TheSkySearchers

What is the smallest eq mount with setting circles that work?

It is not really related to the mount size but the circle size themselves.
I have had a older EQ-2 that had reasonably accurate circles that would get you close to the target and EQ-5 ones that were horrid.
If they are readable and function properly they will be good enough to get you close.

My TAL EQ which is a EQ-5 equivalent has circles almost half again as large as a standard EQ-5 and work a bit better as well.

The person that produces Byers mounts has stated before that a fully functional circle should be at least 8" in size.

Want something way smaller than my Orion Skyview Pro for darksite trips. I will be using my Vixen 70mm f/13. Would like to be able track with the mount.

Lady Fraktor wrote: ↑Thu Nov 07, 2019 10:21 pm It is not really related to the mount size but the circle size themselves.
I have had a older EQ-2 that had reasonably accurate circles that would get you close to the target and EQ-5 ones that were horrid.
If they are readable and function properly they will be good enough to get you close.

My TAL EQ which is a EQ-5 equivalent has circles almost half again as large as a standard EQ-5 and work a bit better as well.

The person that produces Byers mounts has stated before that a fully functional circle should be at least 8" in size.

That is 8" round?

Well, not too sure what you're after, but I have an old mount that might be equivalent to an EQ2. It support a 60mm f/11, but I wouldn't push it any further than that. However, once in the proper position, the setting circles work just fine on it, thankfully, as the finderscope is useless...



Hope this helps,

A Losmandy G11. It has additional engravings for accurate positioning.

https://www.bing.com/images/search?view ... &eim=1,2,6

Refractordude wrote: ↑Thu Nov 07, 2019 10:40 pm Want something way smaller than my Orion Skyview Pro for darksite trips. I will be using my Vixen 70mm f/13. Would like to be able track with the mount.

Do you want to track for visual or AP? If AP, then you really need a substantial mount, and anything less that the one you already have would not be up to it.

Presumably you are talking visual if you are using a f13 70mm OTA; and in that case why do you need an EQ mount? I use an early model iOptron Pro for visual use and public viewing: this is go-to and tracks quite well, and can cope with my 150mm f5 refactor or my 102mm f8 for visual use.

For visual usage with your scope you might want to look at something like the Skywatcher "Star Discovery" or "Mini-Az GTI" mounts.

All the best,

Dean

I've been looking at the Orion tabletop EQ, but it would have to be mounted on a tripod. I've also been looking at the Exos Nano. (And the SVP, of course, for something more substantial.) Higher end mounts are beyond my current hobby budget.

I have no personal knowledge of any of these though.

May have just found what I was looking for. Anybody have experience with this very light weight eq mount. I sent an email to Explore Scientific asking about tracker attachment possibilities.

https://explorescientificusa.com/produc ... snanot1-00

There's a long thread over on CN about it. Counterweight might not be sufficient for some scopes. If you get one, please post a review.

pakarinen wrote: ↑Fri Nov 08, 2019 7:10 pm There's a long thread over on CN about it. Counterweight might not be sufficient for some scopes. If you get one, please post a review.

Cool

If it is good setting circles you want, consider a wedged fork mount instead of a GEM. The RA circle on the mount for my old orange-tube C-90 is about 8" in diameter. It has markings every 5 minutes of RA, and can be interpolated to the nearest minute with ease.

Best of all, the circle is driven by the motor, which is something that GEM manufacturers seem unable to master. So I have none of the GEM nonsense where you have to re-set the circle after the mount has tracked for a while. At the start of the evening, I set the setting circle to local sidereal time, and it is good for the rest of the night.

The Dec circle is not quite as large, maybe 5" in diameter. It is marked for every degree, and can be interpolated to about 1/4 of a degree.

So that's a single-arm fork, I take it?

Refractordude wrote: ↑Fri Nov 08, 2019 7:04 pm May have just found what I was looking for. Anybody have experience with this very light weight eq mount. I sent an email to Explore Scientific asking about tracker attachment possibilities.

https://explorescientificusa.com/produc ... snanot1-00

I have that mount, I think it's quite stable and usable, excellent for the price. It works very well wit my 80 mm Apo. On the AF there was someone who hooked up a motor and did some AP with it. Of course there are no bearings on this mount so the stiction is a real problem for motorized tracking. But it will take a tracker, it has the right size screw, 1/4" I think.

pakarinen wrote: ↑Fri Nov 08, 2019 7:40 pm So that's a single-arm fork, I take it?

Correct.

SkyHiker wrote: ↑Fri Nov 08, 2019 8:01 pm

Refractordude wrote: ↑Fri Nov 08, 2019 7:04 pm May have just found what I was looking for. Anybody have experience with this very light weight eq mount. I sent an email to Explore Scientific asking about tracker attachment possibilities.

https://explorescientificusa.com/produc ... snanot1-00

I have that mount, I think it's quite stable and usable, excellent for the price. It works very well wit my 80 mm Apo. On the AF there was someone who hooked up a motor and did some AP with it. Of course there are no bearings on this mount so the stiction is a real problem for motorized tracking. But it will take a tracker, it has the right size screw, 1/4" I think.

Do the setting circles work for you?

I never used its setting circles but I suggest that you need a very wide field of view say 3 to 5 degrees for any luck, with good polar alignment. This is just based on my experience with the Losmandy G11. Sky and telescope published an article about how various types of misalignment easily add up. What I can say is that the Nano is remarkably solid considering what its made of.

I looked at my Nano and sorry there was no screw but there is a Vixen adapter for the iOptron Skytracker. It is also quite easy to make an adapter from a piece of wood and a piece of 1/4" thread.

Refractordude wrote: ↑Fri Nov 08, 2019 7:04 pm May have just found what I was looking for. Anybody have experience with this very light weight eq mount. I sent an email to Explore Scientific asking about tracker attachment possibilities.

https://explorescientificusa.com/produc ... snanot1-00

[mention]ARock[/mention] ARock has this mount. Perhaps he can chime in?

I use the EQ Nano with a 80 mm F/5 and it is stable enough to do basic AP. I have never used the setting circles, but it does have them. The only concern would be the length of your F/13 scope. ES does sell this with a 80mm F/11.5 scope but I think this will be prone to vibrations. Also, the Counter Weight that comes with the mount might not be enough for your scope.

You can fit a cheap Celestron R/A Single Axis Motor Drive on it with some bracket adaptation with a hand drill (see the drive thread below).


Or you could build a RA drive with a Stepper motor and Arduino for it.

Here is a link discussing the mount on CN
https://www.cloudynights.com/topic/6087 ... eq-thread/

and another one discussing RA drives on it.
https://www.cloudynights.com/topic/5702 ... his-mount/

Here it is in action as we speak for the transit of mercury...