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Equipment Discussions >> Mounts

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Cliff Hipsher
Pooh-Bah
***

Reged: 12/31/08

Loc: North Chesterfield, VA
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: wolfman_4_ever]
      #5720155 - 03/08/13 09:52 AM

Quote:

2+4 star calibration is not polar aligning. Once you finish your 2+4, slew to a stat near the meridian and Dec 0 and then hit the align button, then choose polar align, then follow tge directions. The 2+4 star calibration is a star model for the mount, not polar alignment.




Amen Brother! Preach it! If your hand controller does not prompt you to physically adjust the mount in Alt and AZ (like my LXD75 does for a 1 star alignment), you are not doing a Polar Alignment.

I tripped over this for a long time and could not figure out what was "wrong" with my mount.

What it boils down to is Polar Alignement affects TRACKING which explains why folks serious about AP prefer drift aligning.

All this felgercarb about 2, 3, and 4 star alignments and calibration stars is about generating a pointing model for GoTos.

Basically, your Polar can be off and GoTos can be spot on and vice versa. What matters for long exposure imaging is the accuracy of your Polar alignment, and here is an easy way to prove that.

Fire up your mount, and do a Polar alignment, then do a drift. DO NOT run any of the multi-star "alignments". Use the hand controller and slew to a star, any star. Get the star centered and then walk away. Come back 15 minutes later. Barring any errors in the gear train the star should be right where you left it.

If the star has drifted you can run what ever test motors/calibrate motors/train drive/ PEC train functions your mount has and then run this test again.


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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: wolfman_4_ever]
      #5720954 - 03/08/13 06:13 PM Attachment (17 downloads)

Dave...I understand all of that and have done the 2 + 4 several times for various reasons. In the sequence of events that follows, one is prompted to polar align with the All-star Polar Alignment. I had tried drift alignment and Kochab method and others, but the Celestron method gave me the best results. What may be a problem on my mount is the knob which points down vertically (see photo) that determines latitude. I had to insert a piece of metal and glue it in order to get latitude correct because the knob and and screw were not long enough and use a pipe wrench to adjust. There is a guide which is not very accurate. Doing polar alignment watching the monitor in Maxim DL with 1 sec or less continuous exposures, I get the crosshairs dead on the alignment star, going back and forth with latitude knob and the horizontal logitude knob which work very easily. I did get 00-00-00 and tracking from then on was quite exceptional. My observatory is at 44 degrees; 81 min North latitude and 85 degrees 42 minutes West longitude.

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WadeH237
Pooh-Bah


Reged: 02/24/07

Loc: Snohomish, WA
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5721044 - 03/08/13 07:06 PM

Um, did you not realize that the plate for the altitude adjustment can be moved?

Celestron ships the mount with it in the upper position, which works from low latitudes, to about 45 degrees. That silver plate at the top of the circle in your picture can be moved into a lower position for higher latitudes. I believe that there a 4 hex bolts on each side that you need to remove, and then re-add in the lower position.

-Wade


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5721046 - 03/08/13 07:08 PM

Quote:

Dave...I understand all of that and have done the 2 + 4 several times for various reasons. In the sequence of events that follows, one is prompted to polar align with the All-star Polar Alignment. I had tried drift alignment and Kochab method and others, but the Celestron method gave me the best results. What may be a problem on my mount is the knob which points down vertically (see photo) that determines latitude. I had to insert a piece of metal and glue it in order to get latitude correct because the knob and and screw were not long enough and use a pipe wrench to adjust. There is a guide which is not very accurate. Doing polar alignment watching the monitor in Maxim DL with 1 sec or less continuous exposures, I get the crosshairs dead on the alignment star, going back and forth with latitude knob and the horizontal logitude knob which work very easily. I did get 00-00-00 and tracking from then on was quite exceptional. My observatory is at 44 degrees; 81 min North latitude and 85 degrees 42 minutes West longitude.




Looking at your photo I see why you had trouble with the latitude adjustment. The plate that the adjustment knob screws into can be moved further down in order to adjust to higher latitudes. If you look at the side of the base casting there are two holes further down on each side for mounting the plate. Simply remove it from the current location and attach it in the lower location and then the knob will be long enough to reach your latitude and will also push the axis housing at a better angle. With the additional wieght this could actually be a flexure point for you since the angle between the knob and the contact plate gets lower as the latitude gets higher. Adding addition wieght with the knob threaded all the way in could actually cause some flexture.


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wolfman_4_ever
Pooh-Bah


Reged: 07/15/11

Loc: El Segundo, Ca, So. Cal
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5721051 - 03/08/13 07:10 PM

You can move that plate, that the latitude bolt goes through, to the bottom of the mounting brackets. Thats listed in the manual for high latitutes. Yes, polar aligning in altitude can be tough when the mount is fully loaded.

You polar align the mount and not the telescopes. Take off all but your little finder, if weight is an issue, and polar align.


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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: EFT]
      #5721245 - 03/08/13 09:20 PM

Ed Thomas...I see what you're saying about moving the plate down. Anyway, I know I am reasonably well polar aligned. I did have SUCCESS TONIGHT! I took off some stuff and rebalanced everything. Then I went to utilities and went to factory settings. I had to enter all the info...state, city, time, etc. Then I did a 2+4 and a precise-go to M42. Dead on after hitting the go to star. In Maxim DL it tracked with no star drift for 60 sec. I tried to autosave, set image path in my flash drive, but then as I hit start, the error message came up "Cannot autosave sequence because of no sequence" or something like that. Never happened before. Remember I have a Starlight Xpress one-shot color M25C camera, so I don't autoguide.

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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5721378 - 03/08/13 11:26 PM

Quote:

Ed Thomas...I see what you're saying about moving the plate down. Anyway, I know I am reasonably well polar aligned. I did have SUCCESS TONIGHT! I took off some stuff and rebalanced everything. Then I went to utilities and went to factory settings. I had to enter all the info...state, city, time, etc. Then I did a 2+4 and a precise-go to M42. Dead on after hitting the go to star. In Maxim DL it tracked with no star drift for 60 sec. I tried to autosave, set image path in my flash drive, but then as I hit start, the error message came up "Cannot autosave sequence because of no sequence" or something like that. Never happened before. Remember I have a Starlight Xpress one-shot color M25C camera, so I don't autoguide.




I don't really know Maxim DL so someone else will have to address that. But if reducing the load helped, then I would definitely look at relocating that latitude adjustment mechanism since it could be a flexure point with the increased load. I would probably also consider autoguiding. At f/11 with the C14, even shorter exposures migth be a challenge.


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TxStars
Pooh-Bah
*****

Reged: 10/01/05

Loc: Lost In Space
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: EFT]
      #5723384 - 03/10/13 05:14 AM

Off hand I would say that adding the C-6 piggybacked is overloading the mount thus causing something to slip.
If it is a clutch you may be able to adjust it to fix the problem.
If you are wanting to guide to just keep the scope on target you could use one of the small "Finder/guides" and save a lot of weight.
You could also get a bigger mount to solve the weight problem.


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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: TxStars]
      #5724133 - 03/10/13 03:24 PM Attachment (9 downloads)

TX...Did you read that I got the problem of star trailing to stop by resetting to factory default? Before that I removed some stuff but left the 6" OTA on and balanced in RA and DEC. Today I added everything back in a different more balanced way. I have problems with getting to my observatory. I use a snowmobile, so I can't just walk out there. I'm closing in on solving this. The CGE Pro is well able to handle my add-ons. One Crayford has to go, though.

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TxStars
Pooh-Bah
*****

Reged: 10/01/05

Loc: Lost In Space
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5725164 - 03/11/13 03:12 AM

I read that you got it to not drift for 60 sec with stuff taken off, but not with everything on.

Quote:

Ed Thomas...I see what you're saying about moving the plate down. Anyway, I know I am reasonably well polar aligned. I did have SUCCESS TONIGHT! I took off some stuff and rebalanced everything. Then I went to utilities and went to factory settings. I had to enter all the info...state, city, time, etc. Then I did a 2+4 and a precise-go to M42. Dead on after hitting the go to star. In Maxim DL it tracked with no star drift for 60 sec. I tried to autosave, set image path in my flash drive, but then as I hit start, the error message came up "Cannot autosave sequence because of no sequence" or something like that. Never happened before. Remember I have a Starlight Xpress one-shot color M25C camera, so I don't autoguide.




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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: TxStars]
      #5725327 - 03/11/13 07:49 AM

TX....I will do the rebalancing today but will have to wait until I get a cloudless night (which may be a week or more looking ahead) to redo the factory defaults, 2+4, etc. Will post results at that time.

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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: TxStars]
      #5726280 - 03/11/13 04:35 PM

TX...As to balancing my add-ons in RA, which included another 80mm scope to offset the PST, two Imaging Source cameras, and two finderscopes... one on each side of the 14" OTA...the process was a trial and error process, but successful. In balancing all this stuff in DEC, I replaced the counterweight tube stop knob with a slightly longer bolt and washer and the four counterweights were able to offset the loaded system.

Now all I have to do is wait for a cloudless night to go to factory defaults of the mount and do the 2+4. I should be good to go!


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jrcrillyAdministrator
Refractor wienie no more
*****

Reged: 04/30/03

Loc: NE Ohio
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: ejjh]
      #5726391 - 03/11/13 05:24 PM

Quote:

In balancing all this stuff in DEC, I replaced the counterweight tube stop knob with a slightly longer bolt and washer and the four counterweights were able to offset the loaded system.




That's RA balance. How does declination balance look?


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ejjh
member


Reged: 03/16/09

Loc: Michigan
Re: Problem of star trailing with loaded CGE Pro Mount new [Re: jrcrilly]
      #5726540 - 03/11/13 06:23 PM

John...did I screw up the terms? Both RA and DEC balance well.

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