… and now the heavy metal

An order for an assortment of steel sections and galvanized metal sheeting was made and the day after ..the crane arrived.

Picture6

Picture7
Some of the steel sections being unloaded

..and the Iron Curtain falls

..from that day on and for about a year my workshop became rather crammed and at times I had hardly room enough to squeeze my way to the door..

Picture8
Cutting corners for the frame

Next I welded a square frame of  5 cm wide angle  that would serve as the metal  support for the wooden circular base on which the castors would be arraigned.

This would also define the perimeter of the roof of the observatory and serve as a convenient frame to work on during the construction.

For this purpose a set of four short ‘legs’ cut from the same angle iron were bolted to the four corners converting the frame into a low table. To improve support of the circular beam four sections of angle iron were welded at the corners converting each corner into an isosceles triangle and the metal frame support for the doughnut into an octagon.

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Base beam resting on the metal frame. Corner supports being fashioned
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Base beam tied to the steel frame by 8 bolts

With the circular roof beam bolted and the whole checked for horizontal by spirit level, the mating ring of double plywood that would form the base of the dome was placed over it and the two clamped together to make sure they matched perfectly. The router jig was placed over the top one and a circumferential channel about ½ inch deep routed along half way the width of the beam. This formed a gutter for the flat bar that would form a metal rail to glide over the castors.

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Rail channel routed into the base beam. Bending jig shaping the rail.

 

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