Side by side mount v over and under

[telecasterguru (Frank)]

I currently have my scopes over and under on my EQ6 e.g. ED127 on the mount and ED80 mounted over the top on the ED127 OTA rings for guiding. I also have a 200mm Newt that I put on the mount with the ED80 over the top once again.
I would like the pros and cons of getting a side by side mount to fix the scopes to the EQ6.
Which is easier to balance, are there issues of hitting the tripod legs if the scopes are mounted side by side, which is easier to set up etc.

All answers and advice appreciated.

Thanks

Frank

[leon]

Frank, side by side can be effective and also looks good, I used to have, about a week ago a triple side by side arrangement, and I have to admit it worked fine.

The only issue with this set arrangement is that you have to get balance from three different points, and that can be a bit tricky.

However if you can do this than there is no difference at all.

This is my new set up compared to the one, one a week ago , both work equally as well as the other.

Leon

[rally]

One advantage of Side by Side is that it can (in some cases) reduce the amount of counterweight required to otherwise balance your rig.
The alternatve is being forced to add extra counterweights with consequent problems.

Without wanting to enter into argument - a Mount was designed to carry a total maximum payload which includes the standard counterweights.
The further from the centre of rotation of the axiis you place the mass, the more leverage is applied (Mass x length) and so more counterweight is required at the bottom to compensate.
If you can keep the weight low and as close to the axiis as possible, you can eliminate the need to over weigh your mount by adding extra counterweights (which usually but not always) exceeds your mount's rated capacity.

This is especially the case where the primary OTA is a large diameter and you put a secondary scope piggyback style above it, or where the secondary scope is quite heavy, or where you are already close to the maximum counterbalance position of all your counterweights before adding the extra scope

Some say that a side by side is likely to introduce the opportunity for more flexure, but if you are using appropriate hardware and ensuring things are done up tight this should not be a problem.
Lightweight brackets, too few bolts and poor mounting design can cause this.
Good solid OTA rings are best for piggyback style, whereas adjustable saddle plates are best for side by side..

Being able to look through the seconday OTA may be hard if its up high !
Likewise you may have t lift the secondary much higher for cameras ect to clear the primary OTA

Its all "Horses for courses".

As Leon has pointed out - the balance issue becomes slightly more complex to achieve. It can become a non trivial exercise with lots of gear in triple arrangements

There are more pros and cons but these are the ones that have been at issue for me.

Cheers

[Hagar (Doug)]

Originally Posted by rally

Without wanting to enter into argument - a Mount was designed to carry a total maximum payload which includes the standard counterweights.

This statement may well be true if mount manufacturers stipulated the "Maximum Payload" but in all cases I have seen the rating is the maximum load excluding counterweights. This will probably lend itself to argument but you need to get all the facts correct.

[telecasterguru (Frank)]

Thanks for the information.
I think I will give the side by side a go and see how that affects the balance and the overall operation of the mount.

Frank

[Paul Haese]

My experiences with both are varied. I found that using a side by side system (made by ADM) introduced too much flexure and this gave me elongated stars. I actually think that the problem stemmed from the use of the Takahashi clam shell and some slight flexure on the rear of the guide scope.

Since going to a piggy back design, I found that this error is all but gone. There is more rigidity in the design and less likely to prove problematic.

If I were to use a side by side again, I would go with a much heavier system and with more rings to hold everything in place.

My vote is for piggy back.

[gbeal]

Mine is too, piggy-back. Using a side by side looks good, but if you factor in the extra weight of the side by side system it loses some of its appeal. Unless you make it extremely robust like Paul suggests it can introduce flex.
Gary