For me learning something new when taking on a new project
is always a thrill. I have been reading
about a simple rubber powered free flight model known as the Blue Ridge Special
that uses a more advanced construction technique that creates a very rigid
structure. One person had referred to
this as “Union Jack” construction, my search for this brought up mainly
information on the official flag of the UK which is known by the same term. The
angled lines in the flag do have the look of a pattern of diagonal and crossing
horizontal lines like you see in the wing structure. Diagonal ribs connected to a spar through the
wing make for a wing that is very rigid. Tail surfaces also have diagonal
bracing.
The price for the kit of the Blue Ridge Special is
reasonable but it appears that it is not available right now as a note on the
Pal Model Products website indicates they are busy working on products. I was able to find plans that were similar to
the kit and used hobby shop balsa so my plane might be slightly heavier than
the kit, weight was 11.32 grams without rubber.
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| Wing Structure |
If you have built other simple rubber models of this size you might be wondering if more advanced construction technique is really necessary. This type of construction is normally seen in higher-powered glow or electric free flight models that scream skyward which can cause wings to flutter. What I have noticed is that my plane as well as the Blue Ridge Special planes other people have built flew perfect from the start with no trim adjustments needed. I have to believe that with this method of construction it is easier to build an airframe with no warps.
The airplane has only been out for one flying session so far
but it flew very well. Most of the flights were with 3/32” rubber using a 6”
diameter propeller. It was rather windy
and I sure did not want lose the new plane so I did not use anywhere near
maximum winds in the rubber. The
airplane climbed but not steep, I tried 1/8” rubber with even fewer turns and
the climb was steeper. I am really
anxious to try more winds on a calm day and see what this airplane can do.
Bill Kuhl
http://ideas-inspire.com
Additional Resources
New - Blue Ridge Special now available from Volare Products
Thread on Hip Pocket Forum About Blue Ridge Special
It is a great idea to have a prototype of the original plane to understand the mechanism of aerodynamics completely.
ReplyDeleteThanks
Sanola Jerry
Plos Constructions
I notice that the kit is still not available from Pal Model Products.
ReplyDeleteWhat alternative set of plans did you find to build this and where might they be found?
Jeff email me at scienceguy33@gmail.com
ReplyDeleteI have a Blue Ridge Special, bought and built many years ago, back when Blue Ridge Models was located in Ashiville, NC. It weighs 11.0 grams without rubber motor, and this after I added a wing saddle to keep the wing from rocking on the fuselage. Does the "Union Jack" construction add to or detract from the aerodynamics (?) - do not know, but I can say for sure that it makes the wing rigid and warp resistant.
ReplyDeleteRichard I was wondering the same thing. One has to wonder if it would cause more drag over the wing. But when the wing is slightly twisting in flight maybe that causes more drag. It does stay in trim much better than less rigid models.
DeleteI built another one with a viscous DT system https://youtu.be/iOT6h2BYUDE?si=Anyjw9uN4ivW5feN
ReplyDelete