This is how I put my setting circle on the base, I had it printed at a printers in Brecon on vinyl and then lacquered this cost me £15. I did not want to cut the base about. the pointer is held in place by 2 tracks of magnetic tape around the underside of the base plate. the pointer was made out of a flattened tent peg and suitably bent, this then can be placed anywhere and then held by the magnetic tape (19mm) £5.50 of ebayI then purchased a digital angle finder from wixey this has a magnetic base so sits on the tube. I have included the pdf file for the setting circle it is both clockwise and anti clockwise and it fits the 200 nicely as can be seen in the images setting circle for 200mm dobson.pdf Alignment is simple as Valleyman wrote: There is no need to put the Base facing North. You can use Stellerium to get the RA. First center a bright known star in the EP. Check its RA in Stelllerium. IE : Vega RA 110 degrees Then put your pointer at 110 degrees mark Job done.