DIY Setting Circles

[Astralstroll]

I have been pondering addng a setting circle to my Dob to go with the inclinometer recently added. I have checked out the Ron Willetts rather excellent site for creating setting circles. I think I will go with one of these to see if they are indeed accurate enough. If they are, however, Im not sure that I can cope with the watermark all ver the setting circles from Rons site.

Before I go and get a subscription to the site, and hence be able to remove the watermark from the setting circles, does anybody know of any other sites that you can use to create circles of any dimension??

Dave.

[leelee970]

I've used the setting circles from the site and they are REALLY very accurate. For some reason when I used the site there wasn't a watermark?

I was lucky to be able to use a large plotter from work to print out the circle so that it just fitted to the edge of the 10" LB upper base.

I then attached a moveable pointer to the lower part of the base – then all I need to do is point the scope to Polaris and then adjust the point to 360°/0° mark and I’m all set (close enough for me to find every object using medium EP's).

[sunshine185]

Startrak.Co.uk there's a free program that allows you to print out a large 180 degree protractor, I did it twice and made a full 360 degree one, I fastened it together, cut it down so there was a cm of my dob base visible around the outside then marked the base with a thin permanent marker. Easy to do and I'm really impressed with the accuracy, I can now easily find dim targets.

[sunshine185]

Some pics here

[Carbon]

Copiers can distort an enlarged image to some degree. You can pretty much determine the accuracy of the printed degree circle against the center point by using a long straight edge (180 degree marks intersect the center point), a carpenter's square, and perhaps a large protractor.