AWR Intelligent Drive System Pt.10: More [useful] scrap metal!

Yesterday's visit to the scrap merchant produced some nice 80mm round alloy tubing and some shorter lengths of 70mm square. Plus a large sheet of thinner, flat aluminium for baffles. I had been forced to buy expensive roof flashing for refractor baffles before now. I want to add another full baffle to the folded refractor. Probably using the focused sun to guide the hole marking. A folded refractor needs some very odd baffle cut-outs. Almost figure of 8 holes are sometimes required as the light bounces back and forth between the optical flats. 

The 80mm round tube is lighter at 2mm wall than the square stuff. It should be ideal for extending the refractor focuser to a small first [or rather last] baffle. This will help exclude stray light on the folded 7" refractor. Apart from a single, thin, flat baffle I did not spend much effort in baffling. I did manage to find a cardboard poster tube and cap to act as a focuser baffle but wanted something more permanent for the longer term.

If I ever find an affordable Herschel prism, for solar viewing, the plastic and cardboard baffle would have been at the intense end of the focused heat. I found no difficulty setting fire to plywood with the bare 7" objective. Even at f/12 there is plenty of heat in the focused sun. Fortunately a full aperture, Baader foil filter rejects all of this heat before it reaches the 'innards' of the telescope. So there is no real risk of a fire. Now I have to discover a way to fit the 80mm tube to the inner face of the Vixen 2" R&P focuser. The cardboard tube was just a perfect push fit. Though I worried about it dropping out and landing on the first, folding, optical flat when the OTA was vertical. The alloy tube will have to be more securely fixed!

I downloaded the AWR ASCOM driver, last night, which was recommended by AWR. I had quite a tussle at first to get the download  past the W10 watchdog. It seemed I needed to download the latest ASCOM platform, before the AWR driver would install properly. Things went better after that and I played a little with the "virtual" telescope simulation. Then I watched some YT videos of the ASCOM and Stellarium telescope control. No videos on AWR have been uploaded yet. I may be the first to do so once I have something to show. Not just a boring old computer screen but a moving mounting.

As I have said before, I am hoping to use Stellarium for direct Gotos with mouse clicks on the "live" computer screen. Which should then dutifully follow the field of view of the telescope to the target. I shall have to wait for a fully functioning mounting first. One which has been properly polar aligned. Before I can make the most of this software and AWR's Intelligent Goto drive system. The ASCOM driver is supposed to be more user friendly for PC control and offers a much greater range of possibilities. Auto tracking and powered focuser options exist. Plus the ability to follow different object which change in RA and Dec. Asteroids, comets and satellites have such traits. Presuming, of course, that the drive system can move the telescope quickly enough. 

Still no mention of dispatch of the 6mm aluminium angle so I can't mount the stepper motors yet. The 70mm square tube could have been adapted to the job but is slightly too thin wall [at 4mm] for this purpose. I have no desire to risk flexure at this late stage of drive and driver expense and effort. Had I found the newly arrived, square alloy tubes earlier I might have been sorely tempted to use them instead.

I keep looking at the possibility of covering the worms and wormwheels with the base sections of large, round, baking pans. This would help to exclude the grime which is attracted when such objects are exposed. Particularly if they are lubricated. The pans offer a neat solution for these covers if I can cut off the bases neatly and without any distortion. The material thickness is not substantial and immediately loses its remarkable rigidity when the vital rolled rim is removed. When the rim is left in place, even with the base mostly cut away, the pan still retains most of its strength. I used this method to mount the 1/20th wave, Zerodur optical flats in the folded refractor.

Unfortunately these covers would be far too large to spin in my 9" lathe. You can't just take a hacksaw to such a job either. It needs something much finer toothed or even a powered tool. A jeweller's saw cannot cut at right angles and coping saws do not have fine enough blades. Perhaps a slitting saw in a drill in a fixed jig would do it? Rotate the pan slowly against the tool. Rather than moving the tool around the pan.

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