chickens whirligig revisited.
In the year since I first posted my Chickens whirligig, some problems have come up. This is my attempt to fix them.
The main problem has been that it takes quite a bit of force to get the whirligig spinning. My solution is a set of geared pulleys and a 3-D printed ninjaflex geared belt. The pulleys offer a 2 to 1 ratio, so for each revolution of the propeller, the chicken cams only go through half of a revolution. This has the effect of making it easier to drive the mechanism, slowing down the action and making it smoother.
One pulley is mounted to a new bearing block under the front bottom base, while the other is mounted to the original drive shaft. I designed a new bottom front base that incorporates the new bearing block, and also included a design that is just the bearing block for anyone who (like me) just wants to retrofit an existing whirligig. It can just be glued to the front of the existing base.
Some other changes I made include moving the pivot point on the hen so she looks more natural and a redesigned and hopefully better worm cam.
In an effort to further make the action smoother, I inserted lengths of teflon bowden tube for 1.75mm filament into each of the holes that have chicken movement wires running through them. The tubing has an o/d of 4mm and just fits nicely in the existing holes. This step is not necessary, but I had the tubing, it was cheap, and it fit, so why not?
One more thing, after most of a year outside, the ABS plastic I used for this print has gotten brittle. For most of the whirligig, it doesn't matter much, but none of the chicken legs held up very well. The ones that weren't already broken when I started broke while I was working on it. I have replaced the ABS plastic with TPU for the legs. I think this will work out much better. I haven't tried PLA, but doubt it would do any better than ABS.