Framework V2

This V2 project was primarily inspired by the work John Pursley has done to build very lightweight large airframes using unconventional methods. Another influence was the desire to accurately model the hammered sheet metal appearance of the V2. It struck me that I might be able to build both a lightweight and realistic looking V2 by building a lightweight covered frame instead of the usual heavy tube.

What came out of this experiment is an 8 inch V2 that stands about 67 inches tall and weighs 650 grams empty.

Design

I created a full size scale drawing by scaling up the V2 image from Peter Alway's book Rockets of the World. I scanned it, scaled it using Photoshop, then printed out a full-size sheet where I laid out the rib design. Read more about the design and download a RockSim model in the design section.

Some of the assumptions made in the initial design were changed during construction, as noted below.

Laying out a rib	Gluing ribs to core	Basic structure complete

Construction

The basic contruction philosophy is a 29mm tube from base to tip which will carry the thrust load and distribute it to a framework which will transmit the force to the skin. The framework is designed to balance the loads of thrust and aerodynamic drag. The frame is a series of balsa trusses running lengthwise down the core tube. The trusses are joined by small strips of 1/64th plywood to provide torsional strength and to support the skin.

The ribs were built directly on the plan against a straight-edge, then glued to the body tube. The 1/64th plywood reinforcement was built onto the rocket itself. In the fin area, some of the balsa structure is laminated with basswood strips for extra strength. Read more in the frame construction section.

Covering

Several experiments were done with various covering treatments. I wanted to hide the ribs, create the "hammered" look, and still keep it fairly light. I settled on painted newsprint glued on with silicone. I added some foam to the nose cone to help support the paper cover against the aerodynamic pressure. Read more in the covering section.

Flights

photo by Tom Montemayor

Maiden flight was at Skyedance 32 at the end of the day. The winds had dropped off to almost dead calm - a requirement for launch. The boost was fairly straight, though it did turn a bit into what tiny wind there was. Instead of carrying over in a typical arc, as the thrust tapers off, the rocket is blown back away from the wind. (in the movie below, the wind is from the right and behind the camera) Since there are no reference points in the sky, the rocket appears to go straight up and pitch back slightly, but it is actually blown a considerable distance downrange before the chute opens. There was a tiny tear in the fuselage about an inch long in one of the panels, and a tear on the edge of the nose cone (probably from ejection). In the original video, you can see the motor being spit out - have to work on that for next time.

Links

The following links contain scale reference data, particularly data on the appearance of the skin, plus construction info.

• The mother of all V2 web sites V2rocket.com
• V2 photos, including many views of the skin from Phil Broad's Model Builder's Reference Vault