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Doc's Gilbert Erector Satellite Tracker

Hi folks, Doc here. In the last decade of Erector set production, one of the model "types" that began to appear frequently in the How to Make 'Em manuals was the radar or satellite dish. They ranged in size and complexity from small and simple to large and elaborate. Invariably the motor was used to rotate the dish, and in some cases, this Satellite Tracker from the Musical Ferris Wheel set being one, the dish also pivoted up and down as it rotated. This model is the first in a series of these radar dish models that I will be presenting here in the Model Gallery over the next few months.

Actually, this same model has already appeared here, submitted by a friend of Girders & Gears some time ago. I present it again to better illustrate some of the details which make it special. In addition, video of the model in action will be here soon, so be sure to check back again.

Now, on to the Satellite Tracker. It features a square four-legged tower made from BE and DP angle girders topped by an MY base plate; the tower sits on a platform made from 3 MN base plates. The tower tapers towards the the top, and has an MD base plate bolted between the legs about 2/3 of the way to the top which functions as a motor platform.

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!