1st May 2020 Removals.

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Friday 1st May: Not much to report because it has been raining on an off all morning. Even though it brightened up in the afternoon there far too much cloud to allow solar imaging.

I tested both ZWO cameras on the PC indoors with the original, USB3, ZWO cable to see if the grainy artifacts were still present. It seemed not on the tests I made on indoor scenes. I can't explain the problem.

As I have been making such progress, I have decided to concentrate on solar imaging. So have removed the 7" f/12 from the mounting, yet again, to optimise the drives. The big refractor has so much mass and moment that it sometimes stalls the drives. Probably through imbalance issues. Causing backlash and slow reactions to drive corrections. The 6" f/10 h-alpha, solar, modified PST telescope, on its own, is crisp and responsive to the control paddles. With no asymmetric imbalance problems there is no bias to the drives. Something as simple as adding the big Lacerta solar prism to the 7" would demand complex balance adjustment.

It is quite a struggle to remove the big refractor. So I used the overhead pulley system again. It copes effortlessly with the considerable weight. Though the long tube and objective cell is always fiddly to clear the opened mounting rings. They are so far out of reach that I have poke the top ring with a 4' batten to get the telescope tube to slide slowly and safely downwards.  Both refractors had to come off the saddle to allow me to remove the "side by side" plywood crosspieces. 

Once the 6" was back on the mounting I had to add the four brass weights to the saddle. This was to achieve balance with only one 5kg counterweight on the other end of the Declination shaft. The counterweight was already as far in towards the worm housing as possible. So adding weight at the telescope side was essential. I really ought to refit the IKEA, stainless steel, towel rail, sliding weight bars back onto the saddle. There is no room for them with the 7" fitted alongside the 6".

With the 7" on the mounting it needs four, 5kg weights to balance. I backed off both worm housings to allow complete freedom for careful balancing of the 6". More adjustments followed and now I should be able to start solar imaging again without any problem. 

There was a cloudburst during this process. So I had to quickly close the shutters to the leaden sky. It was lucky I had trimmed back the tops of the inner shutter ribs to stop drag on the zenith cross board. With the rain hammering on the plywood dome I noted a few drips from the shutter area.

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