Wednesday, September 24, 2014

Building the Big Bertha - Part 1 (For N00bs)

Tom Petty was right - the waiting is the hardest part - when waiting for the glue or paint to dry on your rockets. Bet you didn't know Tom Petty was into rockets, did you?

While I wait, I'm going to show you some of the steps to building a Skill Level 1 rocket - in this case, the Estes Big Bertha. You'll see all the basics to build any Skill Level 1 rocket here, so if you're ready to build your first rocket, this will all apply to what you're doing.

The Big Bertha is a classic, two-foot-tall rocket with huge, swept back fins, a rounded nose cone and a goofy name. It also has kind of a goofy look, if you go by the "classic" paint job and decals.

The picture on Amazon when I ordered the rocket was a cooler, black look, with cool, white decals.

But sometimes Estes and Amazon don't agree. Mine came with the big, goofy 1970's looking Up With People-style decals, so I tossed them out.

One good thing about rockets is that you can paint them however you want. If you have an idea. I was kind of stumped. I thought about a black and yellow checkered pattern, but I plan on building the V-2 at some point, and that's the classic look I'd use for that one.

Anyway, I'm getting ahead of myself.

First thing you do when building a kit like this is to check to make sure all of the parts are there. Now here's where I should post a picture of all the parts, but I guess I forgot I was now writing a rocketry blog, because I didn't photograph the whole process. Oops. But you can visualize the first couple of steps without pictures, or you can scroll down to earlier posts I've written - the Crossfire ISX and the Mini Honest John - and look at all the photographs I obsessively took of those builds.

Your fins on a kit like this come pre-cut from a sheet of balsa wood. They are held to the sheet with just a few tiny tabs of wood. First you take the sheet and some medium to fine grit sandpaper, and sand the wood smoothish. You're not going to get rid of any wood grain at this point, just make the sheet of fins less fuzzy.

Now, my fins basically fell out of the sheet right away, so I had to sand them individually. Not hard with fins of this size. Also, the fin sheet was slightly warped, so the fins were ever so slightly curved. You don't want this. I figured out a fix for this. If you have slightly warped fins, take the sheet - or individual fins - and spritz them with a spray bottle. Just a mist. On both sides. Wipe off the excess moisture, then place them on a sheet of parchment paper, put another sheet of parchment on top of that, and add a heavy book. The Riverside Shakespeare is an excellent choice for this, and the Complete Works of William Shakespeare is one of my unexpected rocketry tools.

Let the fins dry out. The parchment will wick away the moisture, and your fins will be flat.

Anyway, if your fins are still tabbed to the sheet, carefully - CAREFULLY - cut those tabs with a hobby knife. It's really easy to actually cut into the fins themselves if you're not careful.

Once your fins are free, put them together with the grain going the same way, so that they're all the same shape facing the same direction, and stack sand them. This means you make a stack of them, line them up as perfectly as you can, and sand the edges flat and even. You want to take off the remnants of those tabs of balsa and make them smooth and even. (Man, I really wish I'd taken pictures of this... If you're just learning to do this, go take a look at those previous builds.)

Alright, that's enough for now.

Oh, I played around with OpenRocket, and I did up with a paint job I'm going to use. Something clean and simple. Here it is:

[Click here for Part 2]

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