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How Do You Balance Your Small Refractor for Heavy Eyepieces?

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#1 Sarkikos

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Posted 04 November 2019 - 12:26 PM

Yes, this is an old and well-known story for observers with small scopes.

 

I have several small refractors for grab-n-go.  I mount them on a MicroStar Deluxe head on Vanguard Auctus Plus 324AT.  When I put a heavy eyepiece in the diagonal, the setup is out-of-balance and the telescope OTA tends to fall back, even when the altitude knob is clamped down hard.   The dovetail cannot be pushed far enough forward to compensate for the imbalance.

 

I don't want to replace the MicroStar and tripod with a more heavy-duty setup.  I have those options already, but I don't want to increase the size and weight for grab-n-go.  I'm looking for ways to improve the balance of the setup I already have.

 

Mike


Edited by Sarkikos, 04 November 2019 - 12:28 PM.

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#2 Sarkikos

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Posted 04 November 2019 - 12:26 PM

I'm especially interested in improving the balance for my AT72EDII.  At this time it's on an AT 7" dovetail.  https://www.astronom...unts-black.html  At the end of the dovetail is a 1/4"-20 threaded hole.  Before that is a 6.9mm unthreaded hole.  One possibility I'm looking at is to attach a small counter weight to one of these holes.

 

Mike


Edited by Sarkikos, 04 November 2019 - 12:52 PM.


#3 Sarkikos

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Posted 04 November 2019 - 12:34 PM

Here is one counterweight:

 

Opteka Chrome Counterbalance Weights  https://www.bhphotov...ce_weights.html

 

The product description claims the hole is 1/4"-20 with "dual threads," but reviews say it is metric.  I can't find anything about the exact threading.

 

Mike


Edited by Sarkikos, 04 November 2019 - 12:40 PM.


#4 Sarkikos

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Posted 04 November 2019 - 12:36 PM

An option from Tele Vue:

 

Tele Vue Telescope Balance Aid  https://www.bhphotov...alance_Aid.html 

 

But will it work on my setup?  What size and threading are the holes?

 

Mike


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#5 Sarkikos

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Posted 04 November 2019 - 12:40 PM

Zhiyun Official 100g (1 PC Kit) Removable Counterweight https://www.amazon.c...617358221&psc=1

 

At least the product description says the thread is 1/4"-20.  And they are stackable.

 

Mike


Edited by Sarkikos, 04 November 2019 - 12:40 PM.


#6 Sarkikos

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Posted 04 November 2019 - 01:00 PM

Stellarvue Lightweight 2.5" Riser Blocks with 1/4-20 Screws  https://www.highpoin...rs-rs-set-rb002

 

These riser blocks lift the OTA 2.5" above the dovetail so the OTA can be positioned closer to the sky-end of the dovetail without butting against the focuser knobs or the diagonal.  thinking1.gif

 

Mike


Edited by Sarkikos, 04 November 2019 - 01:02 PM.


#7 CollinofAlabama

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Posted 04 November 2019 - 01:03 PM

Well, you know my answer -- don't use heavy eyepieces.  I don't own ANY 1.25" eyepieces over 9 ounces, and no 2"-er over a pound.  Works for me, and I think I have a nice set of eyepieces.  I don't wear glasses, however, so eye relief isn't as big a deal.  This has worked for me.  I think Don Pensack mentioned something about a steel tube with a counterweight attached to the Unitrons.  Perhaps there's something like that in the aftermarket?  I like my solution, but if you already have a lot of heavy glass, engineering options is the only recourse.  Good luck.


Edited by CollinofAlabama, 04 November 2019 - 01:04 PM.

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#8 Sarkikos

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Posted 04 November 2019 - 01:10 PM

Somehow I knew you'd be the first to answer my question.  grin.gif

 

There are some nice moderately heavy eyepieces that perform well in small refractors.  Wide fields and well-corrected fields usually mean heavier eyepieces.  Though I think maybe a 31 Terminagler, 41 Pan or 9 ES 120 might be going too far.  

 

Mike


Edited by Sarkikos, 04 November 2019 - 01:12 PM.

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#9 Sarkikos

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Posted 04 November 2019 - 01:15 PM

I think some people are just sitting back waiting to see what interesting gadgets and gizmos I will find.

 

:grin:

Mike


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#10 eros312

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Posted 04 November 2019 - 01:21 PM

If you're talking about your AT60ED, take the tube ring off and remount it backwards. Attach your dovetail rail. Now you should be able to mount it far enough forward to balance. 


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#11 zohsix

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Posted 04 November 2019 - 01:35 PM

On a TV 85, I "borrowed" one of my wife's one pound ankle weights, strap it around the OTA and slide it up or down the OTA as needed.  Works, easy, cheap.  It's made of a soft material so no problem scratching the OTA.

 

Dan


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#12 eros312

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Posted 04 November 2019 - 01:39 PM

Or get a longer rail https://www.astronom...s.html?___SID=U



#13 Sarkikos

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Posted 04 November 2019 - 01:49 PM

A longer dovetail won't make any difference, because I can only position the refractor so far foward on the dovetail before the focuser knobs hit the end of the dovetail.

 

Mike


Edited by Sarkikos, 05 November 2019 - 07:34 AM.


#14 eros312

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Posted 04 November 2019 - 01:59 PM

A longer dovetaill won't make any difference, because I can only position the refractor so far foward on the dovetail before the focuser knobs hit the end of the dovetail.

 

Mike

Stack rails or use riser blocks. 


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#15 Sarkikos

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Posted 04 November 2019 - 02:01 PM

If you're talking about your AT60ED, take the tube ring off and remount it backwards. Attach your dovetail rail. Now you should be able to mount it far enough forward to balance. 

I already tried that with the AT60ED.   I don't recall exactly what, but there was something about that setup which didn't work right or that I didn't like for some reason.  For now, I have the AT60ED mounted on a plate for the 501HDV.

 

Mike



#16 Sarkikos

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Posted 04 November 2019 - 02:04 PM

Stack rails or use riser blocks. 

No, I won't stack rails.  That would add substantially to the weight and cumbersomeness for grab-n-go.  But those Stellarvue Riser Blocks back in post #6 look interesting.  

 

Mike



#17 Sarkikos

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Posted 04 November 2019 - 02:06 PM

The best options so far seem to be the Stellarvue Riser Blocks and/or some kind of counterweights attached to the dovetail.

 

Does anyone know any other sources of small counterweights that can be attached to a dovetail?

 

Mike



#18 Sarkikos

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Posted 04 November 2019 - 02:10 PM

I swear there was some Stellar Vue Rise Blocks in stock at High Point Scientific when I first started this thread.  Now it says, "More on the way." 

 

Did someone here already order a pair?  thinking1.gif  

 

If you did, let us know how they work out.

 

grin.gif

Mike


Edited by Sarkikos, 04 November 2019 - 02:10 PM.


#19 Sarkikos

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Posted 04 November 2019 - 02:13 PM

One possible problem I see with the Stellarvue Riser Blocks is that the pictures show them on a wide dovetail, not the narrow dovetail I'm using now.  It might not be worth it to use the riser blocks if I need to put them on a bigger, heavier dovetail.  This is for grab-n-go.  I'm trying not to add too much to the weight and size of the setup.

 

The riser blocks and wide dovetail are more something I might put together for a trip to a dark site, not something for quick and easy grab-n-go at home.

 

Little counter weights are looking like the prime option now.

 

Mike


Edited by Sarkikos, 04 November 2019 - 02:15 PM.

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#20 eros312

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Posted 04 November 2019 - 02:16 PM

The best options so far seem to be the Stellarvue Riser Blocks and/or some kind of counterweights attached to the dovetail.

 

Does anyone know any other sources of small counterweights that can be attached to a dovetail?

 

Mike

Like this? https://www.admacces...3-threaded-rod/


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#21 Sarkikos

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Posted 04 November 2019 - 02:21 PM

Good concept, but 3.5 lbs is probably more weight than I need for these small refractors.  I might be able to use it on other scopes, though.  Or maybe I could finder smaller weights for it.

 

Mike


Edited by Sarkikos, 04 November 2019 - 02:22 PM.


#22 Sarkikos

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Posted 04 November 2019 - 02:32 PM

Steadicam Balance Weight for Solo https://www.bhphotov...nce_weight.html  

 

1/4"-20 Screw & Threading for Stacking, 4.6 oz.

 

BUT ... More on the Way.  fingertap.gif

 

Mike


Edited by Sarkikos, 04 November 2019 - 02:32 PM.


#23 eros312

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Posted 04 November 2019 - 02:39 PM

Good concept, but 3.5 lbs is probably more weight than I need for these small refractors.  I might be able to use it on other scopes, though.  Or maybe I could finder smaller weights for it.

 

Mike

Yeah, I was thinking it would be too much. Anthony could probably make you a custom weight, something around a pound would be good. 


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#24 Sarkikos

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Posted 04 November 2019 - 02:40 PM

SmallRig 2285 Counterweight  https://www.bhphotov...ASABEgIAUPD_BwE

 

"Designed for easy stacking, this counterweight has a 1/4"-20 screw on one side and a 1/4"-20 threaded hole on the other."  1.8 oz, 3.5 oz and 7 oz sizes.

 

Mike


Edited by Sarkikos, 04 November 2019 - 02:41 PM.


#25 makeitso

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Posted 04 November 2019 - 02:53 PM

Have you looked at any of these yet? Scroll down for more.

 

https://www.highpoin...r_optical_tubes

Jack




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