From: frechett@spot.Colorado.EDU (-=Runaway Daemon=-)
Subject: Re: Throwing tuning
Organization: University of Colorado, Boulder
Date: Mon, 25 Jan 1993 00:51:18 GMT

In article <C19uJw.7nw@boi.hp.com> bblohm@boi.hp.com (Bill Blohm) writes:

>However, I think I was perhaps not quite clear about spin definition.  I was
>thinking more along the lines of the actual amount of spin and it's effect.  I.e.
>10 rpm vs 30 rpm (or whatever the rate is).  I would think that the more rpm I
>give the 'rang as it leaves my hand, the higher it would climb.

Few boomeranges have much of what you might consider a helicopter effect.  
That is, you spin them more and they climb.  More often they have an autogiro
effect, which means that they will hover more the faster they spin.  What
this means practically is that the more spin you can impart the longer the
boomerang will stay airborn.  A very well behaved boomerang will come back
to you sweep in low pull up just over your head and hover down.  The more
spin you put on it, the more likely this is to occur.  There are plenty of
exceptions too of course.

My favorite homemade is a large triblade which when thrown with good spin will 
cut a nice oval anever getting more than about 6 feet off the ground, but as it 
turns for home it drops down to about 3 feet and starts to level out (flatter 
angle).  Around 15 feet out it pulls up and stalls about 25 feet above my head.
At which point it starts to fall straight down.  It however does something that
I've not seen others do.  The spin rate increases dramtically as it falls to 
the point where I can hear it whistling.  It's possible to catch it by clasping
it from above and below, but a miss is deadly.  I've bruised my hands a few
times.   Bliss. ;)

>I know about true side-arm being bad.  I wasn't thinking and threw one almost
>purely sidearm and boy, did that give me a sore muscle!  However, I had not

Generally it's more than that..  When you throw a boomerang sidearm it tends to
do 1 of 2 things.
1. It carves a nice arc straight out and up eventually ending up upside down
at which point it can generally go in any direction at all.  If you've ever
thrown your boomrang upside down, you'll find that some of them can fly 
for very long distances upside down albeit a bit unpredicable.  I've seen
more boomerangs lost this way than any other.

2. The other thing they do is start by flying straight out and up to about 
90 degrees angle (angle of the boomerang to the horizon)  at which point
they lose all steam and start to lose altitude before there is enough
airspeed to get it to curve back towards you.  Ussually the rang ends up
picking up a tremendous amount of speed just before it slams into the ground
at about a 60 degree angle.  I lost a nice rang to an idiot this way.

>noticed any tie-in between angle from vertical and flight pattern (circular vs
>elleptical vs straight out and back).  Perhaps I had too much wind for that
>to have any effect on the flight path.  That is another think I'll have to
>check out.

The more vertical the more likely it will fly a circular or eliptical
pattern.  If you go more horizontal, it will go out, up over down and back
tracing a distinctly different shape.  I think even xrang will show you this to
some extent.

>Why don't you like the plastic ones?  Mine is wood, but I was thinking of
Looks to me like he doesn't like them because they don't do well in heavy
wind.  I've seen very few plastic boomerangs with any weight.

>building some of my own as I progress and was thinking of making one out of
>some plexiglass I have, just to see how it worked out.

If you feel like cutting your fingers of, this might be fun.  Plexiglass 
will do a few things.  It will spin very fast but not give you much 
lift.  I doubt it will ever come back, and if you try to catch it, you 
risk knocking your fingers off.. Although I suspect the most likely
outcome is that it just smashes when it hits the ground.  Just a couple
predictions.  I've seen em made from everything from foam to aluminum.

I find that wood is much more rewarding.   If you can, find some 7 ply
marine grade plywood.  Mohaghany is nice to work with.  This and a
spokeshave are all you really need.  My best are three bladers and
are covered with marine epoxy (more flexible than what most people think
of as expoxy) with a varnish coating.  The duals are a little harder to 
tune as they are not symetrical, and most of my better ones have been
broken or lost or both simply because I threw them a lot.  Such is the
price you pay.  I wrote an article or two a long time ago about building
rangs.  Does anyone know if this group is archived anywhere?

>Bill

	ian
Newsgroups: alt.boomerang