2-Stage Estes Indicator Upscale

[shanejohnson2002]

It's been a while since I've posted here, but I'm coming back with (hopefully) something cool.
I've had this design in my head for a while. The stock Estes Indicator just LOOKS like it wants to be a 2-stage. The big, draggy fins on the short 'booster' section definitely make me think "drag separation" and "tumble recovery".


So I decided to upscale it to BT50/60. Here's the result:






You can't see it in these photos, but the booster section stuffer tube *is* vented 1/4" from the top, and it vents to the outside through the centering rings which each have 3 1/4" holes.

The nosecone and transition came from Apogee:
Transition:
https://www.apogeerockets.com/Build.../PNC-41-6-BT-60-and-BT-60-to-BT-55-TransitionNosecone:
https://www.apogeerockets.com/Build...9mm-to-54mm-Body-Tubes/PNC-33?cPath=42_47_60&
I plan on flying it on a B6-0 / A8-3 combo first, to keep it low. I'm also planning on 2 more booster sections: 24mm and a 3x18mm cluster, depending on how this first flight goes.

It's also going to be painted with Duplicolor Metalcast Red and Black Smoke in the style of the original color scheme, , and Hyundai White Pearl on the main tubes. I want to do a shakedown flight first though before I commit to painting it.

 

[neil_w]

Those are all quite slow off the rod, concerning for a 2-stager. Really needs a 24mm motor in the booster.

 

[Raythain]

I love that design, have a kit in my build pile for 2 stage conversion. Nice looking upscale.

The one problem is converting this to 2 stage seems to call for an upscale on the booster engine. Neil's right, try simulating a 24mm motor in the booster. You should see much better velocity off the rod, and have a much lower chance of a cruise missile sustainer.

 

[neil_w]

I just noticed you mentioned you're already planning to building a 24mm booster and a cluster booster. I would start with the 24mm and forget the 18mm, it's just too marginal for a 4+ oz rocket.

Unless you have a secret stash of B14-0 motors you plan to use.

 

[shanejohnson2002]

Those are all quite slow off the rod, concerning for a 2-stager. Really needs a 24mm motor in the booster.

Agreed, on second look. It will be pretty easy to make another booster. I might as well make the 3x cluster while I'm at it.

I *may* try it anyway, but I'll make sure nobody is standing anywhere near it.

FWIW, the 24mm and 3x18mm are both 50-60ish off the rail when I sim them.

 

[shanejohnson2002]

@neil_w @Raythain Getting started...my house will smell like burnt plywood this morning!

 

[neil_w]

I envy anyone with a laser cutter... would love to smell that although it would get me kicked out of the house in a hurry.

 

[shanejohnson2002]

I envy anyone with a laser cutter... would love to smell that although it would get me kicked out of the house in a hurry.

FWIW I bought a cheap one from Amazon (TwoTrees TTS-55), and used Affirm to break it into monthly payments. I don't think my finance dept would have approved the purchase any other way.

 

[shanejohnson2002]

View attachment 604121


@neil_w @Raythain Getting started...my house will smell like burnt plywood this morning!

Also I just want to point out that these were before I added vent holes. These were pre-existing centering rings I copied. My idea is to remove the center of the 3x cluster and just let the space between the tubes be the vent, and I'll add 3 holes to the 24mm for venting.

 

[BABAR]

I tried converting the original to a two stage.

It did not end well….

 

[ljwilley]

Okay, I'm listening....

This should be fun!

 

[shanejohnson2002]

I tried converting the original to a two stage.

It did not end well….

Hopefully I'll have more luck.

What went wrong, specifically? Maybe it's something I can attempt to avoid

 

[shanejohnson2002]

Update:
New rings, fins, body tubes, etc are cut.

I'm just waiting on some more BT20 for the cluster MMT, and the plastic transitions.

 

[ljwilley]

I want pictures!

 

[shanejohnson2002]

I'm at work and won't get home until later tonight, but I forgot to update last night:

BT-20 tubes for the 3x18 cluster have been cut and thrust rings installed. I even made a jig to ensure they are perfectly aligned when glued together, before gluing it in the body tube. I still have to slot the BT-60.

The Apogee plastic transitions also arrived, and it's already installed in the 3x18 booster.

I'll take pictures of where I'm at tonight, as well as slot and glue in the fins. The 24mm should be fairly simple after that

I'm looking forward to sending it as a cluster. I believe the transition/reducer will help focus the gasses / IR that will help ignite the second stage. I expect the separation to be pretty gnarly though, with 3 engines all ejecting at (roughly) the same time.

 

[OC-Patrick]

I've always wondered how well the booster fins would survive under "tumble" recovery with a 24mm (or 3x18mm) and plywood. The only 24mm staged I've launched was an Estes Savage (BT55), and that had plastic fins and it came down relatively fast and survived.

 

[SolarYellow]

I would put a vent near the top of the booster just to be sure the non-burning air doesn't stay there in the way. Or combine the motor tubes into a central stuffer tube, somehow.

 

[shanejohnson2002]

I would put a vent near the top of the booster just to be sure the non-burning air doesn't stay there in the way. Or combine the motor tubes into a central stuffer tube, somehow.

I don't think there will be a need in the cluster. I'm basically completely forgoing centering rings and letting it vent through the gaps in the tubes. As far as combining, I think the transition will do a decent job of that. We'll see. These boosters aren't terribly complicated to make if it doesn't work.

The single motor boosters have holes in the centering rings, which has worked pretty well in the past. The motor mount on those form a stuffer tube, which has internal vent holes about 1/4" from the sustainer, and that vents to the outside through the holes in the centering rings.

 

[shanejohnson2002]

Successful launch on B6-0 / A8-3.

I didn't get good videos of the other launches, but it flew twice on a B6-0 / B6-4 combo. The 3x18 booster also worked just fine on 3x A8-0s

 

[shanejohnson2002]

 

[shanejohnson2002]

Video absolutely refused to upload from my phone....so I made the gif last night before crashing. Here's the video now that I copied it to my desktop.

View attachment Wyatt Rocket.mp4

 

[shanejohnson2002]

Notes:

Single booster:
B6-0 is a little on the weak side. I'm limiting it to C6-0 *only* in the future. I'm also going to make a second version that's as light as possible (cardstock rings, balsa fins, etc).

FWIW we were about 100 feet away, using my new MJG wireless launch controller. I don't think I would have let him press the button on an regular Estes controller.


3x Cluster booster:
A8-0 worked just fine, I think it's because it's essentially a "B and a half" level of thrust. I also think it was able to ignite the sustainer due to the amount of overlap between the 3 booster MMT tubes and sustainer MMT. I assume the reducer creates a bit of a funneling effect as well.

 

[lakeroadster]

Cool launch... congrat's.

 

[SolarYellow]

I'd think C11-0 would be optimum.

 

[shanejohnson2002]

I'd think C11-0 would be optimum.

Probably. I haven't completely finished the 24mm booster though, so I'm stuck with 18mm for now.

I also have to keep it fairly low because I have a small field. I try to keep most of my flights under 300 feet if I can, or 500 with a streamer or JLCR.

 

[kjhambrick]

Awesome, @shanejohnson2002 !

Which MJG wireless launch controller do you have ?

Alpha Firing Module

And how many cues ?

Thanks !

-- kjh

 

[shanejohnson2002]

Awesome, @shanejohnson2002 !

Which MJG wireless launch controller do you have ?

Alpha Firing Module

And how many cues ?

Thanks !

-- kjh

Just the basic single cue Alpha

 

[kjhambrick]

Just the basic single cue Alpha

Shane --

Did you need any additional components besides the Alpha Firing Module ?

IOW, did you get a complete system with one cue for $30.00 ?

if so, WOW !

Thanks !

-- kjh

 

[shanejohnson2002]

Shane --

Did you need any additional components besides the Alpha Firing Module ?

IOW, did you get a complete system with one cue for $30.00 ?

if so, WOW !

Thanks !

-- kjh

Nope. I just ordered the $30 module and it came with the transmitter and receiver as a set.

The receiver connects to the igniter, so unless you're using MJG style starters with wire leads, you might have to rig up some wires with alligator clips for regular Estes igniter.

Its 9V and claims to be capable of lighting 6 igniters in parallel. I only did 3 and it worked fine.

 

[kjhambrick]

Nope. I just ordered the $30 module and it came with the transmitter and receiver as a set.

The receiver connects to the igniter, so unless you're using MJG style starters with wire leads, you might have to rig up some wires with alligator clips for regular Estes igniter.

Its 9V and claims to be capable of lighting 6 igniters in parallel. I only did 3 and it worked fine.

Holy cow !

I saw the connection clips on the receiver and it looks like maybe a clip whip could be connected for Estes ignitors, as long as it provides enough current ?

For $30, it is worth a shot !

Thanks again !

-- kjh