Archives for May 2016

Buzz Bomb Update

Construction is progressing well on my new Stevens Aero Buzz Bomb. All of the balsa wood aircraft structures are now complete and ready for a final sanding. Covering and installation of radio equipment and the motor will be the next building agenda items.

Buzz Bomb fuselage nearing completion

Buzz Bomb fuselage nearing completion

The kit has gone together exceptionally well to date. The only issue that I ran into regarded alignment of the wing tips. The model uses a polyhedral concept with the outer third of the wind having extra dihedral to provide lateral stability. This was a very common technique in the early days of free flight model airplane in an attempt to come up with a more inherently stable design.

Initial construction of wing center section

Initial construction of wing center section

The issue with the kit is that the wing end sections are butt-glued in place to the end of the wing inner section. The outer third of the wing is dry assembled. It is fairly easy to have a wash in or wash out twist, whereby the wing’s outer section is not aligned with the inner wing sections. This is evident when the wing is carefully laid flat on the building board.

Luckily I spotted this early on. I made a few breaks where the wing tip section was glued to the main wing, aligned back to the proper incidence (no wash out, same incidence as the main wing panel) and glued in place. The follow on installation of the upper stringers made the entire structure complete and strong.

View of photo illustrated Buzz Bomb construction manual

View of photo illustrated Buzz Bomb construction manual

Bottom line, for a three channel model such as this (i.e. no ailerons) where the wing is constructed in three segments, ensure that the completed wing is flat and at the same incidence. Note that any final adjustments on the wing’s incidence can be taken care of with final sanding as well as even installation of the heat shrink covering.

Do note the photo illustrated construction manual, a standard feature with all Stevens kits. This covers every single step with a dedicated photo and clear instructions of what needs to be done. The manual is so thorough that full size plans are not included, really quite amazing for any kit. But the unique Stevens Aero interlocking build process works out just fine.

 

Completed Buzz Bomb wing structure

Completed Buzz Bomb wing structure

Start of the Buzz Bomb!

I am happy to report that my new RC workshop is “open” and airplane construction has commenced!

Front view of an ignition engine powered Buzzard Bombshell free flight model airplane

Front view of an ignition engine powered Buzzard Bombshell free flight model airplane

For my first build I will construct the Stevens AeroModel Buzz Bomb. The Buzz Bomb is a modern retake of a free flight classic, the Buzzard Bombshell, designed by Joe Konefes in 1940.

View of my new model airplane workshop

View of my new model airplane workshop

Joe did a remarkable job creating this aircraft. Using an ignition gas engine, the first flight at the 1940 Nationals marked an impressive world record flight time of 49 minutes and 40 seconds. Remember, this was in the age before CA glue, the internet to share learning experiences, reliable glow engines, any sort of radio control system, etc.

Nice stack of premium grade balsa as well as photo illustrated build instructions for the Stevens Aero Buzz Bomb

Nice stack of premium grade balsa as well as photo illustrated build instructions for the Stevens Aero Buzz Bomb

A nice aspect of these early free flight models is that they really had to have sound design and flight characteristics as there was no chance to correct a build or trim error with a radio control system. In short, these planes just had to fly right and exhibit no bad habits.

Stevens Aero adapted the basic outline, areas and moments of the original Buzzard Bombshell in their remake of the Buzz Bomb. The Buzz Bomb should fly in a close-in, slow and realistic manner. In short, an ideal first plane for my foray into larger size electric models.

Buzz Bomb fuselage 50% complete

Buzz Bomb fuselage 50% complete

So far the construction is progressing as with other Stevens Aero kits, i.e. with no problems. Every step is clearly outlined with an accompanying photo. The balsa is top quality and the laser cutting extremely accurate. The fuselage is nearing completion and the wing will be next.

Looking forward to a nice flying electric model and a “shout out” to the free flight pioneers of model airplane flight from 75 years ago.

Rotary Engines

I added a page today on the history of the rotary engine. There are some great YouTube videos included showing these unique engines in operation.

Detail of rotary engine showing connector rods attached to the fixed crankshaft

Detail of rotary engine showing connector rods attached to the fixed crankshaft

Rotary engines were used to power aircraft for around eight years, from 1910 to 1918. They filled a perfect niche in those early days of flight for a powerful and lightweight aircraft engine.  They were primarily used on fighter aircraft.

In-line engines were in the earliest stages of development during this period. These engines were heavier than rotaries due to the materials used and the need for additional equipment such as flywheels and cooling systems.

By the end of World War I technology had advanced sufficiently that in-line, as well as radial engines, became the aircraft power plant of choice for all aircraft.

Rotary engines make for a great visual point on any World War I radio control model. It is a relatively straightforward matter to fabricate a dummy rotary engine and allow it to freely rotate in the airstream, making for a convincing presentation while airborne.

Aviation History

I added a new section to the website menu bar on Aviation History.

Advanced version of the Wright brothers glider show pilot in a sitting position

Advanced version of the Wright brothers glider show pilot in a sitting position

The purpose of this section is to highlight some of the more interesting and lesser known aspects of aviation history by using photographs and video and discuss how this can relate to model aircraft design activities.

My opening piece is centered on a short film of the well-known German World War I ace Manfred von Richthofen and the Fokker Triplane.  Aviators during that era flew less than 15 years after the first flight of the Wright brothers.

Aviation advanced a great deal between the years 1914-1918 but was still in an evolving state. For example, things as basic as aircraft electrical systems and radios did not exist during the entire four years of the war.  Personally, I cannot imagine going on a night bombing mission with large numbers of aircraft with no way of communicating with other formation members or control authorities on the ground.

Fokker Triplane taxiing out for a takeoff

Fokker Triplane taxiing out for a takeoff

The film shows a church bell being rung to summon the pilots to their planes. You can view the amount of heavy clothing needed to survive in the completely unheated open cockpits of that time, with the temperatures at flight altitudes often below freezing.

These historical views are of interest on their own merit. But these images can also be used to provide detailed information for building radio control model aircraft, ranging from rigging and cockpit layouts to the view of a rotary engine being prepared for a start.

Thanks for stopping by! I’ll update the blog as I add additional pages regarding the fascinating background of flight.