Booster Shot: another dubious build thread

[Bruiser]

I'd like to volunteer for the first shot of whatever you got in that syringe. Maybe it'll make me a super-rocketeer!

Serious tough, coming along nicely!

-Bob

 

[neil_w]

Vent Holes

The white paint on the booster is fine, although I didn't get perfect coverage on the inside of the ring. Rings really *should* be prepainted before assembly, but I hate having to do that and decided to just live with the results however it came out. It's good enough.

Now the booster needed its vent holes. I marked a location a bit below the end of the sustainer engine, stuck a spent D motor in the top part of the booster (above the motor block) and drilled a 3/16" hole on each side. Actually I started with a pinhole, then worked my way up in a few steps to 3/16". To head off a couple possible questions:
1) it was not possible to use a hole punch here, for obvious reasons.
2) 3/16" is a fairly arbitrary choice. It looks like it should be plenty.

I got the two holes *almost* aligned pretty well with each other.


Cleaning up the holes after drilling was a pain.

I gave each hole (and the inside of the booster tube) a good coat of thin CA to give it a bit of protection. And here is the finished booster:



Sprinting to the finish line!

 

[BABAR]

More progress.
View attachment 663742

Needle I use for biopsies on a regular basis for comparison.

Looking forward to you taking the plunge.

5Pages​

Yes it is a Six Shooter

 

[lakeroadster]

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Gee @neil_w , that looks Hell-For-Stout? ​

 

[neil_w]

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View attachment 663847​

Gee @neil_w , that looks Hell-For-Stout? View attachment 663846​

Looks can be deceiving!

I think I might beef up the front of the tube in case it lands first (which seems likely).

 

[BABAR]

Looks can be deceiving!

I think I might beef up the front of the tube in case it lands first (which seems likely).

Are you saying the booster is stable post separation?

 

[neil_w]

Are you saying the booster is stable post separation?

Probably just barely. Haven't focused on that too much yet. There is no possibility of a recovery device.

 

[BABAR]

There is no possibility of a recovery device.

not Exactly, although I doubt you will take the cosmetic hit.

You could put “windows” in the ring fins near the pylons, all either clockwise or all counter-clockwise. Your ring is relatively short nose-tail width, so not a lot to work with but I think enough.

This will cause the booster to go into horizontal spin and land sideways.

It seemed to work for @lakeroadster ’s Ahpla.

This is more for people looking at your cool rocket threads and thinking “what can I do based on this?” Horizontal Spin is a GREAT recovery technique for ring fin boosters. And it is very easily done if integrated into the initial design.

Whether that will be more or less durable than ballistic impact is uncertain.

I didn’t look, which way is the fin grain for the booster pylons?

I’m assuming you did the right thing perpendicular to fuselage and not the easy way parallel.

Edit: ahhh, TWO pieces. Brilliant!

 

[lakeroadster]

not Exactly, although I doubt you will take the cosmetic hit.

You could put “windows” in the ring fins near the pylons, all either clockwise or all counter-clockwise. Your ring is relatively short nose-tail width, so not a lot to work with but I think enough.

This will cause the booster to go into horizontal spin and land sideways.

It seemed to work for @lakeroadster ’s Ahpla.

This is more for people looking at your cool rocket threads and thinking “what can I do based on this?” Horizontal Spin is a GREAT recovery technique for ring fin boosters. And it is very easily done if integrated into the initial design.

Whether that will be more or less durable than ballistic impact is uncertain.

I didn’t look, which way is the fin grain for the booster pylons?

I’m assuming you did the right thing perpendicular to fuselage and not the easy way parallel.

Post 61: "For the ring on the booster, I decided to use a piece of coupler (about .047" wall thickness) to make a good match, and also it seemed like it would be pretty robust."​

 

[neil_w]

The needle hub was slid into place and thin CA applied at each end to secure it. Then the leading edge was hand-painted to match.

 

[BABAR]

Awaiting your choice of paint for the metallic business end of this candle.

Of course, that might turn this into a Needle thread…..
(Sorry, I can’t help it sometimes.)

 

[neil_w]

Awaiting your choice of paint for the metallic business end of this candle.

Of course, that might turn this into a Needle thread…..
(Sorry, I can’t help it sometimes.)

It's already painted Rusto Stops Rust Metallic Silver in post 123. I know it's kind of hard to see in the picture.

A bright coat paint would have been better (as opposed to metallic flake) but I had the silver already so that's what I used.

 

[BABAR]

It's already painted Rusto Stops Rust Metallic Silver in post 123. I know it's kind of hard to see in the picture.

A bright coat paint would have been better (as opposed to metallic flake) but I had the silver already so that's what I used.

Ahhh…. Okay. I start getting lost once posts get over two digits.

 

[neil_w]

Misc little fixes

I removed the masking tape from the needle and was surprised and disappointed to see that it took with it most of the blue paint I had applied to the front of the needle hub.

What followed was a series of comical failures to get it redone... eventually I hand-touched it (no masking tape) and periodically wiped off the overslop on the needle with a damp paper towel. The end result is... good enough.


Apparently I forgot to check for lug fillet bubbles. Weirdly this was only on one side, the other side was clean.

Some Q&T was dabbed in the holes. Eventually I'll run a bit of touch-up paint over the fillet to pretty it up.

Also: this is why you should fill the spirals in launch lugs. Look at that, yuck. I didn't even do filler/primer on this one. Dumb mistake.

Anyway, we are ready for decals:

 

[neil_w]

Decals

I struggled with these decals like it was the first time I ever tried waterslides. Don't know why I had so much trouble.

First up, the tip of the needle:

I might have been better off with a white-backed decal here, but no way was I going to print a sheet just for this one tiny thing.

Next up: the plunger piston wrap. Can we all just agree that waterslide body wraps are the worst? Yes? Good.


Finally, the graduations, in two separate pieces. The big one is ever so slightly crooked, probably not enough to notice. I gave up fighting with it after a while.


Everything got a dose of Micro-sol.

Coming up soon: beauty shots.

 

[mbeels]

Finally, the graduations, in two separate pieces. The big one is ever so slightly crooked, probably not enough to notice. I gave up fighting with it after a while.

That looks really good from way over here. I can barely detect an angle, by looking at the reflection from the light. But that's soooo close, I wouldn't have noticed if I hadn't been prompted by you to even look.

 

[neil_w]

That looks really good from way over here. I can barely detect an angle, by looking at the reflection from the light. But that's soooo close, I wouldn't have noticed if I hadn't been prompted by you to even look.

Fortunately, while I am highly critical of my own work and very good at detecting and pointing out my mistakes, I am mostly able to forget about them after I’m finished.

I probably should have cut that decal into 2 or 3 smaller pieces, would have been easier to work with. Come to think of it, I probably should have done that with the wrap as well.

 

[BABAR]

The end result is... good enough.

When you think about it, the real thing is disposable…….

Then you think some more and come up with, “So was the Saturn V!” From ignition to jettison the lifespan of most of the rocket was under 12 minutes.

BTW, I love the needle tip. Even the 2D photo looks 3D. Very clever.

 

[neil_w]

Finished(ish)





Final todos:

1. Shock cord and parachute hookup
2. Paint touch-up on launch lug
3. Adjust fit on booster. It's too tight again, which is very annoying.

 

[jqavins]

The end result is... good enough.
View attachment 664413

The thing is, my friend, your "good enough" is most people's excellent.

First up, the tip of the needle:
View attachment 664420

I second what @BABAR wrote about that tip.

Next up: the plunger piston wrap. Can we all just agree that waterslide body wraps are the worst? Yes? Good.
View attachment 664422

I don't see what you're talking about. Really, the graduations yes, but the plunger is perfect as far as I can see.

Finally, the graduations, in two separate pieces. The big one is ever so slightly crooked, probably not enough to notice. I gave up fighting with it after a while.
View attachment 664423

I second what @mbeels wrote about that.

 

[neil_w]

I don't see what you're talking about. Really, the graduations yes, but the plunger is perfect as far as I can see.

End result: excellent. Process required to achieve that: miserable.

 

[Bruiser]

I gotta agree with the others. This rocket is excellent! No one else sees any problem with the decals, which by the way, are most excellent. The needle tip is soooo damn realistic looking! Great job

Btw, is this your first two stage?

-Bob

 

[neil_w]

Btw, is this your first two stage?

First scratch 2-stage, and first gap-stager. I really haven't done all that much with either multi-stagers or clusters up until now.

 

[jqavins]

First scratch 2-stage, and first gap-stager. I really haven't done all that much with either multi-stagers or clusters up until now.

Oh, now that's got me thinking about what sorts of cluster designs might come out of your style of design and level of skill. Maybe a linear three in separate tubes, and each tube has its own interrupted ring tail?

 

[neil_w]

Oh, now that's got me thinking about what sorts of cluster designs might come out of your style of design and level of skill.

Something interesting visually. Just jamming a bunch of motors in the back of the body tube doesn't particularly interest me (although I love seeing Boris Katan's stuff).

One challenge for me with clusters is that they often/usually require interesting centering rings, which I cannot make myself. I do have a 24mm/BT70 Deuce motor mount kit in my supply box that I've been debating what to do with for a long time.

 

[jqavins]

See my updated post #144. (Your reply ninjad my edit.)

 

[neil_w]

See my updated post #144. (Your reply ninjad my edit.)

That's an interesting starting point. I'll fiddle.

 

[BABAR]

. Process required to achieve that: miserable.

soooooo, kind of a PITA?

(You’ll get it in the end,)

 

[mbeels]

That came out great! I love how your finished pictures just look like slightly glossier versions of your pre-build rendered artwork.

 

[boatgeek]

One challenge for me with clusters is that they often/usually require interesting centering rings, which I cannot make myself. I do have a 24mm/BT70 Deuce motor mount kit in my supply box that I've been debating what to do with for a long time.

Balsa Machining may be able to help here. They have a pretty wide variety of cluster centering rings.