2 Stage Big Bad "Big Daddy"

[scadaman29325]

Has anyone 2 staged a Big Daddy?

I found 2 kits at Micheal's, $12 each.

Need some suggestions/ideas...

Here goes mine:
2 Stage,

Build first one stock (almost)...
laminate fins with copy paper and CA,
double-up on centering rings,
raise bottom CR 1/2" to make room for coupler of lower stage.

Second one, Cut in half, use lower half for 2nd stage and upper half to extend main BT, laminate and renforce as above.

 

[Fore Check]

Sounds interesting!

That body tube is a bit of an odd-size... It is a non-standard 3" OD.

If you do that, you'll want to take part of the leftover tube (after you cut it for the booster) and trim out a 3-4" piece to use as the coupler. You know, take a slit out of that 3-4" piece lengthwise and roll it inward just enough to be your coupler. Otherwise, you'll need to place an order with Totally Tubular just to get a coupler!

Also - to "double up" on your centering rings, you may need to cut your own or have RocketGuts or BMS cut you some.

Let me mess around with RockSim and see what I come up with.

If you do have rings cut, I had some made for mine and used an OD of 2.928" on the rings - they fit GREAT!

 

[Fore Check]

Too bad I only have the demo version of RockSim - I can't post the sim I just put together.

On a 2 Stage Big Daddy - if you make the booster 5" long (just to match the root cord of the fins) and then fly on a D12-0 staged to an E9-6, you get a predicted altitude of 1160 ft.

There is a pre-made RockSim file on EMRR for the Big Daddy. I took it, and basically copied the fin can portion to make a booster. I added a piece of coupler as well, and lengthened the motor mount in the booster to 5" (to match the length of the booster.) Obviously, this would be a gap-staged project.

I added 0.75 oz of nose weight in the design to bring the single-stage caliber with an E9-6 loaded to 0.83 - which should be good enough for a "short and stubby" rocket. The 2 stage caliber with an e9 and D12 booster is 0.98

 

[n3tjm]

Put a cluster in the booster. Two to four 18 or 24mm motors surrounding the central 24mm . You are going need a lot of umph to get that off the ground.

 

[scadaman29325]

Fore check:
You are good with that there rocsim stuff!

You did exactly what I'm going to do, except I thought about adding the leftover 5" bt to the front (via slide on coupler).(?) I don't know what that would do to the 'look' of the rocket, just a thought.

1160' sounds pretty high to me. I wonder if that would be "out of sight" for a rocket that big? I really have no idea how high most of mine go.

I rank them a little differently than most people,
low: I need more power, that was embarassing
mid: that was nice,
oh yeah: that was real nice
high: I think I see it,
crap: ain't sticking that one in there again, I hope I get it back


I was planning on making a coupler(s) and centering rings out of HEAVY poster board (or backs of notepads...)

As for gap staging, I was going to 'funnel' the gas via a 2"+/- piece of spent motor up to the sustainer.

Thanks for the info on the nose weight, I'm a little surprised it's not more than that.


n3tjm:
If I can't get a 'high' out of it, clustering sounds like a good option.
How high is '1160' for a rocket that size?


Thanks For the Input

 

[rabidsheeep]

maybe im imagining things, but i remembered the big daddy having a curved BT?

am i off here?

 

[scadaman29325]

No curved BT here, must be the V2.


I can't figure out this rocsim thing. I've got it downloaded, but can't get past launching the premade stuff already there.

Can we get a chat going for some help? Heck, I don't even know how to get that going on TRF.

 

[n3tjm]

Originally posted by scadaman29325

n3tjm:
If I can't get a 'high' out of it, clustering sounds like a good option.
How high is '1160' for a rocket that size?

1'160 is pretty good altitude for a rocket that size. You will see it, but if you are like me... and have bad eyes... that would be stretching the limit.

 

[powderburner]

Originally posted by scadaman29325
I rank them a little differently than most people,
low: I need more power, that was embarassing
mid: that was nice,
oh yeah: that was real nice
high: I think I see it,
crap: ain't sticking that one in there again, I hope I get it back

That is quite possibly the best altitude tracking system I have ever seen. I think I will have to add a new space on my flight data sheets to include this.

 

[Fore Check]

Originally posted by scadaman29325

As for gap staging, I was going to 'funnel' the gas via a 2"+/- piece of spent motor up to the sustainer.

Thanks for the info on the nose weight, I'm a little surprised it's not more than that.

As far as a gap staging arrangement, I wouldn't recommend using a spent motor casing. I'd just use plain ol' BT50 (24mm mount tube). Also, you'll need to "vent" the top of the tube and your centering rings to ensure proper stage ignition before the pressure pops the booster off without sustainer ignition.

I'd suggest doing a search here or on ROL or some other source on gap staging - unless this method you're describing is one you've used before and that you're comfortable with its reliability.

The nose weight is probably a "best guess" - it is based on the assumption that the mass values assigned to the fins and motor mount area on the RockSim file on EMRR are correct. Your mileage may vary - and it usually does.

While RockSim is pretty accurate on determining the CP, the CG calculation is based on entered values for the parts (and calculations on others.) I'd balance the fully loaded and complete rocket to be sure, and the CG should be no more than 3 5/8" from the front of the body tube on the sustainer without the booster attached (assuming a stock 10" sustainer airframe - or the CG should be at least 6 3/8" from the base of the airframe on the sustainer.) Add or remove nose weight as necessary.

And I'm with powderburner on this one: Excellent altitude chart!

 

[sandman]

STOP!

The 3" heavy walled body tube for the Big Daddy is available now from Totally Tubular!

Save the other kit and just buy a 34" length of tube and cut off what you need.

He lists it as a BT-100 for $5.00

 

[Bill]

Originally posted by sandman
STOP!

The 3" heavy walled body tube for the Big Daddy is available now from Totally Tubular!

Save the other kit and just buy a 34" length of tube and cut off what you need.

He lists it as a BT-100 for $5.00

Whoa! Not so fast, there pardner...

The term "BT-100" is generally used to denote the ~3.7" OD tube used in the 1/70 Saturn 1B and the Mars Lander.

Does he have the 3.7" or 3"?

Either way, I want some.


Bill

 

[JRThro]

Originally posted by sandman
STOP!

The 3" heavy walled body tube for the Big Daddy is available now from Totally Tubular!

Save the other kit and just buy a 34" length of tube and cut off what you need.

He lists it as a BT-100 for $5.00

Not a bad idea, but he'll still have to buy various internal parts (motor mount, etc.) as well as balsa for the fins. It might be easier/quicker/simpler for now just to go with the parts he has from the other model, knowing that he'll be able to use whatever is left over at some time in the future.

This is, of course, just my $0.02 worth.

 

[sandman]

The term "BT-100" is generally used to denote the ~3.7" OD tube used in the 1/70 Saturn 1B and the Mars Lander.

Yes, I know and I corrected him (Totally Tubular) on this!

Why would you think I wouldn't know that?

I had ordered some thinking that's what it was.

I now have a nice long piece of the 3" big Daddy tube to make a Pro Series four x 24mm Estes Patriot (That's what you use the extra Big Daddy Nose cone for!!!

But more good news! Totally Tubular IS getting the real BT-100 (3.75" size) sometime this week.

SCADAMAN,

If you want the tube I can send it too you...I can get more...pm ME!

 

[Bill]

Originally posted by sandman
Yes, I know and I corrected him (Totally Tubular) on this!

Why would you think I wouldn't know that?

I had ordered some thinking that's what it was.

I now have a nice long piece of the 3" big Daddy tube to make a Pro Series four x 24mm Estes Patriot (That's what you use the extra Big Daddy Nose cone for!!!

But more good news! Totally Tubular IS getting the real BT-100 (3.75" size) sometime this week.

I hope he is planning to carry both sizes.

What else is Totally Tubular selling that is not on the available parts list?

There are many ways to use 3" tube. For example, check out this nifty 2.25 upscale table:

BT-5    0.544"  ->      1.224"  T-52H
BT-20   0.736"  ->      1.656"  BT-60
ST-8    0.908"  ->      2.043"  ST-20
BT-50   0.976"  ->      2.196"  BT-70
BT-55   1.325"  ->      2.981"  Big Daddy tube
BT-56   1.346"  ->      3.029"  LOC 3" tube
BT-60   1.637"  ->      3.683"  BT-100
BT-70   2.217"  ->      4.988"  still not available from TT

Bill

 

[sandman]

He has a T-2+ tube that just fits over a MicroMaxx motor tube.

He really needs to update his web site!

 

[rocket trike]

There was a couple guys who tried this. It was before I got invovled with the group. One of the people who did this I think is Crashinj. I know that the rocket did not work I am not sure waht happen. Here is a picture of it anyways.

 

[Karl]

wow ! In my eyes those fins look a little too far apart ? Please correct me if I am wrong.

With all 2 stage models ( not CHAD staged ) , is it a good idea to line the inside of the booster's BT with aluminum tape? I mean , the exhaust flame off a motor leaves quite a mark on a blast deflector , and when a sustainer lights , is it the flame what knocks the booster off or pressure?
Karl

 

[JRThro]

Originally posted by Karl
wow ! In my eyes those fins look a little too far apart ? Please correct me if I am wrong.

With all 2 stage models ( not CHAD staged ) , is it a good idea to line the inside of the booster's BT with aluminum tape? I mean , the exhaust flame off a motor leaves quite a mark on a blast deflector , and when a sustainer lights , is it the flame what knocks the booster off or pressure?
Karl

Isn't it the booster's ejection charge that knocks it off, rather than anything from the sustainer?

 

[shreadvector]

Boosters motors have NO ejection charge.

Go to the Estes Educator website.

look at the Classic Collection technical report for pictures and words that ecplain how multi-stage rockets work.

Originally posted by JRThro
Isn't it the booster's ejection charge that knocks it off, rather than anything from the sustainer?

 

[JRThro]

Originally posted by shreadvector
Boosters motors have NO ejection charge.

Go to the Estes Educator website.

look at the Classic Collection technical report for pictures and words that ecplain how multi-stage rockets work.

D*** it! I really should think before I type, because I KNEW that, and that it's pieces of burning propellant from the booster motor that ignites the sustainer, and that it's the hot gases from the top of the booster motor that cause the booster to pop off.

<Bangs head on desk, then staggers off to sit in corner.>

 

[Bill]

Originally posted by JRThro
...and that it's pieces of burning propellant from the booster motor that ignites the sustainer, and that it's the hot gases from the top of the booster motor that cause the booster to pop off.

That may often happen, but that is not the ideal.

You are probably familiar with the staging technique of wrapping some cellophane tape around the joint between the booster and upper stage motor. That tape will allow the stages to separate when the upper stage ignites, but not until.

Early separation of the booster stage by the gasses from the booster motor burning through is often the cause of the upper stage not lighting and the resulting lawn dart.


Bill

 

[JRThro]

Originally posted by Bill
That may often happen, but that is not the ideal.

You are probably familiar with the staging technique of wrapping some cellophane tape around the joint between the booster and upper stage motor. That tape will allow the stages to separate when the upper stage ignites, but not until.

Early separation of the booster stage by the gasses from the booster motor burning through is often the cause of the upper stage not lighting and the resulting lawn dart.


Bill

Bill,

Thanks for clarifying that for me. To be honest, I'm familiar with most things in model rocketry not because I've done them (yet), but because I've read about them, have seen pictures of them (here and elsewhere), have heard other people talk about them, or have seen them done by someone else.

So far, all I've actually done is built and flown a few single-stage rockets, painted one rocket, and bashed one kit by lengthening the body tube. I'm learning a heck of a lot more from reading things here, on EMRR, and on my club's Yahoo! group, than I have anywhere near enough time to actually do myself (darn it!).

 

[Fore Check]

Hey JRThro:

I just read your sig more closely. You should pull that Quest Zenith II out of the packaging! All this talk of staging and you have a two-stager, in hand, unbuilt?!?

The Z-II is a great rocket. If you haven't openend it yet, you should. Read the instructions, look at the parts... *and by all means build it and slap a C6-0 and a C6-7 in her and let 'er rip!!!!*

(Well, you might want lower power at first.... )

 

[teflonrocketry1]

Originally posted by Fore Check
Too bad I only have the demo version of RockSim - I can't post the sim I just put together.

On a 2 Stage Big Daddy - if you make the booster 5" long (just to match the root cord of the fins) and then fly on a D12-0 staged to an E9-6, you get a predicted altitude of 1160 ft.

There is a pre-made RockSim file on EMRR for the Big Daddy. I took it, and basically copied the fin can portion to make a booster. I added a piece of coupler as well, and lengthened the motor mount in the booster to 5" (to match the length of the booster.) Obviously, this would be a gap-staged project.

I added 0.75 oz of nose weight in the design to bring the single-stage caliber with an E9-6 loaded to 0.83 - which should be good enough for a "short and stubby" rocket. The 2 stage caliber with an e9 and D12 booster is 0.98

Is this RockSim version 5 file close to what you are doing?

Bruce S. Levison, NAR #69055 Section #535 Tri City Sky Busters

 

[JRThro]

Originally posted by Fore Check
Hey JRThro:

I just read your sig more closely. You should pull that Quest Zenith II out of the packaging! All this talk of staging and you have a two-stager, in hand, unbuilt?!?

The Z-II is a great rocket. If you haven't openend it yet, you should. Read the instructions, look at the parts... *and by all means build it and slap a C6-0 and a C6-7 in her and let 'er rip!!!!*

(Well, you might want lower power at first.... )

Well, I did pull it out of the packaging the day I got it, just to make sure it hadn't been damaged in shipping, and to confirm that all of the parts are there.

The Super Bird I bought from the same seller on eBay had a damaged BT, the decals and flight prep instructions were missing (from the sealed, unopened bag), and the Kevlar cord was too short (maybe 18" instead of 24"), so I thought I should check the Zenith II right away. All of the parts are there and look good. Of course, it's fun just to open the package and look at everything, too.

 

[scadaman29325]

A lot of good info here...

Right now I'm going to build the first kit with 'staging' in mind and hold off bashing the 2nd.

Besides, it may be better to shorten the booster BT so I can tape the motors together. Short enough for D and an E can hang out the back.

I think a closer fit on the fins and matching the rear sweep would look better any way... as was mentioned 3" BT is available and I've already made some more CRs and I got some 1/8" Balsa fin stock...

If they are going to be discontinued it might be worth a little something in a few years.


Thanks
Phil