Tuesday, August 15, 2017

Recycle, Reuse, Rebuild

I have partially disassembled two rockets - the Fett Boy and the Not-a-MIRV.

Fett Boy - man, I sure liked that name. Although it can fly at MDRA, I decided that it uses too much structural metal that is only required for flight if you just have to fly a Bobba Fett bank. (I still think it is safer than a pointy fiberglass rocket, with or without an aluminum tipped nose cone.) The Not-a-MIRV flew OK but the main thing I liked was the triple tube ejection. So, both will be recycled and reused.

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When disassembling the Fett's nose cone, I found my missing 8" ballistic drogue. I forgot that I attached it to the lead-weighted nose section, which I didn't want coming down by itself on a hard ejection. That's what I get for not launching it for many months after I built it.

So, I have the Fat-Boy body section and the slip-on shoulder from the nose section. I can either mount some other odd item on the latter, make an upscale Fat Boy, or....

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So far on the Not-a-MIRV, I have merely chopped the two parts apart. I may separate these parts with a central rod or...

Now, what to chop up next?


Friday, July 28, 2017

Shai Hulud makeover

My Shai Hulud (a 'desert squid' style rocket) suffered two broken arms/fins/dowels on its fifth flight. I had the forethought to make the dowels removable so they could be easily replaced.  It always had some wiggle on the way up and could have benefitted from longer dowels and maybe a little more angle on them. I didn't have any other projects on the bench so I decided to go in a totally different direction. I decided to retrofit it with a leftover set of Partizon fins and cut the dowels from about 16" to 6".

Before:

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And, after:

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I now have to decide how I want to finish it. I'm tired of the brown body and am thinking about a silver metallic for the legs. That's as far as I've got.

Tuesday, July 25, 2017

Mercury Redstoned rework

I have added a forward launch lug and have selected a new nosecone. I will rename it for the flight card but will keep the old name in tags, folders, etc to keep the variants together.

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Here is what I considered (L-to-R):
  1. Plastic Frankenstein head. The name would be Mercury Fankenstone. I liked the name but it was a bit small.
  2. Soft foam cone that I made for a boink water rocket. If history repeats itself, a squishy cone might be a good thing. However, it is a bit big and would require even more launch lug work. Plus, if history repeats itself, this is going in the trash bin.
  3. Harder foam cone with a plastic tip, also made for a water rocket. It was never used. It fit well and I liked the look. It isn't well finished but seems to fit this oddroc well enough. It might be damaged even on a nominal recovery. Oh well, there are other options after this.
  4. A plastic Apollo LEM that I build for some reason.  I decided there were too many small pieces that would be guaranteed to break off even if the flight was otherwise successful.
So, this was my selection:

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Saturday, July 22, 2017

Mercury Redstoned post-flight analysis

Here is a poor video of the flight:

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It appeared that it hung on the rod. There was some twisting, but I'm not sure if that was a root cause or a symptom.

The hang could have been due to: A misfire (but all motors lit); delayed ignition (possibly), misaligned motor mount(s) (possibly, but they are as straight as my three other forward canted motor rockets).

One interesting observation is that the First-Fire igniter tube that I used as a lug is a bit loose on a 1/4" rod. I've successfully used many of them. However, this one is shorter than the other lugs on my forward canted clusters. It is also well behind the motors. On my other similar rockets, the lug extended past, or was well ahead of, the canted cluster. I have experienced a rod hang on a loose, short lug. So, I'm thinking the angled (and possibly asymmetrical) thrust of the canted motors caused a bind.  There is one other factor that I think came into play. On the next flight, I loaded a rocket with a 'real" 1/4" lug. Before it reached the tape stop from a previous launch, it stopped. I found that the two inches or so above the stop was *very* sticky. There was probably tape there at the previous launch and the nice hot weather made sure the remnant adhesive was quite gooey.

I think I'm going to retrofit a second lug at the top of the body and come up with a new nose. I have a plastic Frankenstein head, so I could call it the Mercury Frankenstone (?)

Launch Report 2017- (MDRA)

Location: Central Sod Farm, ESL-228
Weather: partly cloudy, until the thunderstorm; 93 and felt like 106; wind 0-5 
Total flights: Today - 4; YTD - 24
Total motors: Today - 7; YTD - 28
Motors by class YTD:  A-1; B-3; C-12; D-2; E-4; F-3; G-2; I-1


By all rights, this could be counted as a bad day. Except for the fact that ROCKETS were involved.

It was really hot, a huge thunderstorm cut the day short and two of my three rockets failed miserably. I did get to chat with some old friends, see some nice HPR flights including a YUGE Bullpup, and I got my motors from Kenny!

My Flights:
  1. Apollo Command/Service Module on an F44-4 - When reporting on TRF, I mused that this model would benefit from more airspeed. Nope. It wiggled and then took a fast right turn. It survived but will be cannibalized. I sure had a rough time getting the motor lit. Luckily the F44s have a wide throat.
  2. Transparent Rocket on a D12-3 - Nice flight. The outer tube is fine but you can see the inner one was slightly melted/warped.
  3. Transparent Rocket on an F15-8 - Another good flight. The outer tube is still pristine. The dual fishing line shock cord tangles badly but works well enough.  Someday, I will try to clean the inside but, for now, it has a shiny silver finish.
  4. Mercury Redstoned on 4  xC6-5 - It barely got off the pad. Only the paper capsule perished. This will be the subject of a separate post.

MDRA ESL 228 7/22/2017

Friday, July 21, 2017

Mercury Redstoned ready to fly!

I could use some trim, but time has run out. The important thing is that is can fly this weekend! I found two spots where the paint attacked the foam. I refilled those and a bunch of rough spots and touch painted them.

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The only expected problem is the loss of the paper capsule. I am already losing interest in replacing it. If it doesn't survive, I'm thinking that I will find some other nose section and give it a new name.


Wednesday, July 19, 2017

Mercury Redstone in the buff

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Here it is with everything but paint and recovery components.  It is actually flat black at the moment. I'll snap a photo tomorrow.
Aside: Often, whenever I bitch about not being able to get something completed, it gets done. Conversely, when I think I have plenty of time, other things try to suck up all my time.
I didn't intend to give this a great finish, however, I find a few spots that don't meet my admittedly low standards. I also have to inspect the edges of the fins to make sure the Rustoleum paint didn't eat up the foam.  It doesn't look like it but when the paint is dry and it is bright out I may find out differently.  It now looks like I'm short of time so I don't plan to do much. Except for adding the recovery harness. Tri-fold mount, baby :)