EQ6-R & AZ EQ6 Pro saddle bolts too short for Losmandy dovetails

[oymd]

Good morning everyone

Hope you can advise on a DIY project I am trying to sort.

The saddle on my AZ EQ6 Pro takes Vixen & Losmandy dovetails, but the stock bolts barely catch when a losmandy is used.

I have upgraded the dovetail on my C11 to a Losmandy, and I can barely get the bolts undone to get the dovetail to sit in the saddle. Usually they just fall off completely, however, when I manage to secure it, its all rock solid.

So, short of completely changing the saddle to a Geoptik or ADM which at this point in time I would rather avoid, as I am still in the process of spending on cameras etc, and would rater save the funds for those at the moment.

Can someone advise me on how to get LONGER BOLTS? It needs to be longer by just 1cm.

I went to B&Q, and confirmed that the size is M8, and bought a couple of regular M8 12cm bolts to test, and they fit, hoever I'm not sure the thread pattern is similar?

I looked everywhere of similar M8 bolts with a large thumbscrew, but cant find any of similar design and length.

Many thanks

 

 

[alacant]

56 minutes ago, oymd said:

LONGER BOLTS

Hi

What length do you want? 1cm longer than...?

Guesssing and JTOL, but how about these? Make the shoulder using two locking nuts and/or locktite and take up any extra using washers?

HTH

[CraigT82]

There must be something amiss with your saddle?? My neq6 saddle has m8x1.25mm bolts which are 45mm long from tip to shoulder and works fine with a losmandy dovetail. Are your bolts shorter than this? 

[oymd]

3 hours ago, CraigT82 said:

There must be something amiss with your saddle?? My neq6 saddle has m8x1.25mm bolts which are 45mm long from tip to shoulder and works fine with a losmandy dovetail. Are your bolts shorter than this? 

Just measured it...

Total length from bottom of plastic thumb screw is under 6cm and actual length of metal part is just under 4.5cm.

It definetelt falls off when I try to accommodate the losmandy dovetail.

 

[geeklee]

HI @oymd Mine are definitely the same size and the bolts catch very late but still have what seems like a solid 5mm left of travel to tighten up.  I've attached some photos but I think they just prove we have the same bolts 🙂

Distance after tightening:

Bolt against saddle:

The bolt has just caught in this picture and it measured ~5mm left of travel but when it was tightened it felt solid.

[oymd]

14 minutes ago, geeklee said:

HI @oymd Mine are definitely the same size and the bolts catch very late but still have what seems like a solid 5mm left of travel to tighten up.  I've attached some photos but I think they just prove we have the same bolts 🙂

Distance after tightening:

Bolt against saddle:

The bolt has just caught in this picture and it measured ~5mm left of travel but when it was tightened it felt solid.

Maybe then it’s the quality of your losmandy doveplate that makes seating the OTA easier?

i am using the STOCK orange CGE dovetail with the C11. And it’s very very awkward to get into the saddle. I almost dropped the C11 last week, to the point I have abandoned the idea of using it for now, till I sort this issue out. 
 

Currently using the ED80 which has a vixen dove palate and is super easy to seat. Obviously the weight of the refractor helps as well. 

[oymd]

5 hours ago, alacant said:

Hi

What length do you want? 1cm longer than...?

Guesssing and JTOL, but how about these? Make the shoulder using two locking nuts and/or locktite and take up any extra using washers?

HTH

But they don’t have a shoulder or same design?

how will I make up for the unthreaded part and fixed washer?

thanks

 

[geeklee]

6 minutes ago, oymd said:

Maybe then it’s the quality of your losmandy doveplate that makes seating the OTA easier?

i am using the STOCK orange CGE dovetail with the C11. And it’s very very awkward to get into the saddle. I almost dropped the C11 last week, to the point I have abandoned the idea of using it for now, till I sort this issue out. 
 

Currently using the ED80 which has a vixen dove palate and is super easy to seat. Obviously the weight of the refractor helps as well. 

I was wondering if your losmandy plate could be slightly wider... but they're a standard right? 🙄

This is the plate in my photo:
https://www.firstlightoptics.com/dovetails-saddles-clamps/stellamira-universal-losmandy-style-dovetail-bar.html

Admittedly I thought there was much more travel in the bolts until I did this test!  I usually have an 80ED on a dovetail as well.

Edited March 8, 2020 by geeklee

[CraigT82]

11 minutes ago, oymd said:

Maybe then it’s the quality of your losmandy doveplate that makes seating the OTA easier?

i am using the STOCK orange CGE dovetail with the C11. And it’s very very awkward to get into the saddle. I almost dropped the C11 last week, to the point I have abandoned the idea of using it for now, till I sort this issue out. 
 

Currently using the ED80 which has a vixen dove palate and is super easy to seat. Obviously the weight of the refractor helps as well. 

I wonder if your CGE bar is slightly wider than a losmandy one? Can you measure it? 

[geeklee]

 @oymd I can definitely see how the bolts might just pop off when positioning something on/off the saddle - especially something like a C11.

I just had one bolt pop when taking the above losmandy plate off and I thought I was being fairly careful - it didn't even have a scope on it!

Be interesting hearing thoughts on this from more users.

[alacant]

1 hour ago, oymd said:

how will I make up for the unthreaded part and fixed washer

Hi. Answer in my post.

Cheers.

[CraigT82]

This pic is of my ADM losmandy plate in a neq6 saddle. The bolts are just engaged with the threads.

From this point I need to turn each bolt 4 full turns to lock

This dovetail is 74.7mm wide

Edited March 8, 2020 by CraigT82

[oymd]

1 hour ago, CraigT82 said:

I wonder if your CGE bar is slightly wider than a losmandy one? Can you measure it? 

 

1 hour ago, geeklee said:

I was wondering if your losmandy plate could be slightly wider... but they're a standard right? 🙄

This is the plate in my photo:
https://www.firstlightoptics.com/dovetails-saddles-clamps/stellamira-universal-losmandy-style-dovetail-bar.html

Admittedly I thought there was much more travel in the bolts until I did this test!  I usually have an 80ED on a dovetail as well.

 

1 hour ago, CraigT82 said:

I wonder if your CGE bar is slightly wider than a losmandy one? Can you measure it? 

This is the exact one I have. The 11” inch one. The attached PDF suggests it’s 101mm wide. 
 

https://www.firstlightoptics.com/dovetails-saddles-clamps/celestron-cge-dovetail-bars.html

 

https://www.firstlightoptics.com/user/manuals/celestron_dovetail_bars/Celestron_94219_11inch_dovetail_bar.diagram.pdf

 

but the 101mm width is of the curved part that actually attaches to the underside of the OTA. 

The diagram does not show a dimension of the distance between the actual rails on the dovetail that get locked into the saddle. 

Edited March 8, 2020 by oymd

[CraigT82]

I think that's the overall width of the bar not the dovetail bit that goes into the clamp... that width isn't on the diagram strangely. 

[oymd]

1 minute ago, CraigT82 said:

I think that's the overall width of the bar not the dovetail bit that goes into the clamp... that width isn't on the diagram strangely. 

Yes. Agreed. Have just edited my post to reflect that. 

[geeklee]

31 minutes ago, CraigT82 said:

This pic is of my ADM losmandy plate in a neq6 saddle. The bolts are just engaged with the threads.

From this point I need to turn each bolt 4 full turns to lock

This dovetail is 74.7mm wide

Good view. I've tried to replicate with the AZ EQ6.  It doesn't seem to clear that gap easily.  The threads of the bolt are just engaged here.

Width across the wide bit of saddle part of the losmandy is 73.5mm ... which I've double checked but can't be right if yours is 74.7mm...

[CraigT82]

Just been googling around and it seems there is no set standard dimensions for 'losmandy' or 'vixen' dovetails. Manufacturers of dovetails seem to make them to roughly the right size to fit into either category but saddles usually have a wide opening range so no need for exact dimensions standards - which makes sense I suppose. 

Actual Losmandy manufactured dovetails seem to have the dimensions below, not yet been able to find CGE dimensions other than the diagram listed on FLO.

[CraigT82]

29 minutes ago, geeklee said:

Good view. I've tried to replicate with the AZ EQ6.  It doesn't seem to clear that gap easily.  The threads of the bolt are just engaged here.

Width across the wide bit of saddle part of the losmandy is 73.5mm ... which I've double checked but can't be right if yours is 74.7mm...

Seems like the AZ6 saddle doesn't open quite as far as the neq6 one

[oymd]

12 hours ago, CraigT82 said:

Seems like the AZ6 saddle doesn't open quite as far as the neq6 one

So, I decided to gove it another go yesterday...

Pulled the C11 out, and managed to get it on the mount...

The CGE is 74mm....pics attached