Steps To Help Eliminate or Reduce Flexure
Sirius EQ-G Saddle Upgrade and New Tandem Configuration
In a effort to eliminate (or at least minimize) flexure, I decided to make some upgrades to the Sirius and the mounting hardware for the scopes.
I decided to go with ADM for the saddle upgrades. I'm very happy with the quality of the components and the price was right.
DSAD-HEQ5 saddle upgrade for the Sirius EQ-G
DSBS-2V side by side setup
Desert Sky Astro Rings
For locking down the guide scope, I decided to move away from the 3 point rings to fixed rings for the Zenithstar 66 OTA. These are 75mm rings. The best quality CNC rings I could find at a great price was from Desert Sky Astro.
Desert Astro 75mm CNC Rings
Since the OTA is so short and the focuser needs to be racked out so far, I wanted support back on the draw tube. I did two things to accomplish this:
1) I used Edmund Optics T extension tubes so the focuser only need to be out less then an inch:
2) I used an Edmund Optics T-Mount 48mm Ring Mount
The ring mount needs a spacer and even though Edmund Optics has them in post form
it was best for me to just build a custom spacer that was perfect for my setup (thanks to David Haworth for his fine machining skills!). You can see the aluminum block spacer in the pictures.
Vixen Imaging Train
This part isn't new, but I've had folks ask to see pictures so I'm including this here.
From the Vixen rack and pinion focuser we've got:
Hotech 2" SCA T Adapter
GSO SCT to T Adapter
This needs some explanation. This is a unique adapter in that it has an SCT female collar on one side with male T threads on the other, then a female T to SCT male adapter on the end. In this case, I'm *only* using the female T to male SCT ring from the end of the adapter. Strangely, this is normally a piece you would just toss in the spare parts bin if going from SCT to T - why this is even part of this adapter I have no idea, but I'm glad it is! For me, the rest of the adapter is used on the ZS66 from the male SCT drawtube to the T extension. So I ended up using all 3 bits of the adapter, but in two scenarios. All for only $23 bucks! Sweet!
William Optics WE-FLAT-2 Field Flattener/Focal Reducer (discontinued)
This is not really a great field flattener as it doesn't really flatten the field much at all, but it does reduce the focal length to where the original field of view is flat for the most part. This component really needs replaced at some point. One of the odd things about this flattener is that, because it's made to work with the ZS66, it's got female SCT threads. This works in conjunction with the piece I just mentioned to switch the Hotech male T threads to male SCT threads so the reducer will thread on.
In the end, from a rigidity standpoint and the fact that there are no thumb screws and everything is centered nicely, the setup works really well. I just wish the field was more flat. If I go with another flattener, I doubt it would have SCT threads and I'd have to find another solution for everything else.