Monday, October 15, 2018

No Model Rocketry This Past Weekend...

We received our first Colorado snowfall over the weekend, and even hit a record low temperature.
This is a pic out my back patio door as I wistfully watched the snow fall, wishing I could be out flying rockets, instead.  Had to stay inside and torture myself by watching the Broncos lose....again.
At least I did get some basement shop time in, if nothing more than cleaning and organizing.

Friday, October 12, 2018

Steampunk Protostar #19 - Marking The Parts

Moving right along on the Protostar.....

Marking the body tube....

I have made two marking guides for the Protostars's main tube.

One is for the fins and launch lug, the other for sectioning off areas for simulated riveted panels.

First, I will mark out the lines defining the long sides of the riveted panels.  The body tube circumference will be divided into eight sections for these particular details.

Marks are transferred onto the tube from the guide.

The eight lines are extended the full length of the tube.
I am using a metal shelf standard as a line guide.  This 'U' shaped strip is ideal, as it aligns easily along the curvature of any body tube.  Definitely a huge improvement over the drawer / door sill method.

I must now consult my concept drawing of the Steampunk Protostar.

I note that there are three major sections between the nose and the leading edges of the fins. Each section is defined by a simulated riveted steel band.

A quick measurement of the body tube reveals that I can make each section 3-1/2" in length (that's 89mm for you metric nuts), to get close to the appearance in the drawing.

Using the edge of the marking guide, the lines are traced around the circumference of the tube in the prescribed locations.

Now, the fin and launch lug lines can be marked at the aft end of the tube, using the appropriate guide.

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.....

Monday, October 8, 2018

Yet ANOTHER Must-Build Scale Model

I am continuing to find special items of interest within the pages of Peter Alway's The Art Of Scale Model Rocketry book.

This time, it's all about the page showing the scale plans for the ASP rocketsonde....

The prototype round depicted in these plans just happened to be launched at White Sands on the very day in 1956 that Yours Truly came screaming into the world!

Perhaps this upcoming-build bird will only get launched annually on my birthday.

Friday, October 5, 2018

Steampunk Protostar #17 - Finishing Up Those Pods

I am a slacker.
I got so immersed in this portion of the Protostar build that I totally neglected getting out my cel phone and taking the usual photos of some of the various operations involved in assembling the pods.

So, imagine if you will, the following steps:

Hollowing out the tail 'cones':  Since these pieces are at the extreme aft of the entire model, I would want them to weigh as little as possible.  The parts get hollowed out using a Dremel tool equipped with a cone-shaped sanding stone. 
The parts are very light to begin with, but I still don't want to move the model's CG any farther rear than necessary.

Gluing 'em in:  A little bit of the thicker flavor of CA works well here.

Here is a picture of the glued up 'water tanks' three:

Before filling and finishing the pod / end piece joints, I want to place the requisite marks for locating where the fin should be glued, per the kit instructions.  This is 1-1/4" from the rear end of the plastic parts.

Now a little bit of CWF is 'spackled into the joints...

a little more CWF is applied to the ends of the balsa pieces where some lathe cutoff mishaps took place...that was a lathe operator error.

...and everything is sanded out smooth and even.

The last step is the normal filling and sanding of the balsa wood grain using thinned CWF.

Tuesday, October 2, 2018

Steampunk Protostar #16 - Taking Some Balsa Wood For A Little Spin

Now that the balsa stock for the tail pieces is mounted, its time to take it upstairs to the BlastFromThePast garage - the dwelling place of  the wood lathe.
After mounting the face plate and work piece onto the head stock, it's time to switch the machine on and get busy.

The first operation is to turn the piece into a cylinder that is slightly larger than the final diameter.
A sharp wood turning gouge is used here.

Since balsa wood is very soft and splintery, this operation must be done in a series of very light passes.
Next, a medium grit sanding block is used to bring the diameter of the blank down fairly close to final.

Now, shaping of the first tail piece can be started, again using the medium grit block.  Note that the tool rest is moved perpendicular to the end of the work piece.  This helps steady and guide the sanding block as it is worked around the end of the stock.  The machine is stopped frequently so that shaping progress can be checked against the template.

Finally, the shape is well-established.

Next a pencil mark defining the base is applied while the machine is turning.

The shoulder is turned to the proper diameter using files.  The dimension is monitored by a caliper set to the inside diameter of the plastic part in which this piece will fit.

Finally, the location for the part cutoff is marked, and an application of a razor saw while the machine is turning makes short work of removing the part.

The finished tail piece in hand....

....and a near-perfect fit on the mating pod....

Now to make two more just like it. 

Because I am making three of the parts in series from the same piece of stock, I opted not to seal and finish the parts on the lathe, due to the time constraints involved. I will finish the parts individually after they are glued in place on the pods.

Monday, October 1, 2018

A Definite MUST-BUILD Scale Model Rocket!

I recently downloaded from the NAR website a copy of Peter Alway's "The Art of Scale Model Rocketry".

Within the pages of this excellent book I found this.....and immediately cracked up!

You readers might be wondering why I should find anything even remotely humorous about this rocket.

Here's why....

In my work-a-day world GIRD stands for
"Gastro-Intestinal Reflux Disease".

You, see, boys and girls, I happen to make my living working for a medical equipment company that researches, designs, and manufactures devices that allow Gastroenterologists to detect and diagnose GIRD in their patients.

Of course, the GIRD-09 in Alway's book depicts an early Russian experimental rocket, and has nothing at all to do with chronic heartburn, but I believe it is my destiny to build my very own scale model version - perhaps for no other reason than for the novelty of having a bird in my fleet named  'GIRD' !!