17.11.2020 Testing the ASCOM[AWR] drives [again!]

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Tuesday 17th 53/50F. The 40mm cooling fans have arrived.

While I had the RA drive separated I counted the number of teeth on the timing belt pulleys.[Several times.]  I must have done this several times before in the past. In a desperate bid to discover why the Goto slews are so utterly hopeless. But no, they were to spec. 14:34T. 

The overall drive ratios seems to be okay too. 287/2 turns of the worm to slew from east to west The AWR factory build sheet shows 14/34T x 287T x 200 = 139400.  287 is the  number of teeth on both of the wormwheels. 200 is the number of motor pulses per rotation. 

I just checked the factory specs again on the AWR IH2 handset/paddle. 139400. Okay. It is correct on both axes. So that's not the problem.

I have now used the digital clinometer to set the OTAs horizontal. With the Dec axis pointing north. Which means the telescopes are pointing east and horizontal in their normal parking position. I'll try some slews from East to West using C-Du-C.  First I checked the balance of the OTA and around the PA with the worms withdrawn from their wormwheels. No problem.

I am avoiding using Home because it knows those coordinates. So I am sending the telescopes back and forth between stars, low in the east and west. Any errors should be cumulative.

Well, that was interesting. The telescopes stopped very time they passed the Meridian. With a bleep and message on the IH2 handset. Except that the telescopes were 45°from the meridian! The drive system has completely lost the sky while trundling back and forth in Declination only! ASCOM, AWR and Skycharts have all crashed. With the cursor well below the easterly horizon. Meanwhile the telescopes are pointing up at 45° in the west! 

Reset to Home manually and rebooted. Synced on E and Horizontal Parking Position. Set Pk.

Showing Meridian Crossed at 42° Altitude and 310° azimuth!! What utter nonsense! Skycharts showing the cursor in the western sector, high on a line between SE and NE! AWR IH2 now reports Below Horizon and will not continue the slew to a western star! From 42° altitude!

Observatory coordinates are correct in both C-Du-C/Skycharts and AWR. Time is correct. LST is correct. I'll send the telescopes to Home. [Parking.] The return to Home was fine. Correct coordinates. at 90°E & 1° altitude. Makes no sense that it doesn't know where the Meridian is.

13.00 Lunch time.

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