3]

I dunno if its a bug or a feature. I thought you were supposed to use ALL for the delay if you set launch events tho. Mebe if you mix motor ejection and other events parts of the program keys on one and parts on the other. For instance, the columns on the display window key solely on motor ejection, but the sim doesn't really account for a chute being deployed until your event fires. That would explain what I saw.

 

[ibeblip]

I concur. Is there a difference in max altitude achieved during simulations for motor ejection deployment and altimeter deployment of the recovery system at apogee?

I mean, in using a length of delay for motor ejection of the recovery system at apogee -regardless of available delays for any motor in particular- I have found that the maximum altitude is higher and the velocity at deployment is lower.

Arrrghh, I'm cornfused.

But doing it that way seems to be a whole lot more accurate, because most altimeters have an accuracy of +-10% while pyro delays are usually +-20%.

 

[rstaff3]

I think what you meant is you get more altitude if you set the delay to the optimum?

I have not experimented with events that much but this is what I know for ejection with only the motor delay. Rsim will give less altitude if the delay you picked is less than optimal (because Rsim adds the drag of the chute for the rest of the sim). If you pick the optimal delay or greater, the max altitude will be the same, because the rocket would have achieved its best altitude before ejection in both cases. As for speed at deployment, the only way to minimize that is to eject at apogee, the optimal delay does this.

I just verified these statements, which leads me to believe that the conclusion I reached in my previous post is correct.