[TowerTalk] Flexible coupler assembly

[Jim Lux]

At 10:50 AM 1/25/2007, Dubovsky, George wrote:
>I designed one of the drive shaft couplers into my rotator system, based
>on the suggestion in Dave Leeson's Yagi book. Mine was intended for a
>BMW 1600, I think, and was bought off of the auction site for about $20.
>I am told that all BMWs have something like this - do a search on
>"guibo" and you will see what one looks like. If anyone knows where that
>term comes from, I'd love to know!


No idea of the origin of the term, but if you look at page 1119 in 
the McMaster-Carr catalog, you'll see a bunch of similar couplings.

They're also similar to the flexible spider couplings.

Odd that McMaster doesn't have an almost exact match.. they've got 
just about every other kind of coupling in existence.


One thing to watch out for when putting in flexible/springy couplings 
(as opposed to vibration damping lossy couplings) is that you can 
make a heck of an oscillator with torsional resonance.  On a much 
smaller scale, this is a big deal with stepper motors and 
non-microstepping drives, because the motor itself is quite 
springy.  They make fluid filled dampers (think of a shock absorber 
for rotational motion instead of linear) for this kind of thing.


Jim, W6RMK