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Esprit120 top-of-rings hole spacing

Sky-Watcher Esprit 120ED Refractors Equipment
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Paul Huntley avatar
Paul Huntley avatar
Hi All,

My new Esprit120 is arriving next week, and I want to mount a Losmandy (D-Series) universal dovetail bar on top of the main scope. This will secure guide scope, powerbox, and mini-pc.

I cannot seem to find a mechanical drawing that defines the spacing of the holes on top of the stock SkyWatcher rings.

Could someone who owns this scope, when you have a few moments, please measure
a) hole size 
b) distance from the edge of one ring to the center of each hole on the same ring, and,
c) distance between center of corresponding holes on each ring?

I'm just trying to make sure I have all the attaching hardware on hand when it gets here.

Thanks in advance!

–Paul
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José María Moreno Santiago avatar
José María Moreno Santiago avatar
a) Las roscas de la anilla son de 1/4" rosca whitworth
b) el primero a 12 mm y luego 5 agujeros a 14 mm entre ejes de cada uno  
c)14 mm medido entre ejes

la cola losmandy skywatcher modelo SW0148 la puedes colocar sin problema 

Saludos
Miguel Noppe avatar
Miguel Noppe avatar
Hi,

just measured on mine.
The flat top of the rings is about 4" wide.
I have 2 screws to hold in my losmandy plate in and those are 1" from the side of the rings  and there's a spare hole in the middle.
All holes are for 1/4" bolts UNC (coarser thread compared to M6 anyway).
The middle hole is at 2" from the side.
So side - 1"- Hole - 1" - centre hole - 1" - Hole - 1" - side.
There are other holes in too, but I did'n disassemble my plate.
But suffice to say you have ample mounting options.
I measured on the green D-plate with comes with the scope.
I have another D-plate on the other side with is held on only by the centre srewholes, doesn't budge, I even mount it on that side.
Helpful
Mark Ellis (PhoenixAstro) avatar
Mark Ellis (PhoenixAstro) avatar
I'm not using the Sky-watcher rings,  I replaced they a few years ago with Primaluce Rings and dovetail bars.  There was a lot of frustration trying to find a single dovetail bar that would fit hole spacing along with using the original dovetail from skywatcher.  I Highly recommend getting 2 dovetail bars from either ADM or apature that is SAE measurements.  It would be lower cost to get 2 dovetail bars than a complete ring setup.  I recommend ADM as they seem to always have them in stock and make them onsite and you don't have to wait for retailer to get them in.  

CS
Mark

And you will enjoy the scope.
Helpful
Jay Sottolano avatar
Jay Sottolano avatar
Mark Ellis (PhoenixAstro):
I'm not using the Sky-watcher rings,  I replaced they a few years ago with Primaluce Rings and dovetail bars.  There was a lot of frustration trying to find a single dovetail bar that would fit hole spacing along with using the original dovetail from skywatcher.  I Highly recommend getting 2 dovetail bars from either ADM or apature that is SAE measurements.  It would be lower cost to get 2 dovetail bars than a complete ring setup.  I recommend ADM as they seem to always have them in stock and make them onsite and you don't have to wait for retailer to get them in.  

CS
Mark

And you will enjoy the scope.

Mark, Which set of Primaluce Rings did you get?  Thanksl.
Stephane Perroud avatar
Stephane Perroud avatar
Hi Paul,

I use a Vixen style dovetail to secure my SVbony guidescope and my miniPC on top on my ESPRIT 120.
I bought this one, which is a bit longer than the ring spacing. And the delivered dovetail adapter is compatible with the my SVbony guidescope dovetail rail.
https://www.aliexpress.com/item/1005004784221681.html


But I guess, if you have a heavier guidescope, you still want a losmandy bar. ^^

CS
Stephane
Helpful
Scotty Maxwell avatar
Scotty Maxwell avatar
This is the Primaluce ring set up I switched to when I installed the Moonlite Nitecrawler WR35: 



seen on scope here:

Esprit 120 with Primaluce 155mm, 30mm risers
Greg Meyer MD avatar
Greg Meyer MD avatar
plenty of good responses...here's mine.
Patrick Wood avatar
Patrick Wood avatar
I replaced them with Primaluce rings and dove tail plate as well. The 155mm Plus support rings fit the scope. You will need to order support ring spacers as well.
Paul Huntley avatar
Paul Huntley avatar
Miguel Noppe:
Hi,

just measured on mine.
The flat top of the rings is about 4" wide.
I have 2 screws to hold in my losmandy plate in and those are 1" from the side of the rings  and there's a spare hole in the middle.
All holes are for 1/4" bolts UNC (coarser thread compared to M6 anyway).
The middle hole is at 2" from the side.
So side - 1"- Hole - 1" - centre hole - 1" - Hole - 1" - side.
There are other holes in too, but I did'n disassemble my plate.
But suffice to say you have ample mounting options.
I measured on the green D-plate with comes with the scope.
I have another D-plate on the other side with is held on only by the centre srewholes, doesn't budge, I even mount it on that side.

Thanks Miguel, what is the distance between the rings?
Paul Huntley avatar
Paul Huntley avatar
Greg Meyer MD:
plenty of good responses...here's mine.

*Thanks Greg! Is that an 11" rail, or shorter?

Edit: I missed the markings, 14". Exactly what I'm looking to install.
Paul Huntley avatar
Paul Huntley avatar
Patrick Wood:
I replaced them with Primaluce rings and dove tail plate as well. The 155mm Plus support rings fit the scope. You will need to order support ring spacers as well.

Interesting... I did the same thing with my Evo120. Not Prima Luce, but another generic brand. The flat tops of the rings seems essential.
Paul Huntley avatar
Paul Huntley avatar
José María Moreno Santiago:
a) Las roscas de la anilla son de 1/4" rosca whitworth
b) el primero a 12 mm y luego 5 agujeros a 14 mm entre ejes de cada uno  
c)14 mm medido entre ejes

la cola losmandy skywatcher modelo SW0148 la puedes colocar sin problema 

Saludos

Thank you José.
Jay Sottolano avatar
Jay Sottolano avatar
All,

I also have a Losmandy bar on mine which is where I have my Pegasus Power box..  I can also have the Guide Scope on top as well. 

As an aside for those trying to match "hole spacing", the existing Skywatcher rings can be adjusted in spacing to accomodate holes in whichever bar you're using..

Jay S.
Paul Huntley avatar
Paul Huntley avatar
Jay Sottolano:
All,

I also have a Losmandy bar on mine which is where I have my Pegasus Power box..  I can also have the Guide Scope on top as well. 

As an aside for those trying to match "hole spacing", the existing Skywatcher rings can be adjusted in spacing to accomodate holes in whichever bar you're using..

Jay S.

I didn't realize they could slide. On my Evostar120, they were fixed. I ordered the rail from ADM, and can always make use of the slots on both ends. Thanks!

--Paul
Well Written
Jay Sottolano avatar
Jay Sottolano avatar
Paul Huntley:
Jay Sottolano:
All,

I also have a Losmandy bar on mine which is where I have my Pegasus Power box..  I can also have the Guide Scope on top as well. 

As an aside for those trying to match "hole spacing", the existing Skywatcher rings can be adjusted in spacing to accomodate holes in whichever bar you're using..

Jay S.

I didn't realize they could slide. On my Evostar120, they were fixed. I ordered the rail from ADM, and can always make use of the slots on both ends. Thanks!

--Paul

Paul,

They can be adjusted, but it also changes the attachment on the bottom.  I have matching Losmandy style plates top and bottom.

Jay
Paul Huntley avatar
Paul Huntley avatar
Very cool feature. I can't wait to get started. Could I ask you another question? I removed my image train from my old scope, SW Evostar120 with the SW 0.85 reducer/corrector, and plan to connect it to the Esprit120. I have exactly 55mm back focus. But, am I right that the Esprit 1x and 0.77x flatterners end with an M62? That is odd. But the correct back focus is 55mm from the flattener to the sensor, right, or is it 75mm? How did you manage the M62?

Thanks,
–Paul
Patrick Wood avatar
Patrick Wood avatar
The flattener and spacer that reduce the thread size to m48 and 55mm of back focus come with the system in the US. The picture is the flattener and spacer/m48 thread adapter assembled
Paul Huntley avatar
Paul Huntley avatar
Excellent! Many thanks. Just so I understand, using the M62 - M48 adapter included with scope yields a backfocus of 55mm from camera end of adapter to sensor?
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Patrick Wood avatar
Patrick Wood avatar
Correct