AstroFix Object Locator

[GazOC]

http://www.manortronics-force-gauges.com/Astro

I bought one of these a couple of weeks ago and just finished my 3rd night out with it on my 14" Dob. For those who like to skip to the "conclusion" I can say now that it does what it claims to. It sticks to any alt/az mount using velcro (no fixing, drilling etc) and after a 30 second callibration is ready to go. The display either shows either at or az values of your scope, its claimed to be accurate to 0.5 a degree in alt and 1 deg in azimuth which is more than enough to land most objects on the FOV of a 30mm 70 deg eyepiece in all <16" f5 Dobs and my testing found this to be about right.

For less than £100 its less accurate than conventional DSCs but accurate enough, easier to install and a damn sight cheaper!! You'll need a laptop or PDA to give you the real time alt/az figures but even figuring that into it, its still a great piece of kit for Dob owners.

[ngc2403]

how does that work?

is it using the earths gravity or just the rotational force of the telescope moving about?

very cool piece of kit!

[GazOC]

I'm not sure but I think the azimuth works off magnetic north (hence the sensitivity to iron) and the altitude has some sort of level switch like a Wii controller??

[haitch]

Nice idea - I'll have to consider one for my Dob. Would be nice for Az accuracy better than the 1 to 2 degrees though.

I guess you could also rough polar align a GEM without getting on your knees by attaching it to your polar axis.

[Aaron]

Inetersting find Gaz, I'm looking at either a 12" Lightbridge or the new Orion XX12, what software are you running it with ?.

[ZOG]

Very nice find. I'm thinking of upgrading to a 12" Flexitube dob and this would turn it into a really economical push to system.

[TheThing]

Interesting. Thanks for the review.

Does anyone know who it compares to, say, a Wixey?

Can you use it with equatorial mounts too, or just alt/az?

[ZOG]

Just looked at their website and they do have an EQ verion now.

[lawrie]

Instead of spending cash on gadgets try adding Alt Az scales. I have done this with my Skywatcher 150P.

Adding scales is to a Dob is a simple job. The website www.startrak.co.uk provides suitable scales and examples. The ground board AZ scale is marked out by hand but the paper altitude scale is stuck directly on to a side bearing of the telescope.

The black PVC strip around ground board edge was removed and the raw edge cleaned and sanded smooth, the edge filled with Polyfilla and when dry, sanded smooth and two coats of white matt-finish oil paint applied to give a good surface on which to mark the degrees. The scale is marked out using a paper quandrant made from a print-out from the startrak website. A permanent black laundry marker pen makes the points and numerals indelible. Be careful to mark the scale clockwise as viewed from above.

The same website will also print altitude scales. A datum point is marked on the mount close to one of the telescope bearings. A spirit level sets the scope horizontal and the place marked on the telescope bearing. Set the scope vertical and mark the bearing again. Use the distance between the two marks to print out the altitude scale of the correct length. You get a choice of four scales to suit.

The Alt/Az of any star at a given time can be obtained from one of the PC planetarium programs. Bear in mind that the Alt/az of any celestial object with changes with time, unlike the usual RA/Dec coordinates. Set the Dob up by setting the Zero to North, check with Polaris and adjust the ground board position as necessary.

For very little time and effort you get a, simple, reliable, no-cost system that needs no batteries, wires or calibration. Once done you will wonder how you ever managed without. It really is the "Poor Man's GOTO".

Lawrie

[lawrie]

P.S Perhaps my post (above) would be better in the DIY thread,

Lawrie