Brief
The VB Extreme is a 38mm motor, minimum-diameter, high-performance rocket kit.

Construction
The instructions are comprehensive and accurate. The tubes are LOC-style, and the kit includes a 38mm to 29mm adaptor kit. There are three body tubes to make up the motor section which is coupled to the parachute section which is coupled/bulkheaded to the payload section and finally the nose cone. You can use one or two launch lugs, your option (ie. you cut it...) They are standard LOC heavy launch lugs for 1/4 inch rods. The fins are pre-cut G-10 fiberglass. A nice touch is the included altimeter mounting kit and wiring harness.

Construction is fairly simple, with basic HPR skills needed. I mounted the fins as per the "optional" method which is to slot half way through the body tube. The VB Extreme 38 is made from LOC 38mm motor mount tubing - fairly heavy. To slot halfway through you carefully slit through a couple of layers of paper at a time and peel them out of the slot. This method is described in the kit instructions. A little more work, but a very solid way to do surface mount fins.

The included sleeved Kevlar® shock cord mount is nice and can survive any stress you might subject it to. It is tied to the coupler between the motor section and the parachute section of the airframe. The other end is tied to the screw eye in the bulkhead on the payload section.

The nose cone is a LOC heavy plastic one, the nose cone and payload section come pre-drilled for the included flat-head, countersunk screw. The plastic nose cone is held on to the payload section by a screw. A very good idea for the speeds and altitudes possible with the VB Extreme series.

Finishing
Finishing was as expected for LOC-style tubing. A bit of work to fill the spirals, and a little bit of sanding to roughen up the G-10, then primer and paint. I flew this unpainted the first time - couldn't wait to fly it.

Construction Rating: 5 out of 5

Flight
Motors Used: F40, H115
Out of sight on the Vulcan H115.
Motor retention is masking tape.

wRASP says 6500 feet on an H300 (summer day at Hartsel, CO), 10,300 feet on a J350. Those who saw my H flights agreed that it topped 6000 feet. On its final flight it caught some wind at that altitude, and drifted into a lake about 3 miles away.

Recovery
Light enough for "E" motors, maybe even "D"'s, and out of sight on "H" motors. Should be modified for drogue/main recovery if you plan on flying it on "H" or above motors (I lost mine on an "H"). Take advantage of the altimeter mounting kit. Use tracking powder. Bring binoculars. Take pictures before you launch it, they may be the only ones you get. Consider using a streamer in place of the parachute, it is sturdy enough, and won't drift so far.

Flight Rating: 4 ½ out of 5

Summary
Pros: versatile, high performance
Cons: none

Overall Rating: 4 ½ out of 5

Note: For more Extreme 38 pictures, visit John's site.

We were talking about adhesive strength and how to test it. Of course, my approach is to do an elaborate test which requires building a whole apparatus. Ed Hackett, in a much more practical mood, said: "just go build a bunch of VB Extreme 38s and put a J350 up the butt!"

I don't think this would really provide usable results, but I did like the idea of a full-on test, so I suggested we have a "strong rocket" contest. Each contestant would build a VB Extreme 38 (or perhaps another kit), then the rockets would be repeatedly launched until only one remained intact. No one else took me up on the contest, but I decided to build my entry anyway.

The kit is well designed, basically a Loc/Precision 38mm motor mount tube as the airframe. This makes a very strong body tube, which is a good idea since this is a rocket meant to go high. Since this is a minimum diameter rocket, the fins need to mount on the outside. In addition to the usual epoxy bonding and fillets, I decided to go wild and reinforce the fins to the body tube with 1" Kevlar® strips. Then I covered the whole thing with a double wrap of 4oz cloth and a covering wrap of 2oz.

I think the fins will stay on! This was the real challenge here; making a minimum diameter rocket so that the fins were really not going to come off. Perhaps this was overkill, but this thing is certainly not coming apart easily. We'll see when I fly it on a J350, and maybe even a J570.

Of course, I had to paint the rocket yellow and black because they're the trademark Vaughn Brothers colors. Also, this is a nice high-contrast paint scheme to help me find the rocket again.

On February 13, 1999 at the February ROC launch in Lucerne Dry Lake, the Extreme flew for the first time. The boost was straight and fast on a J350, a large motor in a small rocket!

The rocket was way gone on a J350 and went 11,703 feet high (according to the ALS20). This is craziness, but that was the whole purpose of the rocket. It took is more than an hour to find the rocket; we drove out on the lake three times, farther out each time. Finally, we spotted it about ¾mi away from the launch site! This rocket really needs to be recovered with a Walston radio unit. The rocket was in perfect shape, although I lost the motor casing (which is probably why it drifted so far). Now on to a J570!