experimenting with analogue setting circles on an alt az tripod

[rowan46]

much as the title really I have been experimenting with an azimuth circle and digital inclinometer on my mount. I am waiting for the arrival of my nexus 7 to use to give me coordinates so the last couple of nights have been practising set up. The setting circle is small so I will be using a wide eyepiece on it to improve the chances of finding things.

Set up consists of pointing at polaris, loosening the mount so that I can slide the disc zero mark round to the pointer on the mount then tightening everything up whilst ensuring the scope remains pointed at polaris and that the zero stays on the pointer. It is tricky but hopefully it will get easier with practise. At the moment as I have no computer I am testing the contraption by memorising polaris positon on the circle and inclinometer. going off and having a bit of fun then pointing the scope back to the memorised coordinates and then checking to see if polaris is in the eyepiece. It is in the field of view of my 24mm 82 degree eyepiece but nothing less wide so accuracy is an issue. But it looks like it can be a real boon in polluted skies for finding things. As I write my nexus has been delivered so I just need to find a program that can deliver alt az coordinates and hopefully tonight I will be good to go The lights haven't arrived yet so I guess I will just use the head torch. Any suggestions on making the azimuth circle easier will be appreciated.

[Macavity]

A great idea - And actually works in practice! Do a "one star alignment", then push to objects with significant accuracy!

I used the idea with a Giro III mount. Had a handheld PalmOS to do the maths. But made a (rotatable!) Azimuth circle (anulus) from MDF (wood). Hole saws for downlighting etc., come in all sorts of random sizes... can be "expanded" with anything cylindrical via sandpaper / patience etc. Created / Printed the azimuth degree Scale on thin card via basic graphics program. Took a while to get it to print at just the right size! Beware MDF dust - "Health & Safety", and all...

[rowan46]

I have just thought of another way to make the anulus rotatable. if I stacked 2 panning bases on top of each other and sandwiched the anulus between do you think that would work?

[rowan46]

thinking about it I would only need one panning base

[rowan46]

definitely needs some work on the anulus but it's getting there, It's putting me in the right area. My alignment appears to be a couple of degrees out but the concept has been working as the error appears to be constant. I have been using sky safari for the coordinates and have made the anulus a little larger which hopefully will improve resolution just need the panning head as i am pretty sure that's where the majority of the error is coming from. Will show the complete thing when its finished if anyone is interested. Actually will show it even if nobody is interested

[rowan46]

As threatened the pics. The panning head makes all the difference for dialling in the anulus. Excuse the state of the room took the wallpaper off and lots of plaster came down so in the middle of an extensive redecorate