Wednesday 24th: Motor focuser continued.

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See image right with 20T instead of 14T. The slots in the supplied, motor support plate allowed just the right degree of adjustment. Testing is done by rotating the free knob on the other end of the focuser shaft. There is the same degree of slack as before with the smaller 14T pulley.

I did a quick check, under power from the manual buttons on the HitecAstro controller @ 12VDC. As predicted the focuser moved 1cm in 12 seconds. It also proved that the 20T pulley could manage a horizontal focuser movement. This was with the hefty Lacerta 2" solar prism on its 4" extension. Though increasing angles of the telescope, towards the vertical, became too much.

The motor became far more noisy with increased inclination until no movement was observed with the telescope vertical. It is a horribly miserable, wet, dark and windy day today. We are promised a heatwave over the next four days. So I shall pursue the limits of the 20T motor drive in far better light and far more comfortable conditions tomorrow.

The problem proved to be slackness of the toothed belt. Though the motor can easily be heard to change from free running to labouring as the vertical is reached. It seems sensible to return to the 14T pulley to unload the motor at higher inclinations. Reliability of focuser movement is far more important than mere speed.

Despite another sunny day I didn't go near the observatory today. With a high of 84F in the afternoon it would have been far too hot to sit in there for long. It hit an uncomfortable 84F in there yesterday when it was "only" 77F in the shade. The "seeing" was also awful. With strong turbulence visible in the sun's image on the laptop. Nothing suggested things would be any better today. With the sun devoid of interesting features at the moment it was all rather pointless anyway. I captured a prom on the NW limb yesterday but the detail wasn't up to even my poor standard. The image simply looked "overworked."

Click on any image for an enlargement.

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