Need help identifying a mount


Andrew R Stowell
 

I bought this mount for $25 and it seems to be in good shape. I was told it was a CG5, but I don't think that's right. I'd like to do an OnStep conversion and it would help to know the model name. Any ideas?
https://www.dropbox.com/sh/m85n9x0gdwxgf6y/AAC4EiGsNX2N1S7KsXrajXmUa?dl=0


 

Vixen Polaris clone or Vixen Super Polaris clone. Can't tell, you should take a photo aside.


Drew 🔭📷🚴‍♂️
 

Looks like a Celestron CG3 or a  Orion EQ-2 (same mount, different vendors). Here is a link:

https://www.telescope.com/Orion-EQ-2-Equatorial-Telescope-Mount/p/9828.uts


Prasad
 

It is a first-gen CG5, a Chinese clone of Vixen Super Polaris. 


Drew 🔭📷🚴‍♂️
 

You are right it may have a greater weight capacity than the CG-3. Here is a list of mounts by weight capacity:

https://www.chuckhawks.com/telescope_mount_list.htm


Drew 🔭📷🚴‍♂️
 


Andrew R Stowell
 

https://www.dropbox.com/s/f7uikfg9blf4snw/pxl_20220928_135922823.jpg?dl=0

https://www.dropbox.com/s/lac5foxjbyeb7h2/pxl_20220928_135905946.jpg?dl=0

Here are a couple pictures that might be better.

I'm mostly concerned that there isn't a good spot to mount the RA motor. The RA knob moves with the RA and there is no flat spot near it.


 

Afaik, 1st gen of CG-5 is Grand Polarie clone (I have it). This is somewhat smaller, have worm DEC and polar scope and that's where similarities ends. Vixen super polaris clone at the best.


Andrew R Stowell
 

After looking at a bunch of pictures, it's not a Super Polaris or Great Polaris clone, but an original Polaris clone.

Thanks everyone for the help!

Seems to be lower payload and has doesn't have a great way to add motors. I think I'll convert my CG5 AS-GT or buy a different mount instead.

Here is a picture of the kind of motor bracket I would need. Looks very flimsy.
https://www.cloudynights.com/uploads/monthly_08_2013/post-209529-1407417144666.jpg


Dave Schwartz
 

Yes, very flimsy but the motor is direct-coupled to the shaft so probably works OK for visual RA tracking. That motor would not do GoTo. That flimsy of a bracket would not support a pulley-and-belt system you would need but at least the fact that there's a screw to mount a bracket (you might need to drill and tap a second) shows promise.

Best way to determine if its an EQ5 or EQ3-2 type is to count the number of revs of the knob when turning the DEC... if its 36 then the ring gear has 144 teeth and its an EQ-5... if its much lower then its an EQ3-2 (yes, I know there are some EQ3-2's with 144-tooth Dec but this is probably not one of them).

On 2022-09-28 11:33 a.m., Andrew R Stowell wrote:
After looking at a bunch of pictures, it's not a Super Polaris or Great Polaris clone, but an original Polaris clone.

Thanks everyone for the help!

Seems to be lower payload and has doesn't have a great way to add motors. I think I'll convert my CG5 AS-GT or buy a different mount instead.

Here is a picture of the kind of motor bracket I would need. Looks very flimsy.
https://www.cloudynights.com/uploads/monthly_08_2013/post-209529-1407417144666.jpg


Dave Schwartz
 

I meant 'when turning the Dec 90 degrees'. Of course you can turn it 180 degrees but 90 will be faster and you'll be less likely to lose count - then multiply by 4 to get the tooth count.

On 2022-09-28 12:13 p.m., Dave Schwartz via groups.io wrote:
Yes, very flimsy but the motor is direct-coupled to the shaft so probably works OK for visual RA tracking. That motor would not do GoTo. That flimsy of a bracket would not support a pulley-and-belt system you would need but at least the fact that there's a screw to mount a bracket (you might need to drill and tap a second) shows promise.

Best way to determine if its an EQ5 or EQ3-2 type is to count the number of revs of the knob when turning the DEC... if its 36 then the ring gear has 144 teeth and its an EQ-5... if its much lower then its an EQ3-2 (yes, I know there are some EQ3-2's with 144-tooth Dec but this is probably not one of them).

On 2022-09-28 11:33 a.m., Andrew R Stowell wrote:
After looking at a bunch of pictures, it's not a Super Polaris or Great Polaris clone, but an original Polaris clone.

Thanks everyone for the help!

Seems to be lower payload and has doesn't have a great way to add motors. I think I'll convert my CG5 AS-GT or buy a different mount instead.

Here is a picture of the kind of motor bracket I would need. Looks very flimsy.
https://www.cloudynights.com/uploads/monthly_08_2013/post-209529-1407417144666.jpg



George Cushing
 

I always look at the latitude hinge. This is a Celestron CG-4, also sold as the SW EQ3-2. The RA drive is usually mounted on the side of the mount.
See:
https://onstep.groups.io/g/main/message/34610
https://onstep.groups.io/g/main/message/26869
https://www.flickr.com/photos/148909624@N05/albums/72157713887362823
https://onstep.groups.io/g/main/message/33055
https://stargazerslounge.com/topic/207487-motorising-the-eq3-2/
https://www.thingiverse.com/thing:4419314
https://www.thingiverse.com/thing:4386847
https://www.thingiverse.com/thing:2476084

In the '80s Celestron filled it's light to medium weight class mount line with the Vixen Polaris. This was replaced with the Synta made CG-4. IIRC the early version did not have the dovetail for scope attachment. It shares some features of other Japanese mounts, which clearly influenced it's design.



Andrew R Stowell
 

George,

Thanks for all those links! That's exactly the kind of info I've been looking for. I'll see if I can use some of those 3D printed designs. They look good enough to give a try with parts I already have.


Andrew R Stowell
 

Dave,

I counted the teeth this way and it's 130 teeth on RA and 65 teeth for Dec. That matches the EQ2/3 and CG-4. Based on the color, I think mine was sold as a Celestron.


George Cushing
 

That's what they should be. IIRC, The early EQ3s may have had a different count. The EQ3-2 is the same as yours.

The new EQM-35 I'm working on is 180:1 RA, but still 65:1 Dec. For the factory GR1 spur gear reducers I'm using 10.5: for RA and 21:1 for Dec based on a count from photos. So the proposed configuration with the OEM steppers looks like this.




Gear Reduction
Est. Tracking

STEPS/arc-deg Stepper-Steps MICROSTEPS GR1-gears GR2-Mount Trkg Res
RA 16800 200 16 10.5 180 0.31
Dec 24266.6667 200 32 21 65 0.31