HM293 Flying Flea
Here are some links to YouTube videos that explain a little bit about the Flea and show the details of its construction
Building the Flying Flea: The Project (introduction)
Building the Flying Flea: Wing Ribs
Building the Flying Flea: Wing Spars
The Flying Flea was designed in the 1920's by Frenchman, Henry Mignet. After some early design issues the tandem wing design has proved safe and easy to fly. There have been lots of variants in the evolution of the concept. The HM293 is the version that I have chosen as my next project, like the one above. It is very simple to build with no ailerons. And, quick folding wings make for compact storage.
I made a wood kit for the airplane and took it to Florida to have something to work on as we spent the winters there. But, I've been so busy with other activities so the building progress has been very slow.
The wood, Sitka Spruce and some lumber store softwood, all milled to the correct dimensions.
This is the wing rib jig that has the 4 different size ribs layed out, 2 on each side.
4/25/2020 - However, back in Pennsylvania we are stuck home due to the COVID19 virus so I have started working on the metal parts.
The control stick assembly cut, welded, and powder coated.
Assembled and ready to go.
60 - .090 4130 steel flat metal pieces that make up the wing folding mechanisim weighing almost 7 lbs
Here are the wing ribs under way. About 36 of the 51 needed have been completed. Production was interrupted for a little while as I worked on an Avid model C.
I fiished up the ribs and totalled the parts that went into making the 51 ribs and this is what it took: 871 pieces of 1/4" square wood, 1996 1/16" plywood gussets, and 5812 staples plus about 1/2 quart of T-88 epoxy.
Now it's on to the wing spars. There are two wings, each built in 3 sections, with each section having 2 spars. That totals 12 spars and no 2 are the same.
The main spars are just wooden boxes. The center section spars are straight, but the wing tip spars curve to the front and to the top. Here you can see that the interior of the box gets sealed with polyurethane before getting closed up.
It looks like an elephant tusk.
The trailing edge for the wing tips need to be laminated to take the curved shape. This can be done on the work table with little clamping blocks.
Several thin strips of pine are used.
Along with a bunch of clamps and wax paper.
The ribs are glued to the spars and foam false-ribs are added for additional support for the leading edge sheeting.
The thin plywood leading edge gets soaked and clamped to take the tight radius without cracking.
Because the tip panel is not straight, each leading edge panel must be fit and installed seperately. I used ratched straps and staples to hold the plywood in place while the glue dryed.
I used a thin piece of pine for the wing tip. The result is an elegant looking wing panel.
It was a bit of work! Now to make 5 more.