Build your own set of extendable plywood wings! This was the fifth kit in the Monthly Make It
How It Works
This project uses what’s called a “lazy tongs linkage” -- if you want to be fancy, a plane translational scissor linkage -- and modifies it a little bit to make large-scale wings that can fold and extend. This linkage is typically used for reaching and lifting loads, with the pivot points tranforming vertical motion (squeezing the ends) into horizontal motion (extending the arm). This model works on the same principle, but the dimensions are slightly offset to give you longer extension on the wing tips.
Here, too, you have ten pivot points, each one transferring motion along the span of the wings as they open and close.
All The Parts
The wings kit should contain the following parts:
4x long plywood struts (20" x 1" x 1/4")
4x short plywood struts (12" x 1" x 1/4")
10x bolts (1/4" diameter x 3/4" length)
10x nuts (1/4")
10x washers (1/4")
Hot glue (not included)
Assemble The Kit
Step 1: Build the outer wings
The long pieces form the outer wings. You should have two sets, one with two holes (B pieces - holes are 3” apart) and one with three holes (A pieces - holes are 11” and 8” apart, respectively). Start with the A pieces and connect them to make a “V” shape. These are 20” lengths, roughly 1” wide.
Turn the A pieces so they form a “V”with the short end (8” gap) facing you. Connect the ends.
Now take the B pieces -- the long lengths with holes 3” apart -- and connect them to each side.
Connect each joint with a bolt, a washer, and a nut. Tighten the nut to hold the bolt in place.
The back side of each joint should look like this, with a washer and nut holding the bolt in place.
Your “V” shape should now look like an “M”. These are your wing lengths! They extend pretty well, but they’re not very sturdy.
Step 2: Build the inner struts
The short pieces are the inner struts; they will stabilize and complete the linkage so your wings can be folded and extended. Here too, you’ve got one set with two holes (D pieces - one hole on either end) and one set with three holes (C pieces, holes are 3” and 8” apart, respectively). These are 12” lengths, roughly 1" wide.
Start with the C pieces, with the short end (3” gap) facing you. This time, instead of making a “V” shape we’re going to make a tent.
Connect the D pieces to each side. The short lengths should make a “W” shape. Tighten the nuts so the bolts stay firmly in place.
Lay the “M” and the “W” on top of each other like so. You should be able to see how the wings and struts come together. Now all that’s left is connecting the remaining pivot points!
Step 3: Connect the wings and struts
Connect the two pieces to complete the linkage! When you’re done, flip it over and add a dab of hot glue to the back of each nut to hold the bolts in place. This will keep them from unscrewing as you open and close the wings. This step isn’t necessary, but it will help keep you from losing pieces.
Go through one by one and line up the remaining holes to connect the two sets.
As you connect them, you’ll see the interior shapes start to line up
Tighten the bolts one last time, then flip it over and glue the nuts in place. Be careful to glue the nut to the bolt, not the washer.
The final version should look something like this!
Step 4: Test it out!
Put the wings on your back and hold the inner struts to open and close them. To test them out, slide the whole assembly under the straps of a backpack for a pair of wings you can walk around with.
Decorate your wings! There are lots of ways you can expand and extend them. One of our favorites is to do some cardboard modification -- adding colorful feathers or wing tips or building them into an existing costume. Play around and explore!
Wings don’t close! Check your A struts and make sure they’re right-side up. If they’re backwards, your wings will be lopsided.
Alignment is off! This can happen sometimes -- usually if we cut the dimensions slightly off or if the strips are cut slightly wide.
Bolts unscrewing themselves! Put a dab of hot glue on the back of each nut to hold it place
Wings too small! These are kid-sized wings; they’re designed to roughly match the arm span of an 8-year-old.
This documentation describes Open Hardware and is licensed under the CERN OHL v.1.2.
You may distribute and modify this documentation under the terms of CERN OHL v.1.2. (http://ohwr.org/cernohl).
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