American's have become fascinated with the video format, having developed their addiction to camcorders and furthered with the advent of the personal computer, the Internet, and more recently, YouTube, Google Video and the plethora of look-alike video content sites.
 
Prime-time television leveraged this popularity some time back, through the highly-watched America's Funniest Videos television show on ABC.  Millions have laughed and giggled along to the hijinks and calamity of AFV's video clips over the years.  Imagine my surprise to see my favorite hobby showcased in video on the show after all these years.

Arizona Rocketry Team poses with their 15X Fat Boy at Plaster Blaster 2006. Standing left to right: Guy Smith, Roy Polmanteer, Jacob Dennis, Jay Dennis, Susan Dennis. Kneeling/sitting left to right: Greg Poehlman, Larry Foster, Joanna Foster. Ken Sparks. Vanderschaegen Photo

Arizona Rocketry Team made it onto America's Funniest Videos with their 15X Fat Boy upscale, a 36 inch diameter, 15 foot tall behemoth that flew on three 98mm M motors. And, the team won the AFV $1000 third prize to boot. The show featured a launch video of the monster from this past year and made for a good show.

Planned to debut at Plaster Blaster 2006 in Plaster City, California, the Arizona Rocketry Team began construction last summer, and utilizing their unique brand of teamwork they were able to make the event.

The team had originally considered using sono-tube to build the Fat Boy, but decided to deviate and build it using a system of stringers and bulkheads. The bulkheads and stringers started life as 1/4" KEVLAR honeycomb sheeting that ART sandwiched between four layers of 5.5 ounce fiberglass cloth which were vacuum-bagged to compress the composite and remove excess resin.

It was quite a process, considering the size of the pieces. They cut out the honeycomb beforehand, making oversized blanks that would be cut to final size after curing. Then began the tedious layup process that involved wetting out two layers of fiberglass cloth, placing it on the release film, positioning the honeycomb cut outs, then wetting out two more layers of fiberglass cloth and putting that on top of the honeycomb cutout. Finally, the top layer of release film was added and the blank placed in the vacuum bag. Whew!

Here Jay cuts out the stringers with a router.

They had to make nine bulkhead blanks, six 4" wide stringer blanks and three double thickness 12" wide stringer blanks in total. Considering the length of the Fat Boy, we are talking about man-handling some really large pieces and lots of West Systems epoxy. ART had things covered though, with plenty of team members helping apply the fiberglass cloth and resin, wrestle the parts into vacuum bags and shuttling epoxy around.

The vertical stringers were cut out from the blanks using a router and a pre-cut template while the various bulkhead plates were cut by a machine shop. The uniqueness of stringer and bulkhead construction is that the stringers fit in slots cut into the bulkheads, so proper alignment of the slot is a critical concern.

To assemble such a beast, ART built a 4x4 wooden frame over which they placed a 20 foot length of black iron pipe to serve as the central spindle, or spit, to rotate the airframe. With the nine bulkhead plates placed over the pipe spindle and suspended between the 4x4 uprights, the team began the process of fitting the vertical stringers in preparation to cut the foam blocks that would fill the open spaces in the airframe.

This is what's called really getting into your work.

The entire airframe structure is built to be lightweight but strong. Three lengths of 1/4" all-thread joins the motor mount area together to add to strength, but the real key to the airframe is the foam blocks that were used to fill in the airframe openings. Using the airframe for a cutting guide and a hot-wire setup, each block was cut to fit a particular opening, and then numbered so it could be installed permanently into that same spot later.

At this time, before the final installation of the custom cut foam blocks, ART installed the internal PVC launch lug and constructed the fin boxes. The fin boxes were installed into the airframe using construction adhesive, and then it was time to start gluing in the custom cut foam blocks, which were installed using construction adhesive as well. To finish the airframe construction, two-part foam was poured into the motor-mount/fin box area to fill and stiffen the airframe assembly.

Now if you think you have fiberglassed big projects before, imagine a project the size of the Fat Boy. Imagine precutting 27 yards of fiberglass cloth! That's a lot of cloth and a lot of epoxy. One person was required to mix epoxy while eight others put it on the airframe. Now that's a glassing party!

This is what the stringer blanks looked like: LONG.

Once ART had the fiberglass cloth wet out, they applied a layer of release film and breather to the airframe. This was covered with the stretchy plastic wrap used for loading pallets, such as you see at Home Depot's loading dock. It is very stretchy and when pulled tight against the release film, should work just like shrink wrap tape. It sounded like a good system, but the team discovered the next day that it caused wrinkles to be formed in the fiberglass. Fortunately for the team, because of the breather and release film, the wrinkles were formed in the excess resin it squeezed out and not the fiberglass cloth itself.

ART pointed out that the reason for wrapping an airframe in this manner was to keep the wet-out cloth from falling off the airframe. That was certainly a good cause for concern with an airframe as large as this one was. They worked it out with some additional elbow grease and it didn't cause a problem overall.

Ken Sparks applies the heat — with a hot wire.

The project of painting a rocket this large did not go unnoticed and ART had to drag out the big guns to get it done — big PAINT guns that is. No spray bombs for something three feet in diameter and 15 feet tall. A heavy duty compressor and automotive spray painting guns made easy work of painting the Fat Boy, beginning with a base of white primer before being covered with the traditional Fat Boy colors. Well, the equipment was up to the task, but the team had to train a few members on the proper way to use a spray gun. Hey, it all worked out!

Wednesday, October the 3rd, 2006, found the Fat Boy sitting on a bright yellow custom transporter ART had constructed to make moving the large project around a little easier. At 9:40AM, the team hit the highway headed to Plaster City, California. With Ken Sparks in the lead pulling the Fat Boy, followed by Guy in his truck and with Roy in the motor home bringing up the rear.

Arizona Rocketry Team's Fat Boy really is a big'un!

Averaging around 65MPH, the team made Yuma shortly after noon, and figured it was a good time to stop for auto and human fuel. During lunch, ART had a forehead-slapping moment when they remembered that they had not brought the all-thread that held the fins on. Not to worry, Guy took off ahead of the pack and made a necessary pit-stop at Home Depot in El Centro to secure the needed pieces.

This wasn't their last scare, as shortly after Guy rendezvoused back with the team, a jostling rail-road track crossing sent the Fat Boy into a shower of sparks as the hitch came off the trailer ball! After re-hitching the trailer and cleaning their pants, the rest of the trip was uneventful, and they arrived at the launch site shortly after 3:00PM.

The team quickly found out that Mother Nature wasn't in a good mood, as she was pummeling the launch site with 10-20MPH winds. This was cramping the teams plans as they still had things they wanted to get done, and had to settle for sorting out electrical details. Few flights were made that Thursday so there was nothing to do but wait for Friday. As it turned out, Friday was no better.

Saturday, though, turned out to be what the team was looking for. They awoke to find no wind Saturday morning. Time to get to work. Motors were prepped, chutes where packed, electronics checked and double checked. A lot of heaving and ho'ing and the Fat Boy was sitting upright and looking more like a rocket every second.

After the obligatory group photo, the Fat Boy was ready to fly. And fly it did, screaming above the beautiful red roar of three M1550 Redlines. Reaching approximately 1500 feet, the drogue chute deployed and pulled out the three Rocket Rage RRQS150 main chutes. Fun maybe, but there's nothing funny about this Fat Boy at all.

Cutting the Fat Boy's stringer slots in the various bulkheads. Fitting it all together, the Fat Boy starts to takes shape. Foam blocks were hand-fitted into each airframe opening. A belt sander shapes the foam and makes it snow inside. It's an airframe fiberglass party for Arizona Rocketry Team. Ken Sparks gets in the classical art act applying the red color. The Fat Boy gets the old heave ho as it's lifted into place. Team members line up the Fat Boy's internal launch rod. That's the beautiful color of three M1550 Redline motors. Three Rocket Rage parachutes lower the Fat Boy back to earth.

02-05-2007 10:51 PM  #1
crontab Certified Level Three   Joined: Aug 2006 Posts: 204	Great article! I want to tell all the people at Rocketry Planet that I really enjoyed this article. The photos really made it! It is SO nice to be able to get interesting rocketry articles online again. It's like having a free subscription to a daily rocketry magazine! Keep up the good work.

03-11-2007 03:04 PM  #2
Raider Rocketry Low Power Enthusiast   Joined: Mar 2007 Posts: 128	That is a very nifty looking upscale! Congrats on the successful flight.

03-21-2007 09:35 PM  #3
jmiller no title   Joined: Oct 2006 Posts: 23	Actually, wasn't it shown on ABC's AFV because it lawn darted into the flight line and hit a car last October? (not a good submission to AFV for "HPR being safe" it seems....) Is the video online any place?

03-22-2007 07:14 AM  #4
DumasBro2 I Felta Thi Frat Boy   Joined: Aug 2006 Posts: 200	Quote: Actually, wasn't it shown on ABC's AFV because it lawn darted into the flight line and hit a car last October? (not a good submission to AFV for "HPR being safe" it seems....) Not a "lawn dart", it was under chute.

03-22-2007 08:59 AM  #5
ddmobley Administrator   Joined: Jul 2006 Posts: 2142	Quote: Not a "lawn dart", it was under chute. And, the video didn't include the fact that it fell on a car. Dents happen.