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#1 donald41

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Posted 25 August 2019 - 12:46 PM

i have had this mount for about 5 years and really like it. i have both the 6 and 8" sct scopes. no problem with the alignment but when it moves to the object ive selected it will drift out of the fov so i have to use the arrow keys to center it and keep doing this until it stays centered. is there a way to correct this or is it doing this because of the age of the mount. i have tighten the altitude bolt but it didnt seem to help. thanks, don 



#2 sg6

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Posted 25 August 2019 - 01:09 PM

Reads of 1 mount and 2 scopes?

If so does it happen on one or both?

 

The 8" scope is said to be at the limit of the mount, often said to exceed the capabilities of the mount.

 

You will have to get both OTA's well balanced if you are changing them around and usually a little off balance is considered best, suspect it just causes the gears to engage better.

 

Is there a sort of goto target sequence? You could find that the OTA is best if it goes to the target, passes it a little then goes back to center on the target. Sometimes the software does it and I suppose that means that some software doesn't. Which is where you may come in by having to adjust.

 

Gears etc will be wearing a little, so more "slop" in the gear train. Not sure if you can tension things up a fraction, and it would be only a fraction.

 

You also have the inherent narrow field so a little drift moves targets out of view with just a give in the system. A 30mm plossl gives 67x and that is 0.74 degree. If target is centered then a "movement" of just 0.4 degrees puts it out of the view. You are likely having to recenter with a movement of 0.2 degree to be safe and that is not a lot of drift so you do it a lot of times.

 

I guess you will have to determine the best balance such that gear remain in contact (slight rear heavy maybe). Final target approach is another. Suspect no option about checking the tension/pressure between the gears and drive and adjusting, which is general wear.



#3 donald41

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Posted 25 August 2019 - 01:57 PM

sg6, thanks for the suggestions, never thought about the ep mm. i was using a 9mm ep when moving to a target. next time out i will use the 9mm for alignment then put in a 20mm went targeting and if i wont to see the object at a higher mag, i can replace the 20 with a 9. don



#4 barbarosa

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Posted 25 August 2019 - 02:09 PM

...i have to use the arrow keys to center it and keep doing this until it stays centered. is there a way to correct this or is it doing this because of the age of the mount. i have tighten the altitude bolt but it didnt seem to help. thanks...

Is the boldface section accrurate? Are you saying that repetitive use of the arrow keys to center eventually prevents further drift? If the movements in both alt and az or in just one eventually create a stable tracking condition I am going to take a flyer on backlash as the cause. 

 

If you haven't done so read the manual section on adjusting the ANTI-BACKLASH settings. What those settings do is is add a bit of extra to a slew to wind out the gear lash. You find the best settings for each axis by repetitive trials. You may have to redo the settings if you change payload.

 

Find the best go to direction setting for your mount. There are many posts about this. My  recollection is that I just left it at the default.

 

The other thing you should do as a best practice is run the CALIBRATE GOTO item in the UTILITIES MENU.

 

Try all these things first before you get the idea of tearing down the mount and changing the lubricants or giving it a good cleaning. The grease is probably still doing its job but that is a separate  topic.



#5 donald41

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Posted 25 August 2019 - 03:10 PM

barbarosa, on the subject of setting the anti-backlash, while in the settings azm positive came up and i set it to a number then press enter but from that point the instructions are unclear about how to go to the next step, so what do i press in order to continue. don



#6 donald41

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Posted 25 August 2019 - 08:08 PM

barbarrosa, i got some instructions online on how to. thanks, don



#7 mclewis1

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Posted 26 August 2019 - 07:46 AM

https://www.nexstars...ds/Backlash.htm




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