Wednesday, October 10, 2018

Steampunk Protostar #18 - Making Custom Marking Guides

Now I have arrived at the part of the Steampunk Protostar build where I can cram the kit instructions into the glove box, make a sharp right turn off of the normal 'Model Rocket Interstate', kick the build into Four Wheel Drive, and do a little off-roading!

It's time to immerse myself into the rugged, uncharted territory of Steampunk detailing.

The first step is to mark out the main body tube for the location of the following items:
  • Riveted panels
  • Fins
  • Launch Lugs
  • Various surface details
In my rocket-building world, I usually don't use the fin marking guides that come with the kits.
Instead, out comes a piece of typing paper which is cut to size and carefully wrapped around the tube.
A mark is made on the factory-cut edge at the exact point where the paper overlaps.








The paper is then unrolled and a precise measurement of this circumference distance is made using a digital caliper.

The trusty slide rule is pulled out to divide the measured distance by the number of required segments.  In the case of the Protostar fins, I am dividing by three.

















This new dimension is then marked on the guide, again using a digital caliper. I do not mark out all of the segments on the guide.  You will see why in a moment.
The new precision guide is now taped securely and evenly around the body tube, and the two guide marks transferred to the tube surface.
















I then rotate the guide until the first mark on the guide lines up with the second mark made on the tube. Another mark is made at the next location.

This process is followed all the way around the tube.  If the marks on the guide were made correctly to begin with, the final marks should line up exactly.  This means that the marks are equidistant around the tube.
If, perhaps, that final mark doesn't quite line up, the guide can be adjusted slightly, and the tube re-marked.  (That's remarkable!)

A quick note:  I have made such marking guides for nearly every sized Estes body tube, both three and four finned varieties. These are a permanent part of my 'jigs and  fixtures' box.

One quick question:  Does anyone ever keep gloves in the 'glove box' of their car any more?

One more thing...I didn't really use the slide rule.....