Andromeda Update for 1-1-07
 

I just created a new simulation file of the Andromeda, with the addition of two CR-713 centering rings mounted at the openings of the shrouds. This will block off the flow of air through the shrouds and prevent them from acting as ringfins. The first indication that this may be important is the altitude gained: 910' versus 881' over the non-plugged non-ringfin simulation. The second indication that something changed was the stability margin; when using a C6-5 the margin dropped to 0.74. A ballast weight of 0.10 oz was added to the back of the nose cone, and the margin came back up to 1.13.

The fins were altered to allow the shrouds to fit better, and a slot was drawn in to allow for the two centering rings. A corresponding interlocking slot needs to be cut into both rings.

I'll work up the latest patterns and post them later tonight, or tomorrow.

Huh??
 

Craig said,


This leads me to suspect that just maybe Rocksim is not accounting for airflow through both the Ringfins and Tubefins. I wonder?? :confused: It may be the extra wieght of the added CR-713 that accounts for the altitude change.

James Pierson
NAR# 77907

Andromeda Update for 1-1-07, Revised
 

Here's the latest incarnation of the Andromeda, incorporating the changes I mentioned in the earlier post. I'll try to get the outlines of the modified centering rings posted sometime tomorrow.

Andromeda Update for 1-1-07, Revised
 

Here's the latest incarnation of the Andromeda, incorporating the changes I mentioned in the earlier post. I'll try to get the outlines of the modified centering rings posted sometime tomorrow.

Length: 23.95"
Diameter: 1.04" (BC-760) [Shrouds ST-16]
Fin Span: 5.799"
Weight: 1.9112 oz

CP = 14.8467" from nose tip

A8-3......138'......Dv 18 FPS......Requires 40" of guide length
B4-4......374'......Dv 3 FPS.......Requires 36" of guide length
B6-4......384'......Dv 4 FPS.......Requires 36" of guide length
C6-5......908'......Dv 16 FPS......Requires 36" of guide length

Enjoy!

Oops...
 

Sorry for the almost-duplication. Computer-related glitch... :o

When I read this, the first thing that popped into my mind was
"There's a town I know where the hipsters go called BEDROCK, glitch, glitch."
Must be the anti-biotics.... :rolleyes:

Wowsy, wowsy, woo, woo...

"And I can't get it outta my head..."

Kicking the "PhotoBucket"
 

Kicking the "PhotoBucket" This is going to take me a while so please reamin calm and stay in your seats please, JP

Here are the mini Jets I have built as far #1- #5 I think.




And here is the Neptune Lander.




Here is the real version of the Static Probe with the three PNC's




Here is the Sabre Dart.




How about the Master Blaster as well.




A naked Cosmic Poo :eek: .



Here is my first serious attempt at scratch building. I call it he Old Ranger.



Hope you all enjoy these, JP

James Pierson
NAR#77907

JP amazes Jay... yet *again*
 

James,

*Nicely* done on all of those models. I have to confess, sometimes I see the new stuff that you come up with, and I think, "Where does he *get* these ideas?!?" :eek:

Then I have to console myself with the thought, "At least my Tau Zero will have cool decals." :p :D ;)


Cheers, buddy,

Nice images, James. I need to match your gallery with some shots of my Barclone fleet. I've been wanting to get some "actual photos" of the models posted on the website for a long time, as opposed to just the RockSim rendered images.

It will help folks who are downloading the plans to see what the actual model looks like, and how large it really is.

More "kicking"
 

Thanks guys, I am glad you like the photo's. I ran out of room on the last post some here are the remaining photo's.

Here is my version of a true space missile. I call it the A.S.M. short for Anti-Spacecraft Missile. Rocksim simulation need some more work before posting.




Here is a close up of the Old Ranger. 7 McDonald's straws fit good into a Bt-20 tube. :D




And finally is a unloaded Six shooter.


Thanks Again, JP

James Pierson
NAR# 77907

Neat rockets, James! You might think about getting some Microscale or Bel decal paper and make some simple decals. If you don't have the patience to draw any, you can download the ones on JimZ's or other sites then copy & paste windows, hatches, cockpits, and other stuff that would fit with the theme of the rockets. It wouldn't take much at all to take really cool looking designs and make them even more outstanding. :)

New Plans -- Whippit and Whippit-X
 

Schoolyard Sounders.

These are two-stage designs for 13mm motors. The design is inspired by the old Estes Farside and Estes Delta models; they are not simple reductions of those designs. Both of these models will provide reasonably good small-field action, gaining less than 700'.

Whippit:

Length: 22.45"
Diameter: 0.908" (ST-8)
Fin Span: 4.41"
Weight: 1.38 oz

A10-0T / 1/2A3-4T......446'......Dv 6 FPS
A10-0T / A3-4T.........695'......Dv 27 FPS


Whippit-X:

Length: 20.75"
Diameter: 1.04 (ST-10)
Fin Span: 4.41"
Weight: 1.41 oz

A10-0T / 1/2A3-4T......437'......Dv 6 FPS
A10-0T / A3-4T.........683'......Dv 25 FPS

All motor combinations reach safe flight velocity on a standard launch rod.

Enjoy!

OOP Motors
 

Great designs Craig. So what's the scoop? A10-0Ts coming back? I've got a Seattle Rocket Works Mirv Gryphon that's waiting to be put together..... ;)

I don't think that's in the works, but A10-0T's are still in fairly plentiful supply. There are several on-line vendors who stock them and the prices aren't too bad.

And I did mention some time back that I had several of these "what if" ideas for the Schoolyard Sounders series in the works. I sometimes enjoy seeing what would be possible "if only..." :rolleyes:

New-ish Plan -- What a SEMROC Orion might look like
 

With all of the talk about the Orion of late, I thought I might whip up a quick RockSim file on this model, using SEMROC balsa components instead of the original plastic ones from Centuri. What came out was a mixed bag performance-wise. The only safe motor right now to use in this model is the Quest C6Q-5, which allows safe flight velocity in 45", thus requiring a 48" x 3/16" launch rod. The Estes C6-5 takes a whopping 63". When I used the Apogee D10-7, I finally got a set of numbers that fall into safe categories. The model requires only 26" of launch guidance, and deploys at a much milder 23 FPS. The altitude is better at just over 1200'.

What I will probably do is revise this plan for 24mm motors and see what I can get closer to safe launch and deploy numbers.

Length: 22.65"
Diameter: 2.04" (ST-20)
Fin Span: 7.34" (Uses same fin sheet as Taurus)
Weight: 3.6 oz

Ponder!

Orion Rocksim
 

Oh Boy, I wish I had rocksim. I hope you will post the results. I'll find a launch date to give you my stats as soon as the paint dries.

And using SEMROC parts, could you figure in the added weight of the six balsa 710 cones, an "E" size mount (2 CR-920 with a HTC-20 1.75 coupler) a ST9-16 x1.75 CA coated bell shroud and one of those 1 inch? 24mm "E" to "D" engine tube adapters. I used 3/32 balsa with paper laminate copied from the Taurus fin set, a single ST-20 tube length so no coupler six inches from BC-2032 cone - an EB 20 baffle instead. Corrugated cardboard resined wrap comes in at 1.4 times the weight of same size standard wall st-20 tubing. (I weighed a mock up, mine was already attached.)

Never mind, I'll just give it a swing and a launch!!!

Oh no, I just gave away my parts list! LoL

Bob

Orion 24
 

Here's the 24mm version of the Orion. The changes include a 4" length of ST-9 and a shifting of the first centering ring 1" forward. A longer engine hook and thrust ring round out the mods.

Length: 22.65"
Diameter: 2.04" (ST-20)
Fin Span: 7.34"
Weight: 3.68 oz

D12-5........997'......Dv 32 FPS......36" x 3/16" rod
E9-6........1622'......Dv 26 FPS......48" x 3/16" rod
E15-7.......2305'......Dv 16 FPS......36" x 3/16" rod
F21W-8......2855'......Dv 7 FPS.......36" x 3/16" rod

As you can see, the larger motors are much better suited for this model.

Enjoy!

The simulations here use a balsa bulkhead to represent the weight and drag of those nosecones. RockSim just doesn't allow me to put a nose cone anywhere except the very front of the rocket. It also doesn't allow a transition anywhere except the centerline of the rocket, meaning I can't even use that component to simulate a NC. It does allow those bulkheads, go figure...

For the rest of the components, I've used pretty much what you've described. The wrap is probably not to the exact weight, but it's going to be close. Keep in mind, since the original Orion used cut-down Saturn wraps, a SEMROC kit can simply borrow from the S1B kit and be "keeping in spirit", if not spot-on, with that original Centuri kit.

Right On Target
 

I was hoping to get her up to 1500 with D power, but had no Idea about an E. These seem a likely possibility. Thanks

Craig

Thanks for posting the Orion RockSim file!

.

New Plan -- Rhemus
 

This is a simple design with great performance, low Dv numbers, and good looks as a sport modroc. It has over 1000' capability on a C6-5.

Length: 16.92"
Diameter: 1.04" (ST-10)
Fin Span: 5.04"
Weight: 1.262 oz

A8-3.......217'......Dv 2 FPS
B4-4.......498'......Dv 10 FPS
C6-5......1039'......Dv 11 FPS

Enjoy!

New Design: Interstellar Traveler
 

Great job with all the new designs Craig. Looks like my build pile just got a little bigger :rolleyes: .

Here is a design I call the Interstellar Traveler. I was going for a vintage look again, so I hope you all like it. Lately I seem to be in a design rut or you might call it a design block or information overload. All three of my personalities can't figure out which :D .

Here are the flight specs:

Interstellar Traveler
Launch guide length: 36.0000 In

MOTOR----MAX. ALTITUDE----DEP. VELOCITY
B4-4 --------272.04549 Ft-------20.4662 ft/s
B6-4 --------281.21422 Ft-------15.8254 ft/s
C6-5 --------729.72207 Ft-------0.5625 ft/s


Enjoy and Thanks Again, JP

James Pierson
NAR# 77907

Andromeda Update for 1-14-2007
 

Here's an updated set of fin patterns, including the slots for the shrouds and two centering rings. The rings close off the passage of air through the shrouds, effectively turning them back into simple tubes, and not allow them to act as ringfins.

Hey Craig - it's looking good. I'm looking forward to building this one.

I'm hoping the second prototype comes out lighter than the first one. Somehow the weight built up in the construction, and killed any chance it had of flying correctly. It took a full quarter ounce of lead to bring the CG/CP margin into the safe zone, on top of that.

If the second prototype balances where RockSim says it should (and I have my doubts even now), the flight performance should be quite good on a "B". I think RockSim is calculating the weight of the nose cone heavier than Carl's BC-760 actually is, and it's throwing the margin out of whack. I need a digital scale that can resolve finer points than a typical postal scale.

ADDENDUM: THAT'S ONE PROBLEM! RockSim is recording the weight of the nose cone as being 0.2258 oz, while the SEMROC website is saying the nose cone only weighs 0.09 oz. That's roughly 2.5X what it should weigh. What this means is, RockSim is over-estimating the typical weight of bulk balsa. I will go into the file and re-compute the design based on the website weight, and report on the results shortly.

Andromeda Update for 1-14-2007, Part II
 

I was right in thinking the CG would be adversely affected by the change in weight. Look at these numbers:

OLD:

Weight: 1.9115 oz
CG: 14.845" from tip of nose cone
CP: 18.5037" from tip of nose cone
Margin: 3.52


NEW:

Weight: 1.7757 oz
CG: 15.6683" from tip of nose cone
CP: 18.5037" from tip of nose cone
Margin: 2.73

Just in this change in the weight of the nose cone, the CG was pushed backwards nearly 7/8".

Now, interestingly enough, it suggests that I might still be able to launch Prototype #1 and achieve something near the original projected altitude. I just need to compensate with some ballast, and plug those shrouds. The school where I fly will be out tomorrow for MLK day, but we're expecting rain and colder temps by evening. It may be a crap shoot, but I'm going to try and get in a couple of flights with it if possible.

Revised Plan -- Andromeda
 

Here is the Andromeda Mk. V, with some corrections. The model has been lengthened with the addition of a 4" piece of ST-7. This shifts the CG far enough forward that it has the correct margin for a C6-5 motor. The final weight is still below the original weight computed by RockSim.

Length: 27.95"
Diameter: 1.64" (ST-16 shrouds)
Fin Span: 5.799"
Weight: 1.8053 oz
CG: 18.6329"
CP: 22.4176"

A8-3......147'......Dv 15 FPS......34"
B4-4......388'......Dv 3 FPS.......27"
B6-4......398'......Dv 5 FPS.......30"
C6-5......910'......Dv 14 FPS......28"

All motors reach flight velocity on a standard launch rod.

Enjoy!

Revised Plan -- Andromeda Mk VI
 

The Andromeda has been a work-in-progress for some time, now, and I hope you don't mind the constant revisions. Discovering the issue with the ring fins and simple inside tubes didn't help, but at least I have a better understanding of what to expect in future designs with this detail. Now, as I look more at the last-posted version (Mk V.2) I see the need to "dress it up" just a bit. So with that, I give this additional caveat: These details add visually to the design, but they also kill about 150' off the top altitude with the C6. I don't think it's the weight as much as it is the negative stability this detail works against the static margin when applied to the forward shroud, and what I had to do on the rear shroud to compensate. Visually, these details make sense...

Length: 27.95"
Diameter: 1.64" (ST-16 shrouds)
Fin Span: 5.799"
Weight: 2.022 oz

CG: 19.5362" [empty location]
CP: 22.8574"

B4-4......316'......Dv 16 FPS
B6-4......324'......Dv 12 FPS
C6-5......756'......Dv 7 FPS

All motors in this list reach flight velocity on a standard launch rod. The A8-3 had poor overall performance and required a longer rod, so it was dropped.

Enjoy!

Addendum: As with all the other issues in RockSim, I think this detail issue is over-calculated by the program. These shroud details should never have caused as much instability as shown. The problem is these items had to be created as FINS, and not as raised surface items, which probably would not affect the flow of air to the same degree. I am sure, with more research into the program, I can compensate for the extreme effects. I really need to pull out those older "Peak Of Flight" newsletters and rummage through them for anything on fins...

New Plan -- Tau Borealis
 

I don't remember if this model name was requested by anyone (Jay?), but it just came to my mind today and I noticed I didn't have one already in the line-up...

Here's something just familiar enough to be called a sibling to the Andromeda, but not exactly the same to be just a copy. This is also another (in)famous Cracker Barrel sketch come to life. It's a "Chicken & Eggs, smothered in white gravy" design. (There's a scarry bit of unrequested extra information for ya!)

Length: 22.44"
Diameter: 1.64" (ST-16 shrouds)
Fin Span: 3.76"
Weight: 1.52 oz

A8-3......180'......Dv 7 FPS
B4-4......443'......Dv 6 FPS
B6-4......451'......Dv 10 FPS
C6-5......976'......Dv 12 FPS

All motors reach flight velocity on a standard launch rod.

Enjoy!

"Mr. Borealis? --Meet Miss Aurora..."
 

Nope. I'm *so* into "Aurora," though... :eek: :rolleyes: ;) :D

Okay, for extra credit (Bill?), identify the "fabulous" 80's song this quote is from:

"Aurora comes in view..."


(--That means she shows up. *Not* the alternate meaning. :eek: :o )


Chuckling,

A Flock of Seagulls.......the group.....oh, but you wanted the song........I ran........

"I Ran," sang the Flock of Seagulls...
 

(Announcer's voice) "Ladies and gentlemen, Don Barone takes home ALL THE CANDY!" :D :cool: ;)

Thanks for playing. :D


Cheers,

AFOS reference! Niiiiiiice.

<WARNING - GEEK ALERT>

What's really scary is that I have a picture of me on stage singing with Mike Score (lead singer) at the end of a Seagulls concert from the 80's...

Later,
EV

Did you have matching hair-do's? :D

Thank God, no.

What most don't know is Mike's "tailfin" hair-do was probably the world's most elaborate comb-over. By the time the concert I was at (later 80's, after their prime), he'd mostly lost it all on top and had the "bald-mullet" .

Later,
EV

New Plan -- Tau Cygnus
 

It's been a slow January and February around here...

This design is another in the (in)famous TAU series, and draws some influence (OK, maybe more than just "some"...) from the Andromeda. It is a simplified model, but it retains the family styling with the reactor shroud and coils, the open fins, and the stylish nose cone.

Tau Cygnus also fits into the VR Class with its under-800' altitude on a C6-5.

Length: 23.95"
Diameter: 1.64" (ST-16 reactor shroud)
Fin Span: 6.04"
Weight: 2 oz

B4-4......330'......Dv 13 FPS
B6-4......340'......Dv 8 FPS
C6-5......787'......Dv 7 FPS

The A8-3 is not recommended as it does not reach safe flight velocity on a standard rod, and only attains about 125' at best. All other motors listed reach flight velocity in the length of a standard rod.

Enjoy!

Need RockSim Help
 

OK folks this one has me stumped. Flight simulation says it won't leave the rod and 2D profile shows it starting parallel to the ground (launch rod @ 0 degrees). Did I miss something? Software problems? Any help would be appreciated.

Look at the fin thickness of the rocket image when you prepare for launch to load a motor or view the line diagram in the 2D base view of the design.

It's your fins. I'm assuming that you wanted 0.09380 instead of your 0.9380 for the thickness of the fin material since these fins are almost an inch thick? You also selected "custom" for the fin material and that has a "zero" mass for the fins. Instead choose balsa or one of the other materials.

I changed the design to balsa and 0.09380 for the fin thickness and it flys fine.

The 3D export did look kinda cool ..... :)

.