10.07.2021 GRP Dome + more GRP.

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 Saturday 10th 58F, heavy overcast after earlier rain.

The new dome project is dragging on. I am confronted with a sealing problem between the slit cut-out and the plywood, slit reinforcing ribs. Any plan to use silicone sealer has been shelved. It would not provide a long lived seal and would be prone to flexure cracking. The ribs would probably part company at some point. Leaving me with a serious access problem for repairs. Hiring a cherry picker platform would be costly and time consuming. 

So it looks like polyester resin and fibreglass matting are in my stars. To seal and fix the location of the ribs in the slit cut-out. I have lots of experience with GRP, going back decades, but would have preferred not to get involved again. The resin is not going to adhere to the dome's shiny top surface without abrasion. The added matt will not be "tidy." So there may well be a cosmetic issue. Luckily it will be completely unnoticeable so far off the ground. I'll use colouring to match the dome. Fortunately grass green is one of the easily available range of colours.

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Having tested the DC focuser motor I tried some slews of the mounting. I have been getting loud noises and stalls during slews. The counterweights are very slight heavy but it takes almost nothing to balance them out. The axes move completely freely when I withdraw the worms. As they should with these huge, self aligning, journal ball bearings.

I then tested the worms and motors while not engaged. Having added more screws and washers as end loading I feared that might have been the problem. Yet all was well when unloaded. 

I shall continue playing with this after lunch. The overcast is lifting to patches of blue and even watery sunshine. New ARs are reported in the north east and south east on the sun.

 

14.39 First useful image. 90% cloud in sun's track.

14.56 Signs of flaring and a spot forming.

15.00 Trying for the NE AR but too much cloud to see the sun. Let alone centre the area.

Found it right on the limb with large proms nearby. 

No captures due to solid cloud.

15.13 Captured NE AR with spot.

15.20 Changed to PST BF to capture the large prom on SW limb.

 

 

 

16.31 Slightly sharper image of SE spot area. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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