Inclinometer and setting circles - DIY feasible?

[ED209]

Now I've got my scope up and running I'm looking to cheat in every possible way to help me find stuff. It's no doubt a sad reflection of my inexperience but trying to locate messier objects by star-hopping/scanning the approx area gets me fewer results than just holding a protractor against the scope to get a rough guide to the angle! So time to make my dob the ultimate DIY 'push to' I think...

I read good things about the Wixey digital inclinometer, but want a cheaper option ()...are the mechanical inclinometers that sell for ~£4 any good? Or should I bite the bullet and go for the 0.1 degree accuracy of the wixey. And another question, does the wixey measure inclination absolutely or relative to the starting point (i.e. do you 'tare' it with the telescope vertical or horizontal and then it reads relative do that point?). I don't think I'd be particularly good at setting it accurately to begin with!

Secondly, I fancy marking the base of my dob with angle measurements to give me a rough idea of azimuth. Before I just get a CD label pen and measure out blocks of 5 or 10 degrees by hand, is there a way that I could generate accurately marked circular sections tailored for the size of the dob's base on my PC and print them out, laminate them in plastic and sticking them on? I've tried to print out woodworking plans to precisely the correct scale before for a different kind of project - scaling DPI on my printer etc - and found that to be a bit of a mission TBH. Wondering if I'd be better off to just have a go by hand, would that be accurate enough? Better than nothing, I suppose?

[Doc]

Check out my mods:

http://stargazerslounge.com/diy-astronomer/79817-my-dob-degree-circle-modification.html

http://stargazerslounge.com/diy-astronomer/75298-lightbridge-azimuth-encoder-modification.html

http://stargazerslounge.com/diy-astronomer/68393-wheelbarrow-mod-my-dob.html

[JamesM]

Hi there,

The Wixey unit is pretty good and like most products of this kind, the 'quality' can at times represent the producer's budget for advertising and getting their stuff out there. My personal view of Meade is similar, in that when you see them everywhere - you think hey, they "must be good" kind of principle. That is not to say they aren't but my approach is that you've got to turn over every stone out there to see what else is you can find.

Do not buy the £4 version. They're cheap for sure but not reliably accurate in my view. In my workshop, I need to ensure all my machinery is at the angle I want it, so I've chosen an alternative called the "Beall Tilt Box" made in USA. (Toolpost- 01235 511101 can get them) It is as accurate as you want it (0.05 degrees) You can measure any angle relative to true zero degrees or or any angle relative to a zeroed reference surface - which should tick all your needs, and you won't need to look through a phone book to work out how you do it. It also has two proper earth magnets on each side. I can't give you a price as mine was purchased years ago and I suspect (along with everything else) the unfavorable exchange rate might put you off for now but give the above a ring and see.

I would like to add, I do not work for any of the companies mentioned and my views are personal based upon both my and others experience.

I can't comment on the second part of your question as I'm not qualified but hopefully someone will be along to advise.

Best wishes and good luck

James

[Macavity]

See above?

I would just add an encouraging ramble. Even with a small alt-azimuth mount, and a bit of thought, it's quite easy to set the azimuth to a couple of degrees or so - Even with a scale the size of a onetime(?) school protractor. It is obviously far easier with a Dob-base sized setting circle! As you surmise, with a Wixey gauge (I would recommend one for many an astro use!) you can read to (say) p\m 0.2 deg in altitude. But the ability to fix one coordinate to greater accuracy is IMO useful. If you "zero" the setup on a single star, you should be able to "PushTo" a field WELL WITHIN the typical 4~7 deg finder width. Of course you will need a computer of some sort to "do the maths" for each object. But, if you use a computer-based star map that shows Alt-Azimuth coordinates of objects, no problem. But overall considerably better than nothing and, unlike the (albeit fine!) electro-mechanical GoTo, totally SILENT!

[Doc]

There's a little story I can tell you here that will be backed up by quite a few in attendance at the Salisbury star party.

In one corner was me with my low tech wixey and azimuth printed degree circle and a lap top. In the opposite corner was Paul (Sponcom) and his go-to ready scope.

The goal was to find an object the quickest, who would win.

I'm not sure of the exactly how many objects we saw but the winner was ME the low tech ALT/AZ set up.

If I remember right Paul was still fumbling around with his controls and i was observing the object, it was really that simple.

It made alot of people laugh their head off, it was quite a laugh

[Rusty Strings]

I've just finished fitting setting circles and a wixey to my dob after witnessing Doc's low tech "goto". Only been out with it once but I found M53 almost immediately which for some reason I couldn't find with star hopping.

[Doc]

Steph christened my version as "Doc's Doofer"

I quite like it

[ED209]

Wow, that's a very nice circle degree mod.

I've just taken a sewing tape measure to mine and marked off 10 degree increments around the top of the base...then scribbled a little 'north' arrow on one of the three feet that protudes from the bottom part of my base (which isn't exactly round, but a bulging sort of triangle which gives me a wider base for the rubber feet).

Just now I pointed the arrow roughly to Polaris, pointed the telescope to the moon then read the moon's alt/az off stellarium to check the orientation, adjusted the base by just a couple of degrees, looked up Saturn's position on stellarium and put the scope right on it (still using my protractor for the alt) without using the finderscope! Happy with that....now waiting for it to get dark...

[Doc]

One thing to remember the more level your base the more accurate the go-to.

[WayBig]

is a wixey with 0.1 degree accuracy and an azimuth circle sufficiently accurate to get an object in field of view of (foe example) a standard 25mm plossl ?

[Doc]

When I'm perfectly set up all objects fall within the FOV of my 28mm Uwan using a Wixey and a homemade AZ Circle.

[WayBig]

...superb, i'll have to review my upgrade plan then, perhaps a tracking dob with wixey will work out more cost effective than an orion goto dobs or goto sct, plus with the added advantage of adding a synscan goto handset if I dont get on with the wixey...

no rush though, I dont think my scope will get as much use in the summer, so it's one to think about getting in place for the autumn

thanks