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Autoguiding with Vixen polaris?

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#1 bhpnbr

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Posted 18 August 2013 - 12:41 PM

Hi everyone!

I am just wondering if it is even possible to adapt a Vixen Polaris (not the super or great polaris) mount for autoguiding. I am thinking along the lines of Orion EQ- 3M dual axis drive and adding a St4 port to the handcontroller for guiding with GPUSB. From what info I've found so far, it does'nt seem like the Polaris will take a DEC drive, which I'm confused about because the Orion Astroview, which is similar to the polaris,is the mount the Eq -3m drive is meant for.

Anyone down this route before :question: Many thanks in advance! :bow:

I forgot to mention, I'm planning to put a orion st80 on it as an imaging scope with a canon 1100 DSLR. Guiding will be done by a piggybacked celestron 70 mm travelscope with Meade DSI as guidecamera

#2 *skyguy*

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Posted 18 August 2013 - 10:24 PM

The Vixen Polaris mount was not designed for a motorized DEC axis. You could be creative and do a custom modification to add a motor to the DEC ... if you have the skill. ;)

However, depending on the accuracy of the polar alignment and the focal length of the imaging scope, you could get by with just autoguiding on the R.A. axis, only. Good News!

You can just buy the Orion single axis EQ-3 drive, since it will fit on a Vixen Polaris mount and modify the hand controller to accept guiding pulses. Good News!

However, the Vixen Polaris mount has a R.A. drive gear with 144-teeth, while the EQ-3 mount has R.A. drive gear with only 130-teeth. Bad News and maybe a big problem! :(

But, I have a Tasco (Model 1606) single axis drive with hand controller on my Vixen Polaris mount ... that looks exactly the same as the Orion one for the EQ-3 mount. It can keep an object centered in an eyepiece for quite an extended time ... so, maybe it could be made to work with an autoguider!

Good Luck with modifying your Polaris mount for autoguiding. :)

#3 bhpnbr

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Posted 19 August 2013 - 12:04 AM

Thanks for that suggestion! That idea about modifying the RA drive for autoguiding has been lingering at the back of my mind for quite some time now, I think it s time to put it into practice!

Anybody done this before? Any tips or pitfalls to watch out for? I'm thinking of replacing the crystal oscillator in the handbox to match the 144 tooth worm drive on the Polaris.

Thanks :bow:

#4 orlyandico

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Posted 19 August 2013 - 04:15 AM

I have done better - I documented it :-)

http://orlygoingthir...nt-hacking.html

In this case I used an EQ-1M, which is designed for a 100-tooth worm wheel. Replaced the crystal.

Never got as far as adding autoguiding though. But since all of the switches are on the daughterboard, should be trivla using these instructions -

http://www.store.sho....com/eq_mod.pdf

#5 UND_astrophysics

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Posted 04 November 2013 - 09:15 AM

I wonder why page 8 of the instructions pdf is missing? Seems like the most important part of doing this modification






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