Dome building: And then there were three.[tiers]

*

Tuesday, and another hot, 75F day with constant sunshine. As usual I set up the table saw saw under the blue awning for some much needed shade. Cutting out the dome covering panels has become routine. I even managed to get 9 panels out of a single sheet on the third tier. They were all about 50x50cm.

I aimed for close joints and was aided in this by the table saw sled. My hope for crisp angles and flat facets was rather spoilt by the softness of the 4mm birch ply.

The third tier went quickly after my practice on the second. Not one single panel was wasted though there was some earlier wastage from the odd size of the panels on the lowest tier. Wastage, which I hope to use up on the top tier.

Nothing is straightforward though. The top tier should consist of straight lines and flat panels too. I haven't yet decided how best to remove the present curves. A chainsaw massacre? 😉 Not quite. Those rib extensions which could be removed were sawn straight on the bandsaw. The rest were attacked with the jigsaw, where it would fit between the tightly packed ribs. I also used a coarse disk on the angle grinder to cut back the remaining projections.

While I was out there I removed one complete gore to weigh it. About 8.75kg = 19lbs. Let's call it 20lbs per gore when completed and painted x14 = 280 lbs or 127kg. Plus the heavy base ring and slit framework. Then there's the shutters and their rails on top of that. A skirt will also be required to seal the area between the dome base ring and the supporting wheel area.

Click on any image for an enlargement.

*