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Dual saddle setup: C8+RedCat?

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#1 1stSolo

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Posted 23 October 2021 - 11:44 AM

Has anyone tried to put a RedCat next to C8EHD?

I have C8 with Celestron .7 reducer and OAG, EAF and EFW and ZWO ASI294MM Pro; I also have RedCat with ZWO EAF, ZWO OAG and ZWO ASI294MC Pro. I am considering a dual setup: drop ZWO OAG since it’s a parallel setup and one guider is enough, use my ASIAIR V1 on RedCat and ASIAIRPRO on C8.

The mount is EQ6R Pro (44lbs max payload).

My main concerns are 1) total weight; 2) balancing; 3) generally fitting both scopes without OAG and EFWs on both not interfering with each other. I’ll probably need an extra counterweight too. C8 alone required both standard counterweights in almost the extreme opposite position.

I was first thinking of just putting a RedCat on top of C8 but it’s so heavy I’m pretty sure it’s going to rip the screws out of the aluminium scope body.

Edited by 1stSolo, 23 October 2021 - 11:46 AM.


#2 bobzeq25

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Posted 23 October 2021 - 12:20 PM

This can work.  The big issue (which you omitted) is that the weight of the C8 makes guiding the Redcat less good.  It's simply a matter of moment of inertia.  Guide corrections can move the Redcat by itself fast, the weight of the C8 makes motion sluggish.



#3 1stSolo

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Posted 23 October 2021 - 01:59 PM

This can work. The big issue (which you omitted) is that the weight of the C8 makes guiding the Redcat less good. It's simply a matter of moment of inertia. Guide corrections can move the Redcat by itself fast, the weight of the C8 makes motion sluggish.


My thinking is that if I guide with OAG on C8 then a) ASIAIR will calibrate the pulses to have good guiding for C8; and b) RedCat being much wider will be more forgiving of guiding errors. Also 294MC Pro has 4x bigger pixel size than unbinned 294MM.

#4 AstroApprentice

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Posted 23 October 2021 - 03:30 PM

I am also in the planning stage for a dual imaging rig, but using two similar refractors. Sara Wagner suggests it is better to use a guide scope if you’re not using software that can coordinate two camera sequences concurrently:

https://www.swagastr...-adventure.html

Perhaps a guidescope would also be better for your combination?

 

 



#5 bobzeq25

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Posted 23 October 2021 - 10:16 PM

My thinking is that if I guide with OAG on C8 then a) ASIAIR will calibrate the pulses to have good guiding for C8; and b) RedCat being much wider will be more forgiving of guiding errors. Also 294MC Pro has 4x bigger pixel size than unbinned 294MM.

The ASIAir changes how it sends pulses to the mount based on weight?  How does it know?

 

There's also some physics involved here.  Heavier setups _can't_ be as responsive.




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