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astrovienna
Carpal Tunnel


Reged: 12/04/06

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Re: No More Tracking new [Re: brucepech]
      #5914370 - 06/11/13 12:29 AM

Do you guys get the same result when you use Nexremote instead of the hand control? That might narrow down the issues.

Kevin


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brucepech
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Reged: 04/18/12

Loc: Colorado
Re: No More Tracking new [Re: astrovienna]
      #5914484 - 06/11/13 03:13 AM

Since I just bought the CPC to complement my vintage 8" LX-90. I haven't explored Nexremote or other exotic options. I'm stuck with the handbox for the time being. But thanks for the suggestion.

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Monadnock
sage


Reged: 04/24/12

Loc: SW NH
Re: No More Tracking new [Re: brucepech]
      #5914703 - 06/11/13 09:32 AM

Now you guys got me going. I recently replaced my perfectly functioning stock controller (Loooong story) with a Nexstar + controller. Mine, before alignment always defaults to off as well! After a 1 star mock alignment, and accessing the mode via the menu button, it shows tracking in alt-az mode. I used Betelgeuse as the alignment star because it's to the south right now. While I have no idea if it's tracking accurately, it is audibly tracking using both motors.

Is it possible we're all having a "duh" moment here and any visually confirmed tracking errors are simply due to poor alignments? It seems logical that the tracking mode is set to "off" if the scope hasn't been aligned yet.

ETA- I'm still using the stock motor firmware version. Scope manufactured in '11 or '12.

Edited by Monadnock (06/11/13 09:35 AM)


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brucepech
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Re: No More Tracking new [Re: Monadnock]
      #5914943 - 06/11/13 12:07 PM

I dunno Monadnock. I'm just familiarizing myself with Celestron handboxes. My old Meade Autostar 497 always tracked *during* a two star alignment. I set the "mount" (the same, or so I think, as Celestron's tracking mode) to ALT-AZ over a year ago and it's retained the setting ever since. When I align the Meade, the alignment stars remain in the eyepiece FOV while I center them; I don't have to keep chasing them with the Autostar's directional arrows. Since my Nexstar+ deletes the ALT-AZ tracking mode setting and reverts to off every time I set it, I'd have to do a mock alignment to get it to track before doing a real alignment -- which is counterintuitive since it'd have to be done every time the handbox is turned off and on between observing sessions. Moreover, unlike ALT-AZ, the EQ North and South tracking mode settings are retained by the handbox. Again, it seems coounterintuitive that ALT-AZ reverts to "Off" while the other modes don't. But, as I said, I'm new to Celestron products.

PS. I can hear the tracking motors whirring too after a mock alignment. I'm beginning to think that a non-sidereal tracking rate (even though the Handbox is set to and retains a sidereal setting) is the problem both in centering the alignment stars in the FOV during a real alignment and in the post-alignment drift of the goto target object.


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Monadnock
sage


Reged: 04/24/12

Loc: SW NH
Re: No More Tracking new [Re: brucepech]
      #5915053 - 06/11/13 01:11 PM

Hmm. I've never actually taken note as to when the scope starts tracking. I normally use the 3 star alignment, or whatever it's called, and I assume that after the 3rd star is centered and ALIGN is pressed, it starts tracking.

If I'm understanding everyone's previous posts, and my own recent discovery, the CPC defaults to alt-az mode and shows "off" before an alignment. After the alignment it may show as being off, though I haven't seen it, but still tracks in that mode. Perhaps it showing as off is some sort of trivial software glitch? Not even sure if that makes sense. I'll have to look into it further after work.


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jchaller
Pooh-Bah


Reged: 05/29/08

Loc: Tenino, WA.
Re: No More Tracking new [Re: Monadnock]
      #5915073 - 06/11/13 01:32 PM

It shows off if not aligned and alt-az after alignment.
If it tracks, but tracking is off, make sure your time/site info is correct.


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dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: No More Tracking new [Re: Monadnock]
      #5915097 - 06/11/13 01:43 PM

This might apply to you, Prior page post,, and yes I have folded LOL
""Just a FYI, just before I deforked my 9.25 I had upgraded handset and seem to remember that for one mode to stay locked in (alt/az?) the scope has to be aligned. Put it into just a quick or fake align and see if it changes""
Kasey
And as previously posted, spent much time on phone with 3 people and third one said needed to be aligned for Alt/AZ to work


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brucepech
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Reged: 04/18/12

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Re: No More Tracking new [Re: Monadnock]
      #5915115 - 06/11/13 01:54 PM

Once again, Monadnock, I dunno. I just replicated your result by doing a mock one-star alignment to Betelgeuse and tracking(?) a faux Jupiter. When I returned to tracking mode, ALT-AZ was, surprisingly, on (as you noted). However, the menu doesn't allow you to do a manual two star alignment w/o turning the scope off (I tried) -- and when you turn it off the ALT-AZ mode also reverts to off. Which means that the scope won't track during a manual two star alignment making it darned near impossible to center the alignment stars in the eyepiece and, therefore, extremely difficult to complete the alignment procedure.

Taking into account the near impossibility of doing a real, non-auto two star alignment, I remain persuaded that, unlike my LX-90, the scope doesn't track *during* a two star alignment or that the tracking rate isn't (even though it's set to it in the Nexstar+) sidereal. I'm basing my supposition on the serially more inaccurate gotos I experienced after each (imprecise) two star alignment.

Since most experienced observers say that the manual two star alignment is more accurate than other procedures (which was my experience with my LX-90) I ordered another Nexstar+ from "that river place" (at *half price*). I'll report back if it performs differently.

Edited by brucepech (06/12/13 12:31 AM)


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brucepech
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Reged: 04/18/12

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Re: No More Tracking new [Re: brucepech]
      #5916166 - 06/12/13 12:25 AM

Well, page 10 of the Celestron Manual explicitly says that tracking doesn't begin until the scope is aligned (at least when doing a manual two star alignment, but probably with all alignment procedures):

"Once the second star alignment is completed properly, the display will read Alignment Successful, and you should hear the tracking motors turn-on and begin to track."

How you're supposed to accurately center a star moving at 15 degrees/hour in a 12mm illuminated reticle eyepiece like Celestron's Crossaim (or any high or moderate power eyepiece for that matter) remains a mystery to me. In my experience, the star will traverse the non-tracking eyepiece's FOV pretty quickly making centering problematic,

The Manual suggests adjusting the directional arrow slew rate to facilitate centering, so I suppose you could adjust it to a sidereal or 2x sidereal rate by pressing the "Motor Speed" (or "Rate") button followed by buttons "2" or "3," chase the star across the sky until it appears centered, then quickly mash down the "Enter" and/or "Align" buttons. But this procedure is almost guaranteed to be inaccurate unless the direction of the star's motion and the direction of the slew are precisely aligned with one another. (See all the threads about the importance of accurate centering to proper alignment in the Cats and Casses Forum.)

C'est la vie I suppose. If that's the way Celestron designed the scope, that's the way Celestron designed the scope. (BTW Dragonslayer and Jchaller are correct: the handbox won't lock in "ALT-AZ" until the scope has been aligned.)

Edited by brucepech (06/12/13 12:38 AM)


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cn register 5
scholastic sledgehammer


Reged: 12/26/12

Re: No More Tracking new [Re: brucepech]
      #5916311 - 06/12/13 03:35 AM

How would the mount know what direction to move until it's aligned?

In practice it's quite easy to position the star just in front of the cross hairs and press the Align button as it passes them.

Chris


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brucepech
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Reged: 04/18/12

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Re: No More Tracking new [Re: cn register 5]
      #5916369 - 06/12/13 05:40 AM

cn, all I can say about my 2003 LX-90 is that it does -- perhaps because alignment begins in what Meade calls the "Home" position: w/ the OTA level and pointed at a reasonable approximation of celestial north.(Easily accomplihed by orienting the tripod so that the front two legs are at the 10:00 and 2:00 positions and the rear leg is at the 6:00 position in relatio to a N-S line, manually pointing the OTA at Polaris by loosening the AZ and ALT clutches, tightening the AZ clutch, leveling the scope, tightening the ALT clutch, and beginning the alignment procedure. I can't visualize the geometry, but I suspect that it then tracks at a sidereal rate roughly aligned with the celestial paths of the target alignment stars. (Perhaps this was the precursor to Meade's later, automated LNT technology and its successful patent infringement suit against Celestron.)

If my intuition about starting an alignment in Home position is incorrect (as well it might be), then I don't have the faintest idea why the target stars remain comparatively stationary in the LX-90's eyepieve's FOV while I center them.

In any event, I guess I was wrong when I initially said that I had a "problem." I think I'm just suffering from cognitive dissonance as I try to reconcile Meade's familiar alignment procedure w/ Celestron's.

Edited by brucepech (06/12/13 08:44 AM)


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rmollise
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Reged: 07/06/07

Re: No More Tracking new [Re: brucepech]
      #5916516 - 06/12/13 08:49 AM

Quote:

How you're supposed to accurately center a star moving at 15 degrees/hour in a 12mm illuminated reticle eyepiece like Celestron's Crossaim




Not much of a problem IMHO. I've been doing it for over a decade without a problem, anyhow. The GPS series of scopes worked exactly the same way: tracking off till aligned, then alt-az tracking kicks in.

Alt-az tracking requires different motor speeds depending on _the position the scope is pointed to in the sky_, so until the alignment is done, there's not much point in starting tracking.

Edited by rmollise (06/12/13 08:51 AM)


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KerryR
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Reged: 12/05/07

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Re: No More Tracking new [Re: rmollise]
      #5916545 - 06/12/13 09:07 AM

I've had no issues aligning either. It's been pretty easy to slowly guide the star to the center, finishing movements in the same direction goto's finish to absorb any backlash, and hit "align".

I believe there's a bit of wiggle-room built in to the software-- things can be a LITTLE off and the computer can still figure out the alignment accurately.

This is just the price we 'pay' for not having to start in a 'home' position, as I must with my LX90.


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Monadnock
sage


Reged: 04/24/12

Loc: SW NH
Re: No More Tracking new [Re: KerryR]
      #5916630 - 06/12/13 10:04 AM

I agree with KerryR. I'm not even sure the scope cares if the first 1 or 2 stars, depending on your alignment method of choice, are centered in the FOV. I believe its just an identification thing for the scope to get it's bearings. The last star is the "money" star as far as centering goes, and it can be tweaked after alignment WHILE the scope is tracking. I believe what is far more important is choosing good alignment stars as described in the manual. These choices can make or break a successful alignment, or cause somewhat poor tracking.

Out of the 10 or so (ya, wow, that many) times I've used my CPC, I've never had an issues aligning the scope or tracking an object, providing I've chosen bright stars. Never actually left the scope on one object longer than a couple hours but it has always tracked virtually flawlessly.


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brucepech
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Reged: 04/18/12

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Re: No More Tracking new [Re: Monadnock]
      #5916662 - 06/12/13 10:28 AM

Rod, Monadnock, and Kerry ... as I said in my post to cn, what I thought was a firmare issue appears instead to be cognitive dissonance after several years if experience aligning a Meade LX90 and no experience whatsoever in aligning Celestron scopes. At least I've learned a good deal about my new CPC from your explanations. I apologize for any confusion I've caused.
Bruce


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dwitek
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Reged: 07/03/08

Loc: White Lake, Michigan
Re: No More Tracking new [Re: brucepech]
      #5922416 - 06/15/13 02:55 PM

And I apologize, too, for starting this whole thing if it is in fact just a misunderstanding on my part. The CPC is a bit of an anomaly for me as I am used to using equatorial scopes. I just don't remember having any drift when doing an alignment with the CPC. I've reset the original hand controller and pushed the CPC software into another with the same results.

If I do a mock Two Star alignment I now get tracking in Alt-Az and I can do GoTos to anything in the sky. Perhaps I did have a software issue initially because after getting Align Success in the field it still wouldn't track. So, maybe the resets cleared that up but I was fixated on the Tracking Mode rather than going through the whole process.

I think the discussion was a good one and I thank everyone who stepped in. I'll move the scope back up to it's home next weekend and try it again weather permitting, of course.


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rmollise
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Reged: 07/06/07

Re: No More Tracking [Re: dwitek]
      #5925100 - 06/17/13 09:38 AM

No need to apologize...stuff happens. I have run into a scenario like this using an older version of Bisque's TheSky. Tracking would just freaking go OFF. I finally realized it was a hiccup with the program, but I was going koo-koo for a while.

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Jon Isaacs
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Reged: 06/16/04

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Re: No More Tracking new [Re: rmollise]
      #5928342 - 06/18/13 10:02 PM

Quote:

Not much of a problem IMHO. I've been doing it for over a decade without a problem, anyhow. The GPS series of scopes worked exactly the same way: tracking off till aligned, then alt-az tracking kicks in.

Alt-az tracking requires different motor speeds depending on _the position the scope is pointed to in the sky_, so until the alignment is done, there's not much point in starting tracking.




Is this the case with all Nexstar mounts? The scope knows that it is hopefully close to the intended alignment star so it should be able to track with reasonable accuracy...

Jon


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brucepech
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Reged: 04/18/12

Loc: Colorado
Re: No More Tracking new [Re: Jon Isaacs]
      #5928584 - 06/19/13 01:26 AM

Jon, to quote from a post by cn register 5 on the Cats & Casses Forum where I raised the same question I raised here:

"Part of the reason that the Celestron AltAz mounts don't track before they have aligned on at least one star is because of the Meade patent on starting at a known terrestrial alignment. Without that the scope doesn't know which way to track. If it makes some assumption about which way to track it could be said to be infringing on the patent."

So, yes, it's probably true of all post-patent Nextar mounts.


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Jon Isaacs
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Re: No More Tracking [Re: brucepech]
      #5928731 - 06/19/13 07:12 AM

Quote:

Jon, to quote from a post by cn register 5 on the Cats & Casses Forum where I raised the same question I raised here:

"Part of the reason that the Celestron AltAz mounts don't track before they have aligned on at least one star is because of the Meade patent on starting at a known terrestrial alignment. Without that the scope doesn't know which way to track. If it makes some assumption about which way to track it could be said to be infringing on the patent."

So, yes, it's probably true of all post-patent Nextar mounts.




Bruce:

Thanks for the info...

I better be careful when I align my non-GOTO mounts, make sure I align them on Polaris before turning on the drive.. My property and house are within in less than a degree of being aligned north-south/east-west so I can align very closely just by looking that the house or fence.

Of course maybe Meade doesn't have the patent on aligning to a building, fence or road...

It does seem like a strange patent, no creativity there, it's a no-brainer and people have been doing it forever, I would guess from the invention of the tracking drive. It's not GOTO but its alignment.

jon


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