The sides of the fuselage at the door and boot cowl locations are shaped using some aluminum formers. The size and shape of these formers are shown on drawing #19 of the plans. The best way to make these formers is by creating a plywood formblock of the correct shape and size and then bending the aluminum to shape over the formblock.
Note: The pictures below were taken when I was making the fuselage side formers for my Bearhawk out of steel sheet. The technique is exactly the same, but on the Patrol, aluminum is used, as shown in the plans, instead of steel sheet as shown below.
Start by drawing the shape out onto a piece of plywood:
The shape is then cut out using a bandsaw or jigsaw. Make two plywood formblocks the same size and shape so the aluminum can be clamped in between. The edge of the formblock is sanded smooth and the corners rounded off so the aluminum will have a radiused corner when formed.
Here are the formblocks to make the aluminum formers at station "B" (see
Lay one of the plywood formblocks on the aluminum and draw the shape adding
enough extra for a 5/8' flange:
Now you have the necessary parts to make the flange:
Clamp the aluminum between the two formblocks and line up the flange line
correctly. Use several clamps to keep the aluminum sandwich tightly:
Now use a plastic dead blow hammer and gradually tap the flange over until
it is as far as it will go toward 90 degrees. Due to some springback the
flange will end up somewhere short of 90 degrees. Here it is with the
flange hammered over:
Once you take the former out of the formblock sandwich, it will not lay perfectly
flat. You will need to flute the edges of the flange until it lays flat on
Above fluting pliers are some store bought ones. There are some instructions on how to make your own fluting pliers in the Patrol Newsletter.
Click here to go to Fuselage Formers page 2