Welcome to Boomtown!

aLAcrity Boomerangs is a group of boomerang enthusiasts from Los Angeles. At the moment, it is comprised of three people: Manny (a.k.a. v12aero), phnxhawk and Charles (a.k.a. hey_kuya).

Manny and I (phnxhawk) started this blog to share our interest in boomerangs--throwing and tuning, making our own rangs, as well as unraveling the science behind them. As we continue our journey into the world of boomerangs, we hope to make new friends and to expand our horizons. In this blog, we will post such things as videos from our regular throwing sessions, musings and lessons learned from throwing, and thoughts on making our own rangs.

Manny and I started throwing boomerangs since Spring 2009. It has been a long road as we developed a semblance of technique for throwing 'rangs. Nevertheless, after many a bruised hand or windy day, our fascination with these returning throwing sticks remains undimmed. We most certainly have more to learn about boomerangs, but we'll keep at it as long as we continue to have many happy returns.


Thursday, November 29, 2012

Carver's Corner #2 - Finnishing Time

--by phnxhawk--

So, I know.  Long time, no see.  Suffice it to say that times are tough on the work front.  The weather this year has not been particularly cooperative, either.  "How can the weather ever be poor in sunny SoCal?" one might wonder.  Well, the winds have been consistently calm at our usual boomerang throwing times at the beach for the last several months.  This, of course, is not a terrible thing.  We certainly are able to continue throwing, and it is good practice to adapt to different conditions.  However, our heavier, more wind-loving boomerangs have been sitting in the bag for month after month.

But on to the topic at hand.  Last weekend, I came down with the fever, the sort that drives a man to spend a day carving three boomerangs and then the next, applying the finishing touches.

As I mentioned last time, I acquired a "small" quantity of 5 mm Finnish birch ply from Anderson Trading.  My latest creations are my first using the higher quality material and are also the first to involve the flush installation of weights.

The Boomerangs

For this run, I set out to make a copy of the Rainier, Eagle and Diabolino.  The Rainier has so far been my baseline boomerang against which I measure my results, and it continues to serve in that capacity.  I chose the Eagle for its relatively simple geometry and its circular flight with an easy throw.  The Diabolino was selected at the request of Manny, who regards it as one of his top, go-to boomerangs for its impressive, low and round flights.

New Materials

Again, the main change for this run is the application of the Finnish birch.  My initial set of Rainier replicas were cut from 3/16 in hobby-type plywood from my local hobby shop.  The new material is the sort of which fanciful tales are told and that figures prominently into the advertising lines for
some of my favorite boomerangs.  I oriented the outlines in a similar fashion to Rainier V0002 so that it would be easier to bend the wings to add dihedral than it would be to twist them.

Both the Eagle and Diabolino models call for the installation of weights in the wingtips.  The Eagle appears to feature a single 1/4 in diameter full-depth lead weight in the lead wing.  My Diabolino 2011, on the other hand, appears to have three 1/2 in diameter full-depth lead weights, one in the tip of each wing.

Rather than scrounge for lead shot, I decided to procure brass rod, which I could then cut into slivers of appropriate length.  Brass is, however, a less dense material, so I would need more of it to obtain the same weight.  (Lead is about 30% more dense than brass.)  To this end, I opted to buy a 5/16 in diameter rod as a substitute for the 1/4 in weights.  For the 1/2 in diameter lead, I stayed with 1/2 in diameter brass, as I was concerned that larger weights might take up too much space for them to fit neatly in the wingtip without some shaping work on the contoured side.

(In case you are curious, I picked up my brass material from M&K Metal in Gardena)

New Tools and Manufacturing Methods

Cutting the brass rods to size turned out to be less painful than I expected.  I read in some forums elsewhere on the Internet that a hacksaw would cut through brass rods "like butter."  So, I picked up a miter box and a hacksaw to add to my tool chest.  It was relatively painless and quick to make the cuts; I was probably finished with four pieces of each diameter in about 30 minutes.

My methods of carving and sanding did not change for this run, but the additional plies in the new wood material made it easier to evaluate the progress of the contour shaping.

For this set, I cut the holes for the weights after completing the airfoil sanding work.  I was initially unsure what configuration of weights I would use on the Diabolino, and I opted to make the call after I had a chance to weigh the boomerang post-contouring.  Since I do not have a drill press, I was forced to cut the holes with the Dremel, which resulted in some misshapen holes. Fortunately, I was able to fill in the gaps by slathering more epoxy into the holes when gluing the weights into place.

For future editions of these boomerangs, and for any boomerangs for which I am sure of the weights to use, I intend to cut the holes prior to the contouring work (to make it easier to draw on the boomerang the outlines to follow).

Surface Protection and Finish

For this set of boomerangs, I applied a few initial coats of Bulls Eye Shellac finish and sealer.  I then applied four coats of clear satin Minwax Polycrylic spray as a top coat.

I am quite pleased with how the coatings turned out.  The Shellac adds a nice color to the wood, and the Polycrylic adds what feels like a solid protective coat.  The true tests, of course, will be time and wear, but I like the initial result.

The Result

From Carver's Corner #2

From Carver's Corner #2

From Carver's Corner #2

More pictures are included in this album.

Additional Post-Woodworking Comments

I found that the boomerangs, after applying all the coatings, were consistently heavier than the originals by 6 to 7 grams.  The exception is the Diabolino, which turned out to be the same weight as the original (because I used quantity and diameter of weights, but of less dense material).  Even without the coatings, the boomerangs were slightly heavier than the originals (by about 3 grams).

I rushed the power sanding work on this set, having started cutting wood at about one o'clock in the afternoon on Thanksgiving Day and continuing well into the evening.  The rush is certainly evident in the uneven contouring and the multiple nicks and cuts that remain after completing the hand sanding.  Still, I think the boomerangs turned out reasonably well.

Initial Testing

Manny and I took the boomerangs out for a test drive this past Sunday.  They seem to fly pretty well.  The Rainier and the Eagle have flight behaviors like the originals except that they tend to want to keep flying on the return, just like Rainiers V0001 to V0003.  I chalk that behavior up to the more complete airfoil contours, which might impart better lift-to-drag ratios.

The Diabolino has a somewhat more elliptical path than the Diabolino 2010, but note that the original Diabolino 2011 has heavier wingtip weights and wing undercutting than its predecessor.  The difference in weight between my Diabolino and Manny's 2010 is apparent when they are in hand.  For a better flight comparison, I will have to fashion a Diabolino using the 5/16 in diameter brass weights.  Nevertheless, my Diabolino flies quite nicely, and I think the more efficient airfoil shaping helps the boomerang to sail back to me on the return.

All in all, it looks like these boomerangs were a success!

"Putting my spin on boomerangs..."


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