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Doc's Erector Long Range Radar Scanner

Hi folks, Doc here. The next model in my "Radar Series" is one of the more interesting versions of the radar scanner which appears in any Erector manual. Like the Satellite Tracker and other models, it features compound movement, i.e., the dish pivots up and down as it rotates. In addition, the model features a semi-rectangular rather than square or oval dish. Further, the up and down movement of the dish is more extreme than in other models, covering almost a full 90 degrees from nearly horizontal to nearly vertical. This can be readily seen in the accompanying video below.

In order to best allow this range of "tilt" the dish is suspended in a large and heavily-built v-shaped yoke. As the photos below illustrate, the arms of the yoke are constructed of both square and rectangular girders, with supporting members made from 21-hole strips. The base of the yoke consists of two 5" base plates; the lower one has a "sandwich of a BN plate, a 72-tooth gear, and a second BN plate bolted to the bottom. A third BN plate is bolted to the top of the short tower on which the yoke rotates. Because of the weight of the yoke-dish assembly, smooth and easy rotation is a must. To make this possible, the model utilizes a specialized set of parts introduced to the Erector line in 1960 to facilitate movement in such situations, namely the TC bearing plate and 6 TB ball bearings. With these parts sandwiched between the lower two BN plates, the dish-yoke spins as easily as if it weighed ounces rather than pounds.

The satellite dish is made from two concentric rings of E curved girders bolted to C girder "spokes"; at the center of the dish the spokes bolt to hub made from a BN turret plate. The dish is bolted to a carriage which sits atop the tower and pivots freely on an axle driven by the motor via a pair of P48 mitre gears (see photos). This axle in turn drives a series of gears, wheels and 7 & 21-hole strips which cause the dish to oscillate up and down as the carriage rotates. That rotation is produced by an OE flexible coupling which turns a P13B pinion gear on the tower's top platform. The pinion gear drives an OH 72-tooth gear bolted to the bottom of the dish carriage.

     

>My model is a nearly exact replica of the model illustrated in the manual. Besides adding an MX house to the base to be the "tracking control building," I made a couple of small mechanical changes to the dish drivetrain. With the pinion gear on the top of the tower in the location specified in the manual, the flexible coupling was forced to bend so severely that its motion was compromised. As a result, I moved the pinion gear from the center of the upper platform out to its edge, and added an MO angle girder and P79 car truck to the upper tower to help support the upper end of the flexible coupling. This allowed the coupling to move much more freely, which let the motor work easier as well.

     

As a final addition to the original model, I bolted an NH lamp socket to the center of the dish hub and bolted an NJ battery holder to the rear of the dish carriage. Another NH and NJ pair were added to the control building. Now, while the dish rotates and pivots up and down at night, a light marks its position in the sky while another illuminates the control building on the ground below!