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iOptron SmartStar goto

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#51 Talstarone

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Posted 23 November 2007 - 04:17 PM

Hi Jose. The Celestron NexStar SLT does use the same mount and tripod throughout the entire line of scopes.
And I am not 100% sure of the load capacity of the SLT but I think I can safely say it is a larger load then the iOptron Cube.

Will the SLT Mount handle a 8inch SCT,I doubt it.But it should be capable of handling most of the scopes with aperatures less then 8 inches.

#52 allan

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Posted 28 November 2007 - 06:49 PM

Just an update on using the Ioptron mount. Last night I used it as a straight Alt/Az mount ie with no motors running and just loosened slightly both of the axis so it would move smoothly and it worked a charm. Very easy to move using a red dot finder and then view the object. I was looking at Sirius and decided to switch on the motors and without doing an alignment activeated the paddle and picked sirus from the bright star menu. I then synched the mount on it and said to go to M42, Rigel and some other stars. Each were in the center of the eyepiece (20mm). So Ive found it to be a very easy mount to use and am happy with it as a tracking, goto Alt/Az mount for travelling purposes. After testing quite a few scopes with it I find a 90mm MAK is the best for what I need and matches the mounts performance characteristics very well.

#53 gamccain

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Posted 29 November 2007 - 12:01 PM

Hi there fellow SmartStar user.

How did you loosen the AZ axis?

Thanks

Greg

#54 gamccain

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Posted 29 November 2007 - 12:29 PM

Hello again fellow 'Cubers.

I too bought a SmartCube, hoping that it would be an OK grab and go and/or something to take to the big Public Events.
I like the mount (NOT THE TRIPOD THOUGH) and think it will be less intimidating to newbie public event attendees than some of our Big-Rigs.

I've had a TON of fun using it, correcting QC issues and figuring out other shortcomings. I do believe that 7 lbs is really about the practical limit for this machine.

I'm attaching a rambling review that I had posted to the yahoo group (ssmount) recently.

I will be posting, in a few minutes, another update that covers some mods I made to get rid of the large amount of 'slop' in the ALT axis.

And in another few days, I'll have a posting of some 'driving' vs 'Go-TO' tests that I have been running.

Clear Skies,

Greg

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#55 gamccain

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Posted 29 November 2007 - 12:30 PM

And here's the details of the mods I made
to deal with the 'slop' in the ALT axis.

Greg

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#56 mattyfatz

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Posted 29 November 2007 - 01:19 PM

Do you think the Cube can handle a Celestron C6 sct?

#57 gordianknot

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Posted 29 November 2007 - 02:57 PM

I don't think so. The C6 is about 10 lbs and in my experience the Smartstar-E seems to be near its limit with the 6lbs Nighthawk 80ED (NHNG). I would really consider 6-7 lbs to be the absolute limit on this mount.

#58 gordianknot

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Posted 29 November 2007 - 03:20 PM

I should note that I've also experienced the "jumping bug". It happens after a two star align when you try to use the arrow keys to move the mount. After you release the keys, the mount suddenly moves a degree or so. I think I've only seen it in Alt, but I started noticing this after I stopped taking careful notes.

The two star align doesn't appear to be more accurate than the one star align anyway, so I just stopped using it.

#59 tjugo

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Posted 29 November 2007 - 04:55 PM

It can drive a C6 SCT (mine can do it). Please read my small review in this thread.

Cheers,

Jose

#60 Talstarone

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Posted 29 November 2007 - 08:24 PM

Well it looks as if there are more and more users who are getting positive results from the iOptron.

Hopefully this will become contagious and several other users will find that their cube is actually a capable mount.

#61 gamccain

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Posted 30 November 2007 - 12:40 PM

As promised yesterday . . .

I'm attaching a write-up of some
accuracy testing I've been conducting.

If others have a chance to confirm
what I found regarding:
-- the RA/DEC figures that iOptron seems to have stored
-- The apparent ALT error when transforming between RA/DEC and ALT/AZ,
I'd appreciate it.

If I've bumped into a 2nd smoking gun (the 1st being the 'jumping bug') and others can confirm
it, iOptron might fix it quicker.

So . . . I'm done with pointing accuracy tests for now.
Next up, a hunch about tracking accuracy and voltage.

I had found that tracking was marginal at best and
wondered if it might be voltage related. Gut feel was
that tracking was worse on batteries, after the first
hour or user or so and better, but still not great
when using a known good field battery at top charge.

Last night, while running the 3rd night of 'DRIVE-TO'
tests, I used the AC adapter and found that tracking
was EXCELLENT (for visual use). Stars were staying
reasonably well centered for over 5 minutes in a 1.4 degree FOV and the Pleides stayed reasonably well centered for over 15 minutes.

I want to get a dead-accurate adjustable DC power-supply for
some HAM radio projects, but that will be a few weeks.

Perhaps another gear-head on the forum has one and could
run some quick tests in this area?

Clear Skies

Greg

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#62 radsdad

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Posted 09 December 2007 - 12:12 PM

Interesting reading throughout this thread. I've got a Meade ETX-125, the mount continues to work alright but I wonder how long it will last. The Cube mount looks like a possible alternative, think it could handle the Meade 127 Mak?

#63 Dansby

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Posted 11 January 2008 - 05:49 PM

Greg, As for your smoking gun? I think that is probably a major issue with the HC. I noticed that problem a while back and figured it was just because I just guessed at my location but I had gotten it correct. Every time I used Go-To it always went a little high.

And just for a little extra info on the mount its self. "IF" you find a better tripod (AKA a huge iron pole buried 15 ft in the ground) and make sure you attach your telescope at the center of mass, it can handle heavier scopes. I have mounted a 25lb Scope to mine with little problems.

#64 DNTash

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Posted 12 January 2008 - 12:16 AM

Dansby -- welcome to the CN forum! Just to clarify, because I'm thinking about the outer limits the iOptron might support on a reasonably stable tripod, are you basically saying that the more stable the tripod, the more weight the iOptron can handle? And, am I reading you right, you've mounted a 25 pound scope to your iOptron?

I'm basically wondering if it will handle my 120ST, diagonal, and a large piece of EP glass on a sturdier tripod.

#65 Dansby

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Posted 13 January 2008 - 04:59 PM

If you look at the modifications made by greg above, do what you can about the short comings of the mount. I have found the mount itself is made very solid. The tripod on the other hand is not. Weight doesn't seem to be the major issue; its the center of gravity of the scope in relation to the center of the tripod center. My 8" reflector, after adding the dovetail, center of gravity is about 12" from the center of the mount. This puts the outside of the tube almost even with outside of the tripod... There is no way it could stay balanced with that much weight so far from the center of the tripod. I attached the mount to a iron 4x4 in my back yard. The Scope weighs about 25 lbs with all the *BLEEP* I attach to it. I will say, all the problems found by Greg are intensified by weight. My scope is made of mostly cardboard so I get more play from the scope flexing then I do with the mount itself.

It's pretty easy to test if you don't want to spend any cash on mounting just grab your mop, tie some rags on the ends, mount it to the the mount and start pouring water on the rags. See for your self how the mount with react.

#66 tonyb

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Posted 28 February 2008 - 12:39 PM

Hi Allan: I'm thinking about getting one of the iOptron SmartCubes as a grab n go mount to use with my Canon EOS 5D and a 28mm Canon lens for wide fields. Any thoughts on whether I should look at the Alt/Az SmartCube or the SmartCube with the Equatorial Wedge? Also any thoughts on what dovetail to use with my Canon?

Thx.

#67 Cotts

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Posted 28 February 2008 - 04:01 PM

I have just purchased one for a single purpose: To track at Solar rate for about 4 hours at the solar eclipse on Aug. 1 in Mongolia. It is by far the lightest mount with available solar tracking rate in the world today unless I've missed something. I have severe weight limits for my baggage on this trip. The scope will be a William Optics 80mm FD with a CanonXTi camera. I will be pushing the weight limit but the exposures will be all be quite short. The plan is to align the mount properly the night before and then not use it until eclipse time and then only for tracking.
I have one concern, though; Some have mentioned that voltage drop from the 8xAA batteries will cause some problems. Assuming I only do enough slewing to align it the night before and then shut it off and do no slewing during the eclipse, just tracking at the solar rate, will the batteries last for the duration of the eclipse? Or, more to the experience of those on this thread, how many hours do the AA batteries last during normal viewing with lots of slewing? I plan to sell the mount upon my return, perhaps with some dust and sand from the Altai mountains! d.c.

#68 gordianknot

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Posted 28 February 2008 - 08:13 PM

I'm probably the person you're refering to who was worried about battery voltage. I think that the batteries should easily last 4 hours, even if you are slewing a lot. You might want to bring a spare set just in case, but from my experience you can get a high single digit number of hours out of a set of batteries before the mount starts getting unhappy.

I don't think you need to bother aligning it the night before. Just make sure it is leveled and do a one star align to the Sun. In my experience the mount actually behaves better with the one start align than the two star one (it doesn't have the annoying bug where it takes off on its own from time to time).

#69 Cotts

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Posted 29 February 2008 - 09:54 AM

Thanks for the info. Very useful. d.c.

#70 tonyb

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Posted 29 February 2008 - 09:58 AM

Hi: Have you had much luck using the iOptron for AP with a wide field lens such as a 28mm on a DSLR? I wonder what kind of tracking times 3-sec to 5mins can be expected?

Thx.

Tony.

#71 gordianknot

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Posted 29 February 2008 - 03:02 PM

I haven't really tried any long exposure photography, though I have done a fair amount with a webcam on it. Normally I would say "don't even try", but at 28mm, I can see how it might work. At 28 mm, the angular pixel size is on the order of 1 arc minute, while I was doing planetary imaging in the sub-arcsecond pixel size range. Unfortuantely, I seem to have deleted all of my planetary videos; I just have the stacked images. However, a drift of about 150 pixels at 2600 mm with a SPC900 (my usual configuration) would be equal to about a 1 pixel drift for a 28mm lens with a 6.8 micron per pixel SLR sensor. I'm reasonably certain that it didn't drift that far for at least 30 seconds.

If I were trying to do long exposure imaging on the SmartStar-E, I would definitely use the self timer and mirror lock up if applicable. The mount is not very stable and vibrations take a while to die down.

#72 chboss

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Posted 18 May 2008 - 03:40 PM

Hi all

I took Greg's work a step further and did modify also the AZ axis to reduce the vibrations in the mount.

The details can be found here:
http://www.bosshard-.../Equipment.html

with best regards
Chris

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