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How Do You Balance Your Small Refractor for Heavy Eyepieces?

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#101 dhormann

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Posted 04 December 2019 - 01:31 AM

Yes, mounting a small refractor on a riser on a 14" D Plate would raise the focuser knobs above the plate, allowing the telescope to be shifted forward to provide balance with heavy eyepieces.  But as I mentioned in my Opening Post, "I don't want to increase the size and weight for grab-n-go."  A big D Plate would definitely increase the size and weight for grab-n-go.  The D Plate would also require a larger, more heavy-duty head and tripod.  Not what I want to do.

 

Mike

Sorry.  I guess the thread seemed to have drifted a bit from your original question and I drifted along with it. That being said, it appears from your description as if the Microstar is already near its limit given your combination of OTA, diagonal and eyepiece, so here’s a possible solution that I’ve used successfully in the past.  

 

Make a set of risers out of wood, preferably a stable hardwood like hard maple.  I’ve done this to make my focused knobs just clear the dovetail plate thereby giving me more room to slide the OTA and balance the rig.  The advantage of wood is 1) It’s relatively cheap, so prototyping won’t break the bank, 2) it’s light, 3) you can customize it as needed to match the type of rings and plate you’re using, and 4) you can make the risers just tall enough to solve any clearance problems thus keeping them nice and light for your grab-n-go rig.  I promise, they will work just as good as aluminum ones. The last set I made took me about 15 minutes to make and weighs maybe a bit over two oz. at most.  If you don’t have your own, find a buddy with a drill press to bore the holes, but everything else can be done with hand tools.   In any case, good luck!

 

 (If you like, I can dig mine out and send you a photo)

 

Doug


Edited by dhormann, 04 December 2019 - 02:19 AM.

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#102 Sarkikos

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Posted 04 December 2019 - 07:50 AM

The MicroStar head and Vanguard tripod are able to support the weight of the AT72EDII, 2" diagonal and heavy 2" eyepiece.   The problem, of course, is that the focuser knobs hit the dovetail if the OTA is shifted forward far enough to compensate for heavier load.

 

Well, I suppose I could saw a couple pieces of wood with a hand saw.   But I don't have a drill press and I don't know anyone who has one.  Though is a drill press really necessary to drill holes in wood?  I have an electric hand drill.    

 

Mike


Edited by Sarkikos, 04 December 2019 - 07:55 AM.


#103 Sarkikos

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Posted 04 December 2019 - 07:59 AM

Maybe there is something available off-the-shelf that I could repurpose as risers.  I already posted a link to risers back in this thread (post #6). 

 

https://www.highpoin...rs-rs-set-rb002

 

I thought these risers were for a D Plate, not a Vixen dovetail.  But I looked closer at the product description and found this:

 

What's in the Box

 

Pair of Riser Blocks for Refractor Telescopes

Four 1/4-20 screws for Losmandy dovetails

Two 1/4-20 screws for Vixen dovetails

 

Dovetail or Attachment Type

 

Dual (D & V)

 

$69 is a bit high.  And they are not in stock.  "More on the way."

 

Mike
 


Edited by Sarkikos, 04 December 2019 - 08:01 AM.


#104 Sarkikos

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Posted 04 December 2019 - 08:32 AM

Here is another set of riser blocks from Stellarvue.  These are $49.

 

STELLARVUE - RISER BLOCK SET

https://telescopes.n...BCABEgKiK_D_BwE

 

If I made a pair of riser blocks myself, it would probably burn up much more than $49 worth of my time.  grin.gif

 

These risers are not in stock either.  "More on the way."

 

Worse than that, they "have been discontinued and are no longer available."  This is according to the product description at High Point Scientific:

https://www.highpoin...t-only-rb002set

 

Mike


Edited by Sarkikos, 04 December 2019 - 11:04 AM.


#105 Sarkikos

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Posted 04 December 2019 - 10:25 AM

More risers/spacers:

 

PRIMALUCELAB - PLUS 30MM SPACERS $39

https://telescopes.n...m_source=criteo

 

PRIMALUCELAB - PLUS 20MM SPACERS $34

https://telescopes.n...mm-spacers.html

 

PRIMALUCELAB - PLUS 10MM SPACERS $29

https://telescopes.n...mm-spacers.html

 

The Stellarvue risers are 2.5" (63.5mm) tall.  

 

The Primalucelab spacers come with M6 screws.  The Stellarvue risers come with 1/4-20 screws.  IIRC, the rings for the AT72EDII have holes with M6 threading.

 

And the Primalucelab spacers are all in stock.

 

Mike


Edited by Sarkikos, 04 December 2019 - 10:40 AM.

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#106 dhormann

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Posted 04 December 2019 - 11:04 PM

The MicroStar head and Vanguard tripod are able to support the weight of the AT72EDII, 2" diagonal and heavy 2" eyepiece.   The problem, of course, is that the focuser knobs hit the dovetail if the OTA is shifted forward far enough to compensate for heavier load.
 
Well, I suppose I could saw a couple pieces of wood with a hand saw.   But I don't have a drill press and I don't know anyone who has one.  Though is a drill press really necessary to drill holes in wood?  I have an electric hand drill.    
 
Mike

A drill press ensures that the holes are bored perpendicular to the plate and ring holes.  doing it by hand is possible, but requires a steady hand.  Any chance you could do a sketch of what you need?  I could run the blocks off my tablesaw and drill press for you and drop them in the mail.  I have some scrap pieces of maple or hickory that would be suitable.

 

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Edited by dhormann, 04 December 2019 - 11:24 PM.

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#107 Sarkikos

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Posted Yesterday, 07:45 AM

A drill press ensures that the holes are bored perpendicular to the plate and ring holes.  doing it by hand is possible, but requires a steady hand.  Any chance you could do a sketch of what you need?  I could run the blocks off my tablesaw and drill press for you and drop them in the mail.  I have some scrap pieces of maple or hickory that would be suitable.

Thanks.  But I'll just order one of the risers that are available off-the-shelf.  I want to see how well they work for my setup.  I bet there are others here on CN that would want to see, too.  Probably many observers are like me and don't have a drill press.  

 

Mike


Edited by Sarkikos, Yesterday, 02:49 PM.


#108 Sarkikos

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Posted Yesterday, 07:55 AM

Last night I measured how much extra space I'd need for the focuser knobs on my AT72EDII to clear the dovetail.   The side with the fine focus knob would need over 30mm.  The other side needs over 10mm.  

 

I think I'll eliminate the Stellarvue risers right away.  They provide 2.5" (63.5mm).  That's over twice as much as I need for the AT72EDII.  Positioning the OTA 2.5" farther to the side of the head might unbalance the setup side-to-side.  I would be correcting imbalance in altitude but possibly creating imbalance in azimuth.  

 

I like to have the scope on the left side of the mount as one faces the sky.  Unfortunately, the fine focus knob is on the right side of the OTA, where it could hit the dovetail.  The 30mm riser would probably just allow the dovetail to nick the fine focus knob.  I suppose I could shim the riser to allow the knob to clear.   Or I could move the fine focus knob to the left side of the OTA.  At this point, I'd rather not do that.

 

For now maybe I'll attach the scope on the right side of the mount.   (I have a MicroStar head.  I can just flip it around.)  This would position the shorter focuser-knob between the scope and mount.  For this setup I could get by with the 20mm riser. 

 

But maybe I'll get the 30mm riser.  It just might fit with the fine focuser knob.  If not, a couple wide, thick washers could make up the difference.

 

Mike


Edited by Sarkikos, Yesterday, 08:19 AM.


#109 Sarkikos

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Posted Yesterday, 12:40 PM

I ordered the PRIMALUCELAB - PLUS 30MM SPACERS.

 

Mike


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#110 joseph07081

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Posted Yesterday, 02:06 PM

I ordered the PRIMALUCELAB - PLUS 30MM SPACERS.

 

Mike

I just ordered a set of these as well.

Thanks for posting the links for these spacers, they were exactly what I was looking for.


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#111 TNmike

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Posted Yesterday, 05:15 PM

Last night I measured how much extra space I'd need for the focuser knobs on my AT72EDII to clear the dovetail.   The side with the fine focus knob would need over 30mm.  The other side needs over 10mm.  

 

I think I'll eliminate the Stellarvue risers right away.  They provide 2.5" (63.5mm).  That's over twice as much as I need for the AT72EDII.  Positioning the OTA 2.5" farther to the side of the head might unbalance the setup side-to-side.  I would be correcting imbalance in altitude but possibly creating imbalance in azimuth.  

 

I like to have the scope on the left side of the mount as one faces the sky.  Unfortunately, the fine focus knob is on the right side of the OTA, where it could hit the dovetail.  The 30mm riser would probably just allow the dovetail to nick the fine focus knob.  I suppose I could shim the riser to allow the knob to clear.   Or I could move the fine focus knob to the left side of the OTA.  At this point, I'd rather not do that.

 

For now maybe I'll attach the scope on the right side of the mount.   (I have a MicroStar head.  I can just flip it around.)  This would position the shorter focuser-knob between the scope and mount.  For this setup I could get by with the 20mm riser. 

 

But maybe I'll get the 30mm riser.  It just might fit with the fine focuser knob.  If not, a couple wide, thick washers could make up the difference.

 

Mike

Mike thanks for posting this. I had asked Gary about this in post 97 but he hadn't replied; I was thinking about PMing him, no need now.




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