Friday, February 13, 2015

Rocket Fever! Part II

I lost my voice a few days ago, and was barely able to speak a word for about two or three days. Yesterday, I sounded like Batman. Today, I woke up speaking like the guy from Sling Blade.

This is... an improvement?

Don't worry - I am now on medication. The hardest part about this is that I've been too tired to work on rockets most days.

However... One day last week, I felt a little better, and got a surprising amount done.

I primed the Trident A, my three-motor cluster scratch build. I also sanded the plastic ridges - or flash - and applied plastic putty to the nose cone. Once this is sanded and painted, you won't see the seam.

I sanded the nose cone of the Sounder I - the tiny, super high-flying rocket I designed on a whim a few weeks ago. I just wanted to see how high I could get a little rocket to go by tinkering in OpenRocket. This one will go high and fast, and if I add a booster stage to it, it'll go even higher and faster - up to 3500 feet at Mach .62!

Both Trident A and Sounder I - especially Sounder I - will need added nose weight to be stable in flight. For that, I'll add some clay to the nose - 5 grams in the case of Trident, and more in the case of Sounder.

So I picked up a little scale to measure components - including fins, motor hooks, payloads - and clay for nose weight.

This one is small - too small to weigh an entire rocket. But it's accurate to a tenth of a gram. There were scales accurate to a hundredth of a gram. That might be useful if you were using a simulator to determine potential performance, and wanted extreme accuracy, or if you were doing competition rocketry. But this one was less than $8, including free shipping. So it's good enough for my purposes for the time being.

Next, after reading something on The Rocketry Forum, I decided I wanted to see if I could fill fins with CA (for n00bs, I mean see if I could make the wooden fins smoother by covering them in cyanoacrylate - super glue). I tried this once before on my Estes Hi Flier, but it didn't turn out great. Either I used too little CA, or sanded them too little, or too much, or used the wrong primer.

Extreme closeup of the Hi Flier - not terrible, but you can still see some wood grain.

In any case, some people seem to have good success with this technique, and I get a little tired of using wood filler sometimes - it always takes me at least three coats of filler before I get a finish I like, and that's a lot of drying time and sanding, and half the time I still notice flaws once I start priming and painting the rocket.

I had some fins lying around from a rocket I never finished - the Ceres B booster from the book Make: Rockets: Down-to-Earth Rocket Science by Mike Westerfield.

The Ceres boosters from the book have four fins. Three is easier, and the four-
finned version can be overstable - especially with a heavy payload on top.

I had a problem with my first build on this, and in the end, I decided to make the Janus II two-stage rocket, and stick the payload from the Ceres on top of that.

Anyway, I grabbed a tube and started gluing on fins. I figured if the filling technique worked, I'd just make the rocket. Then I decided why not just make the rocket anyway? I recently lost three rockets, and this will be a nice big one with an E motor. Even if the finish isn't perfect, I'll still have a rocket that should fly well, and look pretty cool.

So I glued on the fins, without even bothering to fill in the body tube spirals - which is something I always do. But I'm going to experiment here. I'm going to fill the fins with CA and prime the rocket with filler primer, and see how good that combination is at covering flaws.

I'm getting better at using the guillotine fin jig.

Then I started playing around with some of the rocket parts I had lying around. I got some potential new ideas just sticking a transition and more tubes on top of the Ceres B.

A transition and a BT50 make for a different look...

Adding the Sounder I on top make it kind of look like a sounding rocket scale model.

Of course, this rocket was designed to carry the ICU2 camera payload bay, seen here.
I included a standoff for the launch lug, so that I can use this payload.
I even thought how easy it would be to stick three tubes on the sides between all the fins - external motor pods! Then I'd have a four-motor cluster rocket, one with a lot of different potential cool looks! As long as you design your rocket so that it's stable, the looks are kind of up to you. The design possibilities are kind of exciting.

Finally, I started one of my big rockets: the Estes Partizon, a Pro Series II rocket, which I got during the Estes holiday sales.

I picked this rocket to do first, I guess, because it was the one I was least excited about, so I wasn't too worried about messing it up.

I can't tell you why I wasn't as excited about it - maybe it's the Estes suggested paint job, a kind of ugly purple and orange I find rather dull. But the thing about building rockets is that you can make them any color and pattern you want.

Of course, once I start building a rocket, I am really consumed by that rocket, and devote lots of care to it. This one is freakishly tall for me - 56 inches! That's only 4 inches shorter than my mother... Now I have to pick a color scheme. I'll post pictures of the build soon.

I haven't blogged in a week, so I wanted to let any regular readers there may be what I've been up to.

I have a couple pieces of exciting news coming up. Stay tuned!

[EDIT] Oh, I nearly forgot! I emailed Estes about the wonky fin on my Nike Smoke, and they got right back to me. They're sending me a new rocket, and I don't even have to send the original rocket back. So, I guess I get to keep that for spare parts.

Good job, Estes!

Like my Facebook page for blog updates.

1 comment:

  1. If this is what you are able to when you are sick a a dog, I can't imagine your output when you are up to par!

    Get well soon Dan.