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Anyone using drives on a CG-4 (Omni)?

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#1 eljackso

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Posted 14 April 2009 - 08:05 AM

I'm thinking of getting the drive kit for the CG4 mount that came with my celestron omni 120 refractor; anyone else using this or have any comments? I'm thinking of setting up a pier type system using the CG4 head and drives until I can afford an autoguide/gps system. Any input would be appreciated.

#2 RAKing

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Posted 14 April 2009 - 10:29 AM

When I came back into this hobby, I picked up the Omni 102. The scope is very nice, but the CG-4 was too weak for that scope, so I immediately bought a CG-5.

IMHO, I would not spend any extra money on that mount. My suggestion would be to save your money until you can upgrade to a CG-5 or something comparable.

Ron

#3 eljackso

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Posted 14 April 2009 - 01:26 PM

Thanks for the input Ron, I was already leaning towards doing what you recommended but thought I would seek more input. My background prior to entering the legal profession was in electrical engineering and instrumentation so I was thinking of doing a pier-mount in a removable top shed and installing my own encoders with an AB plc watching over things... kind of a Losmandy drive clone. I'm sure I'm going to eventually do this, but was curious if the tolerances in the CG-4 combined with the momentum from slewing the 12.5 lb OTA would just make it useless from an accuracy viewpoint. Now I'm thinking of just getting a used CG-5 to try this on and in the meantime save up for a G-11 head and a C14 to go on top of it; I'm quickly learning how addictive this hobby can be...

#4 oldtimer

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Posted 14 April 2009 - 03:19 PM

I have a 6" F 6.75 newt mounted up on a CG4 with drives and it all works very well.

#5 solshaker

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Posted 14 April 2009 - 04:43 PM

you cant go wrong with getting the drive. you dont really need the dec drive unless you just really want it. the ra is the one that matters.

i have an orion astroview (same mount as the cg4) with the drives and when i had my 120mm on it worked fine. plus, you will always have it for when you mount that short widefield grab an go scope you know you want...

#6 RAKing

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Posted 14 April 2009 - 04:55 PM

Thanks for the input Ron, I was already leaning towards doing what you recommended but thought I would seek more input. My background prior to entering the legal profession was in electrical engineering and instrumentation so I was thinking of doing a pier-mount in a removable top shed and installing my own encoders with an AB plc watching over things... kind of a Losmandy drive clone. I'm sure I'm going to eventually do this, but was curious if the tolerances in the CG-4 combined with the momentum from slewing the 12.5 lb OTA would just make it useless from an accuracy viewpoint. Now I'm thinking of just getting a used CG-5 to try this on and in the meantime save up for a G-11 head and a C14 to go on top of it; I'm quickly learning how addictive this hobby can be...


Life is so funny. I went the other way - from a beginning lawyer to an engineer. I just liked to tinker with things too much I guess. My dad (the real lawyer) was a little disappointed at first, but he knew I was happier and it's all worked out. :lol:

I'll be honest - I have no clue how accurate a CG-4 can be. The doggone thing wiggled and jiggled so much - settle times were well over two seconds - that I was happy to get a stable peek at the object.

Your happiness with any mount/scope combo will be determined by how much of this jiggling you can stand. If you don't mind the scope jumping around when you touch the focuser or get a gust of wind, you will be happy with a much lighter setup than I am.

I like my stuff to be solid. With my current setup (8 inch f5 Newt / GM-8 / A-P Portable Pier), if I give the scope a good solid Whack! - it settles in less than a second. That's okay for me. I would prefer zero time, but that's very expensive to get and would be too heavy for me to enjoy.

The CG-5 is such a big step up from the CG-4, yet doesn't cost an arm and a leg. The -5 has 2 inch tripod legs and these really help stabilize things. A lot of people have been very happy with the CG-5 and a 120mm refractor. :)

Your future plans sound great and I think you will be very happy with a G11 - it's a magnificent mount and not too expensive in my book.

Take care,

Ron

#7 letimotif

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Posted 14 April 2009 - 06:29 PM

You know, I picked up an Omni/CG4 combo while I was on an extended stay on the UP in Michigan.

I was going to try to add something here based on my experience, but Ron said it all. He's spot on.

So, just consider this just an addition to my post count. ;)

#8 o1d_dude

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Posted 14 April 2009 - 08:19 PM

Does your stay in the YouPee make you an honorary Yooper?

I have a older CG-4 that I like well enough now that I replaced the tripod with one from a CG-5. I even went so far as buying and installing a dual axis drive setup.

Any more, I'd not recommend a dec drive for a simple EQ mount. If you want drives on all axes, get a GoTo mount instead and you'll be much happier.

The CG-5GT mount can be purchased from most of the usual suppliers under $600.

#9 letimotif

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Posted 14 April 2009 - 09:18 PM

Does your stay in the YouPee make you an honorary Yooper?


I s'pose. My sister and her husband live in Houghton. I have a couple of postcards from my stay. On one is a picture of a highway information sign. It reads:

Edge of the Earth 2 mi

Houghton, MI 4 mi

What's funny about the sign is that the distance to Houghton is closer to 5 miles. :grin:






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