1/10 Vanguard, NARAM 41, PA (1999)
The NARAM-41 Vanguard project actually began as the testbed for my planned R&D project on guidance… and it sort of mushroomed on me, much like the NARAM 40 Mercury Redstone had.
Though it didn't fly at NARAM-41 due to wind conditions and small field (the required minimum engine combination would have lofted the upper stage to over 1000 feet and likely would have led to a loss of that stage to the surrounding woods…along with about $400 worth of electronics) the model did prove the concept of a very large sport scale entry of its type and the viability of such an entry at the national level.
The NARAM-41 competition model has now been "reduced" to the third of my Vanguard boilerplate models and is currently being extensively modified to ease prepping, improve reliability, and reduce weight.
The first boilerplate model, shown here, was originally conceived to get an idea of the strength, rigidity, and weight of the ultra light .4mm plywood construction technique that it utilized. It was also originally intended as a single stage model to test aerodynamic characteristics (without guidance). As the project advanced, this boilerplate eventually acquired the guidance package of the NARAM-40 Redstone, a second stage utilizing the engine gimbal from the NARAM-40 Redstone, a new gimbal for the first stage motor, a pneumatic recovery system for the first stage, and a new mechanical recovery system deployment mechanism for the upper stage. In the configuration you see here, it weighed about 2.9 pounds.
The first test flight turned out to be an accidental launching of the upper stage (just a couple of minutes after this photo was taken) due to a glitch in the R/C-triggered upper stage ignition.
Dan Steuttgen is holding the upper stage before installing it on the booster. The upper stage actually weighed more than the first stage as it contained all the electronics and the majority of the batteries (there were four sets in this version of the model).
Upper stage ignition was via R/C and would not be armed until it was plugged into the first stage. After an unintentional flight of the upper stage shortly after this photo, upper stage ignition was changed and would be accomplished via inertia switch with the circuit armed via R/C after the model becomes airborne.
Though the stage was tremendously underpowered, the guidance showed its functionality as the upper stage popped from the booster stage and struggled to stay pointed skyward during thrust before falling to the ground.
This is the "business" end of Vanguard BP1 (first boilerplate). What you see here are the 29mm gimbaling (two-axis) main motor, two 13mm mini motor mounts (to act as simulated turbo-pump exhausts), the pneumatic fill valve, and the scale gimbal support struts.
Even after close examination, most people can't figure out how the "stick shift" multi-axis gimbal mechanism works. The entire mechanics (servos, linkages, etc) is sandwiched into the small gap you see between the end of the body and the circular thrust ring.
Also on the thrust ring are two coaxial pullout plugs (one just visible above-right of pneumatic filler), external charging plug for first stage batteries, and the electrical supply posts for the 13mm motor igniters.
Based on Martin Company drawings, the gimbal is very nearly scale in size and configuration.
For the first Vanguard boilerplate model, the gimbal assembly from the NARAM-40 Redstone was used without modification (except for the addition of the ignition power supply posts visible to the left of the motor).
The hodge-podge appearance of the ring surrounding the motor is a result of additional reinforcing added at the last minute to the Redstone at NARAM-40 to eliminate the risk of ring flex with a higher thrust motor.
The entire gimbal can be unbolted and removed from the model as a unit and the cylindrical extended shell of the gimbal cartridge slides into the staging coupler of the first stage.
The two coaxial plugs above and below the gimbal in this picture provide for first stage gimbal signal and power. Passing a noise-free signal from the fore end of the second stage to the aft end of the first stage while providing for secure fit and perfect alignment without undue friction was a major issue during the first three boilerplate phases.
The autopilot (it really isn't a "guidance" system...it just makes sure the model flies straight up) and electronics package (left) and the upper stage gimbal removed from model.
The electronics are all secured to the "platform" with foam mounting tape. Between the two rings at the bottom of the platform are the four horizon sensors and recovery servo. The entire platform design was dramatically changed for the competition model.
The gimbal shown here is the 2nd generation unit and can house up to a 32mm motor. A total of 11 conductors interface here. The gimbal also has to be pressure-tight since it must contain the pressure of staging which forces the stages apart.
Click on images below to enlarge.
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Scale Projects-1/10 Vanguard