Black Brant VI

Getting accurate scale data on this bird was tough, Alway's dimensioned drawings on Jim Ball's Scale Site don't contain enough info to properly create the fins. I am, however, in possession of the Excel spreadsheet Peter used to create a number of the plans in the above titled book, and it contains both enough and more accurate data on this bird. Missing from everything is the fin thickness, but from the photo at right, it would appear that they're fairly thin. (A little tip guys; if you want to look tough, you shouldn't wear geeky glasses. Gesh.)

I did this one for a sport scale competition, so body tube joints had to be exactly placed. To get a smooth tube for most of the rocket, I used a T-34 tube from Rogue, which comes in 34 inch lengths. Two sections, one 23.6" long and another 1 inch long, make up the body. The short section is glued directly to the nose, and this assembly is coupled to the main body by an Estes BT-55 tube coupler. The nose cone is their PNC-55AC, the same as on their Bullpup, and contains a ¼ ounce of clay weight. Its joined to the main body with a two foot length of 250# Kevlar from Pratt Hobbies and an equal length of ¼ inch wide elastic. Recovery is by 12 inch 'chute, which brings it down a little fast, but it only has to fly once. At less than an inch span, I figured I could use ¹/32" G-10 fiberglass from Vaughn Bros. for the fins, which would give me a nice, smooth surface. For the fold-over fin mounting tabs I cut some strips of cardboard and glued them onto the body next to the fins.

This bird has three documented paint schemes, the "company colors" one being the most striking. I liked the White Sands round (pictured at right) better, though, as it had less details. First I primed in white, then painted the body in red, both store brand paints. The nose and two fins were done in Krylon Gloss White (1501), and the whole thing clear coated in Frog Spit. (Well, the second time, anyway; I originally used Rust-oleum and it solvated the color coat, running it all over the white fins.) Then I applied the lone decal so it would keep its semi-flat appearance and look like a real stencil. The decal was done in white on my ALPS MD-1000 printer and the graphic at left should be printed @ 300 dpi to size like mine. (Its probably a bit too big.) Without a clear coat the decal will wear badly (there's already a chunk out of one of the zeros), but I don't care.

The B6 and C4 motors eject pretty late and the Ds might shred her, so for my one flight, she'll go on the C6-5. Pity, the composites might have gained me some mission points, being the same propellant as the prototype. I should have built her with a 24 mm motor mount, the C11-5 is perfect for this bird. Ah, well, who knew?

I wound up not entering her in the Sport Scale event after all, as my Rigel would garner me more complexity points. I still flew her at the competition, though just for grins and tee-hees. She did pretty well on the C6, ejecting right at apogee and recovering close enough for me to catch. She's a nice looking bird, so I'll keep her in the rotation for a while.

While I wasn't real sure that the fin attachment would hold up under the power of the D motors in her matrix, I decided to try one anyway. She obviously needs more nose weight for the D13 reload motor, as she cocked pretty severely off the rod. She ejected just after apogee and landed a good half a mile away, but suffered no damage. I'll add the required nose weight before I fly her on the reload again. I've reflown her on the C6-5 motor to a perfect ejection and recovery, she really does quite well on that motor.

Other folks have built the BB6, check out Frank Ross' BT-50-based ~1:5 biurd painted in company colors. And from the Trivia Department, this is a real Black Brant; its a freakin' goose, fer cryin' out loud.

Specifications

Statistic	Prototype	Scale
Length	111 in.	30 in.
Diameter	4.9 in.	1.325 in.
Weight	Unk.	2.9 oz.

Estimated Performance

Engine(s)	AGL (ft.)	Speed (ft./sec.)	Accel (Gs)
B6-4	225	115	11.1
C4-5	655	180	10.4
C6-5	625	205	12.6
D13-7	1,340	425	20.1
D21-7	1,350	500	30.0