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Dob eqautorial rotary encoder vs Setting circles


knobby
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Hi,

anyone tried one of these http://www.axminster.co.uk/gemred-rotary-angle-encoder-with-remote-sensor-prod806698/ or these http://www.machine-dro.co.uk/rotary-angle-encoder-and-remote-display-with-a-6mm-diameter-shaft-.html on a dob base

I've got a Wixey for the Alt and am seriously looking at fitting one of these to the base for Az.

Does anyone know if these work clockwise or anticlock ?

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call me a saddo ... I just dont like the look of it !

just thought, I have a wixey for the Alt, it would be nice to have it on the Az too.

And its raining, and I like tinkering and I got bored :rolleyes:

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Well here we go!

Don't take the Mick ... its not a pro job by any means :D

Definitely falls in the 'early prototype ' category!

5615f4fd-edc0-ce0a.jpg

Materials include, packaging from skywatcher dob. Packing tape. 22mm long type socket. Genred encoder . Bits from an old copier! And araldite, lots of araldite.

Its all wobbly and delicate, but apart from .5 degree play due to the timing belt having no tensioner yet, its looking promising :D:D

Edited by knobby
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Gemred costs £40 new, paid 15 on gumtree, socket extension for the 22 mm centre nut, £4 halfords, timing belts and pulleys, free off a scrap copier / scanner ... packing tape etc. Free.

If it goes below zero it won't matter coz ill be indoors :D

Edited by knobby
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Hi Knobby - I did think about the Gemred some time ago when I was adding the setting circle but there were two things that put me off.

1 the temperature issue- when it drops it will drain the battery pretty quickly but the main reason was that I didn't want to be using 3 separate electrical devices all at the same time powering on and off - phone, wixey and gemred.

However I've never actually tried it so good luck and let us know how you get on. - the only problem I see for you is you'll need a new scope soon as there just won't be anything left to tinker with on the current set up lol

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Being ATM enthusiast I like to look at any mods but I know that digital setting circles (USB or BlueTooth) can be made for ca. 100GBP so is there any sense in making this kind of mod? ;)

Sorry Pablito, not quite sure I understand the question

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Well here we go!

Don't take the Mick ... its not a pro job by any means :D

Definitely falls in the 'early prototype ' category!

5615f4fd-edc0-ce0a.jpg

Materials include, packaging from skywatcher dob. Packing tape. 22mm long type socket. Genred encoder . Bits from an old copier! And araldite, lots of araldite.

Its all wobbly and delicate, but apart from .5 degree play due to the timing belt having no tensioner yet, its looking promising :D :D

Do you know Mr Heath Robinson....... :grin: :grin: :grin:

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Sorry Pablito, not quite sure I understand the question

I only wanted to say that there are ways to make fully automated DSC with hi-res encoders without breaking the bank. I made a couple of sets with USB or BlueTooth connection that work great with PC, Palm or iPhone :)

But I will understand that more fun you have finding objects using this kind of mod. I know people who don't even want to hear about go-to or DSC and and say that those who use electronics should burn in hell ;)

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I only wanted to say that there are ways to make fully automated DSC with hi-res encoders without breaking the bank. I made a couple of sets with USB or BlueTooth connection that work great with PC, Palm or iPhone :)

But I will understand that more fun you have finding objects using this kind of mod. I know people who don't even want to hear about go-to or DSC and and say that those who use electronics should burn in hell ;)

Thanks Pablito !

I know what you mean about goto and finding things for your self ... but I'm a tinkerer, I like making things ! :smiley:

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People who think people should rot in hell should rot in hell :)

Thus far I've found all but four of the Messier objects, all by star-hopping. I think it's fun and I like the challenge. I'll find the remaining four by star-hopping, too. I still want a Wixey and some sort of setting circle on my dob though. *I* might find it fun, but if I want to show someone else something then it's pretty tedious for them if I can't have it in the eyepiece fairly quickly, or let them "drive" by themselves for a while.

And I agree, knobby, building your own bits and pieces is fun :)

James

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Well I took it out for a test last night and it worked pretty well!

Got most objects in or pretty close to he field of a 32mm EP ... and I forgot to level the base.

Going to improve the mounting to lessen the play but looking promising

Found M13 and Andromeda for the first time, M13 is stunning!

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Just spent a couple of hours in the garden fine tuning my gadgets. Now have the encoder mounted dirictly on the centre shaft ( still using cardboard and packing tape) far less play now, Found M13, M31,M11,M27 and M57. All faint against the Moon washed light polluted Essex sky but visible !

I'm enjoying this :grin:

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Just spent a couple of hours in the garden fine tuning my gadgets. Now have the encoder mounted dirictly on the centre shaft ( still using cardboard and packing tape) far less play now, Found M13, M31,M11,M27 and M57. All faint against the Moon washed light polluted Essex sky but visible !

I'm enjoying this :grin:

Good work there knobby. More pics please!

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I did this mod on my dob some time ago. There is a thread another member started that covers different ways of fixing the gemred but I can't find it on the new forum sorry. I had fixed the centre bolt on the rocker box to reduce any lateral play/ sticktion I was able to centre drill the fixing bolt and then use a grub screw to fix the gemred rotary shaft to the bolt while independently fixing the gemred body to the rocker box using a plate. While I confess I never actually never got around to using it before selling the dob the mod itself was straight forward enough to do but there was some concerns to how well the gemred would perform at temperatures under -1°

I have included a picture of the finished mod. Sorry it's not the best but it's the only one I could find.

post-8355-0-44217700-1344001066_thumb.jp

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