5.02.2022 Arched tube antics.

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Saturday 5th 36-41F, early sunshine forecast for only a couple of hours. I'll try imaging first but have not had much success recently. Then it's back onto the dome and fitting the arched tube over the original doorway. No imaging. Solid cloud!

Three hours later I was still struggling with the arched tube. I used an oversized, hole saw to make the holes in the slit ribs first. Then found I had to open them out further, into squares, to be able to slide the tube through. While the lower end dragged along the wet and muddy ground.

Once in place I could not align the holes in the tube with those in the doorway gutter. I removed the tube, reversed it and refitted it repeatedly but nothing helped. The bolt mismatch just moved to the other side.

I had removed the arched tube early on in the build. Just to avoid repeated brain damage. It is possible the dome has changed shape with the fitting of the slit ribs.

Luckily, yesterday's older image of the dome shows the tube fitting perfectly and bolts in all the holes. Now I shall have to remove the new shelf brackets. Which are fixing the slit ribs to the base ring. To see if that helps. The dome seems too tall in the slit/doorway area for the arched tube to fit. Not what I had expected at all. I would have imagined the dome had sagged instead. The center of dome was propped on struts for quite a while. Just to keep it from sagging. I may have overdone it!

It snowed, rained and blew, on and off, all morning. It was supposed to be dry and sunny!  13.00. Paused for lunch. Now the sun is shining!  But not for long. It rained, sleeted, snowed and blew in the afternoon too. It was horizontal at times across the front field.

Two hours later and darkness is close. I finally had the arched tube bolted to the gutter. As suspected, the slit ribs were lifting the front of the dome. Once the four brackets were removed the dome settled around the tube. Though not without a little extra help from clamps and more excavation around the holes in the ribs. It became dark far too early for photography. So I had to use flash in the rain. 

Better images tomorrow. When I shall refit the shelf brackets between the slit ribs and base ring. Then I shall raise the shutter bogie brackets. To allow the shutters to sink closer to the new and lower, slit rib height. 

It is a shame I wasn't able to keep the arched tube throughout the build. It is a useful reference for the front of the dome. By helping to fix the width of the original doorway and its height. This square section tube is immensely stiff at 40x40mm. Had it not been so attractive to my head I would not have removed the tube once fitted. It had to come off for the slit ribs to be fitted. Otherwise I would have needed huge slots in the ribs. Which would have weakened them severely.

Unfortunately the tube is at a most inconvenient height. Making accessing or leaving the dome via the observation slit an accident waiting to happen. Made infinitely worse by the raised base ring. Which forces me to lift my feet high. At precisely the same moment that I have to duck under the low tube. I have already applied a length of sponge pipe insulation. In anticipation of my first, head-on collision in the morning. Ouch! 🤕

 

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