Al Conquergood has a Youtube video showing a really neat automaton of 4 hens laying eggs.
It is so cool that I decided I had to build one of these. Using the Youtube video as a guide, I developed the design in Google's Sketchup free drafting program.
Al hand-carved each chicken from Basswood per comments on his Youtube video. I am not artistic at all with respect to hand-carving abilities.
I have used a technique called compound cut scroll sawing to make things like wooden flowers. You developed the front view and paste it onto the wood blank. You develop the side view and past it on the side of the blank. You scroll saw per the front view, save the scraps and masking tape them back on. You then scroll saw the side view. This should give a good approximation of a chicken.......I may have to so some hand work to smooth them out a little.
1st Attempt at Compound Scroll sawing
The 1st attempt did not go well.
So, back to the drawing boards for round #2. I modified my chicken design so the scroll saw cuts were no more than 2 inches to fit the saw. I also modified the 2 images so I left the comb on top of the chicken.
Round #2 worked perfectly. You do have to keep your finger off the top of the block when scroll sawing, or you will get it pinched. I made the 1st piece from basswood, but decided it was too expensive and too soft. I switched to a blank from a standard pine 2x4 for attempt #2.
In the picture above, I sawed the front first, applied wrapping tape to hold the pieces on, then made the right side cut. The rule-of-thumb for compound scroll sawing is to saw the most complicated side first.
Then I sawed the 2nd side..........
Now do the first un-wrapping of the block...........
and the 2nd unwrapping...........to get a finished chicken...........
I am going to paint him up and make sure the beak and comb look ok.
Here is the 2nd attempt chicken painted except for her eyes...........
I think this he really turned out nice
Based upon my experience making wooden flowers and the compound scroll saw methodology, one can consistently make many good chickens.....without the need to hand carve them from scratch.
I hand-painted the 2 eyes using the larger end of a toothpick. They turned out nice!
Based upon my past experience with automatons, it will require some design trial & error work to get everything right. I built up the basic frame as my test rig. I used hot melt glue so I could dis-assemble the basic frame if needed to make modifications.
I learned a lot on the 1st prototype attempt:
-my cam designs were basically ok
-there was too much wobble in the mechanisms because there was not enough
guide length. In engineering, this is called the L/D ratio, or length to diameter.
With 1/4" dia dowels and 1/4" thick wood to guide them, the ratio is 1.0.
Studying Al's video further, you see he added spacers under the 1/4" thick
main board to give more guide length. I modified my design and added 1/2"
thick spacer pieces under each chicken.
-the RH chicken did not have enough weight to consistently go up and down
with gravity. I drilled a 1/4" hole in the bottom and added some lead shot
for weight. I sealed the hole with hot melt glue. The other chickens seem to
have enough weight to activate.
-using the spacers greatly reduces the number of extra pieces required, so
simpler is better!
-you need to add 1 or 2 stops on the LH chicken to control his rotation. If you
have no stop, it would work because it hits the frame side one way, and hits the
adjacent chicken on the other side. I added one 1/8" dowel to the round driven
element so it would not hit the adjacent chicken. One could notch the round
driven element, add a dowel, then it would be controlled within the notch.
Here is a picture of Trial #1 set-up before I quit and went to Trial #2.......
After gluing the 1/2" thick spacers to the main board, I drilled the 1/4" holes on the drill press, and scroll sawed the rectangular holes on the scroll saw.
Lots of Pieces Required
Here are all the small pieces except the crank......
Trial #2 Set-Up
Here is what I ended up with after trial #2.......
On the 2nd hen from the right front view, you don't need to drill the 1/4" dowel hole through, which is what I did. If you do, you see the dowel when you open the little door in front. I am ok with seeing the dowel.
I decided to go with a blue milk-paint finish. I have enough blue powder left to make enough paint for this project. I filtered the solution through 2 coffee filters to remove most of the un-dissolved powder from the paint.
Making the Little Eggs
There are 3 eggs under 1 of the chickens, then 3 more eggs in the underneath door openings. I was a little leary of being able to make these on my 1939 Montgomery Wards lathe with excessive headstock play, but it worked!!
Of course my egg geometry is not as good as Mother Nature's, but they will do.
I made the eggs from 1/2" diameter dowel stock.
Once you get the eggs made, how do you paint them? I did the following method:
-sand a flat on the side of each egg to glue onto the chicken coop
-drill a very small hole in the flat, big enough for a toothpick
-temporarily put a toothpick into the egg
-drill small holes in a piece of scrap pine to hold the toothpicks.........
I gave the eggs 2 coats of white enamel, and dried them in the oven at 120F for 10 minutes per cycle.
I made the 4 small doors from 1/4" thick maple. For the doorknob, I sawed off standard 1/4" diameter axle pegs used on wood wheels for toys.
For hinges, I used 1/8" diameter dowels. I used a 12" long bit, 1/8" diameter to drill the upper holes. I drilled the lower hole from the bottom up. I put the doors in the drill press and drilled 1/8" diameter holes 3/8" from the edge. This method allowed me to install the doors after the frame was built. I used hot-melt glue to retain the lower dowels.
I got some galvanized wire mesh from Ace Hardware in Fairbury. It has squares 1/2 by 1/2 inch. I used staples to retain the mesh.
The straw came from my brother the farmer, Brad Maley. I used hot melt glue to anchor the straw pieces.
Milk Paint Chipping
I had some paint chip between the lower doors. I am out of milk paint powder, so I will touch up after I get some new powder.
Updated Sketchup Drawings
I updated the drawing to show all the changes I made from the original concept.
Finished Hen House
I am sure glad I did not track how many man-hours it took to design, prototype and build this model
All the chickens work well mechanically except the 3rd from the right, the one that bobs in and out of the chicken coop. The cam needs to be very small, and I should have moved the 1/4" dowel that drives the chicken, about a 1/4" more forwards to give it more motion.
I have never built a miniature doll house, but this is what it felt like building this model. I had to use needle nose plyers to assemble some of the parts because my fingers would not fit inside the chicken coop!
This is a very fun model to watch operate.