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PnP Rockler slimline lazy susan for Orion XT8 plus.

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#1 Jim7728

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Posted 25 August 2019 - 02:06 PM

Probably an old dob mod upgrade method, but thought I'd share.

 

The Orion XT8 base teflon on laminated pressboard azimuth motion was functional, but slightly grabby at times.

 

Ordered a slimline lazy susan (that some mass produced dob manufactures use) from  Rockler.    Just replace center azimuth bolt teflon washer with the lazy susan and reassemble with proper bolt tension.  Outer teflon pads remain, no need to remove.

 

Whole lot smoother motion without the grabby sensation. laugh.gif

 

lazy suzan.jpg


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#2 eklf

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Posted 25 August 2019 - 02:57 PM

Thanks for the info. I have been looking for that bearingmfor a while. 


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#3 mjulihn

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Posted 25 August 2019 - 10:28 PM

Most GSO-made dobs (Apertura, Zhumell) use a similar roller bearing lazy susan sandwiched between two metal plates. Creates very smooth azimuth movements.


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#4 Jon Isaacs

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Posted 25 August 2019 - 10:39 PM

Most GSO-made dobs (Apertura, Zhumell) use a similar roller bearing lazy susan sandwiched between two metal plates. Creates very smooth azimuth movements.

 

Many find the bearings do not have enough friction so the scope tends to be too easy to move and subject to overshoot. Another issue is they're not sealed they can be contaminated with dust and grime.

 

People cank down on the center boot the add friction. In the short run it can work but it can lead to damaged bearings.

 

Jon


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#5 Jim7728

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Posted 26 August 2019 - 06:23 AM

Most GSO-made dobs (Apertura, Zhumell) use a similar roller bearing lazy susan sandwiched between two metal plates. Creates very smooth azimuth movements.

 

That seems to be the best combo in mass produced dobs.

 

Many find the bearings do not have enough friction so the scope tends to be too easy to move and subject to overshoot. Another issue is they're not sealed they can be contaminated with dust and grime.

 

People cank down on the center boot the add friction. In the short run it can work but it can lead to damaged bearings.

 

Jon

 

I've had consistent results with a Apetura azimuth bearing kit in a home made mount for my 6" Maknewt.  Yes, do have to tweak tension once in awhile . Too tight will cause wear.   Maintenance is probably  key for consistency. 

 

I've had mixed results with Ebony star and teflon pads for a 12" home made dob base.  Used a combo with a low profile lazy metal lazy susan, but still had issues probably due to choice of plywood not being flat enough.  

 

lazy suzan 2.jpg



#6 Jon Isaacs

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Posted 26 August 2019 - 06:31 AM

I've had consistent results with a Apetura azimuth bearing kit in a home made mount for my 6" Maknewt.  Yes, do have to tweak tension once in awhile . Too tight will cause wear.   Maintenance is probably  key for consistency.

 

 

I have good results with Teflon-Laminate bearings. I manage tracking up to 822x with my 10 inch GSO, more with the larger scopes.

 

Jon



#7 jtsenghas

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Posted 26 August 2019 - 08:54 AM

One thing I've noticed on my personal builds is that a VERY slight chamfer on the edges of the Teflon pads helps with keeping the static friction for startup nearly the same as dynamic friction to maintain motion. After a few experiments with bearings I find I like having three Teflon pads against slightly bumpy laminate, and those work better with centerless bases also. 



#8 dmgriff

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Posted 26 August 2019 - 11:13 AM

If the lazy susan is "too loose" the old velcro mod adds friction (sticktion).

 

Use some double sided tape on the bottom board to attach the velcro strips (2 to 3 eaually spaced). The fuzzy side should rub against the bottom of the top board to provide friction to the roller bearings. Layer the double sided tape to the correct thickness.

 

Works on my Hardin GSO dob with the original teflon roller bearing system.

 

Good viewing,

 

Dave



#9 junomike

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Posted 30 August 2019 - 06:29 PM

I went the Lazy Susan way and it worked great.  As Jon mentioned however I found the friction-less system too good.

I added an AZ brake and all is good again.



#10 mjulihn

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Posted 30 August 2019 - 06:55 PM

That seems to be the best combo in mass produced dobs.

 

I've had consistent results with a Apertura azimuth bearing kit in a home made mount for my 6" Maknewt.  Yes, do have to tweak tension once in awhile. Too tight will cause wear.  Maintenance is probably key for consistency.

Exactly! And this is true whether you have Teflon pads or bearings...


Edited by mjulihn, 30 August 2019 - 06:57 PM.



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