| Model |
Flt
# |
Recovery Type |
Motor |
Comments |
|
Thug
|
9
|
24" nylon parasheet |
Aerotech RMS 29/40-120 F40-4
|
I got a lot of ribbing from people for repeating the combination of
rocket and motor that caused such a disaster at NSL just under a year ago,
but I was confident that I'd learned the cause of that and one subsequent
deployment failures, and I wanted to verify my confidence. I was
careful to ensure that the launch rod was angled well away from both all
spectators and fliers, and the Boeing plant. After one ignition failure
-- my first in which a Laser Fire igniter burned, but failed to ignite
the motor -- I opened the rear closure, verified that the propellant was
still in a condition that would permit ignition, and reloaded with a new,
stiff Copperhead. This time, despite ignition with a low-tech Estes
controller connected to a Pratt battery pack, the motor ignited immediately,
and the rocket lifted slowly off the pad. As I expected, the flight
wasn't very high, but it was completely stable, and though I got approximately
one second of bonus delay, ejection was still only about two seconds past
apogee and thirty to fifty feet above ground. Vindication has been
acheived! |
|
Spike
|
22
|
18" nylon parasheet
|
Estes D12-3
|
Continuing the theme of minimum motors for the rocket, I repeated my
well proven "stunt" of launching my Spike on a black powder D. As
always, the flight was completely predictable; low, slow, but absolutely
straight, with ejection just past apogee. No surprises, and not much
walking at all. |
|
Thug
|
10
|
24" nylon parasheet
|
Aerotech RMS 29/40-120 F52-5
|
With the certification (finally!) of the F52 reload in 1998, I bought
a couple of them, and this was my first time flying one. This is
a much better motor for the Thug than the F40; it gets off the pad
much more smartly, and seems to give up much less to gravity losses; the
altitude seems greater, despite violating the 2:1 ratio that is touted
as ideal for maximum altitude -- I suspect this is because the F40 violates
the rule of getting up to "cruise" speed quickly. Ejection was very
close to apogee; with a more vertical rod position (as would be indicated
on a less breezy day), I think this would be a near-perfect combination,
much like the F62-4. I had the rod angle just right, though; I almost
dropped the rocket on the LCO table. |
|
Thug
|
11
|
24" nylon parasheet
|
Aerotech G40-4W
|
Digging through my motor stash, looking for a motor suitable for a
quick prep and flight (I didn't want to spend the time to assemble another
reload, since the day was wearing on), I found a G40 I'd bought for NSL
-- a purchase made around a year ago. This seemed like a good motor
for the Thug, so I prepped up and put it on the pad. I haven't compared
thrust curves, but the G40 seems to get off the pad faster than an F40
in the same rocket; it may start with higher thrust, and tail off lower,
to come up with the same average. In any case, it was a much more
satisfactory flight, with substantially more altitude and less of the precarious
feel during liftoff. |