On 02/25/2011 05:19 PM, Wes wrote:
The other day I had a Chinese engineer that is currently working at our design facility
making parts on one of my lines. He wanted to understand just how our product is
produced.

Well he saw a vibratory bowl feeder that feeds screws in to the cell.

That thing facinated him. He wanted to know how it worked. I know some of the basics.
There is an electro magnet that vibrates the bowl, there are leaf springs that are ground
to cause the bowl to resonate with the electro magnet. All that seemed straight forward.

Then he asked the hard question. Why do the fasteners move up hill?

When I first explained what I knew he was asking if magnets were moving the parts. I knew
that other than vibrating, the magnetic field wasn't moving them.

So after scratching my head, I explored the art by looking at patents. As I suspected,
pure mechanical feeders exist. I really worked my google fu because I kept looking at it
and could not figure out what was happening.

Asking a few other engineers had one with better googlefu than me finding something. I
read it a few times and wasn't sure I had it and asked my coworker that got it from the
engineer that found it to give it to the Chinese guy so he could read it. It spoke of
pendulums and such, I didn't get it.

After a while working on another project I realized what was going on. I have a bowl with
ramps heading up hill in a spiral. On the bottom there is a plate that an electro magnet
that is grabbing and releasing every 1/60 or 1/120 of a second. The leaf springs are
ground to bring the bowl to resonance at the period of the magnet. The leaf springs are
inclined so that when the bowl is drawn to the magnet, the bowl rotates counterclockwise
and goes down, falling from under the fasterners. when the magnet is de-energised the bowl
rises, contacts fasteners and moves them ahead as the bowl rotates clockwise.

Both the Chinese engineer (doctorial candidate) and this maintenance tech was pretty darn
happy understanding something yesterday. He seeing it for the first time and me seeing
them for years but never really understanding the finer points.

And the most profound and happy-making thing I'm getting out of this?

"Google-fu". I've heard it before, but this is the one time that it's
really _striking_ me.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html