Introduction: Fox and Grapes
This toy represents the part of Aesop’s ‘Fox And Grapes’ where the fox unsuccessfully tries to get the above mentioned grapes. the real fox was jumping, the toy one also jumps; let’s consider the cinematic of this movement shown in the drawings 1 to 3.
D1: the levers 1 and 2 rotate together to the right, the lever 3 begins rotating around its axis common with the lever 4; the fox’s leg begins unbending, the fox begins raising.
D2: the lever 2 touches the stopper of the lever 3; the levers 2 and 3 begin rotating together; the inferior part of the leg is unbent, the fox keeps raising.
D3: the lever 2 touches the stopper fixed on the enclosure; the lever 1 keeps rotating around its axis common with the lever 2; the flexible link (not shown) between the levers 1 and 4 makes the lever 4 rotate around the axis common to this lever and the fox’s body; the fox finishes the jump.
The pictures show how the performer’s fingers should move to get the necessary sequence of the lever movements. First, you keep pushing on the lever 2; when it stops, you start rotating the lever 1.
The fox’s body and the lever 2 are made of a piece of 10 mm thick wooden board available at my workshop. The other wooden parts are made of a strawberries packaging box.
You will also need:
a piece of 1 mm diameter steel wire to make the axis
a piece of adhesive tape or thin flexible plastic
a piece of elastic thread
paints - basically orange, white, black and green
drill with 1 mm diameter drilling bit
brush for glue
brush for paint
Step 1: Body
I downloaded and printed an image of a standing fox, marked its basic parts, copied them on thick paper to make patterns and cut the of wooden pieces. The fox’s body was recomposed to give it the posture of a sitting fox ready to jump. All parts of the fox are shown in the scan, you only need to print them to make patterns.
The body was cut with a fretsaw, worked roughly with a knife and sandpapered to give it the final shape. Two 1 mm diameter holes will be drilled in the body to install the axis of the legs; care must be taken to make these hole strictly vertical. Another 1 mm diameter hole will be drilled approximately in the middle of the tail; an elastic thread will be installed there to hold the tail; otherwise, the fox could rotate head down while jumping.
Step 2: Fore Legs
They were cut of 2 mm thick plywood according to the pattern. A 1 mm diameter hole was made in each leg to put them onto their axis. The legs will be glued to their axis; however, the axis itself can rotate freely in the body.
It’s advisable to put ‘anti-friction washers’ between the legs and the body to avoid that the legs touch the body. I made those washers of thick paper blackened with soft pencil (indeed, graphite is an anti-friction material).
Step 3: Rear Legs
They consist of the upper, middle and bottom parts. The upper (marked as lever 4 in the cinematic diagrams) and the middle parts (lever 3) are made of 2 mm thick plywood according to the pattern.
Two upper parts are glued to their axis which freely rotates in the body; ‘anti-friction washers’ are installed between each part and the body. A short axis for the middle part is installed in each upper part; this axe is glued into the upper part; however, the middle part rotates freely around this axis. A washer is placed between the upper and the middle parts; another washer is glued to the axis to hold the middle part in place.
The bottom part (the 'paws') is, in fact, the horizontal arm of the lever 2; an axis can rotate freely in this arm, and the middle parts of the legs are glued to this axis. There are two 2 mm long spacers placed on each side of the lever; i made these spacers of a pen refill.
A stopper will be placed between the middle parts of the legs; I made this piece of 2 mm thick plywood. It’s advisable to determine the position of the stopper after the assembly of the middle parts of the legs with the lever 2. I put the levers 2 and 3 as it’s shown in the diagram D2 and installed the stopper so the protruding part of the lever 2 touches it; the stopper will be fixed with epoxy glue.
Step 4: Lever With Two Arms
The horizontal arm of the lever plays the role of the paws of the fox; the vertical part moves the body with the legs. The lever is made of 10 mm thick wooden board according to the pattern presented in the scan.
Step 5: Frame
It’s dimensions are 190 x 40 x 15 mm; I just used two short sides of the box to make the sides of the frame.
Then I cut two 11 mm thick pieces of the corner bars of the box and glued those spacers to the sides of the frame. Thus, the lever 2 with its thickness of 10 mm can move freely inside the frame. A 1 mm diameter hole will be drilled in both sides of the frame to install the axis of the lever 2; it’s advisable to make this hole after the frame is assembled to assure that both holes are coaxial.
Another 1 mm diameter hole (an angular hole) will be drilled in the spacer which is near the fox’s tail; the elastic thread will pas through this hole. A stopper will be installed on the inside of the wall turned to the audience to limit the movement of the lever 2. The stopper is a small piece of 2 mm thick plywood. The position of the stopper will be determined after the body with the lever 2 are installed into the frame.
A cut will be made in the wall turned to the performer; the dimensions of the cut are 80 x 10 mm; however, they depend on where you decide to place the fox.
One end of the elastic thread is glued into the hole in the fox's tail; the other end will be passed through the angular hole in the spacer of the frame and fixed with a knot. The tension of the thread should be just enough to hold the fox in place when it's sitting.
Step 6: Subassembly 'body-lever'
The lever 2 rotates freely around its axis which is glued into the frame; I also put a washer on each side of the lever to make its movement smoother. I put a drop of a thick lubricant on a side of the washers and ‘glued’ them to the lever so the holes in the washers are coaxial with the hole in the lever; then I put the lever into the frame while aligning the hole in the lever with the hole in the frame; after this, I inserted the axis.
After this subassembly is installed into the frame, a short 1 mm diameter axis will be glued into the hole at the end of the lever; this is the axis of the lever with circular sector (designated as lever 1 in the diagrams D1…D3).
Step 7: Lever With Circular Sector
This lever consists of two parts made according to the patterns. Its role is to rotate the upper parts of the fox’s legs thus imitating a jump. There’s a flexible link (not shown in cinematic diagrams) between the upper parts of the legs and the circular sector of the lever.
This link is, in fact, a narrow strip of thin flexible plastic, 130 mm long (the surplus length will be cut after the assembly). I made it of adhesive tape: cut a piece of tape, folded it in two, cut a strip with the necessary width (about 2.5 mm). This lever will be installed on the axis at the end of the lever 2; it rotates freely around the axis, but its linear displacement is limited with a washer glued to the axis. One end of the link is glued to the upper part of the leg facing the performer; the point of attachment is behind the axis installed in the body. To position the other end of the link, I proceeded like this:
move both levers until the lever 2 touches its stopper
pull the link so it passes around the upper arc of the lever 4 without slack
glue the link to the bottom end of the circular sector (near the straight part)
It’s advisable to use an instantaneous glue for the gluing to avoid holding the pieces with your hands for a long time, which is boring.
Step 8: Grapes and Support
I drew a cluster of grapes more or less proportional to the size of the fox, cut it of 2 mm thick plywood and painted.
The support is made of the same kind of plywood; I also drew a vine that is supposed to go around the support.
Participated in the
Scraps Speed Challenge