Discussion in 'High Power Rocketry (HPR)' started by Rail Dawg, Nov 30, 2018.
I provided this information to the customer. I prefer to deal with the guy who paid for it.
Not sure where the fin can discussion recently went off the rails.
This is a non-issue.
Mike at Binder Design is without question a premier designer and fabricator of the finest airfoils in our business. His stamp of approval carries a LOT of weight.
On top of this we have a highly-qualified Engineering Dept that gives a final approval to any design that makes it onto this rocket.
We’ve been lucky in that we’ve had one of the most discussed rocket builds ever from conception to actual flight. Hundreds of outstanding inputs have all been combined to create a big rocket that should not only fly well but fly often.
And this design will scale right into the “S” powered project that will begin right after BALLS 28 this year.
Bottom line is you all can discuss the fins to your hearts content... but they ain’t changing ok? They are signed off on and ready for flight in two months.
Thanks guys! Keep up the great work!!!
Not a problem . . . I was just curious to see if those items existed . . . I'm glad they do !
Here is my brief summary . . .
Nothing really went "off the rails". I expressed concern ( Post #1936 ) that your fins appeared to be thinner than the .500" flat plate that was simmed to avoid flutter by AndrewASC.
I was unaware that the fins were being tapered and airfoiled. My concern was/is that the resultant thinning of the fins might cause them to flutter.
Mike indicated that he submitted 3-D files of the fins before they were machined, for approval. I don't recall seeing those files or any sims, using those files from Mike, although it is possible that AndrewASC ran them and they were not subject to flutter. I don't know if AndrewASC simmed the tapered, airfoiled fins, or if someone else did. Data was never submitted here on the Forum, if they were.
At any rate, if the fins have been simmed in their current configuration, and are not prone to flutter, you should be good to go . . . I am hoping to hear, one way or the other, from AndrewASC, as to whether he did or did not run sims with the tapered, airfoiled fins.
Speaking to the "S" motor . . . Velocity will be MUCH higher and, as a result, flutter may, once again, become a problem at that time.
The build is going well.
Getting excited for LDRS which is just around the corner!
Still lots to do but the hard part has passed... testing the motor fit and getting the fin can bolted on.
The 5’ drogue section is next but that’s a fairly easy build. Placing an 8” G-12 tube with centering rings inside the 5’ airframe for strength especially where the drogue section is coupled above the motor.
AvBay just needs altimeters attached to sled. The all thread and eyenuts are fitted and looking good.
Reinforce the nose cone and work on the charge cannons. Still need to test those before installation to ensure they can handle the BP charge.
So there’s the update. A very fun build getting slowly to the completion. Launching this complex project is going to be very cool.
Had an opportunity to 'lay hands on' the motor case last week. Truly amazing!
This thred needs more pics !!!
Is there a date for the motor static testing ? Having "real data" will give us a true picture of performance.
BTW - I have finalized the design for the "Doomsday Charge" ( pic below ) . . .
Though I’m not sure he is looking for the rocket to attain “critical mass” and go “high order”
"Blow it out or blow it up" . . . Maybe I should have said "Glow", instead ? LOL !
Today the extra coupler section that makes the rocket able to accept the 9.5’ Q motor or the 10’ R motor was installed.
It was a design change to accommodate the longer motor. I must admit it confused me as the drogue section needs to mate exactly regardless of which motor is used. It wasn’t until I actually got the 6” coupler assembly installed that it all made sense.
Thankfully the Engineering Dept was patient with me as I worked to understand exactly what was required.
That hurdle is passed now it’s time to build the 5’ drogue section with the 8” G-12 inside as support.
Will post pics in the next few days.
Looking forward to pics . . . When is motor static test ?
looks to be 3d printed
Ok guys this is a shout-out to Buddy Michaelson up there at Rocketman.
The 50' Pro-Experimental parachute arrived yesterday nicely packed into it's Nomex deployment bag.
The first picture is what it looked like when it was pulled out of it's shipping box.
The second picture shows just how beautifully it slides into place in the upper airframe of the rocket.
There is plenty of room! And there is nothing to hold this parachute and deployment bag from ejecting into the airstream when it's time to deploy
Buddy is a young man but let me say he has handled this entire transaction with a professionalism and an eagerness to satisfy that speaks volumes to his character. Trust me there has been a LOT of debate over the choice of parachutes with much of the debate done with all of us here.
We finally chose the Rocketman parachute because I've always been a big fan of Rocketman and just 4 shroud lines. There are some that have made valid arguments that if we lose just one shroud line we lose the effectiveness of the parachute.
The decision was carefully weighed against the fact that a cargo parachute with upwards of 40 shroud lines may experience it's own deployment problems.
Also gained some much-appreciated wisdom from the KloudBusters (who are of course hosting LDRS 38 this year). We discussed the main parachute being deployed with plenty of altitude for the parachute to be released from the deployment bag and unfurled without a g-shattering snap which as we know puts severe loads on the entire recovery system.
Although we haven't decided yet on a minimum altitude for deployment a ballpark figure is at least 5000 ft AGL. We are blessed with wonderful launch sites at both the Rocket Pasture and the Black Rock Desert.
So Buddy my hat is off to you and the great work you and your crew did on this parachute. You were a patient man as we wobbled back and forth in the decision-making process. It's a critical decision on which an entire project rests.
We're sending you out our Rocketman Ballistic Drogue so your team can go through it and beef it up as needed. It will be on it's way Monday.
Again... well done! This is getting more exciting by the day!
That’s nice to hear, Chuck. Buddy is a very nice man, a real gentleman who always takes time to talk to me and my non rocket flying wife.
That's good to hear Steve. Developing the great customer-service skills speaks loudly not only of Buddy but of his father Ky too.
Hey Chuck, it’s great to see you got the parachute, I can’t believe how smooth it fits in you rocket! Shouldn’t be a problem to get that thing out of the rocket and out of the deployment bag in a matter of a second! It’s been an absolute pleasure working with you and being a small part of such a great project, only 2 more months and we can celebrate the success!
The rocket ready for an R-powered flight is pushing 575 lbs.
LDRS with a Q around 35,000 ft and BALLS with an R closer to 40,000 ft.
When is the static test going to happen ?
Is a drop test for the Recovery System still going to be done ?
We could drop test it from a balloon 500ft above the ground, I have connections could have the 23lb Chute and a 25lb weight and see how long it “floats” in the air.
Still deciding on where to do the static tests. There are a few good options.
No plans to drop-test the Rocketman parachutes. The folks at Rocketman have such a good reputation.
As long as the parachutes are reefed and properly packed we’re quite certain we’ll have a successful recovery.
The Drop Test was never about the parachute itself. It's about the deployment system and the extraction method for the Main chute.
BTW - What are your plans to simulate 40,000 Ft AGL for the Drogue Charge Tests ?
Air pressure is only about 2 psi ( 4" Hg ) at that altitude.
If you go back in the thread you can see where we all discussed the charge cannons at 40,000 ft.
I'm feeling very comfortable with our deployment methods.
There have been a lot of good ideas tossed about and the use of charge cannons looks to be the right method for this rocket.
I remember the charge cannons . . .
How well will they function at 2 psi / 4" Hg @ 40,000 ft. AGL, vs. ground level testing ?
Are you going to test them soon ?
Based on earlier discussions the charge cannons should work quite well at 40,000 ft.
Picked up the mobile launch platform from Levi Seaton in Kansas yesterday.
Let me tell you guys this thing is amazing! Levi's attention to detail is incredible. He thought of everything.
The hydraulics work really well and the outriggers stabilize the trailer perfectly.
I am very impressed with his work. Levi is a professional welder and you can see that every weld is done that way. He and his friends at work professionally sandblasted, primered and painted the entire launch platform with a very high quality epoxy type of black paint.
The trailer rides down the road very well and the cradle for the rocket looks very cool.
I can't say enough how pleased I am with Levi's work. For this to be his first launch platform it's amazing how well he did with it.
That looks first-rate . . . Very impressive !
Just for laughs, shoot some video while you are rolling through Toll Booths, once the 20 ft "UpChuckR" is strapped horizontally to the cradle . . . !
You are almost guaranteed to meet some Cops along the way, too . . . Catch it all on video !
Actually, it might not be a bad idea to "forewarn" the various authorities, in advance, to keep you safe from a "Barney Fife"-type wannabe !
This is exactly the trailer I want when I grow up.
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