tuckstar Posted October 8, 2014 Share Posted October 8, 2014 (edited) Wixey gauge with protractor. could this be used instead of a setting circle? http://m.ebay.co.uk/itm?itemId=261447485495 Can't work out if it's measuring the right axis or not. Edited October 8, 2014 by tuckstar Link to comment Share on other sites More sharing options...
+RonC Posted October 8, 2014 Share Posted October 8, 2014 Looks interesting?! Link to comment Share on other sites More sharing options...
tuckstar Posted October 8, 2014 Author Share Posted October 8, 2014 Scrap that idea! Just found user manual and YouTube vid. It only measures angle of tilt up down, backwards and forwards, not degrees in a circumference. Oh well looked interesting for a while. Link to comment Share on other sites More sharing options...
Daz Type-R Posted October 8, 2014 Share Posted October 8, 2014 I might be wrong,but how would it measure Azimuth degrees? The screen does not look big enough for 3 characters. I see it has a level buble display on the right, then 2 (X / Y) axis on the left, but I have no idea how it works out in what direction it is pointing? Link to comment Share on other sites More sharing options...
Daz Type-R Posted October 8, 2014 Share Posted October 8, 2014 Ahh, took me that long to write the above on the IPhone you had already answered your own question. Link to comment Share on other sites More sharing options...
tuckstar Posted October 8, 2014 Author Share Posted October 8, 2014 http://www.manortronics-force-gauges.com/Astro.html This looks alright though. Don't think I want to spend that much though. Looks like a setting circle it is! Link to comment Share on other sites More sharing options...
stash Posted October 8, 2014 Share Posted October 8, 2014 Or you could use this - I am adding this too my Dob mods but I can't say how accurate it is in a real situation. Mod includes attaching rotary counter to centre bolt via cut off box spanner/epoxy resin. You can of course use the above in either AZ/AL http://www.machine-dro.co.uk/rotary-angle-encoder-and-remote-display-with-a-6mm-diameter-shaft.html I will let you know how it runs in the next few weeks. Link to comment Share on other sites More sharing options...
BAZ Posted October 8, 2014 Share Posted October 8, 2014 I had one of the digital setting circles, and despite the claim of 0.01 degree accuracy, it was pants. It started with small errors, which were amplified every time it was moved in opposing directions. I have since fitted the setting circle and have not had any problems since. I would think most modders go down this tried and tested route. A good example was EMS2, Daz found Uranus, Doc and myself got the coordinates off his scope, and both of us got the Planet in our eyepieces Link to comment Share on other sites More sharing options...
tuckstar Posted October 8, 2014 Author Share Posted October 8, 2014 Was just trying to save you some work Baz!!;-) think setting circle is the way to go. Link to comment Share on other sites More sharing options...
Doc Posted October 8, 2014 Share Posted October 8, 2014 I had one of the digital setting circles, and despite the claim of 0.01 degree accuracy, it was pants. It started with small errors, which were amplified every time it was moved in opposing directions. I have since fitted the setting circle and have not had any problems since. I would think most modders go down this tried and tested route. A good example was EMS2, Daz found Uranus, Doc and myself got the coordinates off his scope, and both of us got the Planet in our eyepieces I had one as well and agree PANTS. Once you make an adapter for it to fit onto your centre screw and then screw the encoder to your ground board, you could have made an degree circle. The degree circle turns out to be much more accurate. Link to comment Share on other sites More sharing options...
Rusty Strings Posted October 8, 2014 Share Posted October 8, 2014 I have a setting circle I don't need. I think is is 47cm diameter and sprayed with stuff to prevent moisture damage, Free to good home Link to comment Share on other sites More sharing options...
tuckstar Posted October 8, 2014 Author Share Posted October 8, 2014 (edited) Consider it homed!! Can collect it or post at my cost if you think it would survive the journey. Can pm details. Many thanks, last piece in the puzzle :-) Edited October 8, 2014 by tuckstar Link to comment Share on other sites More sharing options...
stash Posted October 8, 2014 Share Posted October 8, 2014 I had one as well and agree PANTS. Once you make an adapter for it to fit onto your centre screw and then screw the encoder to your ground board, you could have made an degree circle. The degree circle turns out to be much more accurate. While I take your opinions on board and you may well be right as you have attempted this already so experience counts - I do love a challenge - If it doesn't work then I will let you know and admit defeat but have had fun trying - I have had no noticeable errors when changing directions always returning to the same place as marked on my test bed- admittedly not on the scope as yet. However I am not expecting spectacular accuracy with the above off the shelf product just par with large setting circles and the "stepping stone" of a much longer term project. As for the adapter i am using a std threaded rod connector filled with epoxy and centre drilled to fit the encoder. Done in no time excluding the epoxy setting time. So do you use Wixey's for the altitude , vertical setting circles or other methods? Link to comment Share on other sites More sharing options...
Daz Type-R Posted October 8, 2014 Share Posted October 8, 2014 Wixey for me, simplistic is always the best IMO, less to go wrong when you need it. Link to comment Share on other sites More sharing options...
BAZ Posted October 9, 2014 Share Posted October 9, 2014 I still have the digital protractor, and on it's own it seems OK, but if you put any lateral load on it at all, it starts to generate small errors. If you change direction, this has the effect of amplifying them, eventually up to four degrees per movement. I have centred this accurately, but there is still enough play in the centre fixing bolt to cause problems. This could just be my unit which is duff, but I haven't been able to get it to work accurately. So I took it off and stuck on the setting circle, which works a treat. Link to comment Share on other sites More sharing options...
stash Posted October 10, 2014 Share Posted October 10, 2014 I still have the digital protractor, and on it's own it seems OK, but if you put any lateral load on it at all, it starts to generate small errors. If you change direction, this has the effect of amplifying them, eventually up to four degrees per movement. I have centred this accurately, but there is still enough play in the centre fixing bolt to cause problems. This could just be my unit which is duff, but I haven't been able to get it to work accurately. So I took it off and stuck on the setting circle, which works a treat. Thanks for the Info Martyn I have not put it(the Encoder) under load yet (i.e. Telescope + mount etc) just rotated the encoder about the axis on a bolt on a piece of wood (highly techie ) and checked the results on the remote display. Will let you know the results once attached to the mount. Link to comment Share on other sites More sharing options...
Guest MichaelDurban Posted October 11, 2014 Share Posted October 11, 2014 Acknowledging the above sentiment... Setting circle is the way to go...... Together with the Wixey I get consistent readings using Stellarium between 0.1 - 0.2 degrees. Even with a 15mm eyepiece I have no problems.. Setting circle printed on forex board. All you have to do is use Stellarium, find the Alt.Az, coords and away you go. Just make sure the setting circle can move freely between the two boards.. otherwise you have to align your scope.. Link to comment Share on other sites More sharing options...
BAZ Posted October 11, 2014 Share Posted October 11, 2014 I have to admit, I align the scope and I only get any real problems if the ground is very grassy or uneven. I haven't had to struggle though. Link to comment Share on other sites More sharing options...
tuckstar Posted October 11, 2014 Author Share Posted October 11, 2014 So what do people think is the best method for attaching setting circle. Straight to baseboard then align the whole lot, or on a separate piece of wood being able to swivel to suite alignment. If you use separate piece of wood do you clamp it off when aligned? Link to comment Share on other sites More sharing options...
Daz Type-R Posted October 11, 2014 Share Posted October 11, 2014 (edited) So what do people think is the best method for attaching setting circle. Straight to baseboard then align the whole lot, or on a separate piece of wood being able to swivel to suite alignment. If you use separate piece of wood do you clamp it off when aligned? It is easier to put it straight onto the base board but then that would require you to position the base board 100% accurately facing to the pole star. If it is not 100% aligned, then you will have to lift the whole setup, find Polaris, check, still off, lift the whole base board and OTA, align the ep to Polaris, check you setting circle is at 0 and so on. If you put it on a board like mine that is sandwiched between the base board and the top board that can move (mine moves 30 degrees) then if you get Polaris in the middle of the ep, then you just move the setting circle rather than the whole scope and mount. With regards to locking it, I have not done, but it is on my list of things to do as i keep catching mine. Edited October 11, 2014 by Daz Type-R tuckstar 1 Link to comment Share on other sites More sharing options...
Doc Posted October 12, 2014 Share Posted October 12, 2014 My degree circle is sandwiched between two sheets of perspex and can be freely rotated 360°. The weight of it keeps it secured in the same place there is no need to lock it down. It is also kept circular and does not wander due to being guided by three cam bearings. tuckstar 1 Link to comment Share on other sites More sharing options...
stash Posted October 12, 2014 Share Posted October 12, 2014 I think I am right in saying that the setting circle does not have to be aligned - "if" you can pick up a known object - find what the Az is for that object from Stellarium - it's just a case of "simple" maths - e.g. Software says object at 60 - your settings says 76 then just adjust any AZ from Stellarium by 16. No need to move platform. Link to comment Share on other sites More sharing options...
BAZ Posted October 12, 2014 Share Posted October 12, 2014 Yeah, you're right Clive, but why make life more difficult than it is. If you get it even somewhere near, then you can usually get the object in a medium field eyepiece. It really does work that well. Link to comment Share on other sites More sharing options...
Doc Posted October 12, 2014 Share Posted October 12, 2014 (edited) Easy way is place Polaris in your eyepiece as this star will not move while you polar align. Look up your co-ordinates off Polaris and set your AZ circle to that co-ordinate. Then level your scope and reset your wixey to zero. Raise your scope to get Polaris back into the eyepiece and you will find that your wixey will read the co-ordinates for Polaris. That's it, pretty simple. Edited October 12, 2014 by Doc Link to comment Share on other sites More sharing options...
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