First thing this morning, the steel Support Arm for the Chimney was painted with its second layer of the black metal weather proof paint again, outside on the step ladder.

Chimney-Bracket-Painted

Chimney-Bracket-Painted


This afternoon, after we had finished our other job we had on today, we brought the metal arm, now dry, back to the workshop and looked into inserting a large bore plastic tubing (38mm diameter with 2.5mm thick walls) up the middle pole (the one that will appear above the roof surface) and put a curve in it so we can have a gentle bend to make it easier to thread wires and cables from inside the house to the chimney. But we discovered that just simply heating up the plastic pipe with a hot air gun wasn’t enough. It indeed softened the plastic but it was very difficult to make it bend in a gentle curve without buckling or distorting in funny ways. We knew we needed an interior support to hold the plastic in a round shape but we didn’t have anything to hand. We did wonder whether to use fine sand and pack the tube with it and then heat it up and bend the curve but we wondered that the hot plastic will absorb the sand particles and make it rough or more likely that the plastic being stretched to go around the bend (more than 140 degrees around) would make the plastic wall so thin that it may even break apart or be so weak to not be able to take any pushing of threading rods etc.
So we decided that we would manufacture a specialised sweep bend on our 3D printer instead and have sockets and sealant to join all the pieces together to form the necessary path to guide our wires and cables!!

By Shaun

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