CG3 R.A drive on a CG5...SUCCESS
Posted 25 September 2011 - 12:11 PM
this variable speed RA drive was only $30 and will do all the "tracking" i need for high power planetary web-camming.
Was pretty simple. I left the bracket on that came with it, made a small 90* bracket to connect it to an existing hole on my cg5.
was that simple
Posted 25 September 2011 - 02:18 PM
where did you buy the drive? Thanks; Don T.
That's also what I'd like to know - I just bought one that looked like yours for $20, but without the speed control! What model # is it?
Posted 25 September 2011 - 02:48 PM
Posted 25 September 2011 - 04:12 PM
Posted 25 September 2011 - 04:17 PM
Posted 25 September 2011 - 04:33 PM
I see this has part #93514. What is the difference between it and the 93511? It has variable speed too.
They are most likely the same motors.
The model numbers are different because they adapt to different Celestron "package" mounts.
I can only guess, the difference is, the mounting hardware you'd receive in the packages.
David B in NM
Posted 25 September 2011 - 07:30 PM
No problem on the idea.
As you said it is an easy mod that provides one with cheap motorized (variable speed) tracking so you no longer have to manually turn the knob on the old CG-5 mounts.
Now you can enjoy your planetary imaging more.
I am very pleased I could assist you.
Clear Skies and have fun imaging!
David B in NM
Posted 26 September 2011 - 12:29 AM
Posted 26 September 2011 - 10:26 AM
Posted 26 September 2011 - 07:56 PM
I have put these on a variety of EQ-2 style mounts.
Posted 26 September 2011 - 10:36 PM
This motor has plenty of speed. Iam only about a quarter turn up from the lowest setting.
AWSOME how sweet it is
Posted 27 September 2011 - 12:07 AM
Hi Adam, just as a side note, I've counted my CG-3 to have 138 teeth, so it does seem close to the 144 on the CG-5, especially with all that reported speed control - now I've got one on order for my CG-3!
Doesn't the CG-5 have a 1:144 ratio RA gear, versus a 1:130 on the CG-2/CG-3? Does it track correctly? Do you have to adjust the speed control all the way to one side?
Posted 27 September 2011 - 10:19 PM
Posted 01 October 2011 - 06:33 PM
If you ever end up doing this modification in the future, please be sure to post it! I would be very interested to know where to tap in ...
I am considering trying to mod one to allow remote control on direction/speed to allow one to use it as a drive corrector/fine adjust so I don't have to deal with the thumbscrews. I found several a while back at $10 shipped!
Posted 02 October 2011 - 01:09 PM
The heart of the circuit is a Hitachi HA17358 Dual Operational Amplifier. From the Datasheet:
"Description: HA17904 and HA17358 are dual operational amplifiers which, provide internal phase compensation and high gain, and mono power source operation is possible. It can be widely applied to control equipment and to general use.
Features: Wide range of operating supply voltage and mono power source operation is possible. Wide range of common mode input voltage possible to operate with an input around 0V, and output around 0V is available. Frequency characteristics and input bias currrent are temperature compensated.
For a discussion of the use of dual op amps for motor speed control see: http://www.ti.com/li...043/sboa043.pdf
Posted 07 October 2012 - 07:37 PM
I would greatly appreciate a small tutorial or even a parts list for this mod - I'm thinking if giving it a go since the CG-5 single axis motor is $70. Have you tried this for astrophotography or what are your thoughts on it working or not?