Boomerang Terms

How much wind to get boomerang to return?

I am new to the Boomerang scene and was wondering how little or much wind there should be to throw and actually get them to come back.

Personally, I wouldn't choose a zero-wind day, as most booms don't seem to work that well in those conditions, and "no wind" often seems to mean a little wind, but I can't say exactly where it's coming from.

Just my 2 cents,

Christoph

Christoph is right about the best days to throw and the right wind conditions, but some times you don't know what the wind is doing when you have the chance to go throwing. Go anyway.

Learn to look at the tree tops and see how they are moving. Look at flags on businesses. If you have time to go throw and are not sure of the wind, go ahead and try, if it's not so windy it's not worth the effort. If you see large limb movement in the trees, go get a kite. Otherwise, go and see how the booms work for you.

Keep a roll of electrical tape and coins with your booms. When the wind comes up, tape a coin or two on the arms and put some little tape flaps on the wings. Experiment. When the wind is up, trashing up the boom with Velcro dots, rubber bands, or little tape flaps will make them less efficient, but that makes them better returners because they don't fly past you and into the next county.

Remember to watch and learn and not get all balled up if you are doing it right or if everything is not perfect. Throw, observe, make changes, have fun, repeat. It's a learning process and in the beginning, you need time in the field for experience data input.

Work on making smooth throws with lots of spin. See how consistently you can throw the boom, even if it's not coming right back to you. If you can get it to land in the same place regularly, then it's just a matter of dialing it in with some tuning or something which you will learn in time. It's an incremental learning process and you never stop learning.

Once you start getting a feel for throwing and how the booms behave, different wind conditions become interesting and challenging.

There are a number of throwers in the Ohio area. Try to hook up with some of them. You will learn a years worth of trial and error stuff in an hour with an experienced thrower.

Have fun, Pat Tx

Dave Hughes

Crush tape can be found in the duct tape section of your local hardware store.

Velcro dots work well, also, but they are more expensive.

Kendall Rock Island, IL

Has Dave given you a boomerang with positive dihedral on the tips?

Boomerangs with slightly curved wingtips are far easier to throw than perfectly flat ones. They have a much bigger target window. Flat ones have a very small window -- that means you have to throw in just the right spot for a perfect return, that's a pain for beginners.

Greg Courtney Cincinnati Ohio

Tuning model for boomerangs

The tuning method is this - first throw the boom. Let's assume it has
a poor flight for some reason, because if it has a good flight, well, you
just leave it alone. To fix the flight - hold the boom in front of you,
nearly at arm's length, so that it is flat and horizontal, with the
elbow pointing directly away from you, with the "flat" side facing
downwards. Now, envision the flight of the boom you just threw, and
superimpose it just around this boom. If the flight of the boom was too
low on the first half of the flight, you bend that wing of the boom
upwards, just like you'd want to bend the flightpath. If it was too
high at the midpoint of the flight, you bend that first half downwards. If
it was okay at the midpoint but flew into the ground before it got to you,
you bend the second half of the boom (the trailing wing) upwards. If it
flew too high at the end of the flight, but was okay at the midpoint,
you bend the second half of the boom downwards.

In other words, you always bend the wing corresponding to that part
of the flight where the problem lies. It works with every boom, and with
both right and left handed booms (LH are reversed in lead wing/trailing
wing order, but the flightpath is reversed, too, so that cancels out).

Its important to keep in mind that different forms of drag and
variing placements of that drag on the boomerang will have different
effects on the boom. Below is a list of different boom additions
that will incease drag and how that drag will change the flight.

1. drilling holes: in center(three blader) slows the forward
momentum with out significantly slowing the spin rate
at the tips: slows the spin rate and the forward
motion
also, bigger holes increase the effect
2. rubber bands around the wing: rubber bands have similar effects as
the holes but they also add weight. this weight in the center causes
quicker layover and weight in the tips causes slower layover and
extra range.

3. flaps(tape folded to form a raised spoiler on the wing): these
seem to create less drag than say a rubber band but they can be
placed on the top or bottom of the boom to create different
characteristics. top: keeeps boom down. bottom: keeps boom up

4. velcro dots stuck to the wing: same as the flap but with more drag

5. athletic tape: this is the best for minor adjustments. wrapping
a strip around the wing adds a minimum amount af drag with out
disrupting the shape of the air foil. This is good to use when your
fast catch boom is coming in just a little too high but you don't
want to loose any speed. Just wrap a wing and watch it come right in
at chest height. Also if you have a boom that you want to hoover but
it keeps spiraling out, add some to the bottom. It creates just
enough friction to keep the boom from sliding off the air mass. Its
similar to having really rough skis, you won't be able to slide down
the slope.

The details I find are those that Mark mentioned....flaps on top
tend to slow it down while allowing the boom to maintain hover
(like for TC and doublers) while flap on top tends to slow it down
while also bringing it down or keeping it down (like for FC/End?
maybe Aussie and Accuracy) Too much flap and you lose the
ability of the 'rang to cut in the "back door" and you want that for
Accuracy and even Aussie sometimes, though I usually tune my
AC and AUssie rangs for straight in flight...They're coming
straight in on a dime with no "S" out at the end and no curl in (or
back door cut). Although sometimes, especially in dicy or string
wind, I want back door cut which I get by decreasing the
flappage.

I like blunt airfoils for Aussie/AC and TC. I like smoother airfoils
for Fast Catch. For wind FC sometimes I have totally squared off
LE and then I gently sand or file in the field until I have just
enough decrease in drag so the thing comes back! Without
some LE carving the things just flop off into nowhere land, but I
want just enough to bring it in. In low winds, these booms do not
even come close to "back" but in 10-20 they drop right in like a
dream.

Until that is corrected, I wouldn't do anything else. Test it after
that adjustment. It may need several such adjustments. Now, if the
boom is still not making it back, but is gently running into the
ground short of the intended point, only then would I give positive
dihedral to the trailing arm (the unweighted one). This will shorten
the out distance of the flight, but give a more full return.

Here's something to think about - if you hadn't added that
additional weight to the tip, the boom would have laid over even more
quickly, assuming no tuning changes were made while drilling the hole
or adding the weight. Peripheral weighting slows down rate of layover.

Another thing you might want to try is adding more weight. The old joke back in the day when these big hooks were popular was that any problem you could possibly have could be fixed by adding more weight. Many moons ago, I made a Challenger that didn't come anywhere close to coming all the way back and since it was a thick composite (4mm), bend and twist tuning was difficult to say the least. If memory serves, I taped a quarter on the dingle arm (nearish the elbow) and it really improved things. I just moved it around until I got a full return. It shortened the range but at least it made it all the way back. Then I added more weight on the lead arm to get back some more of the range. Then reshifted the coin on the elbow. I think I had 4 quarters taped on it by the end. It was a bear to throw. I much prefer a nice voyager but it did work.

John Cross
Devon, Alberta

Pinch grip vs Full grip

When I began throwing/teaching I used the PINCH grip. A good grip for
thin, light, smaller rangs. BUT....not the best grip for all rangs.

As my skill developed and selection of rangs increased, I discovered that
PINCH was not giving the control & distance large(6oz. Comeback,
Bakwood,Smith) rangs required.

I began relearning. Depending on the particular rang, I might PINCH, I
might FULL HAND HOLD,or I might INDEX FINGER HOOK-AROUND ....

As I began eliminating PINCH, I realized my rangs were not spinning as fast
as before, nor were the flights pretty. Rangs looked like wounded birds,
flopping about the sky.

After a week or so, I began getting proper spin, beautiful flights...all it
took was PRACTICE. Those were not fun weeks, however.

b-man, rich

I highly recommend that beginners throw gripping the leading arm! If they
do, and roll their wrist (baseball throwers), the boomerang will 1. Zoom
upward with the risk of a disastrous descent, or 2. tell the thrower that
he's rolling his wrist by fluttering down in front of him or flying like
cow pies.

After a thrower consistently gets good returns, it's time to throw each
boomerang by both the throwing arm and the dingle arm to see what he
likes best.

A lot of years ago, I discovered that the more crude the airfoil, the
better a boomerang flew for all the diverse throwers. Experimenting, I
found that an airfoil having a 45 degree cut, half the wood thickness
for a leading edge, and a trailing edge taper starting about 3/32 inch
up from the bottom of the wing and ending at a line about 3/4 to 7/8
inch from the trailing edge was about right for most booms, as little as
1/2 inch for wind rangs, to 7/8 or even 1 inch for light wind sport
rangs. Now, what I described has sharp edges all over. I finish sand with
a 150 grit, 2" X 8" pneumatic drum all over, including lightly rounding
the sharp edges. That's it. With tongue in cheek, I called that my
MBA-SC airfoil (Modern Boomerang Airfoil - Semi-Crude!) It still works
well for me. Some things withstand the test of time. This "airfoil" is
one of them!

Part of the learning experience is in evaluating what percentage of
accuracy to attach to what you hear from others (including me). We all
have methods that work for us. As a result, we also produce booms that we
can fly but most others can't. I call these booms, "Narrow throwing
window booms". A boomerang that I, you , Arlene (Sotak's boom babe),
Logan and Devin Broadbent (Gary's 12 year old twins) and the rest of the
boom community can throw, and catch successfully would be a "Large
throwing window boom". If you get the "hang" of it, you can make the
latter as easily as you can make the former.

I own lots of both types. By current definition, a boomerang is a thrown
object that returns to the thrower. Launched vertically, it returns
horizontally, hovering down to the thrower with little forward motion
left.

If true, then a "Twice arounder" is a poorly designed boom, unless it's a
MTA boom designed for that purpose. Actually, a good MTA should be a 1
1/2 arounder since we want the boom as far upwind as possible.

But then, a boom that flies a figure eight pattern is a badly designed
boom, too, because its flight culminates in a dive toward the ground.

A very desirable boomerang for anyone's kit is one that gets the required
distance, spinning horizontally, passes over your head, then slides
upwind, down to you while Your back is turned to the wind, and sun! Some
claim that's why they "designed" a figure eight pattern into it. Sorry,
that's BS! A figure eight boomerang is one that lays down much too fast,
period!

One that does not lay down fast enough is a bad boomerang, too, unless
it's a fast catch boom which, ideally does not lay down at all but has a
lot of differential lift for turning. If it has only a little lift (just
enough to offset gravity) and is launched spinning horizontally, it's
called a Kylie!

Rusty

What is the best beginner boomerang?

BoomerangTalk has had a number of new members join this week, I don't know
what their boomerang throwing experience is, so I thought I'd start a thread
on beginners equipment:

What is the best beginner boomerang?

I think that the best all around beginner boomerang is the Outback Tern.
Every time I introduce a new thrower to boomerangs I get out a selection of
boomerangs (Yanaki, Outback Triblader, Gel Carlotta, Gel Bellen, a few
others) for the beginner to try and they always seem to end up on the Tern.
I think because it has forgiving throw window (but it will not let you side
arm it), it is easy to catch, and has 2 arms.

By the way, the Tern is also a great warm up/warm down boom.

Any other suggestions? Any "brand names" a new thrower should look for if
they happened to find a shop that carried booms?

Where to find booms?
Kite shops sometimes carry quality boomerangs, but getting good advice
regarding boomerangs is iffy.

The BoomerangMan, Rich Harrison, is a great resource
for booms and throwing advice if you can wait for the shipping (Rich
provides great service and fast turn around, but the booms still have to be
shipped to you).

On line - see the BoomerangTalk files section for a list or www.USBA.org

My local supermarket and sports store both carry boomerangs. All
questionable returners at best, some non-returners for sure.

Local throwers often have booms to loan.

Any other suggestions?

- Clay

Note from "Editor Rob": Outback Tern is no longer in production. Most serious boomerang makers have great starter rangs, which are often light and more forgiving than more advanced rangs.
Just ask the boomerang maker of your choice and they will be happy to advice you.

Personally I had good experience teaching new adult throwers with Kendall's Vector. Often the Yanaki is mentioned as a good first choice as well, but I have no experience with that one. I am sure there are plenty of other great starter rangs, so just ask. And for the lefthanders, make sure you get a lefthanded one.

Hi to all. I am having a problem with my elbow, in that just over a week ago I was throwing, mostly longer distance and fast catch, and my elbow began to hurt. It got worse until the next day, I could hardly move it because of the pain. The pain seems to be internal, kind of 'in the middle' of the elbow, but extends above and below. Does this mean I've got tennis elbow? Someone was saying it's probably my technique. Can anyone help with any ideas about how I might improve my technique if this is indeed the problem, or about whether some kind of support would make any difference. --- used to get that all the time, and discovered that I was bringing my arm to an abrupt halt at the end of the throwing motion, which puts a strain on the tendons that retract the forearm. I modified my throw such that rather than stop my arm, I let it rotate inward after the release so as to allow it to continue following thru the motion, ending up with my hand down near my waist. Hard to visualize, I know...but it worked for me. And yes, it is exactly 'tennis elbow'...same thing. Dave Hughes

Anyway the excercise is quite easy. Put your arm to your side as if on an armchair. Hold your fist out, with the thumb facing left (for right handers). Pivot your wrist so the the fist drops straight down and return it to normal. Then twist your wrist to the right, so that your thumb faces up, and return. keep going down, return, right, return, etc. In the beginning only your hand is needed. After a day or two, use a one or two pound weight. fter a couple of weeks, your elbow will have build the strength it needs.

Glucosamine and chondroitin are great for knitting cartilage but no good for tendonitis..

Dave Hendricks Alletown, PA

Undercutting an Omega boomerang .

Actually, Bill, the Aborigines used little to no undercutting, but tuned rather unscientifically by heating in the fire and bending and/or twisting them to fly right. The fire treatment also served to temper the black waddle, making it harder and less susceptible to damage On most of the plans I've seen, the undercutting is the average of what the designer found to be right over large numbers of boomerangs. For beginners, I'd suggest throwing a new boomerang before undercutting to see what it does. First, though, you have to be confident that you're throwing consistently the same way each time you throw. Then, if the boomerang does not lay down to spin horizontally on return, undercut a little on the leading edge of the leading arm and throw it again. Keep doing this until you're satisfied. If the boomerang lays down too soon and flies the famous/infamous "S" curve, undercut a little on the bottom leading edge of the dingle or trailing arm, and throw again. Throw two to three times to be sure you're throwing the same each time. If anyone has a sport boomerang they can't tune, contact me. If I can, I'll adjust it for them but contact me first.

More about Undercutting Omega's

26056
Dear Greg,

I'd go so far as to say any hook or omega shape falls into
this "needs undercut" or "needs rather radical tuning adjustments"
category. King Billy hooks tend to not only have undercuts, but
rather large dihedrals on the lead wings.

Dave's post was good on undercutting. Typically, I'd change layover
rate by central or peripheral weighting. I'd add that undercuts are
actually a version of angle of attack adjustment. That last statement
was short, but possibly more complex than first glance would yield.

There is debate among some as to whether a boom should be grinded
so that minimal tune is needed, or tuned for optimal flight, with
mostly just airfoils applied. Actually, Rusty and I went differing
directions on this one; he was big on grinding, I was big on tuning.
My thoughts were, you can always grind something off later, if
needed. The truth is, the way the air flows over the boom wing is
almost exactly the same, if similar modifications are made by either
grinding or tuning. There are some weight distribution changes to
deal with, between the two methods, but they are minimal.

How a wing affects the circulation of air around it is what
determines flight characteristics, and you can achieve similar final
effects by either tuning or grinding. There are times one or the
other is preferable, but more often than not, you have the option.

Best wishes,

Fred M.

No way to say how much exactly...you cut a little, test, cut a little more if needed, test again, ad nauseam. Don't go and hack a big ol' bevel on there right off the bat, because you can't put the wood back on if you went too far. If it's not laying down soon enough for you, I'd say cut a bevel about 1/8" wide X 1/32" deep X about 2" long on the lead wing, blending the ends of the bevel into the tip and leading edge of the boom. The lead wing, if you're right-handed, is the one on the right looking at the top of the boom, wings hanging downward. Test it and observe the effect. If needed, widen and deepen the bevel a tiny bit, test again. Tiny steps, remember.
If it's laying down too soon, undercut the leading edge of the dingle wing (the other wing) using the same criteria and procedure.

I don't think I've ever made an omega that I didn't have to adjust via undercutting. Kendall Davis makes one he calls 'Dunce' that has no undercutting, yet it does that really cool sudden laydown at the end dearly that I love to see.

Dave Hughes
Austin, Texas

Hello All, this is my first time posting to the group. I joined the
group recently and have found it intriguing. I have been an avid
thrower for 20+ years. Rich the BMan and DaveH will recognize me as
a customer. In the summer of '03 I started making my own booms. I
have made over 100 so far, and they are all different. Some of my
best successes have been lightweight flyers (birch 5ply 3/32inch)
that my daughters can throw successfully and attempt to catch without
getting hurt. I was amazed in late '03 when my youngest, then six
years old, actually made a catch.

The talk about undercuts on omegas so far has been limited to the
wings. But I have found that an undercut on the inside of the elbow
of an omega has a good effect. Most boomerangs I have bought tend to
fly too high for my tastes. I like low circular flights. I have
found that the inside elbow undercut can keep a boomerang upright for
more of the flight, thereby allowing the boomerang to make a nice
circular turn without gaining altitude. I wonder if the master
boomsmiths will agree that the inside elbow undercut is really
helping me to achieve the low circular flight which I crave.

I love to throw and catch - football, baseball, frisbee, whatever. I
got into boomerangs because I always want to play, but there isn't
always someone to play with. Most of my boomerang experience has
been by myself. So, if any lonely boomerangers live near me, lets
get together.

Rick Saidenberg
Pleasantville, NY

John Cross said in his book that undercut at the inside elbow
will give a boom a nice end hover. I tried it and found this to be
true for me. I wasn't looking for a lower flight in these boomerangs
previously, but I have been and do look for an even altitude or a
steady flight path (minimal climbing). This is definitely food for
thought. Undercut is one of many factors to consider in the overall
airfoiling along with the boomerang's size and shape.

John V.

That's an interesting theory (about undercutting the inner elbow
causing a lower flight due to delayed layover rate), but I don't
think the effect you're getting is due to your chosen modification.

An omega has a large portion that is basically semi-circular,
around the CG. This doesn't add much, if any, lift to the boom; in
fact, the vast majority of omegas have no "trailing edge" on this
portion. Most are airfoiled as leading edges, for both the inner and
outer edges.

If you then undercut the inner edge, you are then delaying the
minimal lift discussed above. If that lift (without undercutting) is
minimal, then your effect is even more minimal.

However, by undercutting, you did lighten the elbow section, and
weight of the elbow is hugely important in layover rate. Lighten the
elbow, and you will retard layover rate. If you want a lower flight,
make the central section of that omega with a thinner chord.

You can see the effect of the above by weighting your boom with
pennies. Try it without weights; then, with two pennies near the
elbow section; then, with a penny at each tip. There should be a
rather large difference in layover rates with each weighting method.

In summation, the height of the flight of your omega will be
largely dependent upon two factors:

1) Exact tune (AOA and dihedral) of your boom, especially the lead
wing;

2) Weight of the central "elbow" section versus peripheral wing
sections where lift is generated.

Best wishes,

Fred M.

A lot of folks seem to think of undercutting and the boomerang's airfoil as two different entities. However, the undercut is actually a part of the airfoil. What happens when you undercut at/near the tip of a boomerang's wing is that you're carving 'wash-in' into the airfoil at the wingtip. You alter the mean-line of the airfoil section such that you change the airfoil's angle of attack in that region. I believe that the effect would be the same as if you were to slightly twist the very tip of the wing in relation to the airflow around the airfoil. In general terms, you increase the lift generated by that wing if you undercut the leading edge, and decrease its lift if you undercut the trailing edge.

DLHughes

Fully agreed. This is sort of an expansion of what I wrote in post
26056.

I should mention that this does in some small way disagree with the
post on undercutting all the way around the boom lowering the lift
(post 26078). Undercutting all the way around would increase the lift
for the leading edge undercut, and decrease the lift for the trailing
edge undercut. It would also definitely decrease drag.

Best wishes,

Fred M.

I believe that we who craft rangs tend to do what works for us
and that our techniques progress as a direct result of trial and
error. There's clearcut best way to incorporate all the dynamics of
rangcrafting. If you're following plans from the web and don't know
where to begin, I strongly suggest you try your best to duplicate the
specs given in that particular plan. If in some cases that doesn't
happen to work for you, that's when it's time to apply some
adjustments. Before too long, you'll see what works for you and what
doesn't.

Personally, I tend to agree mostly with Dave Hughes' comments
on undercut. I think the specs he gave for beginning undercut are very
sound as a starting point. I myself (to date) get best results by
undercutting both wings. I'm not particularly conscious of the effect
of laydown caused by undercutting, but I find that using undercut
causes my rangs to turn more effectively.

I also feel that twist tuning to avoid undercutting is sticky
buisiness for a beginner, although I know at least one person who has
never used undercuts since the beginning and he makes some truly
amazing spectacular flyers. He began by using plans right from web as
you're doing now and, not understanding the undercut specs, he
disregarded them altogether. I don't think it's that way for most
beginners though.

I think I'll close my observations for now by saying that one
of the greatest boomerangers of all time generally applies undercut
around the entire boomerang, tip to tip. leading and trailing edge.
And he's not the only who prefers to do this.

Cheers!

John V.

Boomerang Making and throwing can be as simple or as complicated as you want to make it.

I was interested to see some of the comments about undercut.

Rick Saidenberg’s comments,” I wonder if the master
boom smiths, will agree that the inside elbow undercut is really
helping me to achieve the low circular flight which I crave.” Has prompted me to contribute to the discussion.

When I first started making “Lazy sevens”, (about 1978)I had problems with them after painting. They were flying great till then. They had good circular flight, a consistent height, good accuracy. After painting them, they would either crash half way around, or end their flight with a significant dip.

At that time with trial and error I observed that by lowering the angle of camber in the elbow area on the inside corrected that flaw. I then made the unpainted boomerang fly a little high before painting. After painting it came down to where I wanted it.

Conversely if I wanted to lower the flight pattern, I would lower the angle of camber at the outside edge of the centre section. The area I worked on would cover no more than one fourth of the total size of the boomerang. (IE measured from the wing tip to the centre, then centre to the other wingtip. In my example with the total measurement of 48 CM, the area adjusted is 12 CM) Much to the amusement of David Schummy, I still do those adjustments during preliminary field testing.
In 1982 I was invited to compete in the USBA National Championships. I had a warm up at the Portland Rose Festival competition. When I saw a thrower getting dips at the end of the flight I asked if he knew about specific shaping at the elbow. I received many blank looks. The general belief at that time was that the elbow was a neutral point. Somebody had a rasp in their kit. I asked if I could modify the flight for them. After minimal shaping. Yes it did work.

I have discussed this observation on many occasions.(If you were not there you would not have heard it) On the previous boomerang discussion point, Rusty Harding added that his observation was to get the same results from undercut, but the opposite way around.

I understand that weight reduction in the centre will cause a change in flight patterns. My observations though are that a similar reduction in weight at the centre on opposite sides of the wing will produce opposite characteristics flight results.

My comments relate to boomerangs with a rounded centre section. Omegas, lazy seven, “C” shape. My observations are that it is very important to make sure the wings are at least Zero dihedral favoring positive dihedral.

Bob Burwell Brisbane Australia.

I thought about John's discussion here, and believe I do have a
reason why the elbow airfoil and undercut mods act as they do.

Let me preface this whole discussion by saying that there's never
been a two-bladed boom put in my hands that a proper tuning
modification of the tips couldn't fix, if the boom was fixable.
Anything one can do with an elbow modification, one can do with a
leading or trailing arm modification.

Here's why - the elbow, in a two-bladed boom, is a very, very poor
version of a third wing. Did I mention, it is very, very poor? Okay.
The other two "real wings" stick out farther from the CG, and are
true chords with airfoils. Consider the elbow as a "V" shaped wing,
with the chord running all the way from the start of the trailing
arm, across the elbow, and ending on the start of the leading wing.
If you've ever seen a triangular boom (either referred to as
an "open" or "closed" form, depending upon to whom you're talking),
you've seen such a wingtip.

As a quick aside, this elbow must generate much less lift, due to
its "less than ideal" shape ("V" instead of linear), and much less
distance from the CG. Rotational speed has less effect on generating
lift on the elbow.

Now, assuming this elbow is generating some lift, let's look at
what happens when mods are applied. John stated that when one applies
an undercut to the inner elbow, or applies a trailing edge to the
outer elbow, it lowers lift at the outer point of the flight. Well,
let's turn this boom (as it does in flight) until these modifications
look like an airfoil. When you rotate the boom so that the elbow is
facing the thrower (3 o'clock, disc of rotation), you will note that
the first mod looks like an undercut, and the second mod looks like a
trailing edge. In this position, the boom elbow will generate some
lift from the translational (forwards) speed, from these mods (these
mods create more lift, so oriented). Rotate this 90 degrees in the
direction of rotation, because precession says any rotating object
that has a nonfrictional force applied to it effectively has it
applied 90 degrees later, and you get a force applied to the disc of
rotation at 12 o'clock. This lift force will create a delay of
layover in the boom being thrown (layover occurs as the 12 o'clock
part of the disc comes down, and these mods are creating lift there).

A boom with a delayed layover will stay lower; look at almost all
FC booms. A boom won't rise until it starts to layover unless it's
thrown upwards. A more vertical boom has lift generated towards the
center of the circle it's making; a more horizontal boom has lift
generated upwards, usually to keep it aloft for some reason (either
end of a flight, or MTA).

The reverse mods (undercutting the outer elbow, or "trailing edge"
the inner elbow) lines up as an airfoil when you point the boom elbow
away from the thrower. This generates lift at 9 o'clock, which
precession says will occur at 6 o'clock. This increases the rate of
layover (12 o'clock moving downwards is aided by 6 o'clock moving
upwards), which will make the boom rise in its flight earlier.

Another sobering realization from this train of thought is that
there truly is no such thing as a "two-bladed boomerang". Every boom
that has something on the other side of the elbow is using that as a
wing, minimal as it might be. Thinking about LD for a moment, the
trailing wing is minimally 45 degrees off of ideal lift, and closer
to 90 (radial to the CG would be ideal), and its elbow runs almost
horizontally, yet whatever is there, has to function very minimally
as a third wing.

This makes sense to me, at least. It would explain why such effects
work at all, yet don't yield the same effect as seen at the two major
wingtips.

Best wishes,

Fred M

Teach new throwers

Never belittle an errant throw. "Try to get a little more spin on it this time!" is a lot better than, "You didn't get enough spin on it!" "Try to throw it toward the top of that tree!", rather than, "You're throwing it too high!" Turn the thrower a little left or right until the direction's right, then say, "Feel the wind on your cheek? That's the way it should feel when throwing." Start them out on easy to fly, short range, preferably conventionally designed two bladed boomerangs, then graduate to others as skills develop. Teach that boomerangs can be thrown too hard, but they always love more spin. Take pride in helping others enjoy our old but unusual sport, then do in again! Rusty

Some things that are common in helping are;

How the thrower holds the boomerang for optimum spin.

I teach by using a pinch grip, forward throw. (Free wing points forward) Boomerang to lie as close as is comfortable to the forearm as possible. COG low over the forearm.

Flips grip was a combination pinch grip with the end of the boomerang positioned between the index finger and middle finger. The boomerang wing pointing forward. COG directly above the wrist. I believe less spin is generated using this hold.

Where the thrower begins and ends the throw.

I teach that the throw starts with the boomerang behind the head at shoulder height. The release point depends on the boomerang. For most boomerangs it is directly in front of the shoulder and near head height. Some want to start with the boomerang horizontal down near the hip.

The amount of layover required.

Layover depends on the boomerang being used. Layover typically is at about one oclock. There is a significant difference between a conventional boomerangs, Vipers and Long Distance boomerangs.

The boomerang thrower should visualize a target, so as to have a throw point reference.

Flip tended to throw from where the boomerang ended after his throw. If it was close to the throw point, Fine. If it was ten metres away he was not correcting for the wind after his field location change.

For consistent results, return to the same throw point. This maintains the target reference point.

Being able to effect the correct amount of power to get the best result from the boomerang being used.

Knowing when to attempt a catch on the boomerangs return, and when to let it pass by and land on the ground.

When boomerangs are coming in like Gannets vertically entering the ocean for a feed of fish, or a hundred mile per hour falcon coming out of a dive to make a horizontal strike, let it go.

When a catch is attempted, for safety sake it should be done below head height.

Bob Burwell

Warped boomerang

I hate when that happens. Did you give 'em the tap test? Laying the boom on a flat surface, holding the elbow down with one or two fingers and tap the wingtips with the other hand? My first guess would be that all the dingle arms are lacking tapiness. Maybe they're giving you a thud? Maybe the board you cut the blanks from was warped in such a way that all the booms had too much up-warp on the trailing wings, causing the booms to curve in too quickly on the return. The trailng wings may instead have to much positive angle of attack or you might have carved the trailing wings in such a way that they have too much lift, again causing the same result. These are all just guesses. If the booms are already painted, Chet Snouffer has suggested using a hot air corn popper to heat and retune the wings. It won't damage the paint. If the booms are unfinished, you might either do some carving adjustments to reduce lift on the trailing wing or you might use a source of steam to retune the trailing wing. One way or another, I would suggest trying to bend the trailing wing down a little Good luck. Hope you find the solution.

John V.

Big Round Flights

I always enjoy big round flights. Why some sticks make them is a good question. I don't know why. They say people like dogs that look like themselves and I'm getting rounder myself these days. Triblades make round flights, but they don't seem to be as fascinating as longer distance booms, usually more open shapes. I've made a few flat tops that have that flight. http://www.boomerangs.us/images/snowtigr.jpeg They take a more vertical toss than most hooks, say WEL 45/10/20 for the flat tops where I would throw a Sussex copy or Killimanjaro 45/10/50 or so. http://www.boomerangs.us/welsh.htm for the secret decoding of throwing numbers. Windage angle/Elevation angle/Layover angle I've been throwing a bit lately and am learning a few new things about some of my old sticks, like the Delicate Arch. The DA is usually in the top 10 category of favorite booms, but mine's never really done much for me. It needs to be thrown quite a bit off the wind. Apparently I've been laying mine over way too much. It makes it back somewhere close, but there is no magic in the flight, probably 80/10/50 or something like that. The other day I dug mine out and decided to give it a more vertical throw with a bit more sauce on it, 80/10/20 or so. The numbers are not exact, but a much more vertical throw than usual. The DA made a beautiful low round flight and almost came back to my hands. They say that the LD record flight that stood for about 10 years at 149M by Michael Dufayard (sp?) was a big round flight. Now THAT'S a big round flight! Keep'em big and round, Pat

Fingers safety

Speaking of comfortably numb and hurt fingers . A good reminder to all new people who havnt heard this is to keep your finger nails cut very short . A few members have had entire finger nails ripped off their fingers from a returning boomerang .The boomerang misses fingers and palm and catches right on the edge of a finger nail and the sheer fource rips it off . This happens usualy on the left hand of a right handed thrower .I only had it happen a fraction of the way and its bad painfull news ! This is not the kind of info to share during demos/ lessons however .

Just a few thoughts from the other end of the spectrum (so to speak). In colder weather ( less than 10C) I am wearing a golf glove (Nike, 20$) on my left hand. It just keeps my left hand warm which in turn makes it easier for my body to warm my right throwing hand up (and warm hands are very important for a steady throw).

However, once I get my faster fast catch booms out, I am switching to my Snowboard glove (sans pads, of course), rain or shine. Hot or cold. A lot of competition throwers are wearing heavy gloves on the non-throwing hand to have at least some protection between a 10Hz, 100 km/h (These numbers are made up, prove me wrong) razor blade and their body.

However, one thing you never, never, never do (in practice) is to catch before your face. Booms returing higher than shoulder height and its time to step aside. You can still attempt to catch the boom but make sure you do it so you are standing away from the path of the boom, not directly in its path.

Saftey glasses are also a high priority once you get into faster boomerangs.

Tibor Vancouver

How to give spin

I've said it before, but I'll risk flogging the topic again. The spin is a function of wrist movement, snap. Get a small towel or string and tie it to the end of the boom you don't hold. Using your regular grip on the boom, start snapping the string or towel untill you can make it pop like a bull whip. You have just trained your wrist muscles to put about as much spin as you are going to be able to on that stick with that grip. A couple of sessions with the whip will double your spin if you are just learning to throw. The sound will give you feedback and you will naturally start maximizing your wrist arc. It's fast and worth a few minutes. It sounds like I throw like Tim. Dingle and pinch letting the boom release itself. I try to focus on what I want the boom to do, not what I want my arm or wrist to do. Good luck, Pat

Pat

Performance Boomerangs Book

Many time this book is mentioned on the list. It is only available through the author John Cross.

John, in the accuracy section of your book you left off a critical part of accuracy - post throw control. Some booms fly better when you give them verbal instruction after you throw. My favorite person to watch in accuracy is Will Gix, who give continuous verbal commands to his booms, often with opposite commands. Something like, " drop, Drop, DROP, NO, FLOAT, FLOAT, Come on - YEAH!" It works well for Will.

Stay Rad, Clay Bellevue WA

John Cross

Devon, Alberta