Tag Archives: rod end

Talking Birds, Part 4

As previously discussed, the first generation talking bird was mechanically larger than the feathers covering it (fur, actually). While I did not have time to improve on the first bird, the second bird will be mechanically more compact.

The trick is in how to mount the ball-and-socket rod ends. While the the ball-and-socket allows for the rod to swivel 360° around the pivot point, it allows only a couple of degrees of movement up and down. That is if you screw it down on a flat surface.

I figured out that by cannibalizing a rod end, I could screw the ball down atop another ball. This gives a lot greater freedom of movement. By doing this I’m able to place the rod at a steeper angle; thus, the servo can be placed closer. See the rod end mounted to another ball:

Fascinating, you say? If you had spent 4 hours of your life staring at the end of a threaded rod, you too would find it fascinating.

I know I’m not improving my position, so let’s move on.

Having made my minor improvements to Rev. 2, we now have two functioning mechanisms:

Note that I also tightened up on the chain. This is an easy thing to do when working with plastic chain. Twist it sideways and the links pop off, allowing you to shorten or lengthen at will. Assuming the chain is perfectly straight in the sprocket, the chain should take quite a bit of tension before it breaks.

How much tension? I have no idea. Doesn’t matter because I have no idea how much torque is required to lift two puppet wings. Let’s hope not much.

Talking Birds, Part 2

Truth be told, I like planning these projects much more than assembling them. I learned several years ago that manufacturing things is hard. In fact, the smaller the parts the harder it is.

Conceptually, the parts of the bird go together like Lincoln Logs. Objectively, it’s really hard to make anything out of Lincoln Logs that you can fit up the butt of a hand puppet.

It would be great if only my local hardware store would stock a myriad of little brackets in varying sizes; tiny little metal shapes that would have no use in home construction. But they don’t.

I know. Some hobby stores carry some Erector Set like things for mounting servos or other small items, but they often get $4 for a ¼” L-bracket and that just doesn’t seem reasonable. Even at 50¢, you have to ask the question “How long will it take me to make these with a hack saw and a length of L-bar or U-channel?” If you cut the parts yourself, you can have any size you want for very little money.

Here’s an example:

How to create a neck joint at the top of the backbone? It needs to be at a certain angle and have a certain range of movement. I’m not sure how it should be done either. I think that a rod end affixed to the end of the L-bar should work.

And yes, I’m totally guessing at the angle.