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Rotating focuser barrel

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#1 Dmagyar

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Posted 11 September 2019 - 03:47 PM

Just curious, if I'm making too much of the binding that I'm getting when attempting to rotate the focuser barrell when using the scope?  Just had the scope a few nights and it will turn after loosening the thumb screw, but only 10° of rotation or so before binding.  Is there any grease or something that is used for this?   Thanks in Advance, Dan



#2 tog

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Posted 11 September 2019 - 08:40 PM

Dan,

what focuser do you have? Are there other adjustment points on the focuser that will relieve the binding? I have a rotatable fosuser and sometimes I turn the wrong thumb screw by mistake in the dark. Can you get it past the binding point? Some other folks with more experience than I have will be along soon to assist. 


Edited by tog, 11 September 2019 - 08:41 PM.


#3 Dmagyar

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Posted 11 September 2019 - 09:13 PM

It’s a hex 2.5” focuser, not sure who makes it, maybe Bresser?.  So here’s what I’ve noticed after having the scope for four days, see photo. Let me know. If I’m stressing for nothing...

Attached Thumbnails

  • FFE624BC-F994-43DD-ACF7-0286E15A77A8.jpeg

Edited by Dmagyar, 11 September 2019 - 09:15 PM.


#4 Ulmer Spatz

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Posted 12 September 2019 - 07:21 PM

I think the video at the link addresses the issue you're having. Focuser rotation is covered from 1:48 to 3:28. At one point in the section from 2:30 to 2:44, the video seems to show the same scratch you're showing in your photo. The way I understand the narrator, all four screws (the three small hex screws and the thumb screw) act in concert and need to be adjusted just so for smooth rotation. But I need to look at the video again to be 100% sure of that.

 

https://www.youtube....v=SgfE-h8ejr8  


Edited by Ulmer Spatz, 12 September 2019 - 07:31 PM.


#5 JOEinCO

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Posted 13 September 2019 - 05:57 AM

There are three set screws (also called grub screws, and I'm sure other names) that ride in that same groove as the locking screw. They should have little nylon tips on them, but I've had great success by replacing them with full-nylon set screws. This simple upgrade makes setting the "slack" tension more precise because you can tighten the set screw much more and never gouge the aluminum groove. Then, in turn, the lock screw doesn't need to do so much work. This has worked well on any rotating focuser I've had below the Moonlite/FeatherTouch level gems. 

 

I think I bought a couple sizes of nylon set screws in bags of 10 on eBay or at ScopeStuff......Cheap, effective upgrade.



#6 Ulmer Spatz

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Posted 13 September 2019 - 09:00 AM

Forget the video I linked. JOEinCO's explanation is much clearer.


Edited by Ulmer Spatz, 13 September 2019 - 09:02 AM.


#7 ThatsMyCoffee

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Posted 13 September 2019 - 12:00 PM

It’s a hex 2.5” focuser, not sure who makes it, maybe Bresser?.  So here’s what I’ve noticed after having the scope for four days, see photo. Let me know. If I’m stressing for nothing...

 

If that is a Bresser, I'm pretty sure that they don't rotate.  At least mine didn't.  



#8 Dmagyar

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Posted 13 September 2019 - 06:48 PM

So far I haven’t heard much of anything from Kent at ES, I see my focuser wasn’t able to rotate like the one depicted in the video, and will have to rely that ES steps up and fixes this new scope, now one week old.  

As I don’t think it’s operation is correct.



#9 Dmagyar

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Posted 17 September 2019 - 02:27 PM

Also noticed when examining the situation, why doesn't the thumb screw have the nylon tips like the "grub" screws have??? Guess that makes too much sence...



#10 Dmagyar

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Posted 17 September 2019 - 02:32 PM

Supposed to have facetime video chat with Kent at ES this morning...hasn't happened yet.  Are there any ES authorized service shops in Northern California, as it seems I'm going to have to bring this OTA and focuser in to have it examined?  Thanks for any response. ( I know I could google this), but wanting feedback from the community also,

Thanks Dan



#11 Ulmer Spatz

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Posted 17 September 2019 - 04:00 PM

Also noticed when examining the situation, why doesn't the thumb screw have the nylon tips like the "grub" screws have??? Guess that makes too much sence...

My guess is this: The thumb screw is supposed to be used as a locking screw only. During rotation, the thumb screw should be backed out far enough so it does not contact the rotating element. Once the rotation is done, the thumb screw is turned back in to lock the rotating element in place.

 

The whole issue might rest on nothing more than a poorly written instruction manual.



#12 mich_al

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Posted 17 September 2019 - 04:25 PM

Supposed to have facetime video chat with Kent at ES this morning...hasn't happened yet.  Are there any ES authorized service shops in Northern California, as it seems I'm going to have to bring this OTA and focuser in to have it examined?  Thanks for any response. ( I know I could google this), but wanting feedback from the community also,

Thanks Dan

Kinda looks like you've been abandoned.  Why continue down this road?  I'd put the whole shootin match back in the box then the box in return mail.  How much crap are you willing to take ?  Why ?



#13 Dmagyar

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Posted 17 September 2019 - 05:30 PM

Spoke too soon.  Finally received the facetime call from ES, where they agreed that the Visual back and focuser are damaged resulting in them shipping me a new OTA and focuser...That beats having to transport to the closest telescope shop or mail back the OTA and focuser, only to have the spectre of being denied and being back to square one. 

 

I'll be returning the damaged specimen that I've got.  waytogo.gif  Sure glad that there's forums like this where all of the combined members experiences can be aggregated.  Otherwise a new owner like myself wouldn't know what to expect, and also talk to someone who's not selling them anything...


Edited by Dmagyar, 17 September 2019 - 05:37 PM.

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#14 tog

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Posted 18 September 2019 - 11:29 AM

I'm glad they stepped up to take care of you!


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#15 JOEinCO

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Posted 18 September 2019 - 03:01 PM

Also noticed when examining the situation, why doesn't the thumb screw have the nylon tips like the "grub" screws have??? Guess that makes too much sence...

You are tightening down the thumbscrew way too hard. If the three nylon-tipped grub screws are properly adjusted, it only takes the lightest of turns of the thumb screw to lock the focuser. 

 

Don't chew up the new one. grin.gif 



#16 Dmagyar

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Posted 18 September 2019 - 07:13 PM

You are tightening down the thumbscrew way too hard. If the three nylon-tipped grub screws are properly adjusted, it only takes the lightest of turns of the thumb screw to lock the focuser. 

 

Don't chew up the new one. grin.gif 

 

Joe, be advised I’m cognizant of the concept you’re referring to and will use all due diligence operating the replacement scope.  With said set screws snugged, the focuser still had more than a few degrees of wobble either way.  The reason that this is being replaced is that somewhere during transit, from where it was made to my doorstep, the packing was not up to the task of protecting the scope and attached focuser.  At some point an impact occurred that damaged both OTA and focuser.  What your describing is the operation that I expect to have once I’ve gotten an undamaged example.  



#17 JOEinCO

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Posted 19 September 2019 - 10:36 AM

waytogo.gif



#18 Dmagyar

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Posted 19 September 2019 - 11:03 AM

Clear sky’s to all.




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