My New 29mm Two Stager

I thought I'd share what I have been working on while the construction of the Black Brant Vb has been suspended and have a little game too. Here she is:



Now the game is "Can you guess the heritage of this rocket"? In other words , what did it start as? Those who know me on the forum know that I never build anything as instructions say... I predict someone will nail it in as little as three posts

Sorry for the background kinda blending in.

-Bob

I recognize the nose cone. Kitbash of two Majestics?

Hmm, Majestic nose cone but Ascender/Trajector fins (I think).

Whatever it is it looks beautiful. Did you cut the North Star logo yourself?

Ascender + Pro Series II Booster is my guess. Though it is possible you had two Ascenders and kitbashed the booster.

Both of you are so close to nailing it already!

Yes, I cut the NorthStar logo on my Cricut machine and thank you

-Bob

OK then, Majestic + two Pro Series Boosters?

Oops, all three are so, so close. Each of you have the idea right that it's pro series stuff.

-Bob

Trajector and Mammoth also had those same fins and Mammoth had the same nose.

Neil got it!

Yes, it's made from a Majestic kit and two pro series boosters.

So I painted the Majestic because I could not find a purple for the booster that matched the Majestic body tube. I painted them Rustoleum Metallic Cobalt Blue.

I wanted the fins to match so I bought a second booster to steal , err borrow, the fins from. The part of the fins that goes inside the body tube and attaches to the centering rings is exactly the same as the Majestic fins. The booster fins are also slightly larger. I wanted the fins to be chrome so I tried painting them with Rustoleum 2X Silver. The cap looks like chrome but the actually paint not so much. I still wanted chrome so I bought some MonoKote chrome trim sheet and put that on the leading edge. It's not sticking down as well as I would like but I'm gonna try a few more things to make it stick better. I did want something to wrap over the leading edge because these PSII fins are known to come apart. I'm sure it'll be fine with the F15 Estes motors but I might get the urge someday to launch the upper stage alone with a Aerotech F or G

I decided that it was no longer a Majestic so I came up with a few names and I liked NorthStar the best so I made up the logo with the star and cut it out on my Cricut. I don't remember the name of the vinyl that I used but it seems to stick real well. If the trim sheet doesn't stick better it might get replaced with this stuff.

It seems good to go in Open Rocket but I still need to check the cg and weight, update OpenRocket with the real data and see if it still checks out.

-Bob

I did briefly think about calling it the Majestic II but I didn't want to get our friends at Estes upset with me



I thought about adding "boosted" in little letters under the swirly thing too

-Bob

So what's this about suspending the BB VB?

Bruiser said:

Neil got it!

Yes, it's made from a Majestic kit and two pro series boosters.

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@Antares JS gets an assist because I had completely forgotten about the boosters until he mentioned them.

To be fair, everyone contributed something along the way. It didn't take long

Kuririn -- kitbash of 2 Majestics

Neil -- recognized the fins from the Ascender (same fins as the booster kit)

Antares -- the booster kits

Kuririn, I haven't worked on the BBVb since January 30th. It takes a little more brain power to build that from scratch than to put some EX2 parts together into something different. I didn't even touch rockets (or post much) for most of February into March. My Chrones acting up, rotator cuff surgery postponed, dog shows cancelled, launches cancelled etc, etc was just weighing me down. Not that my troubles are any worse than anyone else's but my head just wasn't into it. Finally getting my head wrapped back around things so I built the NorthStar. Who knows, maybe the Black Brant will restart sometime soon.

-Bob

Pretty bird!
What’s the smallest motor you can put in the sustainer? It would be nice to get it back for a second flight!

I think OpenRocket was saying about 1900 feet with estes f15-0 f15-6 combo. That might change once I plug in real numbers. I haven't simmed it with anything else yet

One of my Christmas gifts was a chute release that I havent tried out yet

Bruiser said:

I think OpenRocket was saying about 1900 feet with estes f15-0 f15-6 combo. That might change once I plug in real numbers. I haven't simmed it with anything else yet

One of my Christmas gifts was a chute release that I havent tried out yet

Click to expand...

That'll be a darn good use for it.

Where do you get your F15s? Since Hobby Lobby stopped carrying them I've pretty much given up.

Try plugging in E16-0/E16-4 and see what you get.

I have a few I bought when HL was clearancing them. I think I have two packages of each.

When I have to buy more, I'll just have to find a good price and order several to make the hazmat worth while. Might order a few of the g74 motors at the same time. I bet the Ventris or BBVb would really like them

Bob

Btw, I took my coverite iron to the chrome trim monokote this afternoon and it looked pretty good afterwards. I'll see what it looks like tomorrow after it has had the night to relax. I know from my airplanes days that regular monokote will take a few shrinkings before it "sets"

Bob

Here's some of the performance data



I am betting I won't get these figures. My rockets generally come out heavier than OpenRocket says they should. Also I know in this instance I did not add the Estes 29mm retainers to the ork file.

-Bob

I just realized a little something...

I built the booster per the instructions, really. I just realized there are no vent holes for the escaping air. There's not much "free space" between the booster motor and the sustainer motor. It's about three inches and the tube diameter is two inches. I wonder if I should add in some 1/4 inch holes.

Has anyone used a PSII booster? Did it work alright?

-Bob

Bruiser said:

There's not much "free space" between the booster motor and the sustainer motor.

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How much is "not much"?

I've never heard of anyone having that sort of problem with the booster.

I like your idea with the matching fins, very cool. If you followed the instructions for the rocket and booster, then you should not need to modify either, the Booster is designed for the 2" PSII kits. The sustainer nozzle should be close enough to get the heat from the booster end burn to ignite. When you have a longer gap for black powder motors, then you would need to have vent holes near the sustainer nozzle to let the cool air get out of the way of the hot air to ignite it. You built the rocket and booster essentially stock, so no vent holes should be required.

I may use my leftover Prowler fins (I did a kitbash and made my own ply fins for a Prowler) to build a PSII Booster for my Mammoth so the fins will match...great idea! Seems like the fin slots from the E2X PSII 2" kits should be interchangeable with the PSII Booster fins, right?

Kind of ironic that these are E2X no-paint kits with pre-colored body tubes, fins, and cones, but most folks tend to customize them and come up with great paint jobs for them.

GlenP said:

Kind of ironic that these are E2X no-paint kits with pre-colored body tubes, fins, and cones, but most folks tend to customize them and come up with great paint jobs for them.

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True, but that chrome nose cone would be hard to reproduce, so it's a good starting point.

I can't get over how great the whole things looks. That'd be an excellent SPEV for Estes.

From my experience with the pro series booster and the Majestic I do believe the fin slots are the same size. I just looked at my trajector kit and they looked the same also. They may be the same exact fins as on the ascender and the boosters but that rocket is at work so I cant say positively.

I did the actually weight and cg today. Yeah, it is about four ounces heavier. I lose 400 feet with the F15 combo and that's not a huge issue but there is an issue. The velocity off the road drops below 30...

Now really the only things I did to this rocket was add a baffle which was a coupler and two ply disks, then there was the paint. I didnt even fill the spirals.

So I've read that this rockets are slow off the road with the estes engines. So ok, use a composite. That's fine if you're flying a single stage but makes staging much more difficult...

I think the reason why people "play" with this rockets is because of the size. 29mm composites are pretty reasonable and the rockets are a nice size.

-Bob

neil_w said:

How much is "not much"?

I've never heard of anyone having that sort of problem with the booster.

Click to expand...

If you are within an inch you are probably okay. Much more than that, and you need some holes. I used two holes, each with a standard hole punch, for a 53” gap and it worked fine.

Bruiser said:

...it is about four ounces heavier...

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The Estes Mammoth is nearly 4 oz heavier than the Majestic. That Estes kit is the same dia and also rated for the same engines and booster. I think you probably have the margin for the black powder engines. Just make sure you have little or no wind.

So here's the data with the new rates. Keep in mind that the speeds are with a 6 foot rod which the club does not have. They only have 3 foot rods.



I am thinking I need to look at this rocket again and consider adding some rail buttons because the rails are longer than the 3 foot rods.

I did put vent holes in my two stage Citation Patriot build and my two stage Tempest design. Those boosters are basically the same as this booster

-Bob

Bruiser said:

So here's the data with the new rates. Keep in mind that the speeds are with a 6 foot rod which the club does not have. They only have 3 foot rods.

View attachment 411387

I am thinking I need to look at this rocket again and consider adding some rail buttons because the rails are longer than the 3 foot rods.

I did put vent holes in my two stage Citation Patriot build and my two stage Tempest design. Those boosters are basically the same as this booster

-Bob

Click to expand...

Other than MindSim, I don’t do simulator stuff (most of my rockets are square or otherwise weird.).

I do a decent bit of black powder staging, and my experience has been that multistagers seem to have a strong propensity to weathercock. I think this is because they require either more plumage in the tail or more nose mass to counter the extra mass of two engines in the rear. Weathercocking is generally not a good thing, and particularly bad on multistage as (at least with black powder staging) the sustainer is presumably going to light whether it is vertical or not. Definitely not a mode of Rocketry you want to have marginal speed off the rod or rail.

Suggestion. For first flight, go with the lowest rated engine you can in the SUSTAINER. Even consider putting in an adapter and going down a motor size (try a D12). Remember, the sustainer rocket at separation is already in flight therefore presumably stable. So you don’t NEED much in the sustainer to make it a successful first flight. Part of a successful first flight IMO is FINDING the sustainer.

first advantage is that the less mass, the faster your rocket gets off the rail.

Second is the less mass in the tail, the more stable the rocket.

Third is safety (probably should have put that first.). If indeed you encounter fecal turbine interaction and the sustainer goes off non-vertical, the smaller the motor the less the potential energy if the nose encounters something other than sky (generally bad and potentially the badness is proportional to the velocity).

Fourth is convenience. Staging is cool. Long hikes to find rockets that went really high (or weathercocked and went sideways).... not necessarily so cool.

Once you have proven the rocket flies well with a smaller sustainer, you can always go back and try something larger.

Hoping you get two straight trails on this puppy.