(Contributed - by Larry Brand )
I have modified the LOC Aura to a tube-fin design.
Tube fins described above were fastened to the main body tube in the
time-honored, self-jigging manner for tube-fin rockets. Opposite tube fins
glued on first with main tube on a flat surface to insure alignment; next pair
added to the top of this array; last pair added to the bottom of this
arrangement after the first 4 are dry. Standard LOC recovery system can be
used. I prefer to attach the shock cord through the upper hull, anchored with
an external knot that is covered with 1/2 of a BIC pen cap sawn lengthwise. I
spray-painted the rocket in navy gray primer, and left the cone unpainted
The LOC Aura wood fins were replaced with 6 identical tube fins cut from 40.5mm
cardboard tubing from an empty Saran Wrap roll. This happens to be identical in
diameter to the 1.62" LOC Aura fuselage tubing, and the size of standard
38mm motor tubing. Tube fins were 2.5" long, cut with a 22.5 degree bevel
on top, which I find both looks better and improves stability and performance.
PRO: The purpose in this modification was to eliminate two shortcomings of
this popular LOC product: breakage of the wooden fins, and loss of the whole
contraption due to its small size and hot performance. Tube-fin rockets are
significantly stronger in the small sizes, and the added drag slows things down
a bit and straightens out the flight (less weathercocking) so you have a better
chance of getting the thing back. This tube-fin design in particular flies
remarkably straight up, especially on an E30-7 (adapter needed).
CON: There's always loss of speed and altitude with the substitution to
tube-fins, but on anything bigger than an E30, this can't be a disadvantage,
since it goes out of sight anyway. I like to actually see the recovery system
deploy, personally. This is conducive to getting the rocket back, I find.
I have flown the tube-fin LOC Aura exclusively on E30-7 motors. Very fast, very
straight, even in a breeze. I use tape friction fit of the motors in a LOC
24-29 mm adapter tube. There is no reason to fly this rocket on anything more
if you expect to get it back. After 7 flights, not a bit of damage.
The modification completely fulfilled my expectations. I'd like to see LOC
include a tube-fin option like this with the Aura kit -- makes it more
attractive to small-field fliers, and I think the bevel tube-fin structure
looks cool (see attached photo).
I prefer to replace the underpants elastic shock cord included with the kit
with 6-7 feet of parachute cord.