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Now look what you’ve done Tony.  You’ve got me at it too when I could have been outside enjoying low cloud, torrential rain, and 40MPH winds. 

I also managed to scrounge a couple of 100mm diameter balls after Christmas, so the race is on.  I thought they were glass, so I had to work very carefully around the top of the first one and used my mini blowtorch to remove the trimmings.  When I went to file a groove to snap the top off, I realised they were plastic, so I sawed the tops off instead.  There was some trimming remaining inside the hole, so I left it there to make a base for the filler.

After that I marked out the cradle.  I got the exact diameter of the globe by putting it lightly in a vice and using inside Vernier callipers to measure the gap between the jaws of the vice.  I’ve not put numbers on the divisions, because I’m not sure if I want to use longitude, SHA, or RA yet, or if I need any numbers on the cradle at all.  I did mark a 23.5-degree line in case it’s need later.  I’ve got to wait for the plastic filler to set hard (it’s the end of a pack and getting a bit old), sand the top, and paint the globe matt-white, so I thought I might as well invest in a circle cutter to do a proper job of the cradle.  https://www.ebay.co.uk/itm/233467665297?hash=item365bc1db91:g:HUEAAOSwDSxeIYTx   It should be here by Friday.  That’ll give you chance to catch up.  I’ll test the hole diameter by cutting a circle in a bit of spare card first and checking the globe against it.  DaveP

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