Equatorial mount with motor drive & slow motion controls

[nashtok]

Hello from Seattle,

For the past two years, I've been using a 4.5" reflector on an EQ-1 mount.  The OTA has brought me many great views of the moon, the sun (with full aperture solar filter of course), DSOs, planets, and the occasional comet.  However, as I progress in my knowledge of astronomy, I find the EQ-1 mount rather lacking.  So, in the next few months, I will be looking at acquiring a new mount that can better support my current OTA, with some opportunity for expansion.

I am a big fan of manual controls, so I don't have great interest in GOTO mounts currently.  Despite its lack of stability, I very much enjoy getting lost in the night sky at my leisure using the slow motion controls on my current mount.  The problem is, in all the mounts I've looked at, there doesn't seem to be a way to switch between a clock drive and manual slow motion controls in any convenient manner.  Will imaging isn't my main interest, I do dabble occasionally snap some widefield images (200mm or less), and I'd like to be able to expand my exposure times past 6 seconds for 90mm.  

Are there any mounts out there that have the capability to use both slow motion controls and a motorized drive at the same time, or at least switch between the two quickly?  In particular, I'd love to hear suggestions from people familiar with the US marketplace, since there are some differences in what is available here from other locations.

Thanks!

_N

[skfboiler]

I have a motor drive on my Orion Astroview mount, which I believe is an EQ-3 mount.  Still some shakes when focusing but may be a big difference compared to an EQ-1 mount.  My motor drive is connected to the RA shaft. When the drive is engaged, connected to the RA shaft, there is no quick way to switch easily.  You would need a 2mm Allen wrench to loosen if you want to use the RA slow motion knob.  The instructions says that you may damage the motor if you turn the RA knob when engaged.   However, it has been no big deal to me as I turn on the drive leave it on the whole knight.  You can still slew the mount freely when the unlocking the RA and DA clutches to find stuff.  Once I locate the object, I lock the clutches and find tune with the DA slow motion knob and the arrow keys on the RA motor drive controller at 2x or 8x sidereal speed.  This is better than turning the RA knob due causing the mount to shake.   If someone still needs quickly disengage the RA motor to turn the RA knob manually i heard that  "ScopeStuff" sells thumbscrews to replace the 2mm setscrew on the motor drive coupling. If you want to upgrade to the Orion Astroview mount, Orion now sells that mount with the RA motor drive included for $329.99.

http://www.telescope.com/Mounts-Tripods/Equatorial-Mounts-Tripods/Orion-AstroView-EQ-Mount-amp-EQ-3M-Motor-Drive-Kit/pc/-1/c/2/sc/34/p/106938.uts

[jonathan]

Yeah, my thoughts would also be that you would have to unscrew the motor drive and disengage it from the gear just enough to allow the slow motion control to be used without it trying to turn the motor.  The motor is no doubt a tuned stepper motor which may not take kindly to being turned manually (it may generate a current which could feed back to the electronics in the wrong direction, I don't know precisely how they work these days but stepper motors are usually quite stiff because of the strong magnets).

I suppose a manufacturing solution would be some sort of quick-release system, but the market for such a design may be too small for it to be a viable product.  The advantage of not having to touch the mount to home in on a target outweighs the occasional desire to use manual controls IMO.

[Cornelius Varley]

I think this is possible with the Orion Skyview Pro fitted with the basic dual axis non goto motor drives http://www.telescope.com/Mounts-Tripods/Equatorial-Mounts-Tripods/Orion-SkyView-Pro-Equatorial-Telescope-Mount/pc/-1/c/2/sc/34/p/9829.uts . Both the RA and DEc axis drives have clucthes which should allow you to easily disengage the motors and slew the mount using the slo-mo cables if you wished.

[Peter Drew]

If Vixen Polaris GP or DX mounts are available in the USA, they are excellent for this purpose. 

[triton1]

I have a cg5 mount and it,s a case of unscrewing the ring that holds the gear wheel in place slide the gear off then replace the ring and your good to go.

[RichM63]

Yeah, on the Skywatcher EQ3-2, simply loosen the 'thumb' clutch, no tools required, and use the hand slow mo controls on the other side of the axis.

Incidentaly, Vixen also produce this type of clutch, here are a few pics.