Celestron Motor Drive Dual Axis Model (CG-4 Mount)

Comments about Celestron Motor Drive Dual Axis Model (CG-4 Mount):

I bought these drives for use with my Meade 6 inch F5 Schmidt Newtonian which I have mounted on the Celestron CG-4 mount. The instructions are clear and the installation is a breeze. The motor drives handle the 12 pound optical tube with no problems. Initially I was dissatisfied with the performance of the RA drive. With the motor running, high magnification views were blurred by vibration. With the drive off the image was steady and clear. Apparently this is fairly common with stepper motor drives that turn in tiny pulsing increments. The cause of this vibration is due to gear slop in the mount...not the drive motor. The cure is to adjust the gear mesh in the mount as tightly as possible without undue binding. The drive instructions explain how to adjust the CG-4 mount worm gears. but mention nothing about vibration being a possible result of improper adjustment. The troubleshooting section only talks about the adjustment being too tight and stalling the motors, or too loose and causing backlash. However,it is worm gear backlash in the mount adjustment that causes the RA motor to 'click" as the play between the gears is taken up and released by the pulsing on-off rotation of the drive motor. This clicking of the gears then induces vibration. The trick is to eliminate all play in the worm gears. This may require some trial and error to get right, but when dialed in properly the vibration is gone.
The only complaint I have about this drive is that the RA motor has no de-clutching attachment as the Declination motor does. That means that the manual RA slow motion control cannot be used. Other than that small complaint the drive once dialed in works very well and tracks accurately.

Comments about Celestron Motor Drive Dual Axis Model (CG-4 Mount):

These motors were extremely easy to add to the mount and are very quiet. They move my 13.4 pound astrophotography setup and the two counterweights with no problem.
I like that the hand controller light flashes when the batteries are getting low. I use rechargeable batteries and this makes sure I don't lose power in the middle of a session.
The hand controller buttons work well and the cords are plenty long.
Another review noted that there is a lag between pressing a button and the mount moving. That is caused by backlash in the mount. Close observation of the dec motor gears shows that they start turning immediately when the button is pushed.
Yes, there are only 3 speeds and you can't slew the mount around the sky as previously noted but I have no problem getting the pointing close by using the clutches and hand adjusting the mount, then fine adjusting with the hand controller. Making small adjustments at 8x during astrophotography sessions works great.
I've attached a picture (series of stacked pictures) of the Orion Nebula taken with the described setup and the motors were instrumental in getting there.

Comments about Celestron Motor Drive Dual Axis Model (CG-4 Mount):

The German equatorial mount is a solidly constructed apparatus, that is stable and can handle a weighty optical load. I puchased the mount because I was less that thrilled with the go to mounts and I have. I have more experience with this type. I have monuted and observed with a 90mm Mak-Cassegrainan a 102 mm Schmitt-Cas. and a 6"Schmitt-Cas. All have performed very well. I am adding dual axis drives.The only draw back is that this is heavy.

Comments about Celestron Motor Drive Dual Axis Model (CG-4 Mount):

The instructions are great. The only con I found was the R.A. Drive could use a clutch like on the Dec. So you could use that slow motion control also. Other than that great product

Comments about Celestron Motor Drive Dual Axis Model (CG-4 Mount):

Very easy to install onto mount. Keeps alignment well, but as others have said it could use a faster speed when trying to center an object. I found that if you push and hold the button it starts off slow but does speed up slightly after about 8 seconds. Overall great addition to your scope/mount setup.