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XX12g Altitude Bearing Question...

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#1 Dave Bush

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Posted 23 September 2020 - 03:47 PM

Notice in the photo how that my altitude bearing rests on just a little more than 50% of the width of the rollers.

 

For those of you who own this scope (and I suppose the 14 and 16 inch versions as well), is yours similarly positioned?

 

I'm getting more vibration than I would suspect from this mount and I'm wondering if this might be part of the cause.

 

 

67F9EBFE-ABC6-4AE5-B7A8-8F2AAF9298A1_1_201_a.jpeg


Edited by Dave Bush, 23 September 2020 - 03:48 PM.


#2 junomike

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Posted 23 September 2020 - 04:26 PM

I think mine (SW 12/Orion 16) are like that also but maybe not to that extent. 

Never had an issue with it.



#3 GeneT

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Posted 23 September 2020 - 06:04 PM

It just doesn't look right to me. My Dobs were squared much better.



#4 MOwen

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Posted 23 September 2020 - 06:13 PM

I noticed the same thing on my 14 recently (it's about 2 1/2 yrs old) but it does not appear to be an issue.  I checked the rollers carefully and they seem to be quite solid.



#5 darksky.fan

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Posted 23 September 2020 - 06:22 PM

Notice in the photo how that my altitude bearing rests on just a little more than 50% of the width of the rollers.

 

For those of you who own this scope (and I suppose the 14 and 16 inch versions as well), is yours similarly positioned?

 

I'm getting more vibration than I would suspect from this mount and I'm wondering if this might be part of the cause.

My XX12g looks almost the same as yours.  I always thought it was odd but have had no problem.  Glad (?) to know mine is not the only one???  I check the roller bearing almost every outing.  So far no problem, but the cosmetics IMHO are not desirable.



#6 MOwen

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Posted 23 September 2020 - 08:32 PM

There's two possible fixes for this, both of which I am going to investigate while I have my scope disassembled for other purposes.  I'll let you guys know if I come up with a 'better mousetrap'.


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#7 MOwen

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Posted 24 September 2020 - 08:55 AM

OK, the fix appears to be an easy one.  Remove the bearing assembly and add a spacer to move the roller outward by the desired amount.  The shaft size is exactly 5/16".  I strongly suggest that you use a spacer that fits snuggly over the shaft.  A fender washer is not a good choice since the hole is larger than the shaft and may not provide full support.  I'm going to drill a 5/16" (+) hole in some solid material to be certain that there is no stress on the assembly.  You might be able to find a nylon spacer that has the 5/16" hole.  

 

AZ_Bearing.jpg

 


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#8 HubSky

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Posted 24 September 2020 - 12:26 PM

Though I no longer own it, my xx12g was exactly the same way.  It never gave me issues, and therefore never put a second's worth of thought into "correcting" it.  



#9 Eddgie

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Posted 24 September 2020 - 03:22 PM

A possible issue is that the rubber tire on the bearings (there are two bearings under the rubber tire) is rippling as the scope rolls on it. If the adhesive has failed or has not been properly applied, as the scope bearing rolls on the tire, it will ripple up in front of the bearing causing unsmooth movement. 

There is a simple solution and in time it may just provide itself for you.  If the tire feels loose to you, just peel it off.  If it is loose, it will walk off the ball bearings all on its own one day.

 

This happened to my scope in the first six months of ownership.  When the first one walked off of the bearing on its own, I just removed the other one and never worried about it.  I don't know what purpose the tire serves and it just creates unnecessary rolling friction.  My scope worked fine without them for over seven years.  

 

Just something to check.  If it is stuck on tight it is probably fine, but if you can squirm it around, I would just remove them all. 


Edited by Eddgie, 24 September 2020 - 03:23 PM.

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#10 Dave Bush

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Posted 24 September 2020 - 04:46 PM

OK, the fix appears to be an easy one.  Remove the bearing assembly and add a spacer to move the roller outward by the desired amount.  The shaft size is exactly 5/16".  I strongly suggest that you use a spacer that fits snuggly over the shaft.  A fender washer is not a good choice since the hole is larger than the shaft and may not provide full support.  I'm going to drill a 5/16" (+) hole in some solid material to be certain that there is no stress on the assembly.  You might be able to find a nylon spacer that has the 5/16" hole.  

 

attachicon.gifAZ_Bearing.jpg

I just took mine apart and my scope being a 12 instead of your 14 looks a bit different.  The shaft that goes into the board on mine is black and the screw is a silver Phillips but that's immaterial.  What's interesting is that I may have the perfect material for that spacer.  It came with the scope and it's a plastic tube that was used to push the rubber washers onto the captive screws that hold the sides together.  It fits nicely over that shaft with very little play.  I just need to cut it to the right size.

 

I'll report back.



#11 Dave Bush

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Posted 24 September 2020 - 06:16 PM

Fixed.  [see photo below].  Thanks MOwen for the suggestion

 

 

IMG_7818.JPG


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#12 Asbytec

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Posted 25 September 2020 - 08:27 AM

"I'm getting more vibration than I would suspect from this mount and I'm wondering if this might be part of the cause."

Your fix looks nice. Did it stop the vibration?

Another cause of vibration is the feet under the ground board. They need to be placed under the azimuth bearings. I am not sure if your scope uses a Lazy Susan, nor whether this mod will help if so. Mine has three Teflon pads. Placing the feet under them is, by far, the most productive mod I made on my scope. Near zero vibration and almost instant dampening.

#13 Dave Bush

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Posted 25 September 2020 - 01:27 PM

"I'm getting more vibration than I would suspect from this mount and I'm wondering if this might be part of the cause."

Your fix looks nice. Did it stop the vibration?

Another cause of vibration is the feet under the ground board. They need to be placed under the azimuth bearings. I am not sure if your scope uses a Lazy Susan, nor whether this mod will help if so. Mine has three Teflon pads. Placing the feet under them is, by far, the most productive mod I made on my scope. Near zero vibration and almost instant dampening.

The vibration seems to have lessened.  I wouldn't necessarily have expected that this fix would have had much effect but it may have.

 

With regards to the feet, without disassembly I can't tell where or what type of azimuth surfaces the two boards are riding on.  I'm not inclined to take it apart either.  I have been using anti-vibration pads under the feet and that has helped. 


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