Options to mount guide scope

[Jose Auger]

I am looking at two options to mount a guide scope. One is on top of the main telescope (NOT using scope rings). The other is to use an ADM Accessories side-by-side mount. I have read different arguments for and against each type. I would like to hear from those who have actually used these methods so that I can make a decision based on facts, not theories. I shall appreciate other members' comments regarding this subject.

[Bukko]

Hi, Jose,

I have tried both methods.

1st attempt used the "guidescop on top". My guidescope was an 80mm Equinox, which is pretty heavy and meant I needed more counterweights. I don't think I had the build quality right, as I suffered from flexure in the system.

2nd attempt used the "side by side" approach. Again, the Equinox is pretty heavy and it was a nightmare trying to get the whole rig to balance. In this mode, on an EQ mount, I could never get everything stable, when swapping cameras, filter wheels, etc. kept changing the balance points. It was like I was having to balance in 5 dimensions, XYZ and pitch and yaw.

Probably, if I had used a much lighter guidescope, I could have made it work and certainly, the "scope on top" was the easiest to balance.

In the end I gave up and went to an OAG system. Although this has its own issues, it seems to work best for me.

Good luck.

Gordon.

[Jose Auger]

Thanks for your advice Gordon. Seems that I will go with the guidescope on top.

[Bukko]

I had hoped other members would have weighed in, just because I struggled, others might have some tips on how to balance the system better than I managed.

There is another string running showing side-by-side installations of similar sized scopes and I can see how that would be easier to handle.

But if you have enough counterweights, it is certainly easier to balance with the guide scope on top.

Gordon.

[laser_jock99]

I'd agree that balancing is made easier by having all the major components mounted linearly.

On my rigs the guide scope is mounted on a 'top bar'. The top bar is usually a substantial piece of aluminium bar suitably drilled to bolt to the main tube rings and the guide scopes rings. Remember to position the balance point of the guide scope (with camera) above the balance point of the main scope (balance points are indicated using black insulating tape in the photo below!). A top bar also has the advantage of adding some stabilty to the main tube assembly as well- since the rings are 'tied' in two places.

Skywatcher ED80 riding a 10" F4 GSO Newtonian.

[Tinker1947]

This is my guide scope a ST-80, the Guide Rings are used to line the Scope/Lodestar up so the imagine seen in PHD  DSO/Star is centred on  the bullseye, this has the DSLR Sensor centred on the same DSO/Star....