Archive for Bill

Manchester launch rescheduled for May 13

Moved because of weather scrub on May 6

May 6 launch scrubbed…

The May 6 launch in Manchester is scrubbed due to very poor weather prospects.

Geezer TARC is about to commence…

Geezer TARC, HARA’s version of TARC for “older” rocketeers begins with the announcement of the 2016 TARC challenge at Nationals this weekend. It is open to any interested rocketeer over 21, and provides an excellent way for TARC mentors (or potential TARC mentors) to get a feel for the difficulties that will be faced by their teams in the upcoming months.

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Duane Mayer’s winning rocket for 2015 – the yellow and black “Beast”

 

Standard TARC rules for 2016 season will apply, except for the following:

1) Geezer TARC begins with the announcement of the 2016 rules in May and ends with the contestants’ rockets being launched at a single event (date TBD, but well before school starts in late summer).

2) Each contestant may enter up to two rockets. These rockets may not fly before the official launch date, and the score shall be determined by the first flight of each on that date. The contestant’s score shall be the better of the two flights, or the score of one flight if only one rocket is entered.

3) Any commercial altimeter may be used to determine altitude. However, reflights are not allowed if there is an altimeter malfunction; in this case, the flight will be disqualified (So choose a reliable altimeter).

4) There is only one rocket per design, and there are no test or sub-scale flights permitted for the design. Its merit will be judged solely by the rocket’s performance at the contest launch. If two rockets are entered, they must be of substantially different design – different number of motors, fins, or something major – an inch shorter or taller does not constitute a substantial difference, nor does the same design at a different scale (e.g., BT-70 versus BT-80 versions).

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Bullpup 1 – a dual 24mm cluster for 2015. This was my best performer.

Der_Eggcracker

Der Eggcracker – a minimum diameter TARC rocket. This one was too efficient; it went WAY over altitude.

 
In the past, we have launched at a horse farm in Harvest. This year’s launch will probably be at “Pegasus field” in Research Park in Huntsville or at a HARA launch in Manchester. The launch will take place in late July or early August, and yes, you must be there to fly. That’s part of the contest – we want to witness what happens! We will try to pick a date that will be agreeable to all schedules.

Geezer TARC measures your ability to design an rocket to meet the TARC challenge – there are no proxies or test flights, as this would defeat the purpose. There is only one rocket for each design, and its first flight will be at the launch. If you enter two rockets, each must be based on a different design (like “Sure Thing” versus “Hail Mary”). This is a major part of the fun of the contest – we spend a lot of time designing a rocket to meet the challenge, but will it do it without modifications, on the first flight?

Good luck, and see you on the field!

 

The Huntsville TARC Regionals

Today was a good day to fly…

At least 9 TARC teams converged on Bragg Farms just north of Huntsville for our annual TARC regional launch.

Read more

Estes on steroids

by Bill Cooke

Mention Estes to a rocketeer these days, and you usually get a smirk; they are famous for Ready-To-Fly (RTF) and other easily built low power kits. Not much thrill to many in flying birds using 13 mm, 18mm, and 24 mm motors (1/4 A to E impulse). But that’s changing…  Read more

Rocket Design/Simulation Programs for TARC

by Bill Cooke

TARC is like the real world of rocket design in that the teams must resort to design/simulation software to help flesh out the initial concept, making sure it can meet the goals before pressing on to actual construction/testing. Here the vendors have come to the rescue in providing three outstanding packages, any one of which can be used to design a winning TARC entry. Read more

Thoughts on the 2013 TARC challenge

by Bill Cooke

NAR and the AIAA have just released the objectives for the 2013 TARC season. In brief, they are

  1. Altitude mark of 750 feet
  2. Flight Duration of 48-50 seconds
  3. 15″ parachute must be used to recover the egg and the altimeter
  4. Egg must be placed horizontally (“lying on its back”)
  5. Section of rocket containing the egg must be at least 60 mm (2.362″) in diameter
  6. Gross liftoff weight of under 650 grams
  7. Motor impulse must be 80 newton-seconds or less

At first glance. this seems simple; after all, each of these has been used in past years. No surprises, so pretty easy challenge for the TARC teams, right? Read more

Pack 351 Rocket Blast – and indeed it was!

by Bill Cooke

Every year Cub Scout Pack 351 has their annual ‘rocket blast’, in which the cubs fly rockets they have recently bought or built. HARA – in the form of Chuck Pierce and various others who show up to assist – always provides the launch setup and range control, which has been fairly easy for the past couple of years due to the use of the USSRC/Space Camp launch facilities. Read more

Building Rockets, Finale – Decals

By Bill Cooke

A lot of the new rockets come with “peel ‘n stick” stickers these days, rather than decals. Many rocketeers call these “peel ‘n cuss”, because they are not much fun to apply (especially roll patterns and long names) due to their stickiness – very little room to make a mistake. Read more

Building Rockets, Part 6 – Paint

by Bill Cooke

Image

Estes Executioner built and painted by Kimble29 on Ye Olde Rocket Forum

Now that the primer has been applied, we can move on to the paint. The type of paint is the rocketeer’s choice, with many choosing Rustoleum spray, while others use the same Testors enamels used to paint model cars or planes. The more artistic among us will break out the air brush, producing magnificent finishes like that on the Executioner seen at right. Whatever your paint choice, be sure you read the directions on the can or bottle, and follow them – a lot of weeping and gnashing of teeth can be saved by knowing the drying and recoat time of your paint.

Also, it is important to avoid mixing paint brands or types, as this can lead to “crazing”, in which incompatibilities in the chemistry of the paints cause huge cracks and wrinkles in the finish. However, there may be times – usually due to the unavailability of a certain color – when you have to mix brands or types. In these cases, remember that enamels can be applied over lacquer-based paints such as Rustoleum or Krylon, but lacquers cannot be applied over enamels. Similarly, fluorescent paints should be the last coat, as they will craze any type of paint applied over them (I know this from bitter experience). When mixing different brands, such as Rustoleum and Krylon, the best thing to do is to test out the application on a unpainted scrap piece of body tube. Spray the paint on in the order you intend to use with the model, and see if there are any issues. If nothing materializes, you are good to go.

When working outdoors or in an open garage, be mindful of the wind and humidity. The wind part is obvious – you don’t want paint going everywhere and creating a spotty finish on the rocket. Avoid spraying when the humidity is higher than 50%, as this will lead to the paint dulling or “blushing” (areas where the paint appears duller than its surroundings). Here in the South, we have constant high humidity, but it usually drops below 50% between 2 and 4 in the afternoons, providing a couple of hours suitable for painting.

When painting, spray continous light coats down the entire rocket – don’t “spot paint”, as this will create an uneven finish (which means sanding) and don’t lay it on too thick, as this will cause the paint to run. With Krylon, I usually hold the spray can about 10 to 12 inches from the rocket; this same distance should be about right for Rustoleum and other sprays. Start with the lightest color first and then move on to successively darker colors, saving black for last – be sure to allow the right amount of drying time between coats! No matter what the paint scheme, I always apply a coat of gloss or semi-gloss white above the gray primer to serve as a base coat, as applying yellows or other light colors directly on top of the primer results in very dark versions of these colors. White is always a good place to start.

As I mentioned in an earlier post, I use Tamiya masking type to mask off areas of the rocket when painting. You can avoid bleeds and smudges by

  • Burnish down the edges of the tape with your finger – make sure the rocket surface is smooth and that the tape has good contact, else you will get bleeds.
  • It is a good idea to apply another light coat of the prior color, as this will create a “seal” on the tape edge, also avoiding bleeds. If you use Scotch tape for masking, this is a must.
  • Be SURE you have covered/masked the areas of the rocket that are not supposed to receive the paint – you would be surprised to find how easily that fin color can find a way to get on to your nice white body tube. Black is particularly evil in doing this.
  • Remove the masking tape as soon as the paint can be touched – if you wait until it is fully dry, you run the risk of the paint chipping when you remove the tape. Pull the tape straight up when removing it.
  • Use 1000/2000 grit sandpaper to smooth out rough areas and imperfections between coats.
  • Above all, be patient! Wait for the right conditions and take your time.

Here are the Rogue and Aero-Hi after painting – note the nice sharp lines. I am reasonably pleased with how these turned out, so we are now ready for the final step – applying the decals, which will be covered in Part 7.