26.09.2020 Mounting drives testing.

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Saturday 26th, forecast cloudy all day. I had to rebuild the RA motor/worm assembly after discovering a loose grub screw on the smaller, timing belt sprocket. The RA slew had suddenly begun to move jerkily. I had made hex key access to the grub screws via a drilled hole through the edge of the motor plate. Which I had completely forgotten about since building the mounting nearly four years ago. 

Fitting new and longer grub screws required the sprocket be removed anyway. Since there are no celestial targets to practice on [thick cloud] I am sending the telescope[s] east, west, north and south via C-Du-C. A trip to the zenith is another option. Provided the telescopes don't collide with the massive, pyramidal, timber pier. They didn't, but only by 1cm. 

My finger was hovering over the "panic button" on the AWR IH2 paddle. Pressing any of the directional movement buttons will instantly stop a slew. Rapid slews in confined spaces with long refractors are not a happy mix. However frustrating long, slow slews might tempt one to wish for an overdrive setting. 

The tip of the dewshield on the 7" f/12 actually travels at quite a rate. Particularly when the light bulbs used to dangle in its path on overhead slews. These occurred daily when a flip was required after lunch when solar imaging. A 3 meter/ 10' dome is slightly too small for the 7" f/12. A 6" f/15 even worse at 6" longer focal length. [90":84"]  So choose your weapons carefully!

I checked the number of teeth on the RA wormwheel [287t] in case there was a ratio error spoiling my Goto slews. Then I set up a dial gauge to check the wheel perimeter's radius. Not that this tells me anything about the accuracy of the teeth themselves. 

After several slews to cardinal points on the horizon the telescope did not return to the parking spot. It fell well short of the target in RA/Azimuth.

After lunch I repeatedly sent the telescopes between pretend stars on the east and west horizons and back again. Only slight errors accumulated on returns. A brief glimpse of the sun's pale disk through thick cloud had me trying a Goto slew but it missed. More cloud stopped any chance of centering for a Sync. Then it cleared just enough for a sync in the 90mm. So much cloud it looks more like the moon. Tracking.

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