I was asked to develop a Bluebird version of the pecking chicken hens.
A chicken has a long neck, so it lends itself to a toy model with a fixed body and rotating neck and head.
A bluebird does not really have any kind of neck in terms of length, and the whole body rotates around the top of its legs...........so I designed the toy to be similar to a real bluebird.
On the chicken hen model, there is very little mass striking the paddle, but in the Bluebird model there will be a lot of mass striking the paddle. The contact area where the beaks hit the paddle will be small in the hen model and large in the bluebird model. It will probably make a different sound depending on whether it is a chicken or a bluebird.
The first bluebird I built had 2 issues:
1. There was no wall thickness left on 1 side of the 3/16" drilled hole in the 1/4" thick axle bearing piece that goes into the center. On the next 2, I drilled it more on center, but this is a weak point. Maybe I should thicken the center section to give more wall thickness.
2. I forgot to scroll saw the curved ends on the axle bearing piece, so I sanded them. I had to dremel off some more so the bluebird would go clear down and hit the paddle.
OOOPS, I checked the clearance in Sketchup, and I did not leave enough clearance. I modified the part to give enough clearance.
3. I drilled the 1/8" holes in each of the 2 sides before I glued them together. On my first bluebird, the holes did not align well at all, so I switched to marking all holes with the awl when the paper pattern was still on them, then drilling the glued assembly.
total body thickness now = 1/4 + 5/16 + 1/4 = 13/16"
if i made center section 3/8" thick..............3/16 + 3/8 + 1/16" + 3/16 = 13/16"
If I keep 1/4" thickness on 2 outer pieces..........1/4 + 3/8" + 1/16 + 1/4 = 15/16" which would be ok also.
The hens pecking make a clicking type sound.
Because there is more mass and a bigger area hitting the paddle, the pecking bluebirds make a different type noise, which may be ok.
I wonder if I put a steel nail on the bluebird beak, would it make a different sound?
I added some material to the bottom of the body, so there was less chance of splitting the wood.
As I made the 5 bluebird units, my process was:
1. Install brass axle in bluebird body and center red oak pivot piece
2, Put Titebond II glue into 3/16" dowel hole in bottom of red oak pivot.
3. Push red oak pivot down
4. Add 3 strings and wood ball
5. Test each unit after finished building it
I delivered the 5 units to the customer a few hours later. The next day the customer called and said 4 of the 5 units did not work, the body of the bluebirds would not rotate!!
I took the units home and dis-assembled the first stuck body, by removing the brass axle. When I pushed the red oak pivot onto the 3/16" dowel, this forced the glue to travel up the red oak piece, and it glued the axle to the pivot piece!! Because the glue was not dry yet, that is why they tested ok a few minutes after applying the glue.
I cleaned up the brass shafts by sanding, then redrilled the axle hole in the oak piece with the same 7/32" bit I used originally, reassembled and they worked fine.