As a tribute to the pioneers of model aviation engineering, a collection of articles in Aeronautics magazine written by Harry Schwartz dating from 1913.
A few vintage toy airplane plans I found in various publications over the years, including Aeromodeller Annual and Aeronautics Annual.
A few vintage toy airplane plans I found in the Aeronautics Annual of 1913-14 in a series of articles written by Harry Shultz under the title Model Notes
Title of the article is Obst Hydro. I would refer to this model airplane as a canard pusher that takes off from water.
This vintage toy is a rubber powered free flight hydro airplane built by Charles V. Obst of Cypress Hills Long Island. He was the president of the Long Island Aero Club way back in 1913.
Fuselage 40 " long, ½ " square in the middle tapering to ½ x ¼ at the ends. Made from 2 pieces ½ x ¼ laminated.
I would think that the joint runs vertically, which is confirmed when I study the detail A which also shows the small pine plug at the front.
There is a thrust bearing installed at the rear, no details given about how that is made. I conclude this thrust bearing is standard practice for rubber powered models, so there is no need to describe it in detail.
Main wing span is 23 ¾ ", root chord 4 " tapering to 2 " at the tips. Wing area 69 square inches, with a dihedral 150 degrees.
Elevator span 12 " with a 3 " chord.
The text explains that both the main wing and the elevator is made using bamboo.
Flying surfaces are covered in what is called silk fibre paper and treated with Ambroid, a glue originally developed to repair canvas canoes.
There you go, I learn something every day.
The propeller is 9 " in diameter, turning at 1160 rpm producing a thrust of 3 ¼ ounces from 18 strands of 1/8 " flat rubber.
The pontoons are an interesting construction of 1/32 spruce 7 ¾ " long, 1 ½ inch wide, ¼ inch deep with 5 airtight compartments. To me, this seems to be a lot of work, I would substitute light balsa.
Total weight ready to fly is 4 ½ ounces.
This design is more than 100 years old, and I totally respect that. If I was to make one, I would add a vertical stabilizer.
Where to position it? In terms of aerodynamics, in my opinion, at the back end of the model, as part of the supporting leg of the rear pontoon. I think it would have to have a reasonable surface area as well.
Browsing through more articles on vintage toy airplane plans, it seems that an absence of any vertical stabilizing surface is common. Maybe the rather large dihedral angle made a contribution to lateral stability, and I would think at the expense of vertical lift capability.
There is always a compromise. The addition of a rudder would also increase drag.
This is the start of my collection of vintage toy airplane plans. Sign up for my newsletter to keep up to date.
Here is another one, the Funk R. O. G twin boom rubber powered vintage toy airplane plan.
Note the lack of vertical stabiliser, which makes me wonder how well it actually flew.
How about this - the Herzog-Parker monoplane. Not a model, but a sketch of the full size aircraft.
According to the article, it never reached take-off speed, which is probably a good thing, because to me it looks incredibly dangerous.
If I had the skills, I would love to build a model of this. It would make a good talking point.