Skip to content

SMALL STEPS

September 29, 2011

Long ago in a galaxy we all know and love…

Star Trek explored the fictional galaxy while giving honor to engineering as a profession.  The galaxy of Star Trek is gone, and the engineers are going too.  I have enjoyed my menial role in the engineering profession, so I will share this project to inspire others to follow.  I once offered a drafting class to our community youth, so this can be continued here on-line.

To be honest, the last ten years of my employment were going downhill.  Perhaps I am getting old, but I was not being used to the full capacity of my training.  I made a point to grow towards my own career goals.  I volunteered my free services, and gathered learning materials.  The AIAA offers text books and publications for learning.  I took some classes even though I would not get credit.  Aircraft design and basic engineering classes help me to understand what my leaders were doing on our projects.

To identify directions for new space, I searched on-line at sites like Hobby Space and Space.com for current trends.  I identified new aerodynamic trends in blended wing bodies.  I grew up with dad’s aviation magazines from World War Two.  It was natural to consider horizontal launch ideas.  The in-line staging idea provoked the project I am recording here.

http://www.space.com/

The first step of investigation was to buy a model airplane similar to my concept to model a new design on.  I did the first model in white building foam, a fast messy solution.  Using metal templates I was able to shape sections quickly.  The result was crude, but flew right the first time out.  That sent me to the patent office.

TTHIS DESIGN PROTECTED UNDER US PATENT 8,528,853 B2

Early Birds

The second model was to be radio controlled, so it needed structures to mount servos and control surfaces.  I designed to reflect possible future structural solutions for the real aircraft.  My design was based on methods used by jet models, which are usually larger, with more wing area.  It had a wood structure and belly, with a fiberglass cover bolted on.  I expected the fiberglass to be flimsy, so it had a lot of sturdy framework.  The fiberglass was much stronger and heavier than expected, so the product was super strong and heavy.

Talon’s Embryo

After one good flight, our second crash was terminal.  However, since most parts were undamaged, it is restored as a display model now.  If the plane can crash with minor damage it is way too strong and heavy. The second stage was the most challenging for stability, and it passed the glide test well.  The crash was a only problem with the launcher aircraft, so now we need both stages powered up.

This third try will reflect advice from other builders to reach a good compromise between light flimsy foam and the heavier jet type build.  A larger model may use the fiberglass shell method if it can be used for a production kit.  First I need a fast build prototype.  Part of the foam model was made of blue foam, which is less messy and easier to shape.  With a hot wire cutter I can form it easily.

A better idea…blue foam

The blue foam available here is only 1” thick, so I will make sections of that thickness.  Between each section I will place super thin plywood frames.  Thin plywood had proven too flimsy when used in frame construction.  But between foam sections it will be reinforced, and serve as a cutting template.  All plywood parts are laser cut, and have proven to be the best path to great accuracy.

Tail feathers becoming fractal design; details, details.

This hybrid construction uses the plywood in its greatest strength plane.  If you step on an aluminum can, it is strong in the vertical position.  If you lay it on its side, it crushes easily.  The vertical section is strong.  A 2×4 is 4 times as strong on edge as it is when laying flat.  A house floor has trusses on edge, reinforced with cross blocks to prevent twist.

That twist could allow the frames to buckle.  An airplane rivets ribs to the skin to limit that twist.  An “I” beam has a flange on top and bottom for this.  Foam is soft, but fills the space needed for a rib to buckle, limiting its failure mode in that plane.  A thin vertical web is ideal for a fat winged lifting body.  They will not be exposed to handling damage if they are sandwiched under the foam and fiberglass skin.  This may provide a stronger form than foam that is lighter than heavy structures.

Now I have a basic idea that will conform to an aerodynamic form.  All the mechanical systems have to fit into the envelope without compromising other systems or balance.  This becomes a packaging study that requires moving parts around inside the outline shell of the vehicle.  A computer drafting software allows models of parts to be displayed in a see-through model.  Alibre CAD can do this while tracking the center of gravity as the parts are moved.  www.Alibre.com

Since I spent much of my career in computerized design I needed this tool to guide the project.  Fortunately I do not have to buy the $30,000 software I used in industry.  Alibre is only $199 now.  Patience will reproduce every bolt and plank in the 3D world to confirm that parts all fit.  It is surprising how little room there is inside any vehicle you decide to design.  You can see a few bubbles I added when things didn’t fit!

It may seem like making toys is a childish use of time, but it is part of the process.  Space Ship one began as a model airplane.  Models are used often in aerospace as a tool for learning.  As I continue, we will see a lot of challenges to make it all come together.

Air flow inside and out, mechanisms, and a place for everything.

Advertisements

From → NEW SPACE

2 Comments
  1. Brian permalink

    All your links work except for one. When I click on http://www.spacetransportnews.com/ it is bringing up some Asian “adult” website. I even tried to enter it manually in the address bar but it still brigs up the same thing.

    • Viewing the “Small Steps” blog I do not see that link but it may be on a different blog date. I am directed to space transport news by our link, but it is an old broken link. Hard to keep old posts working when the web is constantly changing.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: