Michigan Team #1 Tripoli Prefecture #9
Team Talk!
By: Stuart Davis TRA #2232
Vol 6. No. 3
Winter 2001
West Branch One,
November 2001Three Oaks coverage &
AREM article by Bob Schultz.
Welcome to another addition of
“Team Talk ”, The Michigan
TEAM 1 newsletter. This Issue
covers the first launch at the allnew West Branch field, the very
successful Three Oaks Fall 2001
launch and a technical article by
Bob Schultz.
Jim Summers’ Scratch built
Phoenix takes to the sky at West
branch One under the power of a
J 570
West Branch “One”
A group of 31 fliers and nearly 20
spectators attended the first launch
at the new West Branch field on
October 13, 2001 to initiate this
location to High Power Rocketry.
Our host, Mr. Bert Schick, was
very accommodating to our needs
and made the day pleasurable for
all of us that attended. Although
the weather report was for clearing
skies throughout the day, the skies
stayed overcast with a cloud
ceiling around 3000 feet. We are
all “Die Hard” fliers so we kept
the power down when needed,
flew most of the day and enjoyed
the camaraderie of our friends.
Despite the low cloud ceiling we had many
great flights. From the Big to the small, we
came and launched them all. Tony Sanflippo
flew his scratch built rocket named “Low
Drag” on an I-161 motor. It was a very high
flight and he really got some serious altitude
with it. When the ‘chute came out we
watched it drift quite a ways and it was
heading North-East toward the far tree line.
Although he had to get driven there on Joe
Fullers 4-Wheeler, he got it back. It was
recovered in the primary recovery area, which
helped show us that this field should work
well and have good recovery (about 2/3 mile
wide and 1.2 miles long of nothing but
hayfields).
Most of the flights went right where we
wanted them to be and recovery was easy
(except for the occasional ½ mile walk). As
usual, some flew left, some right, some
straight and some in a less than desired flight
path. All were very recoverable, showing we
had a field that truly could support our flights
below 7000 feet and recover within the
designated area. This was a great relief for
me. I think we found our summer home
thanks to Bert’s kindness.
Jim Summers brought out his 12”
Photo: Dan
McCulloug
diameter, scratch built Phoenix
rocket and launched it on a J-570
motor for a great roaring flight. As the rocket if quite heavy Jim
said it only went to 900 feet. However, since we were close to the
action we really heard and actually FELT the motor roaring as it
lifted off. The echoing of the motor off the distant woods added a
neat aspect to the flight.
Jim Summers (front left) gets help
preparing his Phoenix with the help
of his friends Dan McCulloug (rear)
and Tim Summers (right). Note the
line of cars in the background.
Photo:
Todd
Moore
Harvey Muehl brought up a rocket
that looked like it belonged in a
display case due to its great
craftsmanship and finish. His
PML Lunar Express can be seen
at right. Harvey put the rocket up
on an I-284 for a great flight. The
rocket had great lift off speed, a
great boost and flawless recovery.
What a treat it was to see it fly.
Checking in the rocket was Jeff
Walters, our only NAR Level 3
member.
Alan Grocholski’s
PML Endeavor has
become a regular at
our launches.
Named “Bad to the
Cone” it can be
seen at the right
just at the moment
of ignition on a J570 motor. This
rocket really hauls
ass with that motor
and it put in a
beautiful flight. In
the photo at right,
you can see our
new TEAM-1
“Away” cell pad
build by Paul and
Andy Bonham. It
is a great addition
Photo: Todd Moore
to our equipment
and has been
getting a work out at the
last few launches.
Harvey Muehl checking in
his beautiful
PML Lunar Express.
We also had the crew from PML
again come to our launch to
conduct some demo flights.
Frank Uroda and Henry
Lockwood were seen at the pads
about 8 times in just a few hours.
It is nice to see these guys in
action, and use our launches for
their development.
Bruce Kirchner had a scratch built
electronic dual deployment rocket and
flew it on a an Ellis Mt. J-630 motor.
The rocket roared up, but
unfortunately the main ‘chute
deployed with the drogue at apogee. It
drifted quite farther than Bruce had
wanted to walk. Even though it was
quite a looong walk for Bruce (no,
that’s not a typo), he still had about
1/4 mile to the nearest tree line.
Bruce Kirchner’s
rocket motor
flickers to life.
Also joining us was Steve Lafleur
from commonwealth displays
(www.commonwealth.net) (photo far
right). Steve and his wife Judy came
up and helped keep us all stocked with
motors and supplies. It was nice to
see them there, and we hope they
become regulars at our launches.
Steve use to bring his BBQ to the
Photo Todd
Lansing launches and
Moore
you could buy a
burger and a motor
all at the same time
(Now that was full
service!). Remember,
we need to help
patronize all of our
vendors. We rely on
them, and they rely on
us. Stop by and visit
them if they are at a
launch.
When the day was done, we had put up 102 flights. This was pretty
good as people were waiting for the anticipated clearing of the
weather (that never came).
We even had a birthday celebration at the launch, complete with a
birthday cake that we were all able to share. Crystal Tillman (Jeff
Tillman’s daughter) turned four years old at the launch. We all
took a moment to celebrate her birthday and Marita Macnall flew a
rocket named “Blues Clues” in honor of Crystal’s birthday.
In all, we had a GREAT time. Let’s look forward to launching at
Bert Schick’s farm in the spring and summer when he allows us
there. Bert saw many smiles, and heard many people saying
“Thank you”. Due to a prior rain, the entryway and the field were
pretty muddy and the cars tore up a bit of his crop. We donated a
portion of the launch fee to help offset any crop damage we may
have caused and will
continue this donation at Steve Lefleur from
this field.
Commonwealth Displays,
with his wife Judy, came up
to keep us well stocked with
digs in doing
motors and supplies.
Joe Fuller
a combination of LCO
and Pad Manager duty.
Photo: Todd Moore
Photo: Todd Moore
Fall 2001 Three Oaks
Over 125 registered High Power fliers, and dozens of low power (G
and below) fliers turned out for the fall 2001 Three Oaks launch.
We put up 321 flights during the two day event. I think that is
pretty amazing considering this was just after the Aerotech fire and
motors were in short supply, or people were saving them for later.
This launch initiated a test of our new launch schedule with an
“alternate date”. We had to delay the launch one weekend due to
the crops not being harvested in the field. Rather than just show up
and “take what we get” or cancel the launch, the word was put out
on the web page, via a email or US mail (to those without internet
service) and the “Hot Line” that the “alternate date” was to be used.
This date was set up nearly six months ahead of time, so people
knew it may be used.
Six months ago my plan was to move the launch earlier in
November instead of the traditional “third weekend” of the month
to try and get better (and warmer) weather. I think it worked out
well. This was also the first time at the new hotel, the Holiday Inn.
They were very helpful and since we registered a “block” of rooms
they switched all of our reservations to the alternate date when I
called. I think we will continue to use this type of planning so that
we avoid the crummy weather that frequently plagues our fall
Three Oaks launches.
A group of volunteers arrived Friday and set up the range. Once
the range was set up these helpers were able to fly as I had the
waiver active for them as a “perk”. When Saturday morning rolled
around the range was all set up and the flights started at 9:06 with
Dan McCulloug flying his PML small endeavor on an H242. And
there were plenty more flights to follow him, 321 to be exact.
We had to deal with a wind direction this year that was unusual. It
was blowing the rockets over our heads, and down across Avery
Road (I think that is south-east). We had more than a few rockets
get hung up in the trees that are plentiful in that direction.
Although it slowed us down a little, and it was disappointing when
one got stuck, we kept the skies filled with rockets.
Joe Isca flew his really neat
scratch built 4 ¼” diameter
upscale Estes “Asrton Sprite” on
a cluster of 3 motors. He started
it off with one of the new
Aerotech H-165 “Redline”
motors and then air started two
G-80’s. It was a great flight and
the redline motor really
complimented this neat rocket
kit.
Joe Isca’s upscale Astron
Sprite starting on its H165
redline and waiting for the
G-80’s to kick in.
This launch was also the first
time we had a higher waiver for
the site. I was able to negotiate
12,000 feet for us this time
Photo: Stuart Davis
around. In late October our
waiver was not yet approved and
the FAA guy said, “Don’t call back”. Since I don’t take no for an
answer I called the facilities Director and discussed things with
him. By the end of the day I had our waiver, 12,000 feet of
altitude, an apology from the FAA and we will now have a new
person processing waivers for rocket launches at the Chicago
office. Hopefully we will have no more last minute 3-Oaks waiver
“woes”.
It looked like people like Bob Chmara with his minimum diameter,
scratch built, K1100 powered rocket named “Beep Beep II” we
were going to need more than the old 10,000 feet we use to have.
Bob was planning on a supersonic flight as the predictions said he
should get Mach 1.15. I think he
Marita gets ready
actually did get it to go supersonic
we heard the small “crack” or sonic
with her cert 2
booms and it sure hauled ass on its
way to 10,553 feet.
Marita Mac Nall has been a familiar
face lately. She had been honing her
skills and stepped up to do her level
2 cert flight. Marita built a Yank
IRIS and painted it in a very patriotic
scheme. She used a J-350 motor and
the ignition and flight were perfect.
It boosted to nearly 4000 feet and
her ‘chute was right on time.
Although it got hung up in a tree for
a little while, she got it back intact
and I was happy to sign her cert
paperwork. Congratulations go out
to Marita and ALL of those that got
their cert that weekend.
As Marita is a NAR member we
arranged all of the paperwork so that
I can administer either the Tripoli of
NAR level 2 test on site. I can now
do the complete Level 2 process,
including the tests for NAR or TRA
at the launches
Photo: Stuart
D i
Bruce Kirchner
and Al Jenkins on
their way to the
d
I stopped two familiar faces on the
way out to the launch pad, Bruce
Kirchner (left) and Alan Jenkins
(right). Bruce had his 4” diameter,
scratch built “Barbarian” loaded with
a K-550, and Alan had his PML
Black Brant X loaded with a J-350.
Bruce had been “itching” to fly his
K-550, and the rocket for quite some
time. It really roared off the pad on
a big white trail of White Lightning
smoke. It was another great flight.
Alan’s Black Brant X weighed in at
8 pounds, and had a really high
boost. The wind caught it and the
rocket spent some time in the trees.
Alan was real happy to get it back.
Photo: Stuart Davis
Saturday morning finds the Cub Scouts (left) and Robbie’s Rocket (right) set up. We had blue
skies, moderate wind moderate temperatures and hot coffee. We had a great day for flying!
We all know that the Aerotech fire has serious repercussions to our
supply of motors. Some vendors were pretty short on motors not
long after the announcement. We still had a number of vendors at
the launch such as Red Arrow Hobbies (motors, kits and supplies)
and a rep from Commonwealth Displays (with a variety of
motors), so the supply for this launch seemed adequate. Robbie’s
Rockets was also there with their ejection system, epoxy, ematches, kits and more.
Noticeably absent from this launch were our friends Ross Dunton
from Magnum, and Tim from Al’s Hobbies.
The Cub Scouts joined us once again and served hot coffee and
doughnuts in the morning, and hot dogs and pop in the afternoon.
Our event is a great way for the kids to raise funds for their pack,
have some fun flying rockets, and learn some discipline.
This “eye on the sky”
posture was repeated
many times over the
weekend as they loved
watching us fly.
Remember that these
kids are here, and that
they are watching and
learning from us.
Another familiar person
at our launches is Paul
Bonham. Paul won one
of the two trophies that
day for “Best Flight of
the day” with his
“Thunderbird” rocket
flying on an M1419. In
the picture with him is
an old friend and past
member of Team-1, Jim
Rossin. Jim has been
out west and planned
his visit home to
correspond with our
launch. It was nice to
see him and listen to his
stories of the BIG
motors (like “N” and
“O” size) that they fire
out west.
Mark Roszell received a
“Best Flight of the day”
trophy at the Saturday
evening banquet. Mark had
“Wowed” us with a twilight
launch of his scratch built 5
½” diameter upscale
RAPTOR (based on a
Binder Design kit). He
launched it as the last flight
on Saturday at 5:00 as the
sun was setting. It was a
beautiful flight as the K700
motor roared into the sky
leaving a bright trail of
flame behind it. It was a
cool flight.
Paul Bonham (left) with his
“Thunderbird rocket is joined by an
old friend, Jim Rossin.
Mark Roszell’s Raptor
brightens the evening sky
on a K-700, earning him a
“Best Flight of the Day”
trophy.
William Roszell
(Mark’s brother) has
the honor of being the
only Team-1 flier to
Photo: Frank Coppola
date to land his rocket
out of state! Bill
launched his Level 3
cert flight on a new Aerotech
William Roszell’s Cert
M-1600 Redline motor. It really level 3 rocket on an Mhauled ass up into the sky.
1600 “Redeye” heads
Unfortunately, the large main
for the sky, and Indiana!
‘chute came out at apogee with
the drogue. It drifted, drifted
and then drifted some more.
Thankfully they had radio
tracking gear in the rocket and
were able to keep a bearing on
it even though it was WAY out
of sight. The rocket was
recovered across the state line,
and even across the I-80
expressway in Indiana.
According to my map, that is
about 6 miles! Thanks to the
slick radio locator, and the help
of some friends, Bill got his
rocket back and vows he will
get his level 3 soon.
Photo: Frank
Coppola
Photo: Bob Schultz
Tim Horne has shown up
with some beautiful and
sometimes unique
rockets. He once brought
out an all wood rocket
made by “Retro Rocket
works” that looked very
neat.
Tim Horne’s PML Endeavor
named “ Rainbow Demon”
heads up on a J-275
We also had a second trophy that went to Erick McDaniel for his
cluster attempt. Notice the word “attempt”. Erick learned (like we
all do at times) that some of these projects get complex, and those
clusters are hard to ignite. Erick is a student at the Culver Military
Academy and had built his project under my supervision and the
support of his Science teacher. He brought down a group of his
classmates to help prep the large rocket and watch the launch.
Tim has also become
famous for his “First
thing in the morning J-90
powered Minie Magg”.
Yep, a J-90 Blackjack
motor in a Minie Magg.
Since the winds are
usually dead calm in the
morning, we watch this
rocket chug up into the
sky on a huge trail of
Black Jack smoke.
Pictured at right is Tim’s
J-275 powered PML
Endeavor that he calls
“Rainbow Demon”.
There were so many more
flights that could be
covered, I will just say
that we had a BLAST!
had a hard luck flight on his LOC Magnum powered by a cluster of
three H-238’s. Just after ignition one motor CATO’d and blew
large sections of the airframe off the rocket. It also ejected the
parachute and the rocket kinda “looped” around out in front of us,
about 50 feet up, and kept shedding parts as it went. It didn’t look
like there was much left. Bob won a trophy and a $40 gift
certificate to MAGNUM. I’m sure that helped reduce his
disappointment.
Photo: Stuart Davis
Erick (front left) and his fellow
students from Culver Academy carry
out the project rocket
Photo: Bob Schultz
The Banquet
If you missed the banquet, you missed a GREAT time! Bob
Chmara had arranged for the Diamond Bowl restaurant (in the
Bowling alley) to accommodate us and we were expecting a crowd
of nearly 100 people. I am pretty sure we had that many, as we
sure filled the restaurant. This place had great food and I hear the
steaks were especially good. We had great food, great
camaraderie, great conversation, cold drinks and hot coffee and a
great raffle! We will be heading back there for future banquets so
plan on attending.
We had a lot of great flights, and yet a few not so great flights at
this launch. At the banquet we had two “Best flight of the day”
trophies that were given to Paul
Bonham for his majestic flight of
“Thunderbird” on an M-1419, and
one to Mark Roszell for his twilight
flight of his upscale Raptor on a K700. Both flights were the ones
people talked about throughout the
day, so they were worthy of an
award. I had a Cert level 3 trophy
ready for someone to claim, and it
looks like it will still be available at
the next launch!
We also had some “Best crash of the
day” trophies, and there were two
winners of these also. Bob Lazzari
The project was to fly on a center J-570 with three I-200’s that I
had prepared for him. I kept reminding Erick how complex
clusters were, but he had faith and determination., and myself, I
think we need to encourage that kind of enthusiasm with adult
sponsorship and supervision through people like myself and his
teacher. Several Team-1 members had also helped with this
project. Helping retrofit some last minute modifications for safety
issues, preparing the motors for the guys, preparing the ejection
charges and general encouragement. Erick thanks everyone for the
assistance.
The flight suffered when
only two of the three I200’s ignited. The core J570 that was to really boost
the rocket, and deploy the
parachute never ignited.
The rocket attained a few
hundred feet of altitude,
arced over and nosed in.
Despite this failure, Erick
vowed he would be back.
He accepted his trophy with
pride. That, is the true
spirit of a rocketeer. Not
letting a failure spoil the
whole hobby.
Erick with his “Best
crash of the day”
trophy.
Photo: Stuart Davis
Saturday nights Raffle and the GREAT prizes.
We had an incredible array of raffle prizes that were donated by the
vendors. We decided to try the old format of “$5 per ticket” and it
seemed to work out well. We had rockets, motors, parachutes,
Robbie’s Rockets ejection charges, epoxy, Lions football tickets,
rail buttons, Pro-38 motor systems (2 complete systems), Pete
Alway’s great books, and more. We even had a special ticket and
raffle for the kids. They won small prizes like balsa gliders, rocket
shaped gum containers, coloring books, and more. My thanks go
out to Bob Chmara, Bruce Kirchner, Jim Lyndquist, Bob Schultz
and Tony Sanflippo for helping me put this banquet together. It
seems when the “Team” pulls together, we can do some great
things.
The following vendors supported out banquet, and we should in
turn support them. Please give them a little special treatment when
you decide whom to buy from, and follow the links on our web
page (www.team.org) to visit their Internet store.
Commonwealth displays- $25 Gift Certificates, 3 'chutes, PML
Tiny Pterodactyl rocket kit
Top Flight Recovery - 6 foot dia 'chutes
Aerocon - 2 gift certificates for 66” parachutes
Cesaroni Technologies- Two Pro 38 three case systems
LOC Precision - Cyclotron rocket kit, Legacy rocket kit, body
tubes, centering rings, motor tubes
Missileworks - Little John rocket kit (really cool kit!)
Aeropak – High Tech Aluminum Motor Adapter
Saturn Press - Autographed Poster
Magnum - $30 and $40 dollar gift certificates
Robbies Rockets – Epoxy kits, Pre-made ejection charges, two
LES (Reloadable ejection systems), parachutes
Public Missiles- Mini Endeavor rocket kit
Giant leap- Rail guides
Jim Lyndquist- Four Detroit vs. Chicago football tickets.
Stuart Davis- Two Estes Fat Boy rocket kits. Two H-128 reloads,
F-50 motor.
Bob Chmara- Gifts for the kids (Balsa airplanes, Rubber band
powered gliders, activity books, Rocket shaped gum containers)
In summary, this banquet has become a great addition to our
launches. I am not sure if we will hold it in the spring as we may
keep the range open as long as possible if the weather is nice.
However, meeting at the restaurant will probably be “the thing to
do” after Saturdays flying. You will be with friends and have a
great place to swap stories and of course eat.
IMPORTANT!!!!!
I need your help if this applies to you. We need to keep up our
membership list so that I can effectively get information to you. If
you have a change of address, either US mail or Email, PLEASE
pass that info along to Bob Chmara.
Lately there had been a few Internet providers that have changed,
and I am routinely getting undeliverable Email addressed to some
of you. If you want up to date information from us, you need to
help us. You can send Bob an update at:
Bob Chmara
33228 W. 12 Mile Rd.,
Suite 103,
Farmington Hills, MI 48334
Or via email to: [email protected].
I also have a new email address of: [email protected] for
those of you that wish to reach me.
And a reminder, the TEAM-1 24 hr HOT LINE
number is (248) 944-2036. You can call it 24 hrs a day to
get up to date information on launch events and especially changes
or cancellations.
Launch Schedule:
The launch schedule for the next few months is:
Primary date:
Back-up date
Location:
Feb 10th
Feb 17th
Ithaca
March 9th
March 16th
Ithaca
April 21 & 22
April 28 & 29
Three Oaks
And the annual members meeting Sunday Feb 24th.
Announcement:
We have had significant growth in our hobby over the last several
years. Where one “M” motor a weekend was a HUGE event, we
are now seeing several a day. With the growth in our hobby and
the number of people looking to get their level 3 certification I took
action to expand our TAP member people. I felt we needed
improved coverage and availability to help the Michigan fliers. I
provided nominations to the TAP committee and……
Please welcome Andy Bonham and Mark Roszell to the TAP
committee. Their construction, design and flying skills earned
them a position in this elite group. Paul Bonham is also suppose to
be approved as a TAP member, so stay tuned for more info on that.
Mark Roszell lives in Grand Rapids and can cover the Western side
of the state. So you people from Lansing, Jackson, Kalamazoo,
down to Three Oaks and North to Traverse City can “TAP” into
Mark for help. For those of us in the eastern side of the state we
have Ken Zuener and Andy Bonham for expert help.
So if you were looking for help on that level 3 project, seek out one
of our recognized experts!
Members submission:
You all know that I am always looking for pictures to write the
newsletter around and articles to share with the group. Bob Schultz
had conducted some work with rear ejection systems and
documented his work as he went. Take a look at his work, and
learn about his “ Apogee Rear Ejection Module”.
If you have something that you would like to share with others, be
it in construction, your experience or just a great story, SEND IT
IN. It can be hand written or typed. We all have lots of tricks and
tips, so why not pass them along!
Design and Development of an Apogee Rear
Ejection Module (AREM)
acceleration, particularly with a high-thrust motor. It's critical the
drogue chute not deploy during boost!
by Robert W. Schultz, TRA #5116
Table 2 summarizes the results of shear pin testing for nose cone
retention at drogue deployment. When the AREM deploys the
drogue, the rocket will experience some degree of deceleration – in
other words, the rocket will be “jerked”. The goal here is to ensure
that the nose cone does not slip off when the jerk occurs; if it does,
the benefit of deploying a small drogue at apogee with later
deployment of the main chute is lost. The optimal combination for
nose cone retention proved to be 4 shear pins and 2.0 grams of
FFFF black powder. While the combination of only 2 shear pins
and 1.0 gram of FFFF worked, the use of 4 pins is desirable
because the nose cone assembly is heavy.
Santa Claus brought me a PML BullDog kit for Christmas, and I
decided this was the time to incorporate something I’ve been
thinking about for a while now – rear ejection of a drogue chute at
apogee. My wife dubbed the BullDog Let The Big Dawg Eat – a
familiar expression to those of you who play golf. Rear ejection
will allow the rocket to fall in a controlled fashion nose-down
relatively slowly, without the risk of airframe components flailing
about and bashing each other, until the main parachute is deployed
at a lower altitude.
In Let The Big Dawg
The author performing final field prep at Three Oaks on
The technical challenge was
Eat, the AREM is
to design a system capable
04/15/00.
held in position two
of withstanding launch
ways: the fore end is
acceleration without
secured with a
deploying, yet be
stainless steel
deployable at apogee using
automotive “radiator
commonly-available
clamp” to the motor
methods. My research in
mount tube, and the
old issues of High Power
aft end is secured with
Rocketry magazine yielded
two small steel hinges
only a complicated-looking
and four 6-32 bolts to
system involving some
the boat tail.
metal parts; I wanted
something elegant and
Note that a small radiator
The first actual flight
simple. I was leaning
clamp has been secured
of the AREM
towards gluing a thin balsa
around the aft end of the
occurred at the Teamplate on the end of a
AREM to protect the 38
1 Three Oaks launch
deployment tube, but with
mm tube from damage
event on 04/15/00.
eerily good timing, I read an
upon landing.
The engine was an
article in a recent edition of
AeroTech/Dr. Rocket
the Tripoli Wisconsin’s
J350.
Electronic
control
consisted
of
an
Adept
OBC2 On-Board
newsletter. In that article, Ed Dewey and Dean Roth discussed the
Computer.
The
OBC2
was
programmed
to
actuate
the AREM LES
use of tiny nylon screws as shear pins.
at apogee, and the main recovery system at 1000 feet. Based on
RockSim data provided by Public Missiles Limited, I expected Let
The nylon screws I mail-ordered from McMaster-Carr arrived in a
The Big Dawg Eat to reach a peak altitude of about 1800 feet. She
few days, and I commenced ground testing. I was actually
actually peaked at only 913 feet. I think this is because of the
interested in using shear pins in two applications: ensuring that
added weight of 10 ounces in the nose cone (to shift the CG
drogue chute deployment did not occur during launch, and ensuring
forward), the electronics on board (the OBC2 and an Adept SB50
nose cone retention at the moment of drogue chute deployment.
Sonic Locating Beacon), the added weight of a fin installation
system that allows the fins to be removed, and the AREM itself.
The Apogee Rear Ejection Module (AREM) I designed consists of
a 26-inch-long 38 mm tube with a plywood bulk plate at one end
Consequently, the OBC2 actuated the AREM 24” RocketMan
and a PML piston assembly at the other. The bulk plate has a hole
drogue and the 72” main parachute at the same time. The OBC2’s
drilled in it to allow installation of a Loadable Ejection System
instructions explain that the computer is designed to perform
(LES) canister from Robby’s Rockets. The piston is tethered to the
exactly this way in a situation when the programmed altitude is not
AREM with a nylon strap epoxied to the inside of the tube. The
actually reached. Let The Big Dawg Eat recovered flawlessly and
AREM is designed to be removable from the rocket, to ease the
suffered no damage upon landing.
pre-flight preparation process.
Table 1 summarizes the results of shear pin testing in the AREM
for piston retention at launch. The optimal combination proved to
be 2 shear pins and 1.0 grams of FFFF black powder. While 1
shear pin and 0.5 grams of FFFF worked, I have my doubts about
whether only 1 pin will retain the drogue system during launch
I flew the Dawg again at LDRS 19 in July, with a J460T, a J415W,
a J800T, and a K550. These higher-altitude flights allowed the
AREM to operate correctly. On the J800T flight, the nylon strap
finally shredded; it seems the life span of a nylon strap in this
application is about a dozen discharges. I tested an “open link”
metal chain in place of a nylon strap at Three Oaks in November
2000, and found that one link (the weakest link!) opened under
ejection stress. The result is that the drogue chute & piston
assembly gently wafted to earth separate from the rocket. I plan to
test a tougher “closed link” metal chain at Three Oaks in April
2001, and I expect this will be the optimum answer.
Trial
No.
1
Tube
Dia.
inches
1.52
# of
shear
pins
B.P.
(grams)
1
0.5
Aft
AREM
restraint
s
Result
Pins sheared cleanly, piston
fully cleared the tube (but would
only 1 pin withstand launch
acceleration?).
2
1.52
2
0.67
Pins bent, but did not shear; gas
escaped around the LES
canister.
3
1.52
2
1.0
Success! Pins sheared cleanly,
piston fully cleared the tube.
Photo 2
Side view of the AREM in position in the BullDog’s
boat tail. The fiberglass boat tail was carefully
modified with a Dremel tool to allow positioning of
the AREM.
Table 1: Shear Pin ground testing – piston retention at
launch
Trial
No.
4
Tube
Dia.
inches
1.52
# of
shear
pins
B.P.
(grams)
1
0.5
Result
AREM
Pins sheared cleanly, piston fully
cleared the tube (but would only 1
pin withstand launch
acceleration?).
5
1.52
2
0.67
Pins bent, but did not shear; gas
escaped around the LES canister.
6
1.52
2
1.0
Success! Pins sheared cleanly,
piston fully cleared the tube.
38 mm PML
piston with
eyebolt
38 mm motor
restraint system
brass insert
Table 2: Shear Pin ground testing – nose cone retention
54 mm motor
at drogue deployment
restraint
system
“tee” nut
Hole for passage of actuating
line for Adept SB50 Sonic
Locating Beacon
Photo 3
Aft view of the AREM in position in the BullDog’s
boat tail.
Photo 1
The aft centering ring was modified to allow
passage of the AREM tube during field prep.